BACCH4MAC Short Review / first impressions

[tjcinnamon]

I was told that it is possible to pre-convolve music files in BACCH if you input some basic parameters, such as distance between speakers, and distance to listening position. You need the pro version of BACCH for this. Once you have the file, all you need to do is play it back. I was wondering if any ASR members would be kind enough to encode a file for me to listen? Maybe BACCH themselves should consider offering this service.

So the pre-convolving cant be done with the Intro license (still $1000).

 

[tjcinnamon]

View attachment 272379I am pretty proud of myself as I’m now getting 23db of crosstalk cancellation for each ear. What is anyone else getting with their set up?

Anyone know how XTC can be measured in REW?

 

[Gwreck]

Anyone know how XTC can be measured in REW?

I don’t think it can measure XTC. BACCH measures this itself.

 

[Keith_W]

It would probably show up as differences in phase between the left and right channels based on Theoretica's description of how it works.

 

[tjcinnamon]

Different question: any idea what makes the song Kid A by RadioHead have such massive stereo separation? I wonder if BACCH does that to other songs?

Both Kid A and a number of Yosi Horikawa songs have crazy wide soundstages. I think Yosi’s is outright binaural. Another which is not binaural is 13andGod.

 

[Gwreck]

message me and I will add you to a gdrive with some wav files. The number is the speaker angle the files were convolved.

 

[tjcinnamon]

message me and I will add you to a gdrive with some wav files. The number is the speaker angle the files were convolved.

sent!

 

[Gwreck]

The last song I uploaded was an "8D" remix of a Billie Eilish song. Although the 8D thing is somewhat a gimmick it is very cool to hear over BACCH. Even with the uBACCH on my system the voice spins around my head and I can clearly hear it behind me several feet. Cool demo for friends who may not get the idea as this very clearly shows what the processor is doing as in stereo the sounds just going side to side over and over again. I am not sure if everyone is susceptible to the 8D thing as I imagine they do they remix with some generic HRTF involvement.

 

[Keith_W]

I just tried listening to all the files. I set my speakers up for equilateral listening and eagerly played the files.

I have never heard this music before because it's not what I normally play. And I don't have access to the originals so I don't know what they sound like before BACCH processing. However, I do know what my system is capable of because I listen to it every day.

The result was: there was a dramatic extension of the soundstage, most evident in the three recordings set up for 60deg listening. The sound projected ALMOST laterally, but it never went behind my head as you report. The soundstage also extended further backward. Even though I don't have access to the originals, I have never heard any music that extends that far laterally. If you could provide a track list (or better still, upload the originals), I would be extremely grateful.

 

[Keith_W]

I listened to the tracks again on my DCA Stealths tonight. I know the files were convolved for 2ch. I am even more blown away. On the 8D track, I could hear the drums and singer doing a 360 around my head, and the soundstage sounded so natural, as if I wasn't listening to headphones at all.

THANK YOU SO MUCH for doing this for us! There are very few moments in my audio journey when I encounter something which completely changes my perspective of what I thought was possible. Now I have to really start thinking about how I am going to get BACCH into my system.

 

[tjcinnamon]

I just tried listening to all the files. I set my speakers up for equilateral listening and eagerly played the files.

I have never heard this music before because it's not what I normally play. And I don't have access to the originals so I don't know what they sound like before BACCH processing. However, I do know what my system is capable of because I listen to it every day.

The result was: there was a dramatic extension of the soundstage, most evident in the three recordings set up for 60deg listening. The sound projected ALMOST laterally, but it never went behind my head as you report. The soundstage also extended further backward. Even though I don't have access to the originals, I have never heard any music that extends that far laterally. If you could provide a track list (or better still, upload the originals), I would be extremely grateful.

I had a different experience but my angles are the 46 degree ones . It shows how precise the positions are. My Polk SDAs are the same in terms of their required precision.

I’m going to try more experimenting this weekend to compare the two.

 

[Gwreck]

I listened to the tracks again on my DCA Stealths tonight. I know the files were convolved for 2ch. I am even more blown away. On the 8D track, I could hear the drums and singer doing a 360 around my head, and the soundstage sounded so natural, as if I wasn't listening to headphones at all.

THANK YOU SO MUCH for doing this for us! There are very few moments in my audio journey when I encounter something which completely changes my perspective of what I thought was possible. Now I have to really start thinking about how I am going to get BACCH into my system.

I’m really glad to hear you enjoyed it. I started with the basic BACCH and every year leveled up when my annual subscription for support and updates was due. You do get to keep the software just won’t get updates or support(best support ever). The new base Mac mini m2 is $500 and works well as far as I know.

 

[Gwreck]

I have updated the files and have 46 and 60 degree convolving on both.
Not in order:
Yori Horikawa -Bubbles
Vangelis-Spiral
Santana- Waiting
Radiohead- Kid A
Dr. Chesky- Westside blues
Jordi Saval(not iTunes)

 

[hege]

Thanks for providing.

Doesn't seem to make that much difference here on these tracks. I have 210cm-230cm triangle so somewhere around 46 degrees should be right. Some minor soundstage widening or tightening here and there, not even a clear winner between 46 or 60 as things varied track by track. In the end I prefer my normal setup anyway, certainly wouldn't pay anything based on this demo. And yes naturally I compared all to original tracks, what would be the point otherwise..

Perhaps it's because I have such a damped and headphone-like setup anyway, there isn't any artificial envelopement help from the room. Or maybe I would just need better tuned parameters for my specific setup.

 

[tjcinnamon]

Thanks for providing.

