Andrew Quint Reviews the Unique BACCH-SP Stereo Purifier

[Dialectic]

I need to play more with filter creation to get my XTC values up. With ORC set to the Olive target, I'm at 10 dB and 13 dB now (and no, my room is not perfectly symmetrical). It goes down to 7.5 and 11.5 with the Katz target.

But it still sounds incredible.

 

[Gwreck]

I need to play more with filter creation to get my XTC values up. With ORC set to the Olive target, I'm at 10 dB and 13 dB now (and no, my room is not perfectly symmetrical). It goes down to 7.5 and 11.5 with the Katz target.

But it still sounds incredible.

I can get my XTC pretty reliable to 20+ db but it seems like diminishing returns after 15db from what I can tell. Odd little things can kill my XTC such as objects on a console bar table behind my high backed sofa. Oddly the high back sofa doesn’t affect my XTC when I sit with a cushion behind me so I sit with my head not resting on the sofa headrest. So don’t be afraid to experiment.

 

[onion]

Yeah OK - it's epic! And the good Prof is a bona fide genius! I get 7.5 when reclined (further back) and 8.5 when sitting forward. While I've yet to hear a system going to -15dB XTC, right now it doesn't really matter that much to me.

 

[Dialectic]

I think the XTC values are heavily speaker dependent, with my D&D 8Cs in a dead room measuring reasonably well at 10-13.

The 15+ values that we hear about seem only to occur in systems with electrostatic loudspeakers.

 

[Gwreck]

I think the XTC values are heavily speaker dependent, with my D&D 8Cs in a dead room measuring reasonably well at 10-13.

The 15+ values that we hear about seem only to occur in systems with electrostatic loudspeakers.

I also have thick sheep skins behind my head that absorb those reflections.

 

[onion]

The Genelecs have a reflection-reducing mode. I’ll try this for the back wall next (front to back wall is relatively short).

As ORC is taking care of frequency response, it actually frees up the W371a to explore the less commonly used room correction modes

 

[Justdafactsmaam]

I think the XTC values are heavily speaker dependent, with my D&D 8Cs in a dead room measuring reasonably well at 10-13.

The 15+ values that we hear about seem only to occur in systems with electrostatic loudspeakers.

I think it is more dependent on room reflections. Narrow dispersion speakers in rooms with lots of absorption will measure higher

 

[sweetsounds]

I tested ORC in the last couple of hours. My setup: Mac mini -> Motu M4 -> Classe M600 -> Magico S5 II
For DRC I use Accourate generated, full range filters in BACCH via the HAFConvo VST3 plug-in.

First, some comments on the set up. I probably could have set it up myself, but for some reason the activation code was not arriving, so Edgar Choueri activated it remotely (great service as always). BACCH is easier if you use the default Babyface, but once you get the flow, that's good.

ORC is generated by measuring the typical sine sweep with the binaural mic on. My settings can be seen from the picture below

Here is the ORC window with the freq response (notice: this is mics in my ears, so not a free mic). First window shows my frequ response, second the target. You can change the target curve, default is Katz, which is quite flat. My preference is Olive with a bass tilt. My Accurate target curve is similar.
You can recompute the filter on the fly :

The best for me is to first test any effect with pink noise from Chesky's Best and then Warnes' Bird on a Wire.
During playback you can bypass BACCH (it compensates for the DRC gain loss) and can switch on/off ORC.

Observations:

• uBACCH gives already very good results. My room is symmetric, BACCH audiophile adds another 10degree of stage width. That was the same with version 13 (pre-ORC).
• It's hard to compare my vs ORC filters. because my FIR filters reduce volume by 6dB, means adjusting the dial after switching
• ORC either uses short FIRs or IIRs. Switching ORC on/off is immediate vs. the 0.3sec when switching to my 65k trap FIR.
• ORC with Katz filter changes pink noise to a whiter noise. The Olive filter is more what I would expect from a pink noise.
• The interesting effect of ORC is that it makes the sound richer and more brilliant, giving more atmosphere to instruments and voices, whereas my Accurate filters indeed a more neutral and dry. Kick drums sound more "into the stomach" with ORC and more like a smack with accurate.

More trying is needed for sure. It's great to have both options. It would be great to understand, what filters ORC is actually generating (FIR???) and how it actually treats the 3 frequency domains.

A great option is, that you can use head tracking with ORC, which means you can compensate the bass/room mode differences when moving your head. Haven't tried that yet.

