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BACCH4Mac Pro Edition: a report

oivavoi

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Further question to you BACCH users: How does the headphone thing work? I've been curious about trying out the Smyth Realizer (which apparently externalizes the acoustic scene and places it outside the head when listening to headphones). But if BACCH can accomplish the same thing in one big pacakge it's one more argument for trying it out...
 

Dialectic

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Further question to you BACCH users: How does the headphone thing work? I've been curious about trying out the Smyth Realizer (which apparently externalizes the acoustic scene and places it outside the head when listening to headphones). But if BACCH can accomplish the same thing in one big pacakge it's one more argument for trying it out...
Yes, the headphone feature, BACCH-dHP, can do essentially what the Smyth Realiser does. One calibrates the headphone feature with one's speakers, which become spatial anchors for the sound.

The first few times I used it, I couldn't believe my speakers weren't blasting. I like the effect on most material.
 

oivavoi

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Yes, the headphone feature, BACCH-dHP, can do essentially what the Smyth Realiser does. One calibrates the headphone feature with one's speakers, which become spatial anchors for the sound.

The first few times I used it, I couldn't believe my speakers weren't blasting. I like the effect on most material.
Thanks. That makes it even more attractive, given that there will be no need for the Smyth thingy in addition, should I want to listen without disturbing anybody. But in any case I'll need to save up for a while after breaking my account on getting the Dutch & Dutch... :) (coming next week, btw!)
 

Dialectic

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I wonder how Dr. Toole can be persuaded to listen to a BACCH system.

In any event, that's the most enlightening exchange that I've read on an audio forum. Many thanks to Dr. Toole and Prof. Choueiri.
 

Fitzcaraldo215

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I wonder how Dr. Toole can be persuaded to listen to a BACCH system.

In any event, that's the most enlightening exchange that I've read on an audio forum. Many thanks to Dr. Toole and Prof. Choueiri.
Not Dr. Toole, but I agree with his reasoning. BACCH might possibly be the best synthesis scheme yet for extracting better spatial imaging, envelopment, etc. from stereo recordings. But, I suspect it will be a tough sell for those of us who are already enjoying discretely recorded Mch. For example, Kal has heard BACCH and he does not seem in any hurry to embrace it and abandon 5.1 Mch.

I have not heard it. I remember hearing the much less sophisticated Carver Sonic Holography years ago. No doubt, BACCH is much better, but I was put off by the small sweet spot then, and I expect BACCH would have a similar issue. Although they say it does not require special speaker placement, I also suspect it might be optimized by narrower angular placement than normal for stereo or Mch. Or, if not, then more highly directive speakers to minimize side reflections.

I have no immediate plans for headphones. But, if I did, I would likely go with a Smyth Realizer calibrated using one or more high quality Mch systems, such as my own and those of numerous friends. BACCH might well be a superior extraction scheme from stereo recordings vs. any comparable stereo to Mch synthesis technology yet implemented. But, I have so many excellent, discretely recorded Mch files on my NAS - thousands - that artificial synthesis from stereo recordings has little appeal for me. After trying, I just do not feel the need to synthesize Mch from stereo, and, in fact, I do little listening to stereo recordings. Fortunately, a classical music lover like me has much to choose from in discrete Mch.
 

Brad

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If you don’t have the head tracking, how far can you move your head before the enhanced imaging is lost?

Following on, to try the system without a significant investment (and having to use a Mac), what would be the price for a set of the in ear microphones and a set of filters generated?
 

Frank Dernie

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I would be intrigued to know how many recordings are actually improved by BACCH?? I tend to listen to performances/interpretations of classical music I like. Not all of them are modern (so multi channel isn't worth the clutter, for me) nor are they always simply miked recordings from the 60s and 70s, which I would imagine BACCH thrives on.
I have Macs so that isn't a problem, but so far I have been unconvinced to fire up loads of extra kit to listen to a CD.
I seem to be less bothered by spatial clues than timbral inaccuracies, does BACCH help here?
 

Dialectic

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If you don’t have the head tracking, how far can you move your head before the enhanced imaging is lost?

Following on, to try the system without a significant investment (and having to use a Mac), what would be the price for a set of the in ear microphones and a set of filters generated?
Without tracking, it's not possible to move one's head far laterally without losing the enhancement. Significant forward and backward movement and some upward and downward movement are possible with little loss of the effect.

It is not possible to generate or use the filters without the BACCH software or one of the BACCH hardware units.
 

