Andrew Quint Reviews the Unique BACCH-SP Stereo Purifier

[paulg1]

I understand STC, "XTC for loudspeakers playback makes it like listening to headphones but without the inside head perception."

This is a breakthrough product, to be sure. I'm interested in the u-BACCH VST. I predict it won't be long before this technology combines with DSP room correction.

 

[STC]

This is a breakthrough product, to be sure. I'm interested in the u-BACCH VST.

I have tried various crosstalk cancellations for many years. IME, nothing beats doing your own cancellation as the system often do not behave according to measurements. BACCH achieved what others couldn’t do, that is getting recognition from the Audiophiles reviewers. If not XTC technology would have been part of the main stream of high end 20 years earlier. TAcT did that pretty well long ago but didn’t receive the approval. The only institute that advocated XTC was finally still demoed with TAcT uBACCH didn’t work for me and I find it strange because all other XTC worked with my speakers except uBACCH. I wish the best for BACCH.

 

[Keith_W]

I have tried various crosstalk cancellations for many years. IME, nothing beats doing your own cancellation as the system often do not behave according to measurements. BACCH achieved what others couldn’t do, that is getting recognition from the Audiophiles reviewers. If not XTC technology would have been part of the main stream of high end 20 years earlier. TAcT did that pretty well long ago but didn’t receive the approval. The only institute that advocated XTC was finally still demoed with TAcT uBACCH didn’t work for me and I find it strange because all other XTC worked with my speakers except uBACCH. I wish the best for BACCH.

Do you have a theory as to why uBACCH didn't work for you?

I am the opposite, all the other XTC that I tried has not worked except for uBACCH (you are aware of what I have tried from our email exchanges). My theory why all the others did not work is because I found them difficult to dial in. In one of them, there are 5 dials with labels that make no sense to me except "volume", and they have to be adjusted until the XTC effect is at its maximum. All this has to be done by ear.

 

[STC]

Do you have a theory as to why uBACCH didn't work for you?

I am the opposite, all the other XTC that I tried has not worked except for uBACCH (you are aware of what I have tried from our email exchanges). My theory why all the others did not work is because I found them difficult to dial in. In one of them, there are 5 dials with labels that make no sense to me except "volume", and they have to be adjusted until the XTC effect is at its maximum. All this has to be done by ear.

uBACCH using impulse response and in those days the impulse response was in the Ambiophonics website. I have also used impulse response and do cancellation and it works with my system so I am not sure why uBACCH didn’t work. It could be pc related as even RACE didn’t work with certain laptop.

 

[onion]

Does crosstalk cancellation work only at the listening point or also over a large area?

The clever folk at Bacch Labs have developed Bacch-X which uses 7 or 8 speakers to deliver XTC-enhanced stereo sound to multiple (moving) listeners in the same room simultaneously. I'm not sure if there is anything commercially available yet.

 

[paulg1]

Adding loudspeakers for widening the XTC listening area reminded me of another system.

Sigfried Linkwitz performed some measurement -based experiments about 10 years ago that developed into a clear theoretical basis and physical development of closely-placed additional enhancement loudspeakers or SEL. It evolved a bit, with several updates:
https://linkwitzlab.com/Watson/watson.htm
It works differently than XTC, Development is for a "sweet spot". He subjectively compares it to XTC systems available at the time. But, in update 3, he successfully experiments with SEL placement at further distances, suggesting that it could be extended beyond a single sweet spot. I wish there was more research on this. Intriguing.

Anybody familiar with this? It would be interesting to know how this compares to BACCH Seems a lot less expensive.

 

[Davide]

The clever folk at Bacch Labs have developed Bacch-X which uses 7 or 8 speakers to deliver XTC-enhanced stereo sound to multiple (moving) listeners in the same room simultaneously. I'm not sure if there is anything commercially available yet.

Ok, but if I have to use a multi-channel setup then I listen to multi-channel music, no?

