BACCH4MAC Short Review / first impressions

[Dialectic]

It simulates a 7.1.4 setup using only 2 speakers. I believe cross talk cancellation is the foundation of the product. I'm typically skeptical of such emulators, but after owning BACCH4Mac for nine months I can say the spatial effects are not like any other I'm personally familiar with. I'm supposed to have Stratos installed this week, and can offer subjective comparisons to my 9.1.2 after some time.

BACCH-Stratos

BACCH-Stratos, 7.1.4 Surround emulation from two speakers.

www.theoretica.us

Thanks so much for exploring this. I’m curious to hear about usability under MacOS. It can’t be simple to map all those channels of audio.

 

[Gwreck]

I have a lot of M

Thanks so much for exploring this. I’m curious to hear about usability under MacOS. It can’t be simple to map all those channels of audio.

It should be done internally by the program and set up should
Be with Edgar.

 

[Auke te Winkel]

After reading some more about Stratos I got curious about what the practical differences are with the 3D mixer in the Pro edition (https://www.theoretica.us/bacch-dsp/index#section-4).

One obvious difference is that Stratos uses measurements to determine what the transfer function of loudspeaker + HRTF is for the virtual speakers, while the 3D mixer relies on a set of predefined HRTFs.

The second difference is that the 3D mixer can also simulate room reflections and reverb.

A third one is that the 3D mixer can simulate any speaker configuration, while Stratos seems to be limited to 7.1.4.

If the end goal is to reproduce various surround formats like regular 5.1 but 7.1.4 Atmos as well, would one be better suited than the other?

Has anyone been able to evaluate both?

 

[Gwreck]

After reading some more about Stratos I got curious about what the practical differences are with the 3D mixer in the Pro edition (https://www.theoretica.us/bacch-dsp/index#section-4).

One obvious difference is that Stratos uses measurements to determine what the transfer function of loudspeaker + HRTF is for the virtual speakers, while the 3D mixer relies on a set of predefined HRTFs.

The second difference is that the 3D mixer can also simulate room reflections and reverb.

A third one is that the 3D mixer can simulate any speaker configuration, while Stratos seems to be limited to 7.1.4.

If the end goal is to reproduce various surround formats like regular 5.1 but 7.1.4 Atmos as well, would one be better suited than the other?

Has anyone been able to evaluate both?

The 3d mixer is very versatile but requires one to have a measured HRTF to work. It took quite a bit of set up to get working with the UCX and it worked but I could only get 8 channels and the sound was colored as I did not have my own HRTF. Getting the PCM audio into the Mac from an outside source also requires a $2k unit. So stratos will be a much simpler option that is seemingly better.

 

[Auke te Winkel]

Thanks for the clarification!

Earlier in this thread you mentioned you wanted to try the mesh2hrtf method for the 3D mixer HRTFs. From your previous reply it seems like you didn't get that to work?

 

[Gwreck]

Thanks for the clarification!

Earlier in this thread you mentioned you wanted to try the mesh2hrtf method for the 3D mixer HRTFs. From your previous reply it seems like you didn't get that to work?

I’m not good enough at computer to even get the program running, so
no.

 

[Gwreck]

I’m not good enough at computer to even get the program running, so
no.

I could have gone to Princeton and had my HRTF measured but I think my marriage would not stand that vacation plan.

 

[Dialectic]

Have any users gotten up and running on BACCH Stratos?

 

[tifune]

Have any users gotten up and running on BACCH Stratos?

I have; it's a tricky thing to "review" but I can give you my experience. First off, if you are considering ever buying stratos in your lifetime you should do it now while the promo price is available. It's a 2 week trial minus $100 if you decide to return it. It's such a unique product, I don't know anyone else can help with your decision.

The important question: does it work? Yes, it does. Does it work well? On the LCR, LFE, and side speakers, absolutely. The side channels are even further outside the speakers than typical stereo content and the center/LFE have rock solid phantom center imaging.

The tops and rears are hit or miss for me. I've only found a handful of albums where the rears truly sound like they're coming from behind, same for the tops (front or rear). I play around with the channel solos on every multichannel album I've queued up in the last 2 weeks. Tops seem to work better in pairs; Im not qualified to explain that.

That is to say, if I solo top left rear, it doesn't really sound like it's above and behind me. But if I also enable top right rear, the positioning is much better (but rarely 100%). Presumably this is a mix of: the way the content was recorded/mixed, my measurements/head shape, and the McGurk effect (per the Dr, not my assessment).

There are certainly exceptions, but multichannel FLAC seems to work better than Apple Music Atmos. That could be psychological and/or sample selection bias on my part.

Happy to answer any Q's, but my short answer is: if you have a well-oiled BACCH4Mac setup, Stratos is a no brainer at $1500. At $3000 it's not so straightforward unless $3000 is pocket change for you. I don't know I would do it at that price because I already have a real 9."5".2 setup and most of my favorite music isn't available in multichannel. Bands I like either aren't into the idea or simply can't afford the mixing process.