Doesn't seem to make that much difference here on these tracks. I have 210cm-230cm triangle so somewhere around 46 degrees should be right. Some minor soundstage widening or tightening here and there, not even a clear winner between 46 or 60 as things varied track by track. In the end I prefer my normal setup anyway, certainly wouldn't pay anything based on this demo. And yes naturally I compared all to original tracks, what would be the point otherwise..

Perhaps it's because I have such a damped and headphone-like setup anyway, there isn't any artificial envelopement help from the room. Or maybe I would just need better tuned parameters for my specific setup.

I’ll post a review later. My unique setup is that I already have reduction in XTC based on my speakers.

I plan on borrowing a Mac and trying the demo to give it a further shake. Something doesn’t seem right with what I’m testing. However, there were 2 tracks (which were already binaural that worked well). However, bubbles sounded way off and that is my test track that I’ve heard hundreds of times.

I’ve reached out to the vendor. So I’m holding public comparison until I get the results. I think my angle needs to change.

 

[Keith_W]

I have since heard these same tracks on 5 different systems. I quickly got on the phone with some friends and told them about these amazing files and they were all keen to have a listen. Here is a quick summary of the results.

- My system (horns). Soundstage widens dramatically on some tracks, notably the Billie Eilish track. It goes all the way out to either side of the listener, sometimes very faintly coming from behind me.
- My system (DCA Stealth headphones). Even though these were convolved for speakers, the effect with headphones is quite dramatic. I have described the sound above.
- Friend's system (Linkwitz LX521). Soundstage widens, but not to the same degree as with mine.
- Friend's system (Avantgarde Duo). The effect was disappointing. There was an audibly different sound, but not to any great extent.
- Friend's headphones (Sennheiser HD650). The effect was similar to my headphones in that it was quite dramatic.

I should note that the last system (the Avantgardes) was NOT set up for equilateral triangle listening because of physical limitations of his room. The Avantgardes were pushed up against the wall, and the listening chair pushed up against the opposite wall. The speakers were spaced widely apart to accommodate an equipment rack and TV, and the room was probably too small for the speakers. Likewise, the Linkwitz system also had room limitations. The speakers were too close to the corners, but they were set up in an equilateral triangle listening configuration. My system was the only one where I have complete freedom to move the speakers and listening chair around.

We discussed why the tracks worked on some systems and not on others. These are some of our theories:

- The files were provided for a certain room geometry which some of us were unable to replicate. We suspect that if we had the full version where we can have finer control of the geometry and also binaural microphone recording and head tracking, the effect would be even more pronounced.
- The directionality of the speakers seems to matter. On highly directional speakers like mine, the effect was the greatest.
- If the speaker is placed near the walls, the early reflections probably interfere with the crosstalk cancellation and reduces the effect.
- The Linkwitz is a dipole, which was placed too close to the wall and in a corner. Again, probable interference from early reflections.

Over the next few weeks I will have an opportunity to listen to more systems with the same files. I will get a better idea of what BACCH can do.

 

[sweetsounds]

Thanks for providing.

Doesn't seem to make that much difference here on these tracks. I have 210cm-230cm triangle so somewhere around 46 degrees should be right.

Could you send a photo of your setup and let us know your speaker and room treatment?
It would be interesting to understand when XTC makes a difference and when not.

For instance early reflections in the precedence window break the effect.

 

[Gwreck]

Could you send a photo of your setup and let us know your speaker and room treatment?
It would be interesting to understand when XTC makes a difference and when not.

For instance early reflections in the precedence window break the effect.

I have used BACCH on various systems and some have a strong effect and some barely any. I have a desktop set of KEF speakers in a room with many windows and BACCH barely does anything. Overall the less early reflections the better the effect.the more directional the speaker the better but good sound absorption will make up for much of that. If there are two different forms of electronic XTC that may actually decrease the effect. I suspect speakers against the wall will have less noticeable BACCH due to early reflections. Anything other than the angle listed will likely be less than optimal. I have Sanders ESL’s with acoustic absorption behind them to catch the rear wave. Even with the uBACCH my effect is not that far from the audiophile versions (with the in ear measurements). The Radiohead track obviously a studio recording puts the sounds as far as my right and left shoulder with the uBACCH. With my system the 8d track which is obviously heavily effected will cause the voice the spin around the room and behind my head. I do suspect the 8d is based off a generic HRTF so not everyone will hear that effect. The Santana song puts the guitar just ahead of 3 o’clock and the drum adjust ahead of 9 o’clock.
I’m getting 23db of XTC for each channel with my measured filter and 20db is what is needed for maximum effect. But even 5db can make a large difference in the spaciousness of the sound (which is what I believe that the Polk LS80” XTC has). Little things can change the measured XTC such as I had and 1 ft cubed box 5 feet behind me in line with the direct beam of the speaker and my XTC couldn’t get over 12db and was over 20db when I moved the box. Wasn’t so much noticeable on listening though.

 

[Gwreck]

I can get a headphone impulse response measurement from my sanders without head tracking and will share that for people who want to try headphones.

 

[Gwreck]

I added the Song Bouree by Jethro Tull covolved with the headphone module. Play it back on headphones. Basically BACCH records and impulse response of my system and then add back the crosstalk cancelation to play back on headphones. This file is literally the impulse repose of my system so when listened through high quality(preferable open back) it should sound like my stereo. I cannot record it with the head tracking which is very important for filling ones brain into thinking the headphones are actually 3d space so it will like still sound a bit like headphones still. I COmpaed the track and it does have the same spatial layout of BACCH through my Sanders. The overall sound is basically correct but different headphones add their own coloration.