 

[sweetsounds]

A question for other ORC users: when head tracking is engaged with ORC, are you supposed to see any animation in this window?

View attachment 350981

What do the highlighted (in the red rectangle) buttons do?

Many thanks

The buttons change simplythe view (from back, from front, from left...(

 

[Justdafactsmaam]

I tested ORC in the last couple of hours. My setup: Mac mini -> Motu M4 -> Classe M600 -> Magico S5 II
For DRC I use Accourate generated, full range filters in BACCH via the HAFConvo VST3 plug-in.

First, some comments on the set up. I probably could have set it up myself, but for some reason the activation code was not arriving, so Edgar Choueri activated it remotely (great service as always). BACCH is easier if you use the default Babyface, but once you get the flow, that's good.

ORC is generated by measuring the typical sine sweep with the binaural mic on. My settings can be seen from the picture below
View attachment 353063
Here is the ORC window with the freq response (notice: this is mics in my ears, so not a free mic). First window shows my frequ response, second the target. You can change the target curve, default is Katz, which is quite flat. My preference is Olive with a bass tilt. My Accurate target curve is similar.
You can recompute the filter on the fly :
View attachment 353077
View attachment 353067
The best for me is to first test any effect with pink noise from Chesky's Best and then Warnes' Bird on a Wire.
During playback you can bypass BACCH (it compensates for the DRC gain loss) and can switch on/off ORC.

Observations:

• uBACCH gives already very good results. My room is symmetric, BACCH audiophile adds another 10degree of stage width. That was the same with version 13 (pre-ORC).
• It's hard to compare my vs ORC filters. because my FIR filters reduce volume by 6dB, means adjusting the dial after switching
• ORC either uses short FIRs or IIRs. Switching ORC on/off is immediate vs. the 0.3sec when switching to my 65k trap FIR.
• ORC with Katz filter changes pink noise to a whiter noise. The Olive filter is more what I would expect from a pink noise.
• The interesting effect of ORC is that it makes the sound richer and more brilliant, giving more atmosphere to instruments and voices, whereas my Accurate filters indeed a more neutral and dry. Kick drums sound more "into the stomach" with ORC and more like a smack with accurate.

More trying is needed for sure. It's great to have both options. It would be great to understand, what filters ORC is actually generating (FIR???) and how it actually treats the 3 frequency domains.

A great option is, that you can use head tracking with ORC, which means you can compensate the bass/room mode differences when moving your head. Haven't tried that yet.

That’s a serious improvement on your FR

 

[onion]

I tested ORC in the last couple of hours. My setup: Mac mini -> Motu M4 -> Classe M600 -> Magico S5 II
For DRC I use Accourate generated, full range filters in BACCH via the HAFConvo VST3 plug-in.

First, some comments on the set up. I probably could have set it up myself, but for some reason the activation code was not arriving, so Edgar Choueri activated it remotely (great service as always). BACCH is easier if you use the default Babyface, but once you get the flow, that's good.

ORC is generated by measuring the typical sine sweep with the binaural mic on. My settings can be seen from the picture below
View attachment 353063
Here is the ORC window with the freq response (notice: this is mics in my ears, so not a free mic). First window shows my frequ response, second the target. You can change the target curve, default is Katz, which is quite flat. My preference is Olive with a bass tilt. My Accurate target curve is similar.
You can recompute the filter on the fly :
View attachment 353077
View attachment 353067
The best for me is to first test any effect with pink noise from Chesky's Best and then Warnes' Bird on a Wire.
During playback you can bypass BACCH (it compensates for the DRC gain loss) and can switch on/off ORC.

Observations:

• uBACCH gives already very good results. My room is symmetric, BACCH audiophile adds another 10degree of stage width. That was the same with version 13 (pre-ORC).
• It's hard to compare my vs ORC filters. because my FIR filters reduce volume by 6dB, means adjusting the dial after switching
• ORC either uses short FIRs or IIRs. Switching ORC on/off is immediate vs. the 0.3sec when switching to my 65k trap FIR.
• ORC with Katz filter changes pink noise to a whiter noise. The Olive filter is more what I would expect from a pink noise.
• The interesting effect of ORC is that it makes the sound richer and more brilliant, giving more atmosphere to instruments and voices, whereas my Accurate filters indeed a more neutral and dry. Kick drums sound more "into the stomach" with ORC and more like a smack with accurate.

More trying is needed for sure. It's great to have both options. It would be great to understand, what filters ORC is actually generating (FIR???) and how it actually treats the 3 frequency domains.