But, if B4m is your primary setup, then $3k may still make sense as it's certainly cheaper (and less hassle) than a decent 7.1.4 arrangement. Even if you don't listen to much multichannel content, more is being released every day and your favorite album may soon be available as such, for better or worse.

 

[Dialectic]

I have; it's a tricky thing to "review" but I can give you my experience. First off, if you are considering ever buying stratos in your lifetime you should do it now while the promo price is available. It's a 2 week trial minus $100 if you decide to return it. It's such a unique product, I don't know anyone else can help with your decision.

The important question: does it work? Yes, it does. Does it work well? On the LCR, LFE, and side speakers, absolutely. The side channels are even further outside the speakers than typical stereo content and the center/LFE have rock solid phantom center imaging.

The tops and rears are hit or miss for me. I've only found a handful of albums where the rears truly sound like they're coming from behind, same for the tops (front or rear). I play around with the channel solos on every multichannel album I've queued up in the last 2 weeks. Tops seem to work better in pairs; Im not qualified to explain that.

That is to say, if I solo top left rear, it doesn't really sound like it's above and behind me. But if I also enable top right rear, the positioning is much better (but rarely 100%). Presumably this is a mix of: the way the content was recorded/mixed, my measurements/head shape, and the McGurk effect (per the Dr, not my assessment).

There are certainly exceptions, but multichannel FLAC seems to work better than Apple Music Atmos. That could be psychological and/or sample selection bias on my part.

Happy to answer any Q's, but my short answer is: if you have a well-oiled BACCH4Mac setup, Stratos is a no brainer at $1500. At $3000 it's not so straightforward unless $3000 is pocket change for you. I don't know I would do it at that price because I already have a real 9."5".2 setup and most of my favorite music isn't available in multichannel. Bands I like either aren't into the idea or simply can't afford the mixing process.

But, if B4m is your primary setup, then $3k may still make sense as it's certainly cheaper (and less hassle) than a decent 7.1.4 arrangement. Even if you don't listen to much multichannel content, more is being released every day and your favorite album may soon be available as such, for better or worse.

What loudspeakers are you using in the BACCH setup?

 

[tifune]

What loudspeakers are you using in the BACCH setup?

D&D 8c at 70cm

 

[Dialectic]

D&D 8c at 70cm

70cm from sidewalls?

 

[tifune]

70cm from sidewalls?

Maybe 50cm from right side wall (window), 3m from left side wall and 2m from front wall. The setup is pulled into the middle of my room so I can look out the window while I work, it's not optimal in any traditional sense but sitting so close to the speakers ameliorates most issues

 

[Auke te Winkel]

Do you think that the short listening distance might cause problems with ambiguous localization?

When I tried using BACCH from a very close range, the XTC level went up but felt I could locate the speakers quite easily unless I held my head absolutely still (which isn't feasible in practice). In my experience the head tracking isn't fast enough to fix this.

Listening from about 3 m fixes this but requires either extremely directional speakers or a well treated room.

Also, HRTFs in the near field are different from far field (> ~ 1 m), not sure if that might affect things.

 

[Dialectic]

Thanks to @tifune for the info.

I may inquire whether there's a way to use Stratos with video, such as the Berlin Philharmonic Digital Concert Hall. I would expect sync problems.

 

[tifune]

Do you think that the short listening distance might cause problems with ambiguous localization?

Sorry, I don't feel qualified to answer this and I'm not in a position to rearrange my room to find out. I can tell you, when I explained my setup the the Dr., he said my results should be "[superb given the speakers and the listening distance]"

I may inquire whether there's a way to use Stratos with video, such as the Berlin Philharmonic Digital Concert Hall. I would expect sync problems.

You probably need to add some lip sync compensation, but VLC is included in the setup if you request it. That's what I use to play multichannel FLAC and I believe it can stream just about anything on the planet with a bit of effort

 

[Gwreck]

I’m excited about stratos as through my system these quad recordings mixed down to 2 channel with HRTF are very convincing. https://youtube.com/@binauralsurround3913?si=HSRZ_yMWQ0X1hCOd

 

[Dialectic]

I’m truly torn about whether to get Stratos. It’s pure expenditure because it’s a software license, and I just can’t imagine using it very often unless there is integration with the Berlin Philharmonic Digital Concert Hall. Very grateful for all of tifune’s observations. I’m also running 8Cs (albeit in a larger, treated listening room), so those observations are especially applicable to my use case.

 

[tifune]

I’m truly torn about whether to get Stratos. It’s pure expenditure because it’s a software license, and I just can’t imagine using it very often unless there is integration with the Berlin Philharmonic Digital Concert Hall.

It's only a $100 risk, get it and see what you think. Think of it as a $100 ticket to ride (worst case scenario)

 

[Dialectic]

It's only a $100 risk, get it and see what you think. Think of it as a $100 ticket to ride (worst case scenario)

Good point.

I hate returning stuff, though, including software!