 

[Cbdb2]

Indeed it does and that accuracy can literally be tested in room. The microphones allow you to record in the listening space and directly A/B the playback to the live recording. The spatial accuracy is essentially at an end game level if the speakers and room are up to the task. Of course my other points are the factors that determine whether or not the system is up to the task to make the most of the BACCH SP

How does taking a mix and putting it thru an effects box make it more accurate? Is it closer to what the mastering engineer heard? No. Not much different than using the "Jazz Hall" effect in your AVR.
You want accurate spatial cues listen to a 5.1 channel mix thru a 5.1 channel system.

 

[Keith_W]

How does taking a mix and putting it thru an effects box make it more accurate? Is it closer to what the mastering engineer heard? No. Not much different than using the "Jazz Hall" effect in your AVR.
You want accurate spatial cues listen to a 5.1 channel mix thru a 5.1 channel system.

You could say that digital room correction is an "effects box" in that it changes the signal, but what arrives at your measurement microphone and your ears is certainly more accurate. The idea of DRC is to change the signal to compensate for inaccuracies caused by the speaker and room.

The concept of BACCH is similar. It removes crosstalk, which is an inaccuracy created by a pair of stereo speakers in a room. Given that mastering engineers listen nearfield, they have less crosstalk. A typical home stereo setup has a farfield listening position, with speakers closer to an equilateral triangle, so you have more crosstalk. So yes, it is closer to what the mastering engineer heard.

As I mentioned in this thread (or maybe elsewhere), the "jazz hall" effect works by changing the frequency response and introducing artificial reverb. While the result might be enjoyable, it is certainly less accurate.

 

[Gwreck]

Ok, but if I have to use a multi-channel setup then I listen to multi-channel music, no?

The 7-8 speaker set up is a phased array. Think Yamaha’s ysp.

 

[onion]

Ok, but if I have to use a multi-channel setup then I listen to multi-channel music, no?

I think the point of it is to deliver Spatial Audio to multiple listeners with individual filters (and tracking) for each listener. I think other systems can correct for a single sweet-spot or average things out over a wider area.

Why not use your speakers for both? In my set up, I strongly prefer BACCH over multi-channel - the presence of the voices/ instruments in the room is way more vivid.

 

[Cbdb2]

You could say that digital room correction is an "effects box" in that it changes the signal, but what arrives at your measurement microphone and your ears is certainly more accurate. The idea of DRC is to change the signal to compensate for inaccuracies caused by the speaker and room.

The concept of BACCH is similar. It removes crosstalk, which is an inaccuracy created by a pair of stereo speakers in a room. Given that mastering engineers listen nearfield, they have less crosstalk. A typical home stereo setup has a farfield listening position, with speakers closer to an equilateral triangle, so you have more crosstalk. So yes, it is closer to what the mastering engineer heard.

As I mentioned in this thread (or maybe elsewhere), the "jazz hall" effect works by changing the frequency response and introducing artificial reverb. While the result might be enjoyable, it is certainly less accurate.

Not the same. Room EQ should get you closer to what the mastering engineer heard, his room is probably treated/EQed flat and hes listening to 2 speakers with all the crosstalk, near field dosnt remove crosstalk. This effects box changes things more drastically. There's no way it makes it closer to the original, thats a fantasy. Go listen to a mastering suite, or any good stereo set up, it won't be the same, this is so obvious I can't believe I have to explain it.

 

[Keith_W]

Not the same. Room EQ should get you closer to what the mastering engineer heard, his room is probably treated/EQed flat and hes listening to 2 speakers without this effect. This effects box changes things more drastically. There's no way it makes it closer to the original, thats a fantasy. Go listen to a mastering suite, or any good stereo set up, it won't be the same, this is so obvious I can't believe I have to explain it.

Please explain why you think that. While you are at it, explain what "effects" you think BACCH is performing to the signal and why you think crosstalk cancellation does not work.

