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OK, how about them cable risers?

207.174.191.131

Posted on August 4, 2003 at 20:37:29
Charles Hansen
Manufacturer

Posts: 6984
Joined: August 1, 2001
If you've ever listened to them, you know they make a difference (especially if you are raising them off of carpeting). The question is "why?". It would seem that the two most obvious possibilities are:

1) Reducing or changing the interaction between the electromagnetic field from the cable; or,

2) Changing the mechanical resonance characteristic of the cable itself.

Does anyone have any other ideas? Does anyone have some good ideas about how to test to see which hypothesis might be correct?

Best regards,
Charles Hansen

 

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Re: OK, how about them cable risers?, posted on August 4, 2003 at 20:41:49
Todd Krieger
Audiophile

Posts: 37308
Location: SW United States
Joined: November 2, 2000
"Does anyone have any other ideas? Does anyone have some good ideas about how to test to see which hypothesis might be correct?"

Well, you can try a D...

Darn that rule!!

 

Why which hypothesis is correct?, posted on August 4, 2003 at 20:54:05
Norm
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Posts: 31024
Joined: September 6, 2000
We might have several hypotheses as to why some cars are faster to 60 mph. Horsepower, weight, wind resistance, traction all might be thought of, and all have some bearing. Perhaps which factor is most important would be a better structuring of the question.

If I had a car capable of getting to 60 mph in 4.5 sec., I would smile and not give a hoot (nows there is a good substitute for shit) why it could do so. I really don't care much about why cable supports work except that knowing this might lead to improvements.

 

Re: OK, how about them cable risers?, posted on August 4, 2003 at 21:01:00
If you've ever listened to them, you know they make a difference (especially if you are raising them off of carpeting). The question is "why?". It would seem that the two most obvious possibilities are:

1) Reducing or changing the interaction between the electromagnetic field from the cable; or,

Well, the electric and magnetic fields are modified by the medium which they propagate through. With the possible exception of nails and rebar, there's not much to affect the magnetic field. Carpeting and the like would act as a polarizable medium which would affect the electric field.

2) Changing the mechanical resonance characteristic of the cable itself.

Provided the mechanical resonance were in the audio band.

Does anyone have any other ideas?

There's always the psychological aspect to consider.

Does anyone have some good ideas about how to test to see which hypothesis might be correct?

Dielectric and magnetic effects would manifest themselves as changes in the cable's capacitance and inductance. And mechanical resonance would manifest itself as a peak or peaks in frequency response measurements or impedance measurements.

se




 

Well..., posted on August 4, 2003 at 21:49:54
Charles Hansen
Manufacturer

Posts: 6984
Joined: August 1, 2001
Steve, I don't know why you have a need to restate the obvious in a forum like this. All of us here know about electric fields and magnetic fields and what they interact with. None of us need a mini-tutorial from you on this.

Regarding the "psychological" comment, that type of remark is expressly forbidden on this forum. Please refrain from this in the future.

Finally regarding the tests, I think it is a given that we are looking for phenomena that are too subtle to be detected with existing measurement equipment. What I am looking for is some type of suggestions for (gasp!) *listening* tests.

You're a smart guy, so maybe you can think of a few. If so, please feel free to offer your suggestions.

Best regards,
Charles Hansen

 

Re: "psychological" comment, posted on August 4, 2003 at 22:37:12
Granholm
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Posts: 155
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Hi Charles,

>>Regarding the "psychological" comment, that type of remark is expressly forbidden on this forum. Please refrain from this in the future.<<

I might have misread something because I sure did'nt find anything that would forbid taking into account the psychological effect???

Rgds

 

Re: Psychology, posted on August 4, 2003 at 23:43:43
Sonar_Vermin
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Posts: 182
Joined: May 31, 2002
>Regarding the "psychological" comment, that type of remark is expressly forbidden on this forum. Please refrain from this in >the future.

What has always bothered me about this "argument" being thrown up every time someone mentions hearing an improvement from some tweak is that...

Since it happens in the mind, listening to music is a psychological and subjective process. If I "think I hear an improvement", then I do, because I cannot hear without thinking. Automatically disregarding subjective opinion is folly.

Granted, if someone offers an explanation for what they hear, it must not violate what we know about electricity/sound propagation/other stuff we have formulae for, but questioning someone's internal mental experience gets us nowhere.

People who are healed by the placebo effect... are still healed. We just don't know why, and we can't generalize from those cases to the rest of the population.

--Shannon

 

Re: Well..., posted on August 5, 2003 at 00:36:29
Steve Eddy


 
Steve, I don't know why you have a need to restate the obvious in a forum like this. All of us here know about electric fields and magnetic fields and what they interact with. None of us need a mini-tutorial from you on this.

Who exactly is "us"? This is a public forum and anyone can access it and read the posts here (and typically there are more people reading than posting). How are you able to know the technical knowledge of everyone who may be reading these posts?

Did it occur to you that some people may be reading posts in "a forum like this" because they don't have the same level of technical knowledge as "us" and are hoping to learn something?

Regarding the "psychological" comment, that type of remark is expressly forbidden on this forum. Please refrain from this in the future.

