Welcome! Need support, you got it. Or share your ideas and experiences.
Return to Planar Speaker Asylum
64.252.2.149
In Reply to: RE: IIIa Foil Project Sucess! posted by computerman on May 30, 2012 at 18:59:13
It certainly seems to have enough outputs, and it takes VST plug-ins. Can't say anything about the sound quality, though. At that price, and with all those features, I wonder.
Follow Ups:
I will check around and see if I can come up with an intelligent opinion of the sound quality of the converters.
I will also hookup the Impact Twin to a digital input on my Sunfire. I have a "tape in" hookup with it now, and I can then A-B them. That should give us some idea of the quality of this unit made by the same mfg. It is a $400 net line level preamp, with other goodies, including some of which the Konnetk 48 has. It has 4 analogue audio outs and ins.
I like your idea about using the 1-D tweeters for surround. I am not sure about using the woofers for subs though. I have an AR Sunfire powered sub right now, so would you use both? The IIIa bass panels are not bad and give the 1-D's a run for the money, however as I mentioned prior, I need to move the 1-D's out away from the wall more. I can't imagine the IIIa's sounding as good as the 1-D's for bass could they? Just thinking out loud, maybe the wood frames give them the extra quality and boost.
Unfortunately, I have to rewire the connectors on one panel. I used the old connectors and that was a mistake. I have new ones that Magnepan sent and I should have used them. Live and learn hey? :)
The 1D's will definitely sound better for bass than the IIIa's and you can use them with a single-pole crossover. The only reason I suggested the sub idea was that you still have the IIIa woofer panel there, which puts the 1-D woofers pretty far away from the midrange. And they really want to be close if you're crossing over that high. At 100 Hz, localization doesn't matter as much and the wavelength is about 10' so you won't have trouble with lobing if the woofers aren't by the midrange. It will also diffract more easily around the IIIa's if you have the 1-D's behind. Ultimately, I think you want to go with the 1-D woofers, Neo 8 midrange, and IIIa tweeters up front, which leaves the 1-D tweeter and IIIa woofer/mid for surrounds.
Also, you can use the 1-D's behind the mid-tweeter (or IIIa's) in an arrangement similar to the Tympani IVa split arrangement which I'll be using, it's great for small rooms. I do expect to have to equalize down the bass in mine, but that will just give me lower distortion, more headroom, and more extension!
Do you have any pictures of you're Tympani IVa split arrangement, so I can get a better idea of what you are talking about?
Here's one (these aren't of mine but of someone else's):
Note that the woofers are against the side wall, this makes up for the reduction in baffle size because they aren't next to the mid/tweeter panel. Also, phasing is important, they have to be a multiple of half a wavelength away at the crossover point and need their polarity flipped if they're at an odd multiple to avoid getting a suckout due to phase cancellation. Within this criterion, you want them as close as possible with an analog crossover. None of this matter with a digital crossover, since you can adjust delay and phase where you want it.
I think the arrangement in that image is "off the wall" :-), I mean nuts. It's got a bass panel firing straight into the butt of a M/T panel. Intuitively, it's lousy. Whenever I've split my IV-A panels, anything near that was unacceptable, and I've tried it in different rooms.
Interesting. There were a couple of people here who said they tried it and liked it, Satie and I forget who else. I assume the midbass panel is the one near the wall? The manual says to use the one with the connectors on it. That would keep it line of sight, and the low bass panel would ideally diffract around the M-T panel (but to some extent travel through it).
This arrangement having the T/M panels sitting in front of the B panels with the latter up against the wall is in fact illustrated in the IV-A user manual, as being a solution for listening in narrow rooms. Mention is also made that the listener should try reversing the phase of the T/M panels (swapping their "+" and "-" leads) because of timing alignment.
If it does the trick, I suppose that's what most matters.
Regards,
Norman
Yeah, I have a copy of the IVa manual. The split arrangement was actually one of the main reasons I got the IVa's. I have to accommodate a projection screen and in the split configuration, the IVa's are actually better for that than the "smaller" single panels since the mid-tweeter panel is so narrow. Whereas you can't split a 1-D, the crossover is too high.