A great option is, that you can use head tracking with ORC, which means you can compensate the bass/room mode differences when moving your head. Haven't tried that yet.

Nice observations. Have you carried out the second set of measurements (Pass II, to create a BACCH filter to match the ORC filter) - that should generate a third tab 'measured':

 

[Keith_W]

Now that I think about it, the BACCH ORC must use low latency filters if it is to employ head tracking. This means either short FIR's or IIR's as you point out. These will not give you the best correction.

It may make sense to use two convolvers in series. The first uses long FIR's - its purpose is to provide optimal correction and suffer the latency of the long FIR's as a result. The output is then sent to BACCH ORC - its purpose is to do some final correction and provide head tracking. The only question is - how many channels can BACCH ORC accept as an input, and how many can it output? And whether it messes up the corrections from the first convolver?

 

[Gwreck]

I have an idea that I think would work for BACCH pro users. Anyway with my Mac with atmos audio one can capture the multi channel output in Blackhole. My computer skills are not up to connecting the blackhole audio to the BACCH 3D mixer. With the 3d mixer one should be able to make virtual surrounding with the HRTF. Audiopraise has the vanity pro that can break out 8 channels of surround but that costs $2k. This would be basically free. I have emailed for support about this idea but have not heard back. I think with ORC and the expanded audience for BACCH they are having are Harding time keeping up.

 

[onion]

Edgar upgraded my system to 12.0.4 recently. He suggested that ORC has the biggest impact on narrow directivity speakers and works side-to-side but not so much front-to-back. One can play around with the max allowable boost that is set to 2dB by default. If the measurements suggest a deep enough notch, it's worth setting this higher to improve the frequency response. This would be a the cost of a little headroom which should not matter in adequately powered systems.

 

[doorofnight]

My non-scientific opinion is that it makes my speakers, which I thought sounded amazing prior to ORC, sound broken without it.

Is this the difference 'prior' and ORC with or without any other form of DSP? Or is ORC really much better than DIRAC (or something like that)?

 

[Justdafactsmaam]

Is this the difference 'prior' and ORC with or without any other form of DSP? Or is ORC really much better than DIRAC (or something like that)?

The ORC does two things that no other room correction DSP does. It measures the room in your ears and adjusts the room correction for your ears while tracking them in real time. It also corrects for how speakers direct sound at our ears.

 

[Gwreck]

Is this the difference 'prior' and ORC with or without any other form of DSP? Or is ORC really much better than DIRAC (or something like that)?

Dirac is much harder to use and the results can be worse if one is not careful. ORC improves the tonal balance and imaging and it is easy to A/B the difference. Dirac is better if you use it for a home theater. ORC is best for a single listener. ORC also provides the user the actual measured response pre and post ORC. Dirac only provides a calculated response.

 

[slaweks]

Dirac is much harder to use and the results can be worse if one is not careful. ORC improves the tonal balance and imaging and it is easy to A/B the difference. Dirac is better if you use it for a home theater. ORC is best for a single listener. ORC also provides the user the actual measured response pre and post ORC. Dirac only provides a calculated response.

I started limiting Dirac just to low frequencies, e.g. <300Hz, and this works well with ORC. I am hopeful ART (limited to <150Hz) will cooperate also well with ORC.

 

[Gwreck]

I started limiting Dirac just to low frequencies, e.g. <300Hz, and this works well with ORC. I am hopeful ART (limited to <150Hz) will cooperate also well with ORC.

I would suspect getting the bass correct with Dirac leaves more headroom

I started limiting Dirac just to low frequencies, e.g. <300Hz, and this works well with ORC. I am hopeful ART (limited to <150Hz) will cooperate also well with ORC.

i would think they would cooperate well as they are trying to solve 2 different problems

 

[doorofnight]

Dirac is much harder to use and the results can be worse if one is not careful. ORC improves the tonal balance and imaging and it is easy to A/B the difference. Dirac is better if you use it for a home theater. ORC is best for a single listener. ORC also provides the user the actual measured response pre and post ORC. Dirac only provides a calculated response.

Thank you for your reply and explanation.

I think my question was not very clear. You hear a big improvement now that you use ORC. But compared to what situation? A situation where you used a DSP like DIRAC or something?

I use uBacch also, but not ORC and I use DIRAC for bass controll. Without DIRAC I can imagine that ORC is a *huge* improvement. But coming from DIRAC to ORC?