And you became a moderator on this forum when exactly? Or did you just take it upon yourself to appoint yourself to this position? Either Rod needs to update your user profile or he's going to be a bit surprised to find he has a new moderator he wasn't previously aware of.

Speaking of Rod, he said that this forum is not for the discussion of DBTs. I didn't say anything about DBTs. Or even BTs for that matter. You asked a question, I answered.

Finally regarding the tests, I think it is a given that we are looking for phenomena that are too subtle to be detected with existing measurement equipment. What I am looking for is some type of suggestions for (gasp!) *listening* tests.

What existing measurement equipment are you referring to? Far as I'm aware, it's been possible to measure to levels below that which will produce nerve impulses from the ear to the brain for some time now. How much more subtle can it get?

As for listening tests, while I can see how they might be able to tell you that SOMETHING is going on, I don't see that they hold much hope for telling you what's ACTUALLY going on out of a number of or combination of a number of different things happening.

I mean, what could lead one to listen and say "Ah, that sounds just like the non-linear polarization of nylon carpet fibers treated with DuPont StainMaster!"?

I think you underestimate measurement capabilities by a fair margin. Don't judge such capabilities based on what comes off the shelf from AP or HP.

se





 

Re: Psychology, posted on August 5, 2003 at 02:04:42
In case you missed it, I've replied to this post here.

se




 

Re: OK, how about them cable risers?, posted on August 5, 2003 at 02:07:19
mfc
Audiophile

Posts: 283
Joined: October 30, 2001
Yeah, one thought that crossed my mind is it may be
related to DA. Moving the cables away from the
carpet/floor, reduces the carpet/floor contribution
to this effect.

It might be tested by actually wrapping the cable in
carpeting and then using the risers on this contraption
and seeing if the risers still make a difference, or as
much a difference.

 

Static Electricity, posted on August 5, 2003 at 04:42:00
NEAR SOTA
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Static Electricity might be an effect. I do not think it can be measured at how far it travels.If one walks across a Carpet it does create it I bet. Then is there a charge held that can be measured.That does not seem right though as far as a charge being held.

Just a hunch!

 

But you need to know to design the car, posted on August 5, 2003 at 09:32:07
Commuteman
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Location: Bay Area California
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You said:

"If I had a car capable of getting to 60 mph in 4.5 sec., I would smile and not give a hoot why it could do so. I really don't care much about why cable supports work except that knowing this might lead to improvements"

That's great if you are only a consumer of the vehicle, but it doesn't work if you're trying to build a vehicle with a 4.5 sec 0 - 60 time. How do you know which design choices will work?

Damn! I painted this car blue, just like the other one, but it's much slower! How could that be?

In order to progress with the ability to create better equipment, we need to develop a better understanding of the correlation between design choices and the resulting sound quality. Without that, the design process becomes the random assembly of components, and listening to decide which combinations we like.

Peter

 

Re: Static Electricity, posted on August 5, 2003 at 10:05:40
Charles Hansen
Manufacturer

Posts: 6984
Joined: August 1, 2001
I've heard people having amazing results with anti-static spray on their cables, even ones that are hanging in the air behind their rack. Haven't yet tried it myself, have you?

Best regards,
Charles Hansen

 

I'm not sure that would differentiate..., posted on August 5, 2003 at 10:09:42
Charles Hansen
Manufacturer

Posts: 6984
Joined: August 1, 2001
between the two potential causes. It seems to me that wrapping elevated cable with carpet would still potentially affect both the electromagnetic field and the mechanical resonance.

One idea might be to try risers of different heights. If the effect were due to mechanical resonance, the big change would occur when the cable came up off the carpet. Additional height shouldn't make much difference. But if it were due to fields, a 2" riser and a 1/4" riser should sound noticeably different. Any other ideas?

Thanks,
Charles Hansen

 

Re: But you need to know to design the car, posted on August 5, 2003 at 10:10:32
john curl
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Peter, though that I lost you, once again, in the ozone. Good to see you back, contributing.

 

Re: I'm not sure that would differentiate..., posted on August 5, 2003 at 10:57:45
Ted Smith
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Posts: 10297
Location: Seattle
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Howdy

Well there's the obvious converse, put in, say, 4 times as many supports, that ought not change the height much but should change any resonance some without compromising the electromagnetic fields.

I have to wonder about resonance being the primary explanation. It seems to me tho that any resonance differences would likely be from microphonics which I usually associate with worse sound. Off the cuff I would think that raising cables would be a compromise between changing the effective dielectric of the cable for the better and the resonance for the worse, but anecdotal experience indicating that the changing dielectric is more significant. (I guess there is a possibility of small resonances making the sound 'richer'.)

-Ted

 

Re: But you need to know to design the car, posted on August 5, 2003 at 11:13:38
Commuteman
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I'm back for a while, and I WILL get over there to take a look at the test setup!

Hey, I might even bring the FET-based xover I built, so we can find out how badly it measures!! Sure sounds great....

Peter

 

Re: Static Electricity, posted on August 5, 2003 at 11:20:43
Static Electricity might be an effect. I do not think it can be measured at how far it travels.

If it travels, it's no longer static. ;)

If one walks across a Carpet it does create it I bet.