Satie and I spent a lot of time playing around with possible arrangements. I may still end up with something different. DSP gives me a lot of versatility. My original plan was to put the woofers in the entrance of my living room, in effect extending the wall, and cross them over at 80 Hz. Then I'd only have the mid tweet panels to deal with. But we never came up with a good way to extend the response of the mid-tweets down to 80 or 100 Hz. Genesis does it with the RD-75's, but I could only fit an RD-50 and they use a huge mid/tweet baffle. We talked about stacking some of the smaller models but it gets a bit ridiculous. A pair of MG-10's might do the trick. Another possibility would be to put the midbass panels of the IVa's next to the mid-tweets and then cross over at 100 Hz to the deep pass panels, in a .5-way configuration -- bass handled by both, midbass handled by the midbass panels.
I am splitting the 1-D's. I looked at the connector wires that go between the panels, and they look about the same size as a banana plug. I am going to try to plug directly into the side where the connector wires go. I then thought I would try moving them. I do not have a lot of flexibility here because of my room and the furniture. I hope to be moving in the near future, but for now this has to suffice. Would it make any sense to put my sub behind the 1-D panels and move them parallel (or as close to it as I can get them) to the back wall? This would place them just behind and to the right of the Frankenpans.
Do you have any idea which connector is plus and which is minus for the side connector wire?
I think parallel to the back wall is ideal, with a bit of a fold in the middle as in the manual. That may not even be necessary if you're using them as subs. If you have them within about a foot of the side walls, you'll get a bass boost. This is important since you're removing the tweeter panel. I'm guessing that in your small room you'll end up with too much bass but you can equalize that out in software.Keep in mind though that they have to be a half-integral multiple of a wavelength from the fronts at the crossover point, otherwise you'll get a dip. However, if your software allows you to adjust the timing of the drivers you can put them at any distance and dial it in. Then what you'll want to do is bring the woofer in time with the midrange, which will actually mean delaying the IIIa's. You can do this with test signals, by ear, or just by measuring the distance between them, each foot they are behind the IIIa's is about a millisecond of delay, as measured on a line from your listening position to the lateral center of the 1-D's and IIIa's respectively.
I don't know which side is positive or if the models are even phased the same way. Experimentation is in order, try it both ways and if they're out of phase you'll hear or measure a dip at the crossover point.
Edits: 06/02/12
I've split the 1-D's and have them forward more. They are just about even with the front of the IIIa' and the inner panel is parallel with the back wall.
You mentioned that I might be able to use the tweeters as a surround. I have them in the position that I had my MG.MC1 surrounds at and I was wondering how to hook them up. Is there any way to use the crossover that is built in so that I could use them direct to the amp? I am going to connect them to my Rotel 1077 S.
Also where is a good place to start the measurements? I have downloaded REW and I purchased the Behringer mic and stand. I can run it through my Impact Twin as it has 2 mic inputs with phantom power. - Thanks!
You'll be able to use the tweeters for surround but only after you get the Neo 8's and free up your IIIa's. Then you'd have 1D bass + Neo 8 mid + IIIa ribbon in front, and IIIa bass/mid + 1D tweeter in the surrounds. You might well be able to get away with using the IIIa's internal crossover for that. Not the 1-D's, since it's only two way.Great that you got the measurement stuff. You want to measure around your listening area. Put the mic where your head would be, pointing up. Once you've rough things in, I suggest you take several spaced measurements to the left and right of your listening position. But not too far. The objective here is to separate the effects of room reflections from the response of the speakers themselves. You'll find that the response changes radically with mic position because of interference with reflections -- comb filtering and room resonances.
I assume your primary goal is to match levels of the drivers and get the crossovers right. Once you've done that, you may want to trim the overall response and reduce bass modes. Typically, you want a 4-6 dB downtilt for the overall response curve. Then reduce the irregularities in the bass, but don't at any point increase the bass output beyond a couple of dB, deep nulls can't be EQ'd out, you'll just waste power and overdrive the speakers if you try. Above maybe 250 Hz, I wouldn't try EQ in this configuration, except again to set an overall target curve. It isn't simple, what your ear hears will not be quite what you're measuring, which is room response. At higher frequencies, the ear is more sensitive to on-axis response. With time, as you refine the system and use more sophisticated software, you can try taking gated driver measurements and generating some more sophisticated curves. But for now I'd focus on crossover, levels, and bass modes.
