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Recently got a couple pairs of double posted monitor speakers and thought I wouldnt even bother with the bi-wire option given that it seemed nonsense to me - but having some time and the wire sitting around I went ahead and did it - just with OFC copper standard runs - and lo and behold I felt the improvement was quite significant - and this was after I also substituted replacement jumpers.
The guages of my wiring are quite thick and all. I don't know what to make of it exactly. Plus the connections were all fresh and not oxidized or anything.
Also found it interesting that when looking at buying some new biwire cables then it seems that many out there are not true double runs I think but simply the speaker side is broken out into two pairs of connectors. Is this in fact the case - since it seems to violate the rationale of birwiring?
But yeah, the bass and "coherence" of the speakers seemed improved and also imaging. In this case it is Paradigm Studio 20s and then Epos Epic 2
JaroTheWise
Follow Ups:
I wish I could find John Crabbe's(long time Hi Fi News editor) discourse on bi wiring where if I recall correctly he made some good arguments for it not mattering. John was a heck of a clear writer and his arguments are always well thought out and clearly presented.
See if you can find it. I think it all turns on whether different frequency signals all sharing the same wire have any tendency to conflict with each other in some way, and I think the science would say that they simply do not- especially in a system like mine where power and volume levels are not very high.
Bottom line is that I felt I heard an improvement so either I was mistaken or it happened for a reason other than having two wires.
JaroTheWise
The signal that goes down the wire is not a bunch of separate ones for different frequencies. A single waveform that has all the information in it goes down the wire. Think of the groove on a vinyl record. There is only one groove and the responding stylus is generating a single signal for each channel. The speaker reponds to this waveform. I find this quite remarkable. The human ear plus brain can convert the single continous complex waveform into the sound of different instruments, voices, etc.
As for bi-wiring making a difference, that is controversial as this thread shows. I once asked a physicist who specializes in amplifier design and signal transmission what he thought. He did give it some investigation and concluded that theoretically there could be a difference (it involved power reqirements for the low and high frequencies and how the amp might react with one or two wires to handle the separate frequency domains). He thought it would make no prectical difference so long as a single wire approach had a wire that was up to handling the loads.
FWIW (very little) I have use a single wire and bi-wiring on my Vandersteen 5s and could hear no difference.
Joe
I mean to A/B my Paradigms again to reconfirm that I noticed an improvement, and at the time it seemed fairly pronounced. I will say I tried the same on some Epos that I had around and they did not seem to make a difference. Also need to mess around with some different jumpers.
It may be somewhat speaker dependent - or in my case the Paradigms are version 2 so probably about 15 years old at this point - I bought them used - so in terms of the electronics the age could be some sort of factor. I just picture that the previous owner single wired them all these years and I was the first to connect a bi-wire
Also noticed it is possible to wire them with jumpers in place - one wire polarity to the bottom set and the other to the top set which would be a bit different current path then using one set of posts, but I don't know what that would mean exactly
JaroTheWise
if one is using the same amplifier source for both runs. The only advantage it gives is if one's wire gauge is a little on the thin side for the distance so you double up. Its still no replacement for an appropriate gauge wire based on run length.
See:
http://www.audioasylum.com/audio/speakers/messages/34/343710.html
a post in this thread, where I cite several pages of information, including circuit diagrams that show bi-wiring to be electrically different AND SUPERIOR than single wiring EVEN IF THE TOTAL WIRING GAUGE IS THE SAME.
I provide three major mechanisms that show bi-wiring to be superior to single-wiring, and back-up for those mechanisms is provided in the cited pages.
Jon Risch
I'm an electrical engineer and stopped reading this article after the fourth paragraph. There are so MANY MANY errors in this article. See my responses below.
Edits: 07/24/15 07/24/15
If you are an electrical engineer, then you should be able to comprehend the Fig. 1 thru 6 at:
http://www.geocities.ws/jonrisch/biwiring2.htm
and the further pages referenced.
RE the 1st page, that is more of an explanation for laymen, and does not go into technical details as such.
RE your being an electrical engineer, good for you. I am a Senior Project Engineer at Peavey Electronics, and make my living designing loudspeaker systems. I have written several AES articles, and presented at several conferences, and have several patents to my name.
So rather than dismiss that which you won't bother to read, or perhaps, don't understand, I suggest that you either retract your baseless claims of technical errors, or bother to read the actual pages through, and then comment intelligently on them.
Jon Risch
I couldn't access the links. Who wrote the articles?
The links worked OK for me one second ago. Jon Risch wrote the articles, I believe.
Yet another error in this description. I agree that the removing the jumpers from the speaker terminals isolate the crossovers but that's it.1) First of, it should be noted that speaker A and speaker B terminals are not seperate channels as incorreclty assumed by the author. They are in fact parallel taps of the output stage. So the output stage see's the speaker in its entirety, both woofer and tweeter when biwired.
2) Furthermore, the amplifier output sends full bandwidth signals across the speaker terminals because its both physically and electrically the same output stage. It cannot send different signal bandwidths from the receivers speaker terminals as they are connected electrically and physically across the same output stage.
"The situation is such that when the full range musical signal is applied to the terminals of a full-range speaker system, the woofer only gets sent low frequency signals, and the tweeter only gets sent high frequency signals. Once the crossover networks have been electrically separated, they still continue to function in the same manner, having a low impedance in their passband of application. This means that if separate speaker cables are hooked up for the woofer and it's portion of the network, and the tweeter, and it's portion of the network, not only have the speakers and the frequency's directed and divided for them, but the two separate speaker cables will now also carry different signals, the woofer cable mostly the lows, and the tweeter cable mostly the highs.
Once the highs and lows have been separated in this fashion, the strong current pulses and surges that a woofer demands when reproducing bass or drums will not interact with the delicate sounds of a flute or cymbal. The magnetic field of the low frequency signals cannot modulate or interfere with the highs, and to a lesser extent, the reverse is true. "
Edits: 07/24/15
RE your comment #1, I am not sure what you are trying to say, since you reference Speaker terminals A and B, which I do not in my pages.At the second page, I have Fig.s 1 thru 6
At the third page, I do have a Figure A and a Figure B, but these are clearly labeled, and Fig B does show the results when the crossover is present. Figure A was shown to provide the raw data of the actual output of the drivers themselves when driven by the other driver in that same cabinet.
If you are referring to the third page, then I don't know where you are coming from, Nothing incorrect there, just data never before presented regarding the effects of sound impinging on the loudspeaker components.
While your comment #2 is a true statement, it has nothing to do with the signal once it LEAVES the amp terminals and starts down a path to the speakers. The CURRENT in a set of bi-wire cables IS different, because to the impedance being different.
That is shown clearly in Fig. X, at the page 7 section.Again nothing incorrect here, and again, information never before shown to the general public before.
These things are the result of fundamental research into the operating principles of bi-wiring.
Of course, if you don't really understand the information presented, then that could explain your confusion, and why you think it is wrong.
Jon Risch
Edits: 07/26/15
Biwiring (not biamping) is the process of using both speaker terminal pairs of the receiver and connecting them to the speakers terminals with jumpers removed is it not? Answer this one question first and then we'll move on.
Edits: 07/29/15
I cover some of that in this recent post:
http://www.audioasylum.com/audio/speakers/messages/34/343950.html
A receiver with an A and a B output is not necessarily the best platform to implement bi-wiring, because of the methods used on some receivers to engage both the A and B speaker outputs at the same time.
RE the jumpers, this would be the case for a loudspeaker designed to be bi-wired, that had a set of jumpers at the speaker.
But yes, basically, if the receiver A and B outputs are paralleled when both are engaged, and you run a separate speaker cable from the receiver/amp to each section of the loudspeaker crossover, what you describe is what is commonly referred to as bi-wiring.
Before you dismiss anything, at least look at this page:
http://www.geocities.ws/jonrisch/biwiring2.htm
at Fig. 1 and Fig. 2, and the related charts at the bottom.
This is _one_ aspect of three or four major aspects of bi-wiring.
You will have to do some reading and think about the issues for a while.
Far too many people make the mistake of assuming that there is no electrical difference between single wiring and bi-wiring, but an honest look at the facts will show this to be otherwise.
Jon Risch
Biwiring then offers no advantage what so ever as the output of the amp/receiver is the same point electrically and ultimately controls the drivers whether they are controlled through a single pair of wires or biwired. The vector sum of the amps response through biwiring equals that of a single wire input because to the amp, it sees the complete impedance relationship. Your logic completely ignores this point which is the biggest failing of your arguement.
Your mind is so closed, you can't even be bothered to look at the circuit diagrams I reference.
No point in continuing a discussion then.
Jon Risch
because you throw around pseudo science and incorrectly applying engineering principles to confuse the uninitiated or the untrained. This type of BS is what gives audiophiles and HIFI a bad rep. EOD.