Yes. But the charge is built up at those points where you shoe contacts the carpet. Walking across a carpet isn't going to create a static charge on your cables unless you're walking on your cables which isn't a very good idea.

Then is there a charge held that can be measured.That does not seem right though as far as a charge being held.

That's what a static charge is, a charge that's held. Again, if the charge is traveling, it's not static.

se




 

Although I am just a consumer, it still is true, posted on August 5, 2003 at 11:24:43
Norm
Reviewer

Posts: 31024
Joined: September 6, 2000
that several hypotheses are probably true or alternatively multiple variables affect why raised cables sound better. I doubt seriously whether it is just a matter of resonances or capacitance, but it may be multiple factors.

 

Re: Static Electricity, posted on August 5, 2003 at 11:33:11
I've heard people having amazing results with anti-static spray on their cables, even ones that are hanging in the air behind their rack.

It'd take some damned dry air and a good amount of airflow over the cables to build up a charge if they're just hanging in the air. You could probably do it if the cables were near an AC vent from a non-humidifying AC system. A little humidification would take care of that and their sinuses would thank them as well. :)

se




 

Well..., posted on August 5, 2003 at 11:41:50
Charles Hansen
Manufacturer

Posts: 6984
Joined: August 1, 2001
Steve, once again, the rules of this forum prohibit you (or others) from questioning the subjective experiences of others. I (for one) am not particularly interested in all your reasons why it won't work. There are plenty of other reasons why it could work. The bottom line is that it either works or it doesn't.

Have you ever tried anti-static spray on your cables? Didn't think so.

Charles Hansen

 

Of course..., posted on August 5, 2003 at 13:50:53
Commuteman
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Location: Bay Area California
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but wouldn't it be great if it turned out that it is purely a question of (say) vibration? It would then be possible to produce (and purchase) better-sounding cables much more predictably and affordably.

I believe that the opportunity for hucksterism and false advertising only exists because we don't really understand what's causing the subjective results. The more knowledge we have, the less voodoo there will be.

Here's a question: Which is worse?

Cable manufacturer claims that you should buy his high-priced cable because of his "proprietary" materials and processes, or

Amp manufacturer who says you will enjoy great sound because his high-feedback amp has 0.000001% THD.

Both are lying to you. One group has been branded as charlatans. The other is called "mainstream manufacturers"

You make the call

Peter

 

Re: Of course..., posted on August 5, 2003 at 15:05:00
john curl
Manufacturer

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Joined: May 16, 2000
Being reasonable, are we Peter? I couln't say it better, but I often do worse. ;-)

 

Re: OK, how about them cable risers?, posted on August 5, 2003 at 15:05:22
jensw
Audiophile

Posts: 349
Joined: December 14, 2000
For I.C. cables:

In the air, they will resonate with the sound in the air ( and they do where I live, and listen, and test, etc. )

"Fixed" to somthing else, they will pass on the sound of that somthing else.

For speaker cables I have absolutly no clue (and that is not a clue).

Jens.

 

Re: I'm not sure that would differentiate..., posted on August 5, 2003 at 15:10:29
mfc
Audiophile

Posts: 283
Joined: October 30, 2001
Hi,

>If the effect were due to mechanical resonance, the big change would
>occur when the cable came up off the carpet. Additional height
>shouldn't make much difference. But if it were due to fields, a 2"
>riser and a 1/4" riser should sound noticeably different. Any other
>ideas?

I think you've got it.

The 1/4" riser wouldn't provide enough clearance for droop unless you
use a lot of them. It would make sense to set up the test first with
the 1/4" in order to determine how many risers would be needed to
avoid droop. Then going to the same number of risers on the 2" test.

I've always had a strong suspicion about dielectrics. Since this
isn't Propellar head I'll relay my anecdote with a digital
cable between my transport and D/A. I found that by wrapping the ends
of the cable with electricians tape, I could change the sound quite
a bit. The tape was pretty loose, and I think it had to do more with
the material in the tape then the mechanical resonance effects. It
was kind of weird, but I actually preferred a little tape.

 

Re: Of course..., posted on August 5, 2003 at 15:15:37
but wouldn't it be great if it turned out that it is purely a question of (say) vibration? It would then be possible to produce (and purchase) better-sounding cables much more predictably and affordably.

But that only gets you halfway there and I don't see that one achieves any greater predictability. At least with respect to satisfying customers. When it comes to "better-sounding," for a given design, not everyone is going to agree that it sounds better. Some will find that to them, it sounds worse. So then the life of the cable manufacturer gets a bit more complicated and they have to figure out who they want to market to. Do you go after the pro-vibration group? The anti-vibration group? Do you produce both types of cables and try to appease both groups? And of course there will be those who think this whole vibration thing's a load of nonsense, that the dielectric is the most important issue.

So sure, you've got the answer to your question, but you've singlehandedly caused the collapse of the cable industry with the manufacturers all instituionalized suffering from terminal indecision. :)

I believe that the opportunity for hucksterism and false advertising only exists because we don't really understand what's causing the subjective results. The more knowledge we have, the less voodoo there will be.