BTW, keep in mind that the ear doesn't interpret the graph the way your eye does. Otherwise, may be surprised by how rough the 1/24 octave measurement is. The general rule is that it's more sensitive to broad peaks than narrow ones, more sensitive to positive-going peaks than dips, and most sensitive to aberrations in the midrange. The narrow dips from comb filtering are primarily used to construct a sense of space.
EDIT -- Just wanted to add that the ideal room approach is to set up carefully, and then EQ what you can't fix with careful positioning and treatment. You may want to get the crossovers and driver levels first, then experiment some with positioning and treatment, then go back to do the bass EQ. Since this involves not just bass but imaging and they never seem to be best in the same location, physical setup isn't easy!
Edits: 06/18/12
Thanks for the information. I thought you had some magic way of using the tweeters for a single speaker. :) Is there any way to incorporate it into the mix that would make some sense? What about using a Y adapter? I have plenty of channels left on the Rotel. Seems a waste not to use them. I don't have the space to use it with the IIIa bass/mid panel. I can just fit in in the surround space by itself.
The Neo-8's may be a long ways down the road as well, unless they lower the price which I am sure they won't. I would love to build an insert into the IIIa Frankenpan and string some Neo-8's, just to hear what they sound like. How will I ever get a handle on how well the foil experiment did? Is there a way to measure it somehow and get some comparisons?
My primary goal is to exactly what you said, to get the crossover correct. The Audiofire 12 arrived. I did not think the guy was going to send it as he would not answer any of my emails, but it did arrive and in as new condition. It looks as if it had not been used at all. It is real simple with not a lot of bells and whistles. I think it will work well for a crossover.
I will have to wait to afford the software unless there is a freebie program available. I recall reading something about a plug-in for foobar that is user supported. I believe it was fairly limited though.
Thanks again and I will get started with measuring as soon as work permits. I am looking forward to seeing what I have been hearing and learning more about it all.
I can't think of another way to repurpose the tweeter. It's designed to operate from about 1 kHz up, so it doesn't cover the lower midrange. Best to use it I think as it was intended, in a two-way design with crossover in about the 1 kHz region.
And you can't cross it to the IIIa woofer even if you fix the crossover because you'd lose the midrange in front.
I'm not sure how much of a difference there is between the IIIa foil mid and the Neo's. Obviously, there's a family resemblance there. But the mass of the IIIa mids is compromised because it's on the same sheet as the woofer. The Neo also is push-pull, so it should have lower even-order harmonic distortion. I think the measurement that would be most useful in terms of revealing improved sonics would probably be a waterfall plot, maybe nonlinear distortion would be better as well. But you don't have a measurement of the unmodified mids to serve as a sonic or measurement reference. However, you could make a waterfall measurement of the foil mid and maybe somebody could make a measurement using the same distance/settings of their unmodified IIIa mid, and we could compare that. I think it would be interesting and instructive. It could also be compared to the BG waterfall but it isn't all that easy to compare waterfalls, since the plot you get depends very much on how you do the measurement, e.g., if you go for more time resolution you get less frequency resolution. Also, a waterfall of a single Neo isn't strictly comparable to a waterfall of a line of Neo's, because in any large line source measured in the near field you get delayed arrivals from distant parts of the line and that smears an up close measurement. It's also very difficult to get a good waterfall from a large line source, if you set the gate long enough to get the measurement you start getting room reflections which screw up the measurement. They really have to be measured in an anechoic chamber or suspending in a gym or outside. Also, freq response of a single Neo is very different from freq response of a line of them, though there are some measurements of Neo lines online if you do a search.
For Foobar, all you need is a convolver. As you say, I think there's a free one available. The trick lies in generating the filter impulse response to use with it. I'm not sure what's out there for free that would be practical to use.
I am going to try some moving today. I will let you know how I make out.