Dialectic

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I would be intrigued to know how many recordings are actually improved by BACCH?? I tend to listen to performances/interpretations of classical music I like. Not all of them are modern (so multi channel isn't worth the clutter, for me) nor are they always simply miked recordings from the 60s and 70s, which I would imagine BACCH thrives on.
I have Macs so that isn't a problem, but so far I have been unconvinced to fire up loads of extra kit to listen to a CD.
I seem to be less bothered by spatial clues than timbral inaccuracies, does BACCH help here?
At this point, my conclusion is that BACCH enhances all stereo recordings that were made in natural acoustic spaces. Use of spot mics is more noticeable with BACCH than without, but spot mics do not cause loss of the effect. Even DG zillion-mic jobs with plate reverb from the '70s are enhanced.

With respect to timbral inaccuracies, I haven't found BACCH to do any harm. BACCH does change the frequency response of the system, so there is some timbral change. The added clarity of string instruments in particular with BACCH might be characterized as timbral improvement.

The effect of BACCH is primarily spatial, however, and it's so striking that I now find it difficult to listen without it.
 

svart-hvitt

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Scott: We seem to be very much on the same page, even to our envisaged immersive sound systems. The only difference in mine is the use of Revel Gem2s as surrounds, including +/- 60 deg locations, and the likely be the use of Revel elevation speakers - not timbrally better or worse than the JBL 705i alternatives. The SDP-75, yet to be delivered, will allow for anechoic response refinements, sound field managed bass, and many interesting experiments. I attach a photo of the present situation. The acoustical "secret ingredient" is the scattering from bronze statues of the female form :)

As explained in my new book, I delight in the challenge of delivering superb sound without cumbersome and ugly acoustical devices - a "stealth" approach is more rewarding to me. Not having a "dedicated" home theater is a deliberate choice for our life style. Those suspecting that wall mounting of the Salon2s is a problem (and it is a popular challenge) should note that that surface is deliberately very irregular - it is really a low/mid-frequency scattering surface, and adjacent boundary issues are minimal. Having enjoyed the interim system for a while, it is my impression, and that of other trusted ears that have heard it, that the inverted speakers might sound better than they do in conventional floor-standing mode. The soundstage is at the right height (determined by the height of the tweeter) and the sound is remarkably open and clean. They also liberate several square feet of expensive real estate :)

Yes, the current VR/AR activities are bound to generate new knowledge and supporting technologies. The reward will be fascinating experiences for gamers, personal movie goers, and video concerts. It is a huge asset to have credible visual cues to help guide our aural perceptions. Recordings of live concerts should be especially persuasive with surround visuals and audio. My traditional 10 ft screen and surround audio system provides superb entertainment from the handful of excellent video concerts (most are mediocre, sadly), and it does it for a room full of people.
@Floyd Toole ,

would you share the in-situ frequency response at the listening position of each of your speakers?
 

Dialectic

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svart-hvitt

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I see your point, but from a research program standpoint I wonder about these things:

1) Listener perception/preference with no in-situ DSP processing.

2) Listener perception/preference with in-situ frequency curve related DSP processing.

3) Listener perception/preference with in-situ Bacch DSP processing.

4...etc...

I think it’s easier to discuss if we know what’s a person’s position and how do people in general react to changes of in-situ measurements.

Bacch comments have thus far been of the subjective kind where we don’t know exact what’s the listener’s reference. Can we answer the question what happens with listeners’ preferences when they listen with a DSP calibrated speaker (both «internal» DSP and «external» DSP for room compensation) and when they listen with a non DSP-calibrated speaker, etc.

This may be outside of the scope of the thread, depending on a reader’s view. However, the more we know about a person’s preference and a group of people’s preference, the easier it is to judge a statement.

@Floyd Toole has very strong views on Bacch and DSP related room algorithms; he calls the latter an «enticing marketing story». So I wondered where his (and others’) strong views come from.
 

Floyd Toole

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@Floyd Toole has very strong views on Bacch and DSP related room algorithms; he calls the latter an «enticing marketing story». So I wondered where his (and others’) strong views come from.
My opinions about binaural processing of the BACCH kind come from a lot of listening to a much earlier digital implementation at Harman, called VMAx. Crosstalk cancellation and other binaural processing does what it does, and if it delivers what you want to hear, go for it. Many people find it attractive when the sound stage is expanded from +/- 30 deg to +/- 90 deg with "big" space. But, it is not a "more accurate" rendering of what the musical artists and recording engineers created. Remember I described creating phantom speakers at +/- 30 deg to provide an authentic soundstage.