Voodoo survives largely by exploiting weaknesses in the human ear/brain system which depending how one interprets the rules here is either allowed to be mentioned or prohibited from being mentioned.

Unless you're arguing that the marketing claims themselves are influencing our subjective perceptions of the end product, then what does it ultimately matter, purely from the listener's perspective and not from any ethical or moral standpoint, what sort of marketing claims are made? If the end result is the same regardless, I don't see that it matters except on ethical or moral grounds.

Here's a question: Which is worse?

Cable manufacturer claims that you should buy his high-priced cable because of his "proprietary" materials and processes, or

Amp manufacturer who says you will enjoy great sound because his high-feedback amp has 0.000001% THD.

Both are lying to you. One group has been branded as charlatans. The other is called "mainstream manufacturers"

You make the call

I don't see either being any worse than the other.

But that's ultimately more of an ethical/moral issue at the end of the day.

se




 

Re: OK, how about them cable risers?, posted on August 5, 2003 at 15:29:26
In the air, they will resonate with the sound in the air ( and they do where I live, and listen, and test, etc. )

Resonate or vibrate? A resonant system only resonates when its excited at its resonant frequency or frequencies. However it may vibrate at most any frequency.

Also, a cable laying on the floor doesn't escape the sound in the air any more than a suspended cable does. The floor simply adds another mechanical element (and another path for vibrational energy). You're still left with a resonant system in the end susceptible to the same airborne vibrations although the resonant modes may change frequency.

se




 

Well..., posted on August 5, 2003 at 16:08:35
Charles Hansen
Manufacturer

Posts: 6984
Joined: August 1, 2001
Steve, I guess you didn't read the rules of this forum very well. It clearly states:

"Tech Square is not the place to...question Inmates subjective experiences."

I don't think the word "voodoo" by itself necessarily implies a questioning of subjective experiences. For example, the way I read Commuteman's post, he is saying that there *are* subjective differences that are unexplained by conventional theory and that some manufacturers then create unsupported theories to explain the differences. He calls these theories "voodoo" explanations.

On the other hand, the way I read your post, you are saying that the subjective differences are "voodoo" because they don't exist in the "objective" world, only in the "psychology" of the listener.

Please correct me if I'm misunderstanding your position, but if I'm not, you should refrain from breaking the clearly posted rules of this forum. Instead you should be making postings of that sort to PropellerHead.

Charles Hansen

 

Yes: vibrate. NT, posted on August 5, 2003 at 16:49:18
jensw
Audiophile

Posts: 349
Joined: December 14, 2000
NT

 

Well I thought Lightning was just a form of Static Charges!, posted on August 6, 2003 at 00:03:31
NEAR SOTA
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Posts: 2613
Location: MAINE USA
Joined: July 27, 2002
That was what I was getting at also. If the charges are formed like they during a lightning strike where + and - charges collide to create lightning.

It is a offshoot type of theory ,but it might be along those lines. How this could be measured is anyones guess.

There must be a forming of some sort of prticle transfer to interfer in the wires ability just be nuetral from unwanted charges.Like a magnetic interference. That might be another angle for which lifters have an effect.

Just grasping at straws,byt they give room for thoguht.

 

I have heard a Thing about sprays around CD's and CDPs also!, posted on August 6, 2003 at 00:17:06
NEAR SOTA
Manufacturer

Posts: 2613
Location: MAINE USA
Joined: July 27, 2002
Forgot what they used as a spray,but they have said that spraying something in the air before playing a CD has an effect which was beneficial.

I think we are narrowing down and eliminating the sources so there is progress.

In my last post I described the Magnetic effect happening with wires and carpets. So I think there might be a small magnetic feild happening that is having an effect and with the lifters you are dramaticly reducing the Magnetic effect. That makes sense to why they work!
Friction causes Static electricity,so you can create the feild so that means a rug can conduct.The amount is not the concern,but the fact that it can is important.Coulombs would be a measurement,but how can you get that measurement.

I can live with the magnetic theory till it can be disproved. I was amazed at how much Graphite string or Fiber can conduct. Things like that intrest me especially when I get a shock.Seems to get my attention.OucH!

 

Re: Well I thought Lightning was just a form of Static Charges!, posted on August 6, 2003 at 00:57:47
That was what I was getting at also. If the charges are formed like they during a lightning strike where + and - charges collide to create lightning.

Lightning is basically a DIScharging event not a charging event. Charges build up prior to the strike and then are equalized after the strike.

It is a offshoot type of theory ,but it might be along those lines. How this could be measured is anyones guess.

Static meters are readily available. They ain't exactly cheap, but they're readily available. :)

There must be a forming of some sort of prticle transfer to interfer in the wires ability just be nuetral from unwanted charges.Like a magnetic interference.

Magnetic interference won't produce a static charge. For something to acquire a static charge, it needs to either strip electrons from something else (giving it a negative static charge) or have something else strip electrons from it (giving it a positive static charge).

se





 

Re: I have heard a Thing about sprays around CD's and CDPs also!, posted on August 6, 2003 at 01:20:09
In my last post I described the Magnetic effect happening with wires and carpets. So I think there might be a small magnetic feild happening that is having an effect and with the lifters you are dramaticly reducing the Magnetic effect. That makes sense to why they work!