Your statement "the amp sees the complete impedance relationship" is of course true.
It's the cables that see different impedances, due to their different frequency loads.
The value of bi-wiring is highly debatable, but the electrical properties of the circuit is not.
That just isn't true. In the crossover transition band, where the two sides of the crossover are both conducting, the bi-wired circuit is not equivalent to the single wired circuit. The impedance seen by the amp is different in that frequency band. Further, when you consider the woofer to be a voltage source due to its generation of back EMF, it's pretty easy to see that the amount of back-EMF reaching the tweeter is different in the bi-wire case than the single wire case.
You guys keep forgetting that its all connected to the same source, the only difference being that biwiring uses two physical connections on the same electrical source so what ever back emf affects one line will affect the output stage as a whole. If there were two seperate sources, I would agree with the argument but this would be called bi-amping, not bi-wiring. What has been written about bi-wiring is mathematically and theoretically incorrect.
The amp can be modeled as a voltage source with a series output impedance. When the woofer is acting as a generator, it produces a back-EMF of V volts at the LF speaker terminals. In the single wire case, all V volts of back-EMF are presented to the HF speaker terminals. In the bi-wire case, the wire impedance and amplifier's output impedance become a voltage divider. A typical output impedance for a solid state amplifier is 0.01 ohms. A typical speaker cable impedance is 0.05 - 0.1 ohms. So the back-EMF present at the amplifier terminals is V * (0.01/0.05) to V * (0.01/0.1). So in the bi-wire case, only 10-20% of the back-EMF present at the LF terminals is presented to the HF side.
At lower frequencies, the back-EMF is blocked by the high pass filter in the HF crossover anyway. But in the transition band where both crossover networks are conducting, the woofer drives the tweeter more in the single wire case than in the bi-wire case.
Still connected to the same source and its the source that controls speaker movement. Everything is being examined at the speaker end but you guys fail to bring it back to the source. The analysis is incorrectly seperating the source to two independent points which its not. This makes the modelling incorrect and flaws subsequent analysis.
Edits: 07/31/15
In the case of back-EMF, the source is in the speaker and the amp is the sink.
The cable impedance itself changes when going from single wiring to bi-wiring, at least in the crossover transition band. So even without back-EMF there is a difference. But I assumed you weren't a "cable guy", so if you don't think the cable impedance is significant in the single wire case you wouldn't think the difference between single and bi-wiring is significant either. That's why I made a point of back-EMF.
When was this article written? The first paragraph is technically incorrect and inaccurate by today's standard as each channel is a dedicated channel, not a derivative of left and right channels and its full bandwidth.
"You might want to try bi-wiring, but it helps to use something better than just zip cord, no matter what the gauge.
If you are running 10-12 foot lengths, a decent single wire set of speaker cables will run around $140 or so, so
double that for bi-wiring the two front mains. I would not worry about bi-wiring the center speaker, or using
anything but 12 gauge zip for the surrounds, as the suround signal is processed through a cheap digital delay
as well as derived from signals buried in the main signal, and hence is not that clean or wide bandwidth. "
The 1st page, 1st paragraph was written about 16 years ago, and back then, the HT receivers were using derived analog signals for the rear channels.
Now, with all digital and discrete channels, things are theoretically better, although I have to say, most modern DVD's don't sound a whole lot better sonically than they used to, despite the technology.
I should re-write that paragraph, but I pointed to some existing pages, that were "ghosted" from the old Geocites web sites, and I do not have access to those pages to edit them. They were however, convenient to point to without sending some one to the Wayback Machine (internet Archives)
Jon Risch
Over 20 years ago, AFAIK
Jon, this may be a dumb question, but in a 2-channel amp with A & B outputs, is it preferable to connect both wires to the A terminal, or one wire to A and the other to B?
Or, it doesn't matter?
Thanks
Many amps/receivers put the A and B output in series when both are engaged. This would be a bad thing for bi-wiring, and would not work at all.
IF the amp puts the outputs in parallel, then it would be OK to use them as you state: "one wire (pair) to A and the other (pair) to B".
Jon Risch
Thanks, Jon.
I have said that I plan on doing some more A/B testing since I believed that from the beginning - or at least that if it has benefit then the benefit is exceedingly small and not noticeable in a "mid-fi" system like mine.
If it does occur then I keep thinking it would be for a reason other than really having two runs - like more metal contact at the connections or something such. My wires are not long enough or thin enough to constrain the signal at all in that regard
JaroTheWise
You will not be surprised by the results. :)
Bi-wiring, done competently, should have no negative impact. Whether there is a positive one is debatable (as is being done here).
The subject line should have read... "You will know soon enough"if biwiring was done correctly or not. Incorrectly shorts out the amplifier's output stage which if the protection circuits don't catch will blow out the output stage. :)
Edits: 07/17/15 07/17/15
Yep. This happened in a dealer's store when they set up some speakers for me to audition. I guess it was a little easier to short out the speaker terminals since they were using tri-wire cables. I suppose it only blew the fuse. It was an integrated tube amplifier, C-J, I think. I made them get a SS amp, which sounded better with those speakers.
I've just been using 12 gauge cables for many years.
-----
"A fool and his money are soon parted." --- Thomas Tusser
I've been running 14 Gauge to the mains as my runs are short and 12 gauge to the surrounds because of the distance.
When you consider how good some placebos are that's saying a lot.I think I've heard some positive changes or differences in the sound after bi-wiring, but all wiring schemes sound good in at least some ways. Slap down some wire and start playing the music.
Edits: 07/17/15 07/18/15
Not really.. A placebo isn't real and anything that seemed a cure for an ailment is simply a state of mind. Same goes to hearing gains in biwiring. Its a state of mind, not a reality.
I can only hope for such a thing.
What the biwireable speakers really 'want' is one stereo amplifier per driver pair - one stereo amp for the tweeters, and one for the woofers. Then you'll really perceive the difference. At least at higher listening levels.
And arguably, active speakers are even better. I once heard a pair of active Paradigm Studio 40s (not made anymore) which made a drum set really come alive. In this case more power was better (one amplifier per driver).
I saw a pair of those for sale locally but they were expensive and I didnt understand so much the rationale - given that it is another point of possible failure of the product and that most people spend enough on an amp to be sad to make it irrelevant. I do recall that Meridian did a lot with active speakers back about 15 years ago and had the philosophy to keep the signal digital as long as possible - which on the one hand I think obviates speaker cables but not a big deal really
Funny how many customers at the company I worked at who sold them believed the audio could remain "purely digital" which is nonsense of course
JaroTheWise
If you're still using jumpers, you aren't bi-wiring yet. When Bi-wiring you have to remove the jumpers.
Cut-Throat
I just wrote that sentence badly in adding that I took some measures to improve the sound before I tried the bi-wiring - sort of "added on" that I had tried new jumpers beforehand but obviously took them off to do the bi-wire
for example people will say that bi-wiring seems to work in that the jumpers in place - maybe the stock ones - really suck. Or alternatively that when someone makes a connection change then they "refresh" sometimes the connections they have in place. All stuff that I tried to say should NOT have been a factor in me hearing improvement.
I still mean to A/B it again to make sure I can recreate the improvement
JaroTheWise
biwiring is a big marketing ploy.
Bill
...at least the last time I checked.
He does also emphasize buying the best equipment you can afford first and then worrying about the cables second. He also says that a double run of a lesser cable will usually sound better than a single run of a better cable, a point that Audioquest makes as well (even though they would probably rather sell you the expensive stuff).
when you hear it - you know it - speaker dependent tho
"Man is the only animal that blushes - or needs to" Mark Twain
Edits: 07/15/15
.
Regards,
Mike.
You may be right about that but it doesnt strike me as a compelling one, almost like you sell a person a speaker that has "special needs' just so they can take more trouble then to deal with them
JaroTheWise
I know there is nothing more required with jumpers in place but with them in place the rationale of the bi-wire is not being implemented - at least according to the most common reasoning behind it which seems to be separating the low and high frequency content in the speaker cable run.
As I said before what is funny is how many supposed "bi-wire speaker cables" don't even implement this supposed advantage. Not sure how many do and how many just have 4 pig tails on the speaker end drawn out of two "standard" wires as if they are oblivious of this reasoning, although it is then "cheaper"
JaroTheWise
The rationale is to sell more wire.
But of course even the speaker manufacturers are complicit in making the dual posted units - like I said even in "mid-fi" speakers like my Paradigm Studios and the lay out the rationale in the instruction manual and all - in general they do not benefit from the sales of speaker cabling - unless you stand back and look at the whole "hifi" ecosystem
I notice that Stereophile doesnt spend much time on "wires" unlike I think Absolute Sound. I think Mejas wrote some stuff to say Audioquest was better than "lamp cord" but that is mostly it
JaroTheWise
As I have said before, it is in their financial interest to support their dealers by providing for biwiring. However, it is also in their interest to provide it as an option for buyers who want it. Besides, I see no downside to having/trying the option if it appeals.