I'm not sure what you mean by DSP related room algorithms - that covers a lot of territory. I state quite clearly in my book that Sound Field Management is a superb way to deliver non-resonant and very similar bass to multiple listeners in a room - that is a digital process in which each of multiple subwoofers is individually processed and then combined. I state that equalization of the anechoic on-axis/listening window curves is a good beginning to delivering good sound - also a digital process. However, I go to great lengths to explain why several of the widely used full-bandwidth in-room equalization methods cannot deliver what they claim, and how it is possible for them to degrade the performance of well designed loudspeakers. That also is DSP, and in some of those cases it is truly an "enticing marketing story". If nothing important is known about the loudspeakers in terms of their anechoic performance - the normal situation - it is not possible to interpret the steady-state room curves. There are in-room measurement techniques that may be able to help, but they begin by using time-windowed measurements to interrogate the direct sound. Some may do this, but most do not. Spatial averaging simply ensures that nobody receives maximally optimized sound. In my original Sound Field Managed configuration I had three settings: Me, Me and a couple of good friends, and the whole room. Obviously, "Me" received progressively degraded sound as more of the floor space was averaged. I will have to see what is possible when my under-construction system is completed, but I am hopeful because the SDP75 surround processor is very accommodating.

Somebody mentioned the choice of subwoofer crossover frequency. I needs to be about 80 Hz or lower if localization of the subs is to be avoided. In addition, the low-pass filtering must be effective. This is not always done successfully in preset receivers and processors when subs having aggressive output above 80 Hz are involved. One may need more aggressive low-pass filtering than bass management provides. In-room measurements are the only assurance that the subs are being shut down above 80 Hz.
 

Dialectic

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Last weekend I applied more aggressive DSP in my Dutch & Dutch 8Cs and then re-calibrated BACCH. These two steps seem to have resolved some of the bass issues that I was hearing in my system.

Low frequencies in my system, along with everything else, are now better with BACCH than without.
 

Dialectic

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Version 6.0 of BACCH4Mac has been released, and I upgraded last night. I'm listening now and will report on any material differences from version 5.0.
 
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Version 6.0 of BACCH4Mac has been released, and I upgraded last night. I'm listening now and will report on any material differences from version 5.0.
The Intro edition of BACCH4Mac is now available for $980. It only has u-BACCH which is "based on tape measurements of listening geometry" instead of acoustic measurements.

Have you compared BACCH versus u-BACCH on the Pro edition?
 

Dialectic

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The Intro edition of BACCH4Mac is now available for $980. It only has u-BACCH which is "based on tape measurements of listening geometry" instead of acoustic measurements.

Have you compared BACCH versus u-BACCH on the Pro edition?
I have not but will try to do so sometime this weekend.

EDIT: I said I'd examine u-BACCH sometime this weekend, but in-laws were staying with us, our air conditioner broke in the midst of a heatwave (and we live on a sun-exposed floor in the thirties), and I'm dealing with multiple crises at work. Audio will have to wait another week or two. My apologies.
 
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Dialectic

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I tried u-BACCH this evening, using the default Johann Sebastian settings in BACCH4Mac Pro and some Chesky Binaural+ recordings. The u-BACCH effect, while noticeable, is not as pronounced as that of BACCH-dSP with head tracking. This result is not unexpected, given that BACCH-dSP uses a calibration routine to control for the shape of the listener's head, the listener's speakers, and the listener's environment. u-BACCH controls for none of these factors. It is nonetheless impressive.
 
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I tried u-BACCH this evening, using the default Johann Sebastian settings in BACCH4Mac Pro and some Chesky Binaural+ recordings. The u-BACCH effect, while noticeable, is not as pronounced as that of BACCH-dSP with head tracking. This result is not unexpected, given that BACCH-dSP uses a calibration routine to control for the shape of the listener's head, the listener's speakers, and the listener's environment. u-BACCH controls for none of these factors. It is nonetheless impressive.
So do you think it is good to try u-BACCH in order to evaluate whether worthy to buy BACCH4mac? U-BACCH has no restocking fee and so seems much “safer” for trial.
 

Dialectic

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I think it may be disappointing to you if you are expecting the mind-blowing effects that I have reported with the more sophisticated versions of BACCH. I don't know what the commercial terms of u-BACCH are, but if you can use it on a trial basis before committing to the purchase, sure, why not try it?
 
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