Not sure what you're meaning by magnetic effect. A static charge doesn't produce a magnetic field if that's what you're getting at. The magnetic moments of the electrons are random.

Friction causes Static electricity,so you can create the feild so that means a rug can conduct.

That the rug can become charged doesn't mean that the rug can conduct (and in fact it doesn't conduct to any degree because carpets are made of insulating materials).

Conduction isn't a requirement for acquiring a static charge. The best insulators in the world such as Teflon will readily acquire a static charge.

With insulating materials, static charge is a surface phenomenon and remains localized and doesn't spread out across the surface of the material or dissipate within the volume of the material. At least not to any degree.

With conductors however, the charge dissipates throughout the volume of the conductor.

Things like that intrest me especially when I get a shock.Seems to get my attention.OucH!

Hehehe. Why am I having visions of Jack Nicholson in One Flew Over The Cuckoo's Nest. :)

se




 

I'll second (or third) those views. nt, posted on August 6, 2003 at 09:04:34
clarkjohnsen
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q

 

Re: I have heard a Thing about sprays around CD's and CDPs also!, posted on August 6, 2003 at 09:33:53
NEAR SOTA
Manufacturer

Posts: 2613
Location: MAINE USA
Joined: July 27, 2002
When I worked for a Missle Technology Manf. they use to use Graphite Line which at times would get into the AC receptcles and start to spark and burn! You did not want to touch it or you would get a shock!

Yeah! Me and Jack did have one thing in common,but I have kept my hair!

 

BTW-Graphite Fibers can Conduct so I was thinking that ...., posted on August 6, 2003 at 09:38:22
NEAR SOTA
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Location: MAINE USA
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If Graphite Fibers can conduct maybe some Carpet Fibers can conduct even if it were at a minimum amount which might create a feild that would interfer with the conductivity in a wire.

 

More possibilities?, posted on August 6, 2003 at 17:13:04
Hafdef
Audiophile

Posts: 339
Joined: November 21, 2001
1/ Is it possible carpet fibers vibrating against the speaker cable cause a negative or positive charge in the cable insulator which is ultimately equalized by either the loss or gain of electrons of the speaker cable conductors.

2/ Raising the cables off the floor may isolate the the signal from AC lines buried in the joists below.


3/ Flyash is often used as an ingredient in concrete in quantities up to 25% of total mixture or so. Flyash is a by-product of burning coal in power plants and usually contains ferric oxide (5-24%), zinc oxide, magnesium oxide, alumina and an assortment of heavy metals. Is it possible these metals and oxides have a deleterious effect if cables are placed directly on the concrete? I suspect quantities of ferric oxide close to conductors may be an area of interest.

 

Carpet or concrete?, posted on August 6, 2003 at 17:54:08
Rod M
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Contributor
  Since:
March 1, 1999
That's an interesting idea. I wonder if there's a correlation there. Do people that notice the issue most have concrete under the carpet?

 

Re: OK, how about them cable risers?, posted on August 7, 2003 at 09:51:56
rcrump
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August 29, 2000
That pretty much covers it, but if I had to choose one I would go with changing the field as the better the dielectric of the riser the better the cable risers sound.....Ceramic seems to work best and can be purchased in any garden shop where cable risers are disguised as flower pots :-)

 

Re: OK, how about them cable risers?, posted on August 7, 2003 at 10:36:26
mfc
Audiophile

Posts: 283
Joined: October 30, 2001
If it is dielectric. I wonder if putting the cable near a poor
dielectric makes it worse. One experiment would be to use your
good cable risers, but simply attach some electrician tape to the cable for its entire length. The electrician tape would only have
to be loosely attached - and pressed every foot or so to the cable.
That way it doesn't interfere with any mechanical resonance effects.

 

Re: Static Electricity, posted on August 7, 2003 at 10:59:08
rcrump
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August 29, 2000
Nordost makes and antistatic spray that costs like the devil, but works on cables.....I break in cables and use the spray and Faraday cage bags to keep them that way in transit to the end users....Lots of static in cargo airplanes.....I use the spray in our CES suite in Vegas as the static there is a killer and had a DAC go down a few years ago due to a static discharge.....I have sprayed the carpet every year since and haven't had the problem again......

 

Been there....., posted on August 7, 2003 at 11:44:43
rcrump
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The less dielectric around the speaker wire the better it sounds and getting the wire off the poor dielectric of the carpet does even more.....I don't have any problems with static with the humidity here in Houston, but imagine most other parts of the country folks have that to deal with as well...

 

Re: Been there....., posted on August 7, 2003 at 11:51:51
mfc
Audiophile

Posts: 283
Joined: October 30, 2001
Yes, Trying to rule out the mechanical resonance
effects however. These can be air borne, coming thru the floor,
internally generated.

Try to leave resonance alone and constant...
put cables on good risers...listen...
attach the tape...listen...

Have you done a rule out like this?

 

Re: Been there....., posted on August 7, 2003 at 13:36:40
rcrump
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Haven't tried tape, but have used to make speaker wire with a .825" sanotprene hose over it that damped the heck out of the wire as well as added dielectric.....Have gone with a polyolefin webbing over the wire to hold the twist and no hose recently and like it better.....Floor is concrete with heavy pad and wall to wall carpet BTW....