Mix and match cables.
Cables best suited for high frequency signals are not the same as ones best suited for low frequency.
With low frequency, damping factor of the amp is a big deal, so you want more muscle (cross sectional area = gauge). Some worry about skin effect. Some worry about strand interactions. Some worry about the position of Mars relative to the moon. Choose your own worries wisely.
With high frequency, where damping factor is less of an issue due to considerably lower currents involved, you can get into finer wires that will (allegedly) result in better signal transfer and less "time smear" due to things like strand interaction.
You can make really neat cables out of solid silver wire by twisting two jacketed conductors together. It's SO so simple to do.
You can get Teflon insulated three-nine 99.999% pure silver conductor with Teflon jacket I was told. Twist that up! Or caaaaarefully insert 30 gauge silver wire into Teflon tubing and twist THAT up.
Very nice sound... the silver/Teflon combo!
Cheers,
Presto
I did hear it said by someone - maybe Vandersteen - that if anything the wires used in biwire should be the same as each other I guess to avoid any cable induced differences. Mine are not the same but compositionally so similar that they might as well be
Where do you buy the raw silver cable in teflon though? Links?
JaroTheWise
Cable induced differences? In the crossover region?
That I would have to hear... I think you'd need to compare a course power cable to a fine wire to hear it... But, there is the crossover region with overlap. Thing is, the drivers already have their own character in the crossover region and only so much can be done to "voice" these differences out of the speaker. Often dispersion of each driver for given frequencies will differ which can have even more pronounced effects than SPL differences (which can be compensated for). Distortion of each driver through the crossover region is all a biggie. Yeah, you might have a miniscule effect on over-all voicing, but I bet any change would pale in comparison if you got a mix-match cable set that synergized well with the individual drivers. YMMV.
In any case, that's a big maybe. But the ability to use different cables is a plus in my mind. Using the same cables offers less benefit.
http://www.ebay.com/itm/Pure-Silver-9999-Stranded-Wire-26AWG-Teflon-Audio-Cable-/120573749556
I've never purchased from that seller. If you google "teflon insulated silver wire" all kinds of goodies show up. If you're worried, order a few feet first as a test, and see what you get.
I agree with you mostly but was just repeating what I read about it - will try to find the source again. I suppose if you believe in different cable "character" then it is a valid thing - again here I am referring to two different types of cable used for the two different bi-wire runs. True that it would be mitigated by the crossover and internal wiring which of course is "common" in any case.
Also raises the issue that bi-wiring may have some validity but that the level of the system has to be high enough to notice it which might suggest that dual post sets "trickled down" to lower end speakers that probably arnt good enough otherwise to have it's benefit be noticed - but it was a cheap way to make a system seem higher end
I'm gonna do some other experimenting and A/B and doublecheck my thinking that it benefited the first time around. Also will check out those cables you mentioned. I had a line on some DH labs silver coated copper that I still might get - are supposed to be great for the modest price
JaroTheWise
You may find a stout cable on the midbass has a positive effect on damping factor (and bass response) that outweighs any negative affects in the crossover range.
I've done simulations with different cables and how they affect crossover curve shape (Q) and statements about two different cables causing *significant* response changes are exaggerations at best. I'd call the response changes miniscule at best -> under 0.1 db. Many here claim to hear 0.1db changes, I cannot. Maybe I am deaf! ;)
Cheers,
Presto
I have I think a 12 gauge on the midbass and a 14 on the upper posts - not that I bought them that way but it was what I had around to use and figured the lower gauge goes to the upper frequencies - but still a stout gauge compared to charts showing minimum cable sizes given my runs are just about 12 feet.
I have not experimented much with different speaker cables. I think the differences exist but are likely exceedingly small between basic OFC copper of thicker gauge and anything "better" - or maybe something like pure silver will sound "different" but not necessarily "better" which is another feature of the life of diminishing returns. My bro in law recently tried some Nordost Vahalla with his ASR and Quad speaker setup and said improvement was definitely noticeable but that the cables cost the same as a new Mercedes...
JaroTheWise
...my experience is that bi-wiring most always makes an improvement.
I have also found short high quality cable jumpers are superior to the flat brass ones which come with the speakers if you don't bi-wire.
I find it interesting that the stock jumpers in these units are not done with more care but I guess they assume that audiophiles, being the tweakers that they are, will always come up with some supposedly better thing
I consider myself by personality to be comparatively immune to placebo effect - though of course not completely. But as I said this stuff hits you over the head when you DON'T expect differences but they seem to occur
I am also gonna try what I happened to see on the internet of wiring a single run with jumpers in place but putting one side on the top pair of posts and the other on the bottom. Not certain now to map the circuit path in this case but should be interesting too
JaroTheWise
If you think it sounds better, go for it. Nothing I say is likely to change your mind.
My advice is not to spend very much money, because bi-wiring is primarily buy-wiring. Buy-wiring will lower the resistance seen by the amplifier, but then, why not just get adequately heavy gauge wire in the first place?
Roger Russell, who was Director of Acoustic Research at McIntosh Laboratory Inc. for 25 years, has an on line article on Speaker Wire and he provides a table giving the maximum length of various gauges of wire IF you don't want the resistance of the wire to make an audible difference to the frequency response at the speakers. I have linked to the speaker wire table in his article, but you can still read the whole article.
There are a number of things besides resistance which 'might' make an audible difference with speaker wires, such as high capacitance, which may upset some poorly desinged amplifiers. Roger Russell discusses some of those issues, too.
-----
"A fool and his money are soon parted." --- Thomas Tusser
You may enjoy this
Audio by Van Alstine ABX Comparator Review, Part 1: Audio Store & Wiring
Thanks for posting the link to that article by Russell, There was a later article by Dunlavy reporting similar results in their auditioning rooms; where they used several different tests. One was pretending to switch cables to a much more exotic looking cable, at which point the observers "heard" a difference. Auto-suggestion (AKA, self hypnosis) is a powerful influence, and we've all been caught by it at one time or another.
To avoid auto-suggestion I used to get my daughters to listen while I made changes. It was interesting that when they said they couldn't hear any difference; suddenly, I couldn't anymore either.
In regard to the 5% rule mentioned by Russell, I do use that; but prefer to use 5% of the speaker's minimum impedance, rather than the nominal.
I have personally tried bi-wiring; but gave up on it after I found it made no difference.
I have found that contact resistance does make a difference, and so all my end terminations are gold plated, and are both clamped and soldered to the wire itself. Amplifier and speaker connections are also gold plated. The point behind the gold is that it does not oxidize.
Jerry
I consider a speaker's minimum impedance to be it's impedance, as a rule. My speakers are really 4 ohm speakers, and the lengths are nowhere near enough to cause a change in the frequency response by 0.1 dB or more.
I would think contact resistance could easily be more significant than the resistance of the wires.
I remember the Dunlavy story.
http://www.verber.com/mark/ce/cables.html
The major effect of buywiring I experienced was in a store when I was auditioning the old PSB Stratus Minis, where they demonstrated the speakers I was auditioning with some tri-wire speaker cable. Unfortunately, they were careless with the extra wire, which shorted out across the speaker terminals and blew the amplifier. Just blew the fuse, I trust. THAT made a definite audible difference because the amplifier no longer worked! They had to hook up another amp.
-----
"A fool and his money are soon parted." --- Thomas Tusser
My experience with contact resistance was when I was trying to match up pairs of Advent tweeters by listening to a pair of speakers. The Advents were out in the middle of the room, side by side, and I had no consistency of results among the 3 pairs of Kloss tweeters I had. It turned out to be contact issues at the studs on the back of the speakers. After I solved that problem, the tweeters matched up much more easily.
Earlier, I had some contact issues when comparing two pair of speaker cables. Two different brands of 12 gauge with different jackets, 32 feet long, and matched for length. Fixing the contact issues made them sound identical. I should have remembered that experience when trying to match the tweeter pairs.
Because of my room, I have long cable runs; but I try for no more than 0.25 dB frequency response change due to series resistance in the amplifier source impedance, plus cable impedance. That works for frequencies up to 1-3 kHz; but inductance in the amp and cables causes a rise in total series impedance at higher frequencies. So if you're being really rigorous, that needs to be considered as well. Nelson Pass published some good data on cable impedance a good while ago. Bose also pointed out the 5% rule in a brochure about the 1801 power amp in the mid 70's, and included amplifier source impedance in their criteria. Bryston has also mentioned 5% in one of their papers.
Jerry
Bi-wiring does more than just decrease the net impedance seen by the amp.
Bi-wiring gives lowpass and highpass filter currents a separate place in physical space to propagate magnetically along the path from amp to speaker!