 

[Cbdb2]

I never said it didn't work, I said it wasn't about a accuracy. The effect is changing the localization of sounds, probably by manipulating freq dependent delays/phase, and EQs. So probably a narrow sweet spot. It will not sound like what the masterer, mixer, artist, producer heard. You keep saying it makes things sound like your nearfield (mastering suites often have a far field set up also). Why don't you listen to your stereo near field and compare? It won't be the same, or the claims of huge differences with this box are wrong.

 

[STC]

How does taking a mix and putting it thru an effects box make it more accurate? Is it closer to what the mastering engineer heard? No. Not much different than using the "Jazz Hall" effect in your AVR.
You want accurate spatial cues listen to a 5.1 channel mix thru a 5.1 channel system.

Crosstalk cancellation is not an effect. It supposed to help to deliver the sound meant for the respective ears to be delivered only to the ear like headphones unless you are saying headphones sound ( not the projection inside the head ) is not what the engineer intended.

 

[Anton D]

Back in the day, Monster Cable marketed a sort of sound panel (looked like a cubicle divider) that was about 3 feet deep and 5 feet high that was meant to be placed perpendicularly at the front ‘line’ between the speakers to try and decrease cross talk.

It is so long gone I can’t find pics.

Now look what we can do!

Edited: Found one!

Monster Cable's Soundex 2 acoustical control panels - GOOD !!!

Up for sale is a set of four Monster Cable’s Soundex 2 acoustical control panels.Panels have been very well taken care of, in good to very good cosmetic condition.Dimensions of each panel (H x W x D) are 60” x 32” x...

www.canuckaudiomart.com

 

[Gwreck]

Back in the day, Monster Cable marketed a sort of sound panel (looked like a cubicle divider) that was about 3 feet deep and 5 feet high that was meant to be placed perpendicularly at the front ‘line’ between the speakers to try and decrease cross talk.

It is so long gone I can’t find pics.

Now look what we can do!

Edited: Found one!

Monster Cable's Soundex 2 acoustical control panels - GOOD !!!

Up for sale is a set of four Monster Cable’s Soundex 2 acoustical control panels.Panels have been very well taken care of, in good to very good cosmetic condition.Dimensions of each panel (H x W x D) are 60” x 32” x...

www.canuckaudiomart.com

Serta Also makes a mattress one can use for the same purpose.

 

[Cbdb2]

Crosstalk cancellation is not an effect. It supposed to help to deliver the sound meant for the respective ears to be delivered only to the ear like headphones unless you are saying headphones sound ( not the projection inside the head ) is not what the engineer intended.

Nobody uses crosstalk cancellation while recording, mixing or mastering, so what you hear will NOT be what the artist, producer heard.

 

[Gwreck]

Nobody uses crosstalk cancellation while recording, mixing or mastering, so what you hear will NOT be what the artist, producer heard.

The level of realism of the spatial effect/realism from BACCH is definitely accounted for by Dr Choueiri /Theoretica if you do any research. The most realistic recording are binaural recordings using one’s own head for the most realism all the way down to pop studio recordings. Studio recordings can have an exciting spatial sound but is not as the artist intended or natural ( but the sound stage of a studio recording is artificial either way.) A studio recording made with “q-sound” was a recording made with the intention of having crosstalk cancellation baked into the recording.

 

[onion]

Nobody uses crosstalk cancellation while recording, mixing or mastering, so what you hear will NOT be what the artist, producer heard.

Agreed. But BACCH renders a 3d sound-field (regardless of what the producer/ engineer heard) way more vividly than a stereo system without XTC. And that rendering of 3d sound more closely approximates our experience of hearing sounds in our day-to-day lives and live musical performances (where the sounds emanate from clearly defined points in 3d space rather than from a plane bound by the speakers). I believe this reduces listening fatigue - it certainly does for me. For practically all the electronica/ dance music I listen to, BACCH creates a 3d sound-field that was not heard by those involved in the production process. Does not stop it from sounding amazing.