 

Re: Been there....., posted on August 7, 2003 at 14:18:49
mfc
Audiophile

Posts: 283
Joined: October 30, 2001
Hi,

>Have gone with a polyolefin webbing over the wire to hold the twist

Not visualizing this. Is it an insulating jacket over both wires?
What insulation is on the wire?

 

Concrete and plywood., posted on August 7, 2003 at 17:54:32
Leisure7
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Posts: 9169
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I've heard the effect with lifting speaker cables from synthetic carpet over plywood (my house) and concrete (local dealer).

 

Dielectric first, then vibration..., posted on August 7, 2003 at 18:19:04
Leisure7
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I learned of this tweak from Don Palmer, maker of Highwire Power Wraps. He recommended using ceramic wall tile pieces such as quarter-round and bull-nose, that would lift the cables by about half to three-quarters of an inch, as further lifting did not seem to him to add any benefit, and the pieces are available at any home improvement store for less than a dollar each.

Friends of mine with wool carpets report no apparent benefit from lifting speaker cables.

My experiments with lifting from synthetic carpet over plywood by supporting the cables with the ceramic tile pieces stood on end confirm Don's advice: there does not seem to be as much benefit from lifting by several inches compared to lifting the same cables from the same carpet with the same pieces by less than an inch.

Speculation: the floor is a velocity null for sound wave air motion. Sound waves in the room will move the cables more, and possibly affect the perceived sound, if the cables are lifted further from the floor. However, the floor covering becomes part of the cable dielectric when the cables rest on the floor. If the floor covering is a poor dielectric (wood, Pergo-type laminate, or synthetic carpet), this also might affect the perceived sound by participating in the storage and release of electric field energy in the speaker cable operation. There is a compromise lifting height that minimizes the total degradation from dielectric participation and airborn vibration, and that height is closer to an inch than it is six inches.

A measurement that would reveal the effect of dielectrics in proximity to speaker cables would be a three-dimensional plot of capacitance as a function of signal level and frequency. I have no idea if instruments that could do this over the signal level range of interest exist.

 

Re: Dielectric first, then vibration..., posted on August 7, 2003 at 21:32:27
I learned of this tweak from Don Palmer, maker of Highwire Power Wraps. He recommended using ceramic wall tile pieces such as quarter-round and bull-nose, that would lift the cables by about half to three-quarters of an inch, as further lifting did not seem to him to add any benefit, and the pieces are available at any home improvement store for less than a dollar each.

Wood dowels would work as well. And probably have better dielectric proprties than ceramic. And of course, they're wood. :)

Speculation: the floor is a velocity null for sound wave air motion. Sound waves in the room will move the cables more, and possibly affect the perceived sound, if the cables are lifted further from the floor.

Not sure what you mean by the floor is a velocity null for sound wave air motion. You mean in the Newton's Third Law sense?

As for vibration issues, the floor seems the worst case to me. Especially a joisted solid surface floor (i.e. wood or tile).

In such a situation as this, the cable is in a pressure zone so the cable can be exposed to sound pressure levels as much as 6dB greater than if it were well away from the floor (or wall for that matter) due to the direct/reflected waves adding in phase (which is the principle of pressure zone microphones).

Then you have the vibration of the floor itself due to acoustical coupling subsequently mechanically coupling to the cable.

Lifting would help with regard to mechanical coupling to the floor (and dielectric issues with regar to the floor), but won't help much with regard to the pressure zone issue except at the highest frequencies where there's not much energy to begin with.

The way I see it, the cable is much better off both in terms of vibration and dielectric issues when it's suspended in the air, well above the floor.

se




 

Re: Dielectric first, then vibration..., posted on August 8, 2003 at 22:02:03
Leisure7
Audiophile

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Location: Northern California
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"In such a situation as this, the cable is in a pressure zone so the cable can be exposed to sound pressure levels as much as 6dB greater than if it were well away from the floor (or wall for that matter) due to the direct/reflected waves adding in phase (which is the principle of pressure zone microphones)."

Precisely. This is why the air motion at the solid boundary is zero.

The question is whether speaker cables suffer from acoustic interference from motion or pressure. I suppose a jacketed, loosely-braided design could suffer more from pressure, while a compact design could suffer more from motion. I don't have enough experience to say whether the set of speaker cables contains both types.

 

Re: Dielectric first, then vibration..., posted on August 8, 2003 at 22:55:12
"In such a situation as this, the cable is in a pressure zone so the cable can be exposed to sound pressure levels as much as 6dB greater than if it were well away from the floor (or wall for that matter) due to the direct/reflected waves adding in phase (which is the principle of pressure zone microphones)."

Precisely. This is why the air motion at the solid boundary is zero.

Sorry, still don't quite know what you mean when you say "air motion." Air motion as distinguished from what?

What we're concerned with is sound pressure level. And the sound pressure level at the surface is higher than it is farther away from the surface. So the cable will be exposed to greater vibrational forces at the surface.

