Theoretica Applied Physics BACCH


It seems nice.


Happy Cake Day to Al !


I wonder if the hat brim has interfered with his filters? :smile:

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Yes, “Venturi” referred to the port design. I gave my pair to my college roommate who was still using them until his audiophile son made them go away a couple of years ago. The brown foam grills (or were they orange?) had turned to dust…

When I went to work for the local Pacific Stereo after graduation, we had stacked Advents at home with some monster Phase Linear amp, replaced by AR 11 driven by bridged HK. Later on to KEF, Snell and Meridian.

I’ve got the new Meridian DSP9 in my living room today.

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I still have them in the shop but they haven’t played music in a few years. I should hook them up and see. I actually still have the boxes they came in. That might be considered hoarding. I dunno. :thinking:

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Edgar was kind enough to upgrade my Bacch4Mac setup to the new release software. I have compared it to the Alpha software I was running. It is now extremely fast processing when making ORC and XTC filters. I have made one set without head tracking and one with. Here are some graphs showing the results for the ORC (Optimal Room Correction):

Uncorrected Room

Optimal Room Goal

Measured After Room Correction

A reminder these measurements were made with in ear microphones. This explains the funny dips in the 5khz to 10khz range. If that area appeared flat the sound would be painfully bright.

Music sounds so effortless and relaxed. It’s just present and very easy to engage with.


Indeed! Il est arrivé comme un ORC. The ORC upgrade email has landed. Time to backup the Mac Mini, upgrade to OS 14 and then to do the BACCH4Mac 14 load!

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I have just one word needed to describe what I hear: Analog.
(I am streaming,) Grimm MU1 used only as a Roon Server. The Mac Mini as an endpoint. Streaming 16.44.1 AIFF files off my NAS. This is good stuff, much better than the Alpha.

You are in for a major treat!

Edgar has mad skillz!


You are not making the waiting game any easier. :face_with_raised_eyebrow:


When it arrives you will share the joy and envy other gear no more.


I’m already there except for this one last piece. :smile:



Optimal Room Correction (BACCH-ORC)

Dear BACCH-dSP user,

Theoretica Applied Physics is pleased to release version 14 of its industry-leading spatial audio application, BACCH-dSP. This latest version, aside from introducing a few improvements to the performance, stability and efficiency of BACCH-dSP, is the first to feature Theoretica’s new room correction and speakers equalization technology, BACCH-ORC.

BACCH-ORC is a new paradigm in room correction. It is the most advanced room correction technology today. Unlike any other commercially available room correction system, BACCH-ORC relies on quick in-ear (binaural) acoustic measurements, millimeter-resolution head tracking, and cutting-edge algorithms derived from years of psychoacoustic research, to produce and apply individualized optimal room correction (ORC) filters that elevate any stereo loudspeaker playback system to its ultimate level of transparency.

Not only does BACCH-ORC correct for the spectral coloration of the loudspeakers and the listening room, it also neutralizes the spatial signature of the loudspeakers, which interferes with the spatial cues of the sources in the recording, leading to significantly enhanced spatial imaging. For more on ORC, read its official webpage.

BACCH-ORC requires acoustic measurements with the BACCH-BM in-ear microphone and is therefore available only for the Audiophile Edition and above.

The BACCH-ORC module can be added to BACCH-dSP at any time for $1000. However, in appreciation of the trust and enthusiastic support of our existing customers, we are offering a free perpetual license for the BACCH-ORC module to all those who have purchased BACCH-dSP Audiophile (or a higher edition level) by March 3, 2024, and whose 1-year Tech Support and Version Update Service Plan has not expired by that date.

You are receiving this email message, because your 1-year Tech Support and Version Update Service Plan has expired. Renewing your plan before March 3, 2024, would allow you to get an automatic upgrade to BACCH-dSP 14, and to all future versions for a year, and count on Theoretica’s tech support.

If you your BACCH-dSP license is at the Audiophile edition level or above you will also get a free perpetual license to the BACCH-ORC module when you renew your plan.

If your license is at the Intro edition level, you would still get the benefits of running that latest versions of BACCH-dSP and of our tech support if you renew your plan. if you decide to upgrade to the Audiophile edition and above at any time in the future, we are happy to offer you a free perpetual license for BACCH-ORC.

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Since it was 12 months after Audiophile edition purchase had elapsed i had to also purchase support renewal service. But the ORC upgrade comes along for the ride. Now waiting tng for DSP 14 email.

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My setup session will be tomorrow morning. Anxiously waiting. I hope the orc won’t affect much of the dynamics, as other eq did in my system in the past.


Unfortunately will not have time to play this weekend. But did manage to get ORC loaded, up and running. Will let music play all weekend while I work upstairs. Want to redo the filters anyway since progeny returned for a weekend visit and messed up my listening room by offloading objects on the left side. Never had such lopsided left-right XTC numbers before.

Here are my initial ORC curves at least. It does sound fine!

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I ran into some ORC activation snags after renexal of service license. Didn’t get activation code. So waiting for a call back appointment.

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Oh it will affect dynamics for certain. You will finally have them.

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I really like your sense of humor

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The measured looks fantastic!!!
Click on the ORC Filter Response in the upper right hand corner and you will see the filter that has been created in the same chart.

Aha. Got it. Figured there was a trick for that. Thanks!

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