The question is: does separating these currents for the transmission from amp to speaker terminals have sonic benefits?
Ah, now that's the question. Some say yes.
I think passive biamping/multi-amping would have even more effect and active multi-amping to have the most effects of all, but now you're introducing signal processing equipment which most philes shy away from, be it in the digital or analog realm.
One thing I like about it is how clean the hookup is - that when I made my own jumpers then it's a pain to make sure all the contacts stay in place when plugging them in - not really a big deal but still.. Plus the two cable runs make it look like you concocted something special compared to standard rigs - maybe a bit like using a 5 blade razor instead of 2!
As one guy wrote he has some old Harbeth or Spendors that allow for TRI wiring
JaroTheWise
Yes, of course there is none - how could we forget.
Instead, you'll be beating the old "Roger Russell article" horse, which was stillborn at the time when that article saw the light of day - but you still continue beating it now, when there's just the stink left.
whatever.
I bi-wired my Vandersteens and then I tried some Audience speaker cable with their jumpers made from the same wire. It was way better. So, I'm agnostic, the jumpers that come with speakers probably suck and rest is an unknow that doesn't make me obsess that I'm missing anything.
I'd be curious if you made a jumper from the same wire if you'd notice the same degradation.
-Rod
.... don't you think?
It totally makes sense that higher quality single wire, with jumpers made from the same wire, is superior to lower quality bi-wire. Also, bi-wiring with Audience would probably be too expensive, and the other approach is a nice trade-off.
None of that tells us anything about the merits of bi-wiring though.
Well, according to Pat and others of the 'cooper of the correct gauge is good enough' crowd, my wire was of excellent quality.
I was actually dumb struck that the difference was so obvious. And you're right, another run of Audience cable would have been too expensive for me and to be honest, Audience isn't, or I should say that Richard wasn't, a bi-wire fan.
-Rod
They, or at least Pat, also say that amplifier, if it's "big" (read: powerful) enough, is good enough.
I pay as much attention to their thoughts on cables, as I do to their thoughts (if you can actually call it that ) on amps.
I did make jumpers just from the same copper wire that I had for the runs and it did seem to improve also from the standard gold flat jumpers they supplied with the speakers - just seemed more "fluid" - the treble seeming more integrated and smoother. This was also after I cleaned up the stock jumper things on the Paradigms
I hooked up the Epos Epic 2 that I have here and those I would say do not exhibit such a benefit from the bi-wiring - sounding roughly the same - so it might be somewhat specific to the speaker model - either the post wiring or the crossover for some reason
JaroTheWise
I think you hit the nail on the head. Never had an ounce of success bi-wiring my Spendor 2/3's. Sounded better/more coherent with a good pair of jumpers in fact. That said, other speakers may respond quite positively to bi-wiring. Let your ears be the judge.
Download any of his speaker manuals and read the section on bi-wiring.
He proposes that the Hall effect is responsible for the difference between bi- and mono-wiring, *providing* the bi-wire pairs are separated for an inch or two over most of their run. If true, this explains why some people hear a big improvement (separated wire pairs) while others (both pairs held together in a common housing.)
WW
"A man need merely light the filaments of his receiving set and the world's greatest artists will perform for him." Alfred N. Goldsmith, RCA, 1922
Vandersteen was using a Hall effect probe to measure the magnetic fields. AFAICT The Hall effect itself was not offered as a causal factor. I have a lot of respect for RV, but I don't find his explanation convincing.
The magnetic field established at right angles to a current flowing in a conductorf is the Hall effect. But the inverse is also true: a changing magnetic field can cause a current to flow in a conductor. *That* is what he proposes: the strong magnetic field from the high-current low-freq wires smears/overrides the very small current flowing in the wires carrying the highs.
It makes sense to my ears. With bi-wiring, I hear greatly improved low-level detail and harmonics, which are most welcome with my old Spica TC-50s. John Bau, seeing a pic of his hacked-up crossovers, commented that he expected a big improvement, and that he wished he knew then what he knows now about ground plane interactions. Maybe someone can fill me in on what he was referring to. (He has been out of the Spica world for many years, and I don't bother him with questions.)
WW
"A man need merely light the filaments of his receiving set and the world's greatest artists will perform for him." Alfred N. Goldsmith, RCA, 1922
The magnetic field established at right angles to a current flowing in a conductor is the Hall effect.
No it isn't. That's Ampere's Law.
But the inverse is also true: a changing magnetic field can cause a current to flow in a conductor.
And that's Faraday's Law. You are right that the two cables in a bi-wire configuration will interact via their magnetic fields. This is normally just called crosstalk and doesn't require the Hall effect. The Hall effect is something different, see the Wikipedia page linked below.
I think RV is making a reference to Faraday's Law and crosstalks, but his explanation doesn't work. First, a time varying magnetic field produced by current flowing in one conductor can induce EMF in another conductor, but it's a moot point in biwiring because both conductors are already being driven with the full range single at the amp. Second, the high pass filter portion of the crossover is blocking low frequency currents from flowing through the tweeter, and it doesn't care if the low frequency EMF is coming from the amp, from cable crosstalk, or from the hair dryer in the next room.
The only frequency range where the low frequency and high frequency networks interact is in the crossover range where the low pass and high pass filter responses overlap. In this frequency range, back-EMF from the woofer is the main source of unwanted EMF affecting the tweeter. In the bi-wire configuration, the back-EMF can be sunk by the amp with less effect on the tweeter output.
Also, in this frequency range, the magnetic interaction between the two biwire cables manifests itself as a change in their combined impedance as seen by the amp.
One other difference between single and bi-wiring is increasing the parallel capacitance of the cable (doubling it if identical cables are used).
So there are at least three basic explanations to explain why biwiring might produce different results: damping of back-EMF, changing the effective impedance in the crossover range, and increasing parallel capacitance.
I think RV is making a reference to Faraday's Law and crosstalks, but his explanation doesn't work. First, a time varying magnetic field produced by current flowing in one conductor can induce EMF in another conductor, but it's a moot point in biwiring because both conductors are already being driven with the full range single at the amp.Correct, but not a mute point.
The driving voltage to both cables, at the amp side, is identical for each filter/driver combination. The current in each cable, most definitely, is not. The impedances of each network are frequency dependent, so the current flowing in each of the two bi-wire cables is unique to that filter.
Currents result in fields, and vice versa. Voltage is just something that happens when currents can't move. When currents move unimpeded, there is no more voltage. When a current is totally impeded, you get zero current flow but full voltage (which is also called terminal voltage, aka 'voltage at the terminals'.
In a fault (short circuit) situation the voltage at the fault location is zero or near zero because the impedance to ground at that point is zero or near zero.
Water muddy yet? ;)
Cheers,
Presto
Edits: 07/16/15 07/16/15
I don't think it's muddy at all.
Since you want to debate it, let's be precise on terminology. Voltage is a measurement of the difference in electric potential between two points in an electric field. Current is the flow of charge carriers. The electric field produces an electro-motive force (EMF). When charge carriers are free to flow in the presence of an electric field, EMF produces current. The amount of charge/time flowing (current) is a function of the EMF and impedance.
The Vandersteen hypothesis is that current at bass frequencies in the LF cable produce a magnetic field that induces bass frequencies in the HF cable which modulate the high frequencies. This hypothesis is non-physical for several reasons.
Let's start with curl(E) = -dB/dt. B is the magnetic field produced by the LF cable. The induced EMF is the integral of E over the length of the HF cable. This produces a voltage signal at the input to the HF crossover, which can be summed with the voltage signal from the amp minus cable losses. My interpretation of Vandersteen's hypothesis is that the induced EMF in the HF cable coming from the magnetic field of the LF cable is a problem. I reject his hypothesis on the basis that the bass frequency components of the magnetically induced EMF are blocked by the HPF in the crossover. Also, they are many orders of magnitude smaller than the bass frequency components of the EMF produced by the amp which are also present at the input to the HF crossover.
Another problem is that Vandersteen claims modulation, which would require the cable to behave non-linearly. At typical audio voltages, cables are linear. In order to start seeing non-linear effects in conventional cables, you need to apply destructively high voltages where dielectric breakdown occurs, many orders of magnitude higher than they are designed for. In the case of extruded teflon insulation, the breakdown voltage is around 20 MV/m.
Even if you ignore everything we know about cables and are willing to believe in possibly undiscovered physics that might result in the LF signal modulating the HF, you still have to contend with the fact that the bass frequency content of the magnetically induced voltage in the HF cable is many orders of magnitude lower than the bass frequency content of the voltage applied to the cable by the amp. This is really important, because if Richard Vandersteen were claiming that cable separation made a difference in an active bi-amp setup, his argument might make some sense.
But he's talking about bi-wiring, and in that case his hypothesis doesn't hold up. There are other, better, clearer, simpler explanations for why bi-wiring might make a difference, and there is no need to offer a voodoo nonsense explanation based on magnetic induction and modulation.