The question is whether speaker cables suffer from acoustic interference from motion or pressure. I suppose a jacketed, loosely-braided design could suffer more from pressure, while a compact design could suffer more from motion. I don't have enough experience to say whether the set of speaker cables contains both types.

Still don't see how you're distinguishing motion from pressure. How is a cable that's just suspended in the air experience motion but not pressure when sound is just a variation of pressure (i.e. compression/rarefaction)?


se




 

Re: Dielectric first, then vibration..., posted on August 8, 2003 at 23:38:19
Ted Smith
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Howdy

"Still don't see how you're distinguishing motion from pressure. How is a cable that's just suspended in the air experience motion but not pressure when sound is just a variation of pressure (i.e. compression/rarefaction)?"

Do you see how it could experience pressure, but not motion?

-Ted

 

Re: Dielectric first, then vibration..., posted on August 9, 2003 at 01:01:32

Do you see how it could experience pressure, but not motion?

Sure. Put a gun to its head and say "Don't move or I'll blow your quarks out!" :)

Ultimately what I'm saying is that I don't see that it's experiencing anything different whether it's on the floor or above the floor other than on the floor the sound pressure level will tend to be higher than if it's well above the floor.

It's exposed to acoustic energy in either position and will move in accordance to that acoustic energy.

se




 

Re: Dielectric first, then vibration..., posted on August 9, 2003 at 08:06:44
Ted Smith
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Posts: 10297
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Howdy

But if it's on the floor the motion induced by direct acoustic energy could be dampened (or even prohibited) by friction against the floor and conversely any motions of the floor will be transmitted differently to the wire if it is just laying on the floor than if it is suspended at discreet points above the floor (e.g. there will be at least differing oscillation modes caused by the suspension.)

-Ted

 

Re: Dielectric first, then vibration..., posted on August 9, 2003 at 09:56:07
But if it's on the floor the motion induced by direct acoustic energy could be dampened (or even prohibited) by friction against the floor and conversely any motions of the floor will be transmitted differently to the wire if it is just laying on the floor than if it is suspended at discreet points above the floor (e.g. there will be at least differing oscillation modes caused by the suspension.)

Sure.

What I'm saying though is that acoustically speaking, i.e. the acoustical forces acting on the cable, I don't see that the cable's any better off on the floor than up in the air except that on the floor it can be exposed to significantly greater SPL than if it were up in the air.

Leisure7 seemed to be saying that on the floor, it's in some sort of acoustic "null" zone and thereby escapes all influence from acoustic energy.

se




 

Steve, are you deliberately being obtuse..., posted on August 9, 2003 at 10:52:41
Charles Hansen
Manufacturer

Posts: 6984
Joined: August 1, 2001
just to keep an argument going, or are you really saying you don't understand Leisure7's point?

After all, it seems obvious to me that you're both "right", it's just that you're talking about two different cases. I think Leisure7's case is probably more applicable to the situation at hand, but maybe your's is -- it's hard to say for sure.

One thing's for sure, I've never seen anybody that liked to argue in public as much as you do.

Charles Hansen

 

Re: Steve, are you deliberately being obtuse..., posted on August 9, 2003 at 12:35:42
just to keep an argument going, or are you really saying you don't understand Leisure7's point?

What I'm saying is that I don't quite see what he means by a "null" where there's "no air motion" as it seems to imply that the cable is not at all affected by acoustic energy whereas if the cable where suspended in the air, it would be.

After all, it seems obvious to me that you're both "right", it's just that you're talking about two different cases. I think Leisure7's case is probably more applicable to the situation at hand, but maybe your's is -- it's hard to say for sure.

And that's why I've been trying to get Leisure7 to elaborate on just what he's trying to say. What he SEEMS to be saying is that on the floor, the cable is not subjected to any acoustic energy, it being in a "null" where there is no "air motion." If that's what he is trying to say, then I have to say that I see it being just the opposite, that on the floor it's subjected to even greater acoustic energy as it's exposed to sound pressure levels upwards of 6dB greater than if it were suspended in the air above the floor.

One thing's for sure, I've never seen anybody that liked to argue in public as much as you do.

Perhaps it just seems that way because I don't engage much in the "how things sound" or "I recommend this or that" type of discussions. As I've explained before, I listen intuitively and have never got into the flyspec sort of listening that most others do so I've never had any need to express myself except in the simplest of terms (i.e. I either prefer something or not). So I mostly just stick to technical type issues.

se




 

Well, it's hard for me to believe..., posted on August 9, 2003 at 13:03:28
Charles Hansen
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that a guy that spouts off about Cooper pairs and the like has never heard of a standing wave. But since that's apparently what you're claiming, here goes:

1) You are right about the sound increasing in level when a reflective surface is close by, if certain conditions are met. Specifically, the surface has to be within a small fraction (typically given as 1/(2*pi)) of a wavelength of the receiver at the frequency of interest. However, if I'm not mistaken, the gain is only 3 dB and not 6 dB.

So that takes care of the case where one is outside, with only the ground nearby, and no walls. On the other hand, Leisure7 was talking about listening in a room.