I have been searching for some comparisons on Lynx Aurora, RME Fireface 400 and 800, Konnekt 48, etc. What came up in my search was a great deal of similarity in quality, with perhaps the converters on the Lynx being a bit better quality, but many said that it depended entirely on what one wanted to use it for. Of course most users of this equipment are in the Pro area, not audiophiles. Still the quality of the converters was discussed. One surprise I stumbled on was a interface called the Audiofire 12, mfg.'d by a company named Echo. What caught my attention was the simplicity and price. Most who compared these said that the Audiofire was a very good interface in construction and quality. The only weak area was the clock, but it was acceptable. Some used an external clock like the Apogee Big Ben and found a great improvement. The other area that the Lynx excelled at was latency. All in all the Audiofire could be a very good 12 channel analogue in/out audio interface. While it is not quite as good as the Lynx Aurora 8 or 16, it comes real close, plus the price is a great deal less than the RME, Lynx, and even the Konnekt 48. It can be had brand new for about $500-600. I think I am going to give it a try. Although it may not be quite as good as the Lynx, it should suffice for a while and I am wondering if the difference between the two is that audible when using something like Acourate software. I cannot afford the Lynx right now, so it would fill the need for a while. I believe I would not have too hard a time reselling it, when and if I decide to purchase something better. Any thoughts on this?
More curiosity than anything else. I basically have the same questions you have, and no way of answering them except by trying them. Looks like B&H has them for $508. Twelve channels sure would be nice, enough for two four-way speakers and two two-way surrounds, all with active crossovers.
One thing I do believe, based partly on experience and partly what just about everyone who's used them has said, the sonic advantages of DSP solutions like Acourate or DEQX far outweigh a minor difference in converter quality.
I'm not sure how popular this is, but if it's reasonably popular, it should be easy to resell. You might want to check Ebay first to make sure. You can certainly sell an RME or Lynx. I don't think latency is a problem, since you'll be using the system for playback rather than monitoring.
Was curious if you purchased that second Audiofire 12 as it sold pretty quick after I mentioned it.
FYI: there are some real good buys on eBay for Maggies. I saw a set of 4A's and some Tympani 1-D's, plus IIIa's, IIb's and more. I think it is unusual to see this many and they look for the most part in good shape.
Have you ever thought about trying out the tri-center hookup or something similar?
My mic arrived and I ordered the stand last night. It was shipped today, so we should be in the measuring business soon. I am sure with the stuff I have coming that the sound will improve greatly. I am psyched and waiting impatiently. :) Thanks so much for the help!!
Thanks Computerman, I appreciated your tip and was sorely tempted, but in the end decided not to go for it since I just got a couple of sound cards which I haven't even tried yet. The reason I didn't respond right away to your post was that I was reading about the Audiofire! Then got called away.
All I can do now anyway is bi amp or use the MMG's for surrounds (the limitation being that I only have two amps).
I've definitely thought about the Tri Center. :-) But it wouldn't work for me, I have to accommodate a 114" screen and my room isn't wide enough to fit in the two flanking on-walls, or deep enough to use an acoustically transparent screen in front of it (not enough throw length). I'll just be glad to start on my own Tympani project, had to put that off because I had to cut some vinyl flooring and the only large bare space in the house was my listening room. :-| Between setting up the Tympanis, pulling off the socks to check condition, and building my "new" HTPC (parts sitting in closet for the last year), I'll have my hands full for a bit. Not to mention playing with Acourate once I know where I'm going to position the IVa's.
Someone should bid on those IVa's on Ebay! They don't come along that often and according to the ad, they've been refurbished.
Sounds like your plate is full for a while. Let me know if you need any assistance with the HTPC as that is what I do. I build custom computers for my business as well. I've been doing this for 29 years since the durn' thing came out. Yikes! That dates me.
I wish I had the money and space, I would scoff those IVa's up fast. I might even grab the IIIa's, but they seem a bit pricey. I don't think they have been refurbed.
I have yet to purchase the Acourate software. I guess that is the next one to get. Is there just one place to get it, or can it be purchased at distributors? Have you used it? Have you used anything else? What about the foobar plug-ins? Any experience with them?
Play-Mate's the go-to guy on the Acourate software, I've known about it for a while but I haven't tried it yet. Have you checked out their website? It's much improved, you can actually get a feel for what it does. It looks like it's very, very powerful.