"Bi/Tri Wiring
Improvements can be heard through separating the energy from each filter in the crossover. Cables vary in construction but a good quality cable should be low in impedance, inductance and capacitance. Do not use cables that act as additional crossover components. Experimentation is crucial in this situation and a cable that works well in one situation with a given amplifier may not always perform as well when one of these variables is change."
There's no good reason for you not performing your own analysis, you could even borrow cables from your dealer if need be.
Except, you've convinced yourself, as have others, it won't help.
Until recently, I bi-wired my current speakers with 2x Kimber 4TC. Now I run them single wire with considerably more expensive Tellurium Q cables. I have experienced gains from bi-wiring with some speakers, particularly with the Focus Audio speakers I used to own, and not so much with others.
I've haven't said, anywhere in this thread, that bi-wiring doesn't make a difference. A bi-wiring configuration is a different circuit than a single wire configuration, and there is a real difference in impedance, particularly in the crossover region. I've pointed out multiple reasons why bi-wiring may produce different results.
My original point is that Richard Vandersteen is wrong about WHY bi-wiring makes a difference. His hypothesis is not physical, and it's also not necessary since there are other basic explanations for the difference.
The problem with this thread is that you've been reflexively defending Vandersteen without really reading or understanding my posts and without demonstrating any understanding of basic electronics. When you wrote stuff like "How can there be bass frequencie content of the HF cable?" after a half-page of arguing the point, it became obvious to me that there is really no point in continuing further. So please stop bothering me.
Electricity at any frequency, or multiple frequencies has POTENTIAL to flow through a conductor, but require continuity and a load to do so, as you know.
You wrote
"Running separate wires from the amp to the LF and HF terminals of the speaker does not make the low frequencies magically disappear from the signal at the input to the high pass portion of the crossover, or the high frequencies disappear from the input of the low pass portion."
"Magically disappear" is a poor substitute for attenuated.
The HF cable discussed has the Potential to conduct LOW frequencies, but is not doing so because the high pass filter is showing low frequencies a very high impedance, the lows are attenuated, not just at the speaker terminals, but throughout the HF cable.
Obviously the same is true in reverse for the LF cable.
The above paragraph in quotes shows we both have much to learn about "electronics".
You're correct about me defending RV, I consider him a friend and don't feel it's a problem. Vandersteen doesn't even sell cable, why say "voodoo science " or whatever you wrote, did that make you feel better about yourself?
Why didn't you offer your experiences to the OP who was looking for just that input?
"orders of magnitude lower than the bass frequencies content of the voltage applied to the (HF) cable by the amp".
How can there be bass frequencie content of the HF cable?
Why would cable separation make sense with bi-amp?
You wrote "both conductors are driven by the full range signal at the amp" the reality is both conductors have the POTENTIAL to CONDUCT the full range signal.
You wrote "the high pass portion of the cross over is BLOCKING low frequency currents from flowing through the tweeter". The reality is chosen frequencies are not blocked or shorted, they are in effect shown an near infinite impedance or open circuit, and with an open circuit no current flows.
With a near infinite impedance from the high pass portion of a crossover, no low frequency current flows through the high frequency CONDUCTOR between amp and speaker.
With a near infinite impedance from the low pass portion of a crossover, no high frequency current flows through the low frequency CONDUCTOR between amp and speaker.
You basically restated the same thing I wrote, just choosing some different words.
You wrote "both conductors are driven by the full range signal at the amp" the reality is both conductors have the POTENTIAL to CONDUCT the full range signal.
Both cables are driven by the same voltage source at the amp, but the current is different because the impedance of the crossover is different. It is important to note that both cables are being driven by the same voltage source, because it's relevant to RV's hypothesis. The fact that bass currents in one cable can induce EMF at bass frequencies in the other cable is irrelevant for the reasons I previously stated, most notably that the amp is already driving both cables with the same frequencies.
You wrote "the high pass portion of the cross over is BLOCKING low frequency currents from flowing through the tweeter". The reality is chosen frequencies are not blocked or shorted, they are in effect shown an near infinite impedance or open circuit, and with an open circuit no current flows.
To my interpretation, current flow is blocked because the impedance of the filter network is very high outside of its pass band. But I don't disagree with your elaboration.
It doesn't matter that "both cables are driven by the same voltage source at the amp" because both cables are not exposed to the same frequency loads.
If we were to take bi-wiring further, and (passively) bi-amp, the amp connected to the high pass would not be loaded by low frequencies, and obviously the amp connected to the low pass would not be loaded by high frequencies.
Without load no current is generated. If an amp (or cable) is only allowed continuity with a narrow range of frequencies, only those frequencies will generate load and be reproduced by a speaker.
If a speaker used a shunt or low value resistor to "block" a chosen range of frequencies, your use of the word "block" would be accurate, the cable and amp would be loaded by, and conduct the chosen frequencies.
But since chosen frequencies are allowed to 'pass' and the frequencies that are not to pass, are shown an near infinite impedance, no conductance of the chosen frequencies range takes place, the amp and cables are not loaded by the frequencies.
You contradict yourself with "both cables are driven by the same voltage source at the amp, but the current is different because the impedance of the crossover is different.
If the impedance is different, do both cables see the same frequencies load?
It doesn't matter that "both cables are driven by the same voltage source at the amp" because both cables are not exposed to the same frequency loads.If we were to take bi-wiring further, and (passively) bi-amp, the amp connected to the high pass would not be loaded by low frequencies, and obviously the amp connected to the low pass would not be loaded by high frequencies.
Without load no current is generated. If an amp (or cable) is only allowed continuity with a narrow range of frequencies, only those frequencies will generate load and be reproduced by a speaker.
No kidding. I said as much in my first post. That is the crux of the issue with Vandersteen's hypothesis.
If a speaker used a shunt or low value resistor to "block" a chosen range of frequencies, your use of the word "block" would be accurate, the cable and amp would be loaded by, and conduct the chosen frequencies.
But since chosen frequencies are allowed to 'pass' and the frequencies that are not to pass, are shown an near infinite impedance, no conductance of the chosen frequencies range takes place, the amp and cables are not loaded by the frequencies.You contradict yourself with "both cables are driven by the same voltage source at the amp, but the current is different because the impedance of the crossover is different.
If the impedance is different, do both cables see the same frequencies load?
I don't see anything contradictory in what I've said. The terms drive and block are commonly used in electronics and my usage of them is consistent with their common meaning. A filter 'blocks' some frequencies and 'passes' others. A source 'drives' a load. The amp is (approximately) a voltage source, the load is a linear motor, and in between the two is a cable and crossover network that acts as a filter. The EMF produced by the amp drives the load through the filter network.
I don't want to debate it further because as far as I can tell we both agree regarding the original topic, and this has just become a pedantic argument over common electronics terms.
Edits: 07/16/15
You wrote "his explanation doesn't work" and the oversimplification "the high pass filter portion of the crossover is blocking low frequency currents from flowing through the tweeter"
Where the reality is the high pass filter is also preventing the high pass cable (bi-wire) fron CONDUCTING high frequencies.
You wrote "the only frequency range where the low and high frequency networks interact is in the crossover range where low and high filter responses overlap" which is not true.
So no, I don't agree with you.
I think it's really lousy to say stupid things about a successful industry professional when you could go to his website and discuss (learn) the finer points with him directly.
I ment to write "Where the reality is the high pass filter is also preventing the high pass cable (bi-wire) from CONDUCTING (low) frequencies".
Apologies
Up until your last post, you have been trying to argue with me while reiterating the same points I originally made in different words, which has been bizarre.
You wrote "his explanation doesn't work" and the oversimplification "the high pass filter portion of the crossover is blocking low frequency currents from flowing through the tweeter"
Yes, that is correct, and if you look at your own previous posts they are saying the exact same thing.
Where the reality is the high pass filter is also preventing the high pass cable (bi-wire) fron CONDUCTING high frequencies.
NO! That makes no sense.
You wrote "the only frequency range where the low and high frequency networks interact is in the crossover range where low and high filter responses overlap" which is not true.
Yes, it absolutely is true. This is basic electronic theory at work. And your own previous posts are consistent with this.
I think it's really lousy to say stupid things about a successful industry professional when you could go to his website and discuss (learn) the finer points with him directly.
Just because he's an industry professional doesn't mean he's right. Or in this case, just because he's a world class speaker designer doesn't prove his knowledge of electromagnetics is correct.
His FAQ says this:
"Additional experiments with a Hall Effect probe revealed that high-current bass frequencies created a measurable field around the wires that expanded and collapsed with the signal. We believe that this dynamic field modulates the smaller signals, especially the very low level treble frequencies. With the high-current signal (Bass) separated from the low-current signal (Treble) this small signal modulation was eliminated as long as the cables were separated by at least an inch or two. (To keep the treble cable out of the field surrounding the bass cable.)"
As I stated before, the above hypothesis is not a valid explanation. Faraday's Law establishes that a time varying magnetic field produces an electric field that induces EMF in a circuit. As such, bass currents flowing in the LF speaker cables will generate a magnetic field that induces EMF at bass frequencies in the HF speaker cables. However, this is an entirely moot point because the HF speaker cables are already being driven with a full range signal containing the same bass frequencies by the amp. The high pass filter in the crossover rejects the induced EMF at bass frequencies just as it rejects the amp's EMF at bass frequencies.
There is another problem with his explanation which I didn't even bother to pick on the first time because the point above is sufficient to reject his explanation. The other problem is that he claims there is signal modulation, which is a non-linear process. Audio cables are linear devices and can't produce modulation.
Finally, as I said before, there are a few other explanations for why biwiring would make a difference, starting with the most basic one: the cable impedance is different.
Try this..
Rig up a high pass filter that you can temporarily place at the terminals of one of your speakers, or on a spare woofer if you have one.
Use two individual wires as your speaker cable for this test.
Place a clamp-on ammeter on one of the wires (+ or - but not both) to the speaker.
Play a test CD with a steady low bass tone.
Measure the milliamperes (AC) with, and without the high pass filter over the entire length of the wires.
You will see that with the high pass filter in place the milliamperes are lower, throughout the length of the wires than without the filter.
Do it, and you will see that your statement "however this is an entirely moot point because the high frequency speaker cables are already being driven with a full range signal containing the same bass frequencies by the amp" Is incorrect.
With bi-wiring, the high pass cable is not subjected to the "measurable field" generated by bass frequencies, over the entire length, of the high pass cable.
I saw exactly this same argument occurring on the subject in another forum - at least I think it was the same. Basically if the same current runs through both bi wire cables or if the high pass low pass causes the content of the wires to be different.
I was wondering the answer and I don't know it - but assumed that "nothing exists in the wire until the circuit is closed" and once it is closed with a filter in place then only the unfiltered content will be running in it
If this is NOT true then at least Vandersteen's rationale makes no sense
JaroTheWise
Both cables in a passive bi-wire setup have the same electrical POTENTIAL.
IT's true, "the high pass low pass causes the CURRENT (not content) measured in milliamperes, of the wires to be different".
What exists in the wire untill the circuit is closed is an electrical potential, that can be measured with a VOLT METER or a FREQUENCY METER but not an AMMETER because without electrical continuity (a circuit) to a LOAD there is NO CURRENT or milliamperes.
If you were to separate the two wires on your toaster and place a clamp-on ammeter on one of the wires, you would not see any amperage (current) untill depressing the lever to make toast.
Your statement "and once it is closed with a filter in place then only the unfiltered content (current) will be running in it" is correct.
Regards, Craig
nt
The VOLTAGE delivered to both pairs of speaker terminals by both cables is full range. Due to the different impedances of the crossover networks and the different impedances of the drivers, the CURRENT flowing through both cables is different and not full range.
"nothing exists in the wire until the circuit is closed" is not correct. When connected to a voltage source (i.e. the amp), an electric field exists in the wire regardless of whether current is flowing. The electric field provides the electro-motive force that causes charges to flow in the wire creating current.
Magnetic induction per Faraday's Law would result in VOLTAGE being induced in the HF cable by currents in the LF cable.
Well you certainly know better than I do so I make no claim to contest what you are saying - I just find the topic interesting to prove or disprove the validity of the rationale of bi-wiring - at least the rationale as stated by Vandersteen and the Hall Effect. Some were arguing I think that the whole signal current existed in the wiring despite the crossovers which would invalidate it - but I assumed that Vandersteen could not be so wrong in stating it, even if he might be wrong in saying the Hall Effect is the major element that is responsible for the benefit
Not to mention that many or most "bi-wire" cables are either one cable with a second set of pigtails at the speaker end or alternatively two runs of cable but put in the same sheath which also would not benefit from eliminating Hall effect factors - unless maybe they were insulated in some manner to prevent it
But I find these posts educational - as I was never schooled in this subject
JaroTheWise
He said he measured the magnetic field with a Hall effect probe.
If you draw out the circuit diagrams for the single wire and bi-wire cases and do a bit of algebra to solve for the total impedance, you will find that the total impedance of the bi-wire setup is different than single wire within the frequency region around the crossover point where the filter responses overlap.
You can also draw a circuit diagram with a voltage source at the woofer representing back-EMF and calculate how much of this reaches the tweeter. You will find the answer is different for the single wire and bi-wire cases within the frequency region around the crossover point.
All the discussion about differences in current in the wires is really besides the point. That's not what makes bi-wiring different than single wiring - at least not from a theoretical POV.
Well the reason that I cite it is just parroting Vandersteen mostly - yet I find his explanation improbable enough to gladly accept other explanations - I think some of these other "causes" are maybe more tied into a specific speaker design as being one that would benefit
Heck if the Hall effect was really it then it sounds like you could take a seperate double biwire and put the wires together and then pull them apart and hear the difference - which I can try but seriously think nothing would be audible
JaroTheWise
Try this..
Rig up a high pass filter that you can temporarily place at the terminals of one of your speakers, or on a spare woofer if you have one.
Use two individual wires as your speaker cable for this test.
Place a clamp-on ammeter on one of the wires (+ or - but not both) to the speaker.
Play a test CD with a steady low bass tone.
Measure the milliamperes (AC) with, and without the high pass filter over the entire length of the wires.
You will see that with the high pass filter in place the milliamperes are lower, throughout the length of the wires than without the filter.
No shit.
(I assume you meant for this experiment to be done on the LF terminals of the speaker)
Do it, and you will see that your statement "however this is an entirely moot point because the high frequency speaker cables are already being driven with a full range signal containing the same bass frequencies by the amp" Is incorrect.
With bi-wiring, the high pass cable is not subjected to the "measurable field" generated by bass frequencies, over the entire length, of the high pass cable.
This is where you are wrong. I assume you understand Ohm's Law, V=IR.
Do you agree that at the amplifier end, the voltage signal applied to both cables is the same? And do you also agree that it is full range, so that the voltage applied to the HF cable at the amp end includes the bass frequencies?
Now do you also agree that the current in the HF cable is NOT full range, because the high pass filter in the crossover is blocking current flow in its stop band?
If we're good so far, then apply Ohm's Law to calculate the voltage drop across the length of the HF speaker cable at a bass frequency, e.g. 100 Hz. Since the current is essentially zero at this frequency, the voltage drop is also essentially zero, and therefore the voltage at the speaker terminals is the same as at the amp end. Ergo, a full range signal is present at the HF speaker terminals.
Running separate wires from the amp to the LF and HF terminals of the speaker does not make the low frequencies magically disappear from the signal at the input to the high pass portion of the crossover, or the high frequencies disappear from the input of the low pass portion.
Do I agree that at the amp, the voltage signal applied to both cables is the same? Yep, absolutely.
Do I also agree the current in the HF cable is NOT full range, because the high pass filter in the crossover is blocking current flow in its stop band? That's for damn sure.
Don't need to go any further because we've already proved that CURRENT is blocked by the high pass filter, and it's CURRENT that creates "measurable fields" that we want to avoid throughout the length of our cables.
In reply to your last paragraph, the frequencies don't disappear, they are attenuated, and not just at the terminals, but as you wrote "Now do you also agree that the current in the HF cable is NOT full range, because the high pass filter in the crossover is blocking current flow in its stop band?" So... How would low frequencies make it to the HF terminals, or the high frequencies to the LF terminals without current?
So... How would low frequencies make it to the HF terminals, or the high frequencies to the LF terminals without current?OK, since we're going to be pedantic and precice, what exactly do you mean by "low frequencies make it to the HF terminals"? Specifically "make it"?
Thanks.
Edits: 07/16/15
"Make it" was my poor substitute for conducted, in reply to your less than ideal term "disappear".
As in, when bi-wiring low frequencies are attenuated over the entire length of high frequency cable, and high frequencies are attenuated over the entire length of low frequency cable.
Good evening
Right. It has to be over the entire length. It's the current that is being attenuated. The voltage is not attenuated until post filter. But the current is attenuated all the way back to the amplifier terminals where the bi-wire split is made.I think Dave is adding discussion about interaction between cables where the individual currents can modulate one another when separated into adjacent cables. This is complex, because we need to know about more than just the distance separating the cables, but the cable geometry including insulation thickness and turns per unit length.
If we're going that far, there are lots of details that would need to be added to the theoretical model if that specific detail were to be added, such as the individual voltage drops *across* each bi-wired cable, which would be different, since the currents going through them are also different, despite each cable having the same impedance. In that case the voltages presented to each filter input are NOT identical, albeit close.