2) Standing waves can occur when the excitation frequency corresponds to the distance between opposing boundary surfaces (i.e, walls). When a standing wave exists (which is quite likely when playing music in a listening room), then at the boundaries (i.e., on the floor) there exists a pressure maximum and a velocity minimum.

A cable is going to be disturbed far more by velocity than by pressure, so placing it on the floor will reduce its excitation by standing waves compared to placing it at a pressure null.

Did you really not know the above, or were you just being deliberately obtuse?

Charles Hansen

 

Re: Well, it's hard for me to believe..., posted on August 9, 2003 at 16:43:18
that a guy that spouts off about Cooper pairs and the like has never heard of a standing wave. But since that's apparently what you're claiming, here goes:

Of course I've heard of standing waves.

1) You are right about the sound increasing in level when a reflective surface is close by, if certain conditions are met. Specifically, the surface has to be within a small fraction (typically given as 1/(2*pi)) of a wavelength of the receiver at the frequency of interest. However, if I'm not mistaken, the gain is only 3 dB and not 6 dB.

What exactly are you referring to as the "receiver" in this instance? The cable?

What we're talking about are the conditions at the boundary of a reflective surface. Which will effectively be the conditions of whatever object(s) happen to be at that surface.

And it is ideally 6dB, not 3dB.

From Master Handbook of Acoustics by Everest:

The sound pressure on a surface normal to the indident waves is equal to the energy-density of the radiation in front of the surface. If the surface is a perfect absorber, the pressure equals the energy-density of the incident radiation. If the surface is a perfect reflector, the pressure equals the energy-density of both the incident and reflected radiation. Thus the pressure at the surface of a perfectly reflecting surface is twice that of a perfectly absorbing surface.

Pressure doubles. Power quadruples (as it goes up as the square of pressure). So, for pressure, 20 x log 2 = 6dB. For power, 10 x log 4 = 6dB.

So that takes care of the case where one is outside, with only the ground nearby, and no walls. On the other hand, Leisure7 was talking about listening in a room.

Doesn't matter whether inside or outside. In both cases we're talking about the conditions at a reflective surface. Doesn't matter if that reflective surface is outside or inside.

2) Standing waves can occur when the excitation frequency corresponds to the distance between opposing boundary surfaces (i.e, walls). When a standing wave exists (which is quite likely when playing music in a listening room), then at the boundaries (i.e., on the floor) there exists a pressure maximum and a velocity minimum.

A cable is going to be disturbed far more by velocity than by pressure, so placing it on the floor will reduce its excitation by standing waves compared to placing it at a pressure null.

Velocity of what? The wave? We're talking cables here. Until the diameter of the cable begins approaching a wavelength, I don't even see wave velocity coming into play to any degree. Until that point, pretty much all the cable experiences is pressure change.

The worst case scenario would be when the cable's diemeter corresponds to 1/4 wavelenth which if you've got say a 1/4" cable, you're looking at what, about 14kHz? Ain't much energy up there. Where I'd be concerned is down at the lower frequencies where there's more energy. But at those frequencies, the wavelengths are so long you can't really produce much of a pressure gradient between one side of the cable and the other with which to move it.

se




 

I give up -- it's clear all you want to do is argue..., posted on August 9, 2003 at 19:48:54
Charles Hansen
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Posts: 6984
Joined: August 1, 2001
you're smart enough to know exactly what Leisure7 was talking about, yet you persist in this stupid game. I had hoped on this forum you were learning to behave yourself, but I'm going back to my old rule. From now on, I won't respond to any Steve Eddy post. Goodbye.

Charles Hansen

 

Reflecting boundary, posted on August 10, 2003 at 11:29:31
Leisure7
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"Leisure7 seemed to be saying that on the floor, it's in some sort of acoustic "null" zone and thereby escapes all influence from acoustic energy."

What I did say is "the floor is a velocity null for sound wave air motion."

Sound waves comprise increase and decrease of air pressure relative to the static pressure. Increased pressure requires air molecules to move closer together, on average, and decreased pressure requires them to move apart. There is a net velocity of air molecules back and forth in the direction of propagation of the sound wave to support the increase and decrease of pressure.

At a reflecting boundary the air molecules cannot move into the boundary, so they crowd even closer together than they do at the peak of a sound wave traveling in unimpeded air. The net velocity in the direction of travel of the sound wave is zero at the boundary, while the pressure is double.

A speaker cable resting on the reflecting boundary will experience this increased pressure. If the cable is compressible, and compression changes its electrical transmission properties, then it will suffer from enhanced acoustical interference at the boundary. Lifting the cable above the boundary will reduce this interference.

If the cable is not compressible, then lifting the cable will not affect interference from sound pressure (since that interference is assumed to be zero). However, if the mass and stiffness of the cable permit it to move back and forth from momentum transfer from the motion of air molecules that support the sound wave, and motion of the cable affects its electrical properties (whether through magnetic induction, triboelectric generation, or whatever), then lifting the cable above the boundary will result in increased acoustic interference.

 

Re: Well, it's hard for me to believe..., posted on August 10, 2003 at 19:00:09
Rod M
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March 1, 1999
that there's any progress happening here. What's the point?

Do you have a better theory or something to add? Let's not get bogged down in just shooting down ideas.

 

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