While I use Foobar, I've never actually used any plug-ins for it. Acourate comes with a convolver VST plug-in, so that will be the first. I don't know if they have any distributors at this point, prices are on the website so as far as I know you just order it from them.
I studied the Acourate software and have an understanding of room correction and how the process goes. What software is used for the crossovers? Is that a separate software package? Unless I missed it, Acourate is just for room correction yes?
Thanks again!!
I think it does crossovers as well. I imagine you generate a separate filter impulse response for each driver, then use the convolver VST plug-in and send the output to the DAC for the appropriate driver. But the web site was short on details.
I went back and checked for the crossover filters, and I saw that they said that one could create crossovers, but as you mentioned, I did not see much about it. Play-mate pointed me to some posts of his that he said explained it in more detail. I will definitely check them out. If you are interested I will posts his links, just let me know.
Sure, thanks, sounds interesting.
I looked at the post where he put the links to his info. Probably the best thing to do is to read the entire post as it has good information, plus there is an additional link at the bottom that you might be interested in.
http://www.audioasylum.com/cgi/vt.mpl?f=mug&m=188635
One thing that bugs me is that I do not really understand where this fits into the mix of equipment. Is one able to use anything connected to a pre/pro or preamp as we can with an active crossover? Can it be used in addition to an active crossover, or would that not be desirable?
To use it with a pre/pro or something connected to a preamp, you'd have to bring the output of the pre/pro or preamp into the computer via the sound card, run it through the VST convolver, then out again through the sound card's DAC's and to the power amps. It should be easy enough to do. If you wanted to do multichannel with a pre-pro, you'd just run the channels from the pre pro to the digital inputs of your sound card.
I don't think you'd want to use Acourate with an external crossover, not because it wouldn't work, but because there's no reason for the external crossover, Acourate should be able to do anything the external crossover can and do it better and you have plenty of channels. But you could use it that way if you wanted to.
Cool! Only one problem that I see and that is you say to run it to the digital input on the sound card (which will be Audiofire 12) but this sound card is analogue in and out.
Yeah, that's a problem, they referred to that in some of the reviews I saw. But if you're just bringing in digital channels, maybe you could add a sound card with digital line inputs. Then you'd route the input in whatever DAW/mixer application is hosting the VST plug-in. I don't know how well the drivers coexist.
Would it not be possible to plug the XLR outs from the pre/pro to the ins of the Audiofire using converters or make your own cables? Also there are line outs with regular RCA phono outputs for all channels. What about using them?
Do you recall the link to the tinnitus study that you showed me a while back? I know someone that is interested in the study.
Sure, you could just take the analog outs from the pre-pro and put them in the analog ins of the Audiofire. The one disadvantage is that you're going through double D/A A/D conversions. This could have a negative impact on sound quality, or not.Anyway, I'm not entirely sure why you're going with a prepro at all. Why not just source everything off the PC?
PS -- Don't remember where the tinnitus articles were. But if you do a search for tinnitus and music I imagine you'll find them.
Edits: 06/06/12
The reason for using the pre/pro would be home theater. I like to watch Netflix as well as listen to music, or to play DVD movies.
I always play DVD and Blu Ray stuff directly off the computer, using VLC. Unfortunately, VLC doesn't take VST plug-ins and I don't know how to solve the problem. Here's a thread on it:
http://www.kvraudio.com/forum/printview.php?t=258698&start=0
There's an app called Audio Hijack Pro that can capture streams and takes VST plugins, but it's for OSX. Might work for you, just generate an impulse response file on your PC and then use a VST convolver in Audio Hijack Pro in OS X. I don't know if there's a PC equivalent, VST Host will take plug-ins but I don't know if it can capture the media player stream.
The things that kind of confirmed the quality of the converters, at least logically, is that there are few bells and whistles on the Echo unit. It is essentially 12 analogues ins and outs, so hopefully they did a good job.
I just purchased one that is new and never used with a three year warranty, from a private sale for $375 including shipping. He has two of them so if you hurry you might be able to get the second one. I offered him that if I bought it with "buy it now" would he pay shipping. He replied he would, so it was as we say a "no brainer".