The, introduce two different cables into the model and ALL kinds of mathematical hell breaks loose! ;)
Cheers,
Presto
Edits: 07/17/15
It does not make the full range voltage go away.
It does make the portion of the filtered current go away.
You can't speak of "signal" without confusing the issue.
When you say "signal" are you referring to the full range voltage at the filter terminals? Or the filtered current?
You can't have "unfiltered current" going into the filter unless it is ONLY a shunt filter. If there are series components, then the filter is actually blocking the current below the Fc of the crossover point, with attenuation (impedance) increasing as frequency goes away from Fc.
You most definitely have unfiltered voltage present. Voltage does not get filtered. Current does.
Replace the word "signal" in all of your posts with either the word "current" or "voltage" and the argument would end immediately with either you two agreeing or one of you being wrong. ;)
Cheers,
Presto
You most definitely have unfiltered voltage present *at the input to each filter*.
That clarifies what I said...
It does not make the full range voltage go away.
It does make the portion of the filtered current go away.You can't speak of "signal" without confusing the issue.
When you say "signal" are you referring to the full range voltage at the filter terminals? Or the filtered current?
If we're going to discuss things with pendantry, I guess you have a fair point. But really, which did you think I meant?
You can't have "unfiltered current" going into the filter unless it is ONLY a shunt filter. If there are series components, then the filter is actually blocking the current below the Fc of the crossover point, with attenuation (impedance) increasing as frequency goes away from Fc.Very true, and this is exactly what I stated earlier. We're talking about actual bi-wire capable speakers in this thread, which means parallel LPF and HPF crossover networks. And I don't believe there are any which implement the HPF via shunt inductors only without a series cap. So when I said earlier that the HPF blocks low frequencies, I meant that in the literal sense.
You most definitely have unfiltered voltage present. Voltage does not get filtered. Current does.Not true! Since we're being pedantic now, please reconsider your statement. Voltage most definitely DOES get filtered. If not, the filter wouldn't work. If the full range voltage is present at the output of the high pass filter, bass frequencies and all, what would stop it from producing full range currents through the tweeter? Think about it.
Edits: 07/16/15
Don't move the goalposts. We're talking CABLES. Cables are pre-filter.
Voltage does not get attenuated pre-filter. Only post filter.
Current is attenuated in the whole branch, i.e., in the individual cables - with one feeding each filter.Let's make it even simpler.
In a pair of bi-wire cables, the current to the low pass filter is only low pass current. The current to the high-pass filter is only high-pass current.
The sum of both currents electrically would be equal to the highpass current and the lowpass current combined, which is precisely what you see at the amplifier terminals IF only one amp is used.
If two amps are used, in a passive bi-wire configuration, each amp (like each cable) sees respective filter current only. (High sees high, low sees low).
Cheers,
Presto
Edits: 07/17/15
This should be entirely obvious if you read back through the thread where I've stated it several times, but I'll clarify once again:
I'm talking about the EMF induced on the HF cable from the magnetic field produced by the bass currents in the LF cable.
If you measure the voltage at the HF speaker terminals, it will come from two sources: the amp and induced EMF. Both sources will contain bass frequency content, and the high pass crossover section will filter out the bass frequency content regardless of source.
If the HF speaker cable is exposed to low frequency EMI from any source, it's not going to bother the tweeter as long as the frequencies are well into the stop band of the HF crossover section.
Oh, I am referring to an ideal model where there is only current driven by a voltage source and not induced.
In any case, a case is made for separating high and low pass filters from each other. Some 'philes have heard differences simply by splitting the board in half and moving the respective filters apart. By virtue of this, the cable in a bi-wire config would also move apart. All this said, the theoretical field around two conductors (send/return) in parallel and close proximity is zero. There may be interaction within a single cable jacket with two pairs cables, but if the cables are inches apart, I don't think it matter nearly as much if at all.
Cheers,
Presto
Oh, I am referring to an ideal model where there is only current driven by a voltage source and not induced.
The whole point of this sub-thread was RV's hypothesis regarding the magnetic field interaction between the two cables causing low frequencies to modulate high frequencies.
Oh, okay. To me it sounded like at certain points that things became fuzzy about current versus voltage at various points in the circuit.One thing that came out of this thread that is of interest to me though, ponder this:
Why would having low and high-pass filter currents in the same cable be less deleterious than having two separate, but in proximity, cables for low and high-pass filter currents? Aka, could not the low frequency content also modulate the high frequency content if in the same cable? In that case, the field associated with the lower frequencies is located immediately to the high frequency field.
In the case for separate cables, they can be moved further apart - reducing or even eliminating any possible effects.
Cheers,
Presto
Edits: 07/20/15
Why would having low and high-pass filter currents in the same cable be less deleterious than having two separate, but in proximity, cables for low and high-pass filter currents? Aka, could not the low frequency content also modulate the high frequency content if in the same cable? In that case, the field associated with the lower frequencies is located immediately to the high frequency field.I don't believe the low frequency content in the cable can modulate the high frequency content in the cable. Modulation is a non-linear process. What non-linear property of the cable is there that could produce this modulation?
EDIT: Let me expand on this a bit. Suppose we could replace regular wire with some kind of non-linear semi-conducting material that did cause one frequency band to be modulated by another. Given that a full range voltage is applied to the cable by the amp, and thus a full range electric field is present in the cable, the modulation would occur regardless of whether or not there is induced EMF from the magnetic field of a nearby cable.
Regarding the basic question of how can single wiring be less deleterious, I would expect it's system dependent. The single and bi-wire circuits are different and not equivalent to each other, so it's plausible that with some systems and cables bi-wiring might make things sound worse.
Edits: 07/22/15
The more I think about it the only thing I can up with is that the low frequency content in a full range signal is *supposed* to be there along with the high frequency content where with bi-wire any low frequency current induced in the high frequency cable is *not* supposed to be there.In a moving speaker cone, multiple frequencies being reproduced at once is another matter...
I wonder if cable self inductance can be a possible source of modulation within the cable for a full range signal? (In this case I thought we were dealing with relatively tiny inductance values that had very little effect...)
Cheers,
Presto
Edits: 07/22/15
Self-inductance is still linear
Quite a pantload of info, thanks.
I saw some of his writing on the subject but will review it again - interesting then in that if true it would render most if not all "biwire speaker cables" to be ineffective assuming they are packed together in the same housing - and that is even giving them the benefit to say the cable run is really a discrete pair of runs rather than as I say - simply a combined cable that has 4 ends broken out on the speaker side
Another debate I saw was this electrical notion of whether the amp actually sends the "whole" signal to the speakers on each wire but after it hits the crossover then only the high or low passes - thus comingling the signals anyway - and that debate I guess was never resolved on the forum. I personally don't know enough to answer it
JaroTheWise
....
Consider yourself lucky. You don't have tri-wire like these ! Spendor SP-100.
Interesting table correlating resistance, power loss and power factor with gauge and length.
remember if the cable has inductance that will also have to be factored in, and will vary with frequency and length. Inductance is typically measured per foot.
More wire sounds different. Makes sense to me.I've tried bi-wiring with one jumper removed and with both jumpers removed. I've tried double-run "shotgun" wiring. I've tried plain old single-wire. Each wiring scheme sounds slightly different to me.
Edits: 07/12/15
Carcass,,,You need to go back to grade school...Start with grade one..Bi wire does nothing.
In the Children With Special Needs school?
May be you want to get back there, to Square 1 - you should consider a different one this time around though.
But visit your ENT doctor first, in case you're just plain deaf.
The voice coil wire stays the same..
And what if you get rid of that earwax - does it still sound the same?
How about replacing the crap you have for audio system with something decent - still the same? Why don't you try, and get back here, when you have something useful to say?
Test your ears and your speakers too:1) Bi-wire your speakers in the normally prescribed manner (two sets of cables per speaker/all terminal jumpers removed).
2) Play some music. Make note of the sound you are hearing.
3) Turn off your amp and install only one jumper (across only one half of each speaker's terminal set) per speaker. Turn back on, listen to the music again. After comparing the new sound to the sound you heard the first time, can you hear or remember any difference between the two? If so, then you know you have "bi-wire compatible" speakers and you have ears good enough to be a "bi-wire compatible audiophile".
Edits: 07/12/15 07/12/15 07/12/15 07/12/15
I'm trying to figure what circuit that would create now...to connect one jumper
I noticed some people would have jumpers in place but wire one polarity to the lower left and the other to the higher right - creating also a "circuit" but one slightly different than just using either the lower or higher pair of speaker posts
Again this is interesting to me since I got something I did not expect which runs against the idea of the placebo effect - I really didnt expect to hear anything better but it certainly seemed that I did
JaroTheWise
"GenungoTheJust" says:AA inmate and electrical engineer John Risch (now a Bored Member) was the one who first alerted me to "single jumper bi-wiring" many years ago. I'm not clear on the technicalities but, obviously, altering the ground path in this manner can produce audible results (at least with some speakers). Search the archives here for John Risch's posts if you are really interested.
Edits: 07/12/15 07/12/15
For some of the science behind bi-wiring, see the following links:
WARNING: THE ORIGINAL GEOCITES SITE NO LONGER EXISTS, THESE ARE LINKS TO A GHOST SITE, THAT ALSO HAS POTENTIALLY DANGEROUS PAGES FOR THE UNWARY, BE CAREFUL WHAT YOU CLICK ON!
If you stick with the links as shown, and those pages that are logical extensions of the page you are already on, it should be OK
http://www.geocities.ws/jonrisch/biwiring.htm
http://www.geocities.ws/jonrisch/biwiring2.htm
http://www.geocities.ws/jonrisch/biwiring3.htm
and a portion of my AES paper on a new test tone that was also used on cables:
http://www.geocities.ws/jonrisch/page7.htm
this page has links that take you to pages 8, 9, and 11.
The first link above has a text description of what bi-wiring is, and how it works.
The second link goes into further depth on the how, and has wiring diagrams and charts of inter-driver attenuation that show just ONE of the benefits of bi-wiring vs. single wiring.
The third link shows response graphs of what happens when the woofer drives sound into the tweeter, and vice versa, as well as when other speakers in the room cause a signal to be developed across the terminals of a speaker in a speaker system under examination.
The page 7 and following page's links show IM distortion being reduced via the use of bi-wiring, as well as provide graphs showing the division of current flow in a bi-wire situation as discussed in the first link.
One note: my e-mail is not at strato.net anymore, it is:
j_risch@bellsouth.net
This link:
http://www.audioasylum.com/audio/cables/messages/13441.html
is the one concerning jumpers at the speaker with bi-wired cables.
Jon Risch
I've tried most types of bi-wiring and single-run wiring schemes and I think they all sound slightly different. Everyone should try every possible wiring scheme at least once if they can afford it.
jumping the negative posts on each speaker
"Man is the only animal that blushes - or needs to" Mark Twain
Sounds like you are describing jumping across from one negative terminal to the other per speaker. Have you tried one jumper per speaker, but jumping "upwardly" (from positive to negative)?
Any differences heard?
-
"Man is the only animal that blushes - or needs to" Mark Twain
Jumping "upwardly" or vertically is the same thing as jumping from "negative to negative", at least with most bi-wirable speakers. We're both talking about the same thing. Hyuk!
Edits: 07/12/15
you said connecting positive to negative.
"Man is the only animal that blushes - or needs to" Mark Twain
Oh well, I guess we'll never know what it sounds like. Thanks, anyway.
Edits: 07/13/15
There are two types of bi-wire speaker cable configurations, one is an internal bi-wire cable configuration, the other is an external bi-wire cable configuration. The internal bi-wire cable type means a single run of cable features two separate sets of conductors within the cable, some intended for the high-posts, the others for the low-posts. The internal bi-wire cable conductors are terminated with one pair of connectors at the amplifier end, and two pairs of connectors at the loudspeaker end. The two conductive paths are kept separate all the way from the amplifier output to the two separate sets of bi-wire binding posts, so it completely follows the concept of bi-wiring to avoid the back EMF of the woofer from affecting the tweeter. However, it's better to use two completely separate runs of speaker cable, one for the high-posts, and the other for the low-posts, that are joined together at the amplifier end with a single set of connectors, which is called an external bi-wire cable configuration. Two separate runs allows the high-post conductors and low-post conductors to be spaced far enough apart from each other to eliminate the influence of magnetic fields between the two separate cable runs, which is a worthwhile thing if one wishes to better avoid interactions between the two conductive paths.
I could just stay with what I have except for the WAF factor that my wife doesnt care for even one run of wire much less two of them - LOL.
It would be interesting to see how these "single run" biwire things perform given that they don't really hold to the whole rationale of biwiring, and as you say even a double run inside the same jacket might not be "purist" but I think largely keeping the cables separate, even if close to one another, might fulfill most of the rationale of it - possible "fields" interfering but the wire itself not occupied by the whole signal
I personally have a suspicion it might have to do with the amount of conductor - both in the cables themselves and also the contacts to the speaker - but of course I can't be sure. I could try blind testing but nobody here cares enough about it to help me with that
JaroTheWise
Perhaps you should have posted the question in Cable Asylum where the topic is considered from a productive perspective based on direct experience rather than conjecture.
Second - your experience is very common, and only means 3 things:
- your speakers are designed in the way that allows them to benefit from biwiring;
- your system is sufficiently resolving;
- your hearing is fine.
From my experience with biwiring, they are always double runs, but sometimes both runs are in the same shrinkwrap, with short common piece at the amp end.
On the other hand, one of those that I had in my system - Virtual Dynamics - were separate cables, both connected to a spade at the amp end.
I was just thinking that it may be due to a factor that is not really the explanation that is generally given for the reason that biwiring works - thus I cite a few factors often given for REALLY why it seems to work like fresh connections made or low quality jumpers in place without the biwiring - or perhaps just more wire bandwidth which I again wrote that the thickness of my wires is quite good and shouldnt play a factor under normal allowances for this possibility
JaroTheWise
Bi wire gets you nothing,,Imaging only comes from good mic placement
... anywhere that the only thing bi-wiring could improve or change is imaging - especially "only" imaging?
Cheers,
Presto
Horse Schit!
Playback system,
Speakers and placement,
Room Acuostics and interference,
Listening position distance,
Studio engineer and mastering,
Just some of the things that have a profound affect on the sound stage and imagining.
Yes there are many extremely crappy recordings regarding mic placement but that is not the difinitive answer.
As an example of how imaging and soundstage can collapse and turn horrible I submit my original dedicated two channel room from 15 years ago. My system with some very well respected electronics and speakers that would manage to expand the sound several feet beyond the boundary walls with MANY of my recordings thanks to bi-wiring. Duplicated every time they were played back. Wife decides its time to furnish this room with a sofa, two chairs, a sofa table and two end tables. The system was never moved from its original position, just furnished the room around the available open floor plan. Sat down that night for my nightly R&R and BAM! Nothing was right!
Tonal balance- gone to hell.
Imagining- worst of the problems of all. A total collapse to the point of everything I had heard before outside the boundaries was now stuck between and directly from the speakers. Spent months moving things around and to no avail it never came back with that room, no matter what new and different type of equipment I tried the furniture and floor plan lay out ruined the acoustics of that room.
My point, imagining does not only occur from well mic'd recordings. It's a good starting point but is not the end all be all of imaging.
The triggers that help the brain imagine a three dimensional presentation can come from timing and frequency variations between channels or even varying the frequency and reverberation of a monophonic signal. ( yes, of course a mono signal can provide varying dept. Even front a single loudspeaker)
"The hardest thing of all is to find a black cat in a dark room, especially if there is no cat" - Confucius
feathers
"Man is the only animal that blushes - or needs to" Mark Twain
I disagree and have first hand experience otherwise. I first bi-wired then bi-amped which requires bi-wire of course. Each change made an improvement. Even changing the jumper from the speaker before I bi-wired changed things. I figured I'd upgrade the stock jumper that was wire w/spades. I put on better modern wire in their place and they sounded much worse.
All of my experience is the exact opposite of what you say.
E
T
Imaging with a stereo system is clearly greater or less with a given speaker set - some project it more than others. Just saw a youtube post of an interview of Sandy Gross where he explains how imaging occurs and why certain speaker design encourages it more - namely a narrower baffle and attention paid to the mounting of drivers within it
Oddly I have an old pair of Athena budget monitors that image like crazy despite their low price - those Canadians put a lot of thought into them though the design is basic - there is a sort of waveguide on the tweeter that likely helps and the face is beveled back to be sort of "convex"
JaroTheWise
sadly got phased out way too early. The first models the ASC models were amazing being mstly time and phase aligned. The second generation models followed suit. It is no shame to own and enjoy a pair which puts to shame many more expensive brand names
not sure if you are referring to the Audition series or some earlier models that Athena did I think previous to going mass market - but yeah the Audition series I think were taking all the lower end sales from others and backordered at the retailers - I got mine wholesale at the time which made the value even more obscene.
Klipsch appeared to buy them and then kill off the brand - that was API which I guess had Mirage and Energy as well.
The second Audition series I think was designed to be lighter in weight but preserving their quality - I guess shipping at the distribution level was one of the biggest cost items which again is an eye opener. I have the first series
JaroTheWise
... OP already determined that it DOES give him something - in his system, listened to with HIS ears?
Not even speakers affect the imaging, just the good mic placement, huh?
How about this: Biwire gets you - meaning YOU, personally - nothing, because your system and/or hearing are not resolving enough, to appreciate differences?
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