Here is the link if you are interested. Good luck should you decide to buy it. I think it is a steal.
http://www.ebay.com/itm/IN-BOX-Echo-AudioFire-12-Audio-Interface-With-EXTENDED-WARRANTY-and-Cables-/160815111276?pt=LH_DefaultDomain_0&hash=item257153dc6c
That is interesting and not too unlike how mine are configured. My panels are also next to the side wall. They are at about a 45 degree angle to the side wall or 90 degree to the corner. I don't have much room for moving them either. I am going to separate them from the tweeter and get more flexibility of movement. You can get a rough idea of how they are by looking at the picture that I posted under the post about the tweeter being added. If you look behind the frankenpan, you will see the 1-D's. They are at about a 45 to the side wall, which is to the right and left of them.
I also have a stand planned for the near future for the two panels. I am going to do something fairly simple and not as elaborate as my frankenpans. I was thinking more along the lines of a Mye stand or similar. Any ideas?
You mentioned something about adding the Neo-8's in the future. How do we measure the success and comparison to the Neo's with the foil project? Should I get a rat shack SPL meter and measure them or what?
Ideally, I think you want the woofer panels approximately parallel to the front wall. This will reduce room modes. Also keep in mind that the Tympani woofers like to have a bit of a fold in them, as in the manual. I've been given to understand that this is necessary for optimum power response. I'm not sure if this applies to the against-the-wall scenario, though -- what you're getting with that acoustically is actually four panels, with the center at the physical wall.
I'd be very interested to know how the foil mids compare to the Neos. I'm guessing they're pretty similar in sound, but that the Neos have lower mass and a better waterfall, which will translate into better detail because of superior air damping. Frequency response will of course be idiosyncratic to the drivers. You can measure it, but it's just one aspect of the sound. Even if you take a waterfall it only tells you so much, particularly since the waterfalls we have for the Neos aren't of a line array. So you're comparing apples to oranges since a waterfall of a line array will be messier than that of a single driver.
Bottom line is that for me anyway the best reason to add the Neo's is that you can get rid of the IIIa woofer. It's a matter of proximity, if you're crossing over at 300 Hz you want the midrange to be as close as possible to the aooustical center of the woofer to avoid lobing. But the system you have will work just fine, we're talking subtleties here and I can see that you might hesitate to spend another $1000 and put in all that work.
For measurements, I'd recommend a calibrated Behringer. They're pretty cheap. The Rat Shack meter is useful for checking overall levels and mabe dialing in a woofer, but it isn't accurate enough for meaningful midrange measurements. These guys sell them:
http://www.cross-spectrum.com/measurement/calibrated_behringer.html
You also need a boom stand, maybe $20 online. I'd wait on the mic preamp until I knew what DAC solution I was getting, if it has a built-in mic preamp with phantom power you can use that. Measurement software is Room EQ Wizard, which is free.
I think you'll really want this stuff, tuning a three- or four-way system without it will be difficult indeed. This will let you adjust levels, play with crossovers, etc., quite rapidly. Your ear of course is always the ultimate arbiter but the measurements help you get them quickly to the point at which they sound good.
Yes I am also wondering how the two compare. I am hoping we hit a home run with the foil.
I ordered the Behringer Premium+ Mic and I will also get a boom stand. I have a mic input on the Impact Twin that I can use, so we will not have to wait for the DAC.
I spent quite a bit of time in the last 24hrs. searching for comparisons of the RME Fireface 800, Lynx Aurora and TC Electronics Konnekt 48. To my surprise the Konnekt 48 is favored most of the time. We are talking here about the pro market use, but that is where they are used primarily. I specifically looked for converter quality in the reviews, and again the Konnekt 48 seems to be as good as or better than the rest. The only difference being 96kHz vs. 192Khz, but no one even mentioned that. The big plus is the 12 channels simultaneously. There were some negatives with the Konnekt 48, but nothing that would affect our use. It was with the total firewire ins/outs that some think were misrepresented. All of the reviews were dated somewhere between 2005 and 2010. I did not find anything more recent for comparisons. I am going to spend some more time looking though, before I make a decision and, as you mentioned, check the PC Asylum forum.
That's really interesting. I hadn't even heard of it until you mentioned it.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: