The Theorectica BACCH 4Mac and BACCH-SP

The BACCH 4Mac is the easiest review I’ve written. Yet, it is the most challenging. My reason is simple: I’ve never encountered a product that has impacted my listening experience as profoundly as the BACCH technology has. Unfortunately, I almost missed the opportunity, too. I initially dismissed the BACCH technology without ever hearing it. I recall that about three years ago, my friend Dan Secula discussed the BACCH with great enthusiasm during a listening session at his home. I quickly dismissed the BACCH, recognizing it as nothing more than a fancy digital room enhancer better suited for a home theater environment. This knee-jerk reaction stemmed from my extensive 25-plus years of experience with exotic digitally-based processors, which proved to be more frustrating than fanciful after an extensive love affair. Room correction and sophisticated digital EQs, as seen in products from brands like Tact Audio, Lyndorf Audio, and Z-Systems, have graced my listening space since 1995. My current stalwart (20 years and counting), Behold Audio’s ingenious series of electronics, makes it nearly impossible to part ways even though I’ve turned off its room correction software for more than ten years. My reasoning is simple. Once you give me this many knobs, buttons, and switches, inevitably, something always goes awry. The saddest revelation I had was when I finally turned off the room correction, and the sound improved dramatically. I never went back.

But even before these components began to grace my listening space, I had befriended Ralph Glasgal, a long-time champion of Ambiophonics, a type of crosstalk cancellation technology. In fact, I was always a welcome guest at Glasgal’s northern NJ home to hear about any new upgrades he came up with. At the time, Glasgal was championing the Tact Audio brand and had the most outrageous high-end audio system I’d ever seen. If I recall correctly, Glasgal’s listening room is still composed of ten pairs of the Soundlabs Majestics electrostatic loudspeakers and another ten Tact Audio processors and amplifiers. The two front loudspeakers were about three feet apart. They were separated by a large partition designed to lower crosstalk (years later, more sophisticated software allowed for the removal of this partition). How it all came together remains a mystery. I must admit, I always enjoyed being in this man’s company, even when I couldn’t always understand what his system was trying to accomplish sonically. Without going into further detail, you probably get the idea of why I dismissed the BACCH without even hearing it. However, I’ll be the first to admit that contempt prior to investigation is dangerous.

A brief online search for the BACCH led me to David Chesky, whom I hold in high regard. David was involved with Glasgal’s Ambiophonics, way back when, while developing his Binaural technology in the recording studio. I was eager to find out why he endorsed this new technology unashamedly. Today, Chesky Records offers Binaural+ recordings, which are designed to unleash the full power of the BACCH technology in your listening room. In my discussions with Dr. Chesky, he strongly recommended that I give the BACCH a listen. I began discussions with my friend Dan Secula once again, and we both agreed to start with the BACCH 4Mac Audiophile version ($9k), designed for computer-literate types. There is also the $30k BACCCH-SP and ADIO analogue model available, which is the subject of this review. Oh, the BACCH (in any version) comes with a 90-day, 100% money-back guarantee if you’re not satisfied.

The next thing I did was get in touch with BACCH designer, Professor Edgar Choueiri, who is the President of Theoretica Applied Physics and currently resides as Director of Princeton University’s 3D Audio and Applied Acoustics Lab. The first thing Professor Choueiri did was invite both Dan and me to his Princeton University rocket propulsion lab. We decided to go during the summer (2024), since most of the students would be on summer break. Professor Choueiri and his staff greeted Dan and me with the utmost respect. Professor Choueiri showed us around this enormous rocket propulsion lab, which was coincidentally adjacent to his 3D Audio and Applied Acoustics Lab. Have you ever seen a rocket ship’s thrusters up close? One look and you immediately realize that audio is truly a passion for Professor Choueiri, and not something that he does in the back of his garage. After the one-hour tour, Professor Choueiri invited us to his nearby home to hear the BACCH in a real home environment. Of course, Dan and I were excited to do so, but not as excited to get back home to install our newly purchased BACCH 4Macs.

Truth be told, as much as I enjoyed the sound of Professor Choueiri’s setup, I wasn’t enthralled by the music or gimmicky effects. Oh boy, what did I get myself into? That was what I was thinking when I finally headed home. Would I have to return this unit because it couldn’t deliver the enjoyment I had hoped for from regular jazz or standard classic vocal recordings?

Getting the BACCH 4Mac setup proved pretty straightforward, although I wouldn’t qualify it as easy. Within days of my purchase, Professor Choueiri signed on via phone and prepared me for the measurements needed that would be done via a long run of cables and a pair of in-ear-pods. The 4Mac was going to sit between my Laufer Teknik Music server and my Behold BPA-768 preamplifier. I also needed an HDMI cable to connect to my monitor for access to the BACCH 4Mac software. The 4Mac cannot handle the digital ins and outs needed to connect to your sources. This is where the supplied RME DDC/DAC processor comes in. It’s got the necessary USB and digital connections needed.

The first thing I noticed while doing the crosstalk measurements and room correction was that the in-ear-pods are very different from the microphones used in all the other room correction software done in the past. Instead of using microphones at your listening position (and usually on a stand), these stereo in-ear pods are used directly at your head and ears. My, how times have changed. Without even hearing the differences, I felt much more comfortable knowing these measurements were being done at the exact height and width of my head.

With the press of a single button, the crosstalk and room correction were done. Now, where was all this anticipation and excitement going to take me? The first thing I queued up on my music server wasn’t something I actually had planned on using for my BACCH first impressions, but it turned out to be near perfect: Miles Davis’ “Someday My Prince Will Come.” Here’s this 1961 monster recording that somehow never could escape the era it was recorded in. The assembled musicians are icons today, while this Davis quintet is arguably the best assembled. My personal favorite is John Coltrane, and he’s officially left the group to form his own famous quartet. But he’s summoned back to record for Davis one last time. For someone like me, this makes Teo and Someday My Prince Will Come epic among jazz lovers. Having heard this for over thirty years, I already knew what to expect. Yet, everything was somehow different. Although Miles remained centered and fixed, his instrument had depth and textures I didn’t notice before. Paul Chamber’s bass had an added weight and purity that seemed both cleaner and quicker. Ditto Jimmy Cobb on the drums. His playing is cleaner and better defined in space. In fact, nothing sounded processed or gimmicky. I had never heard this recording sound so unrestricted, free from distortions, and with an added sense of realism. The BACCH 4Mac continued to impress, allowing my densely populated music catalog to reemerge in a way I never could have imagined.

My larger-than-life Sunny Majestic horn loudspeakers are a little more than 10 feet apart. The BACCH 4Mac served as a lion tamer for these behemoths. Yet, through the BACCCH 4Mac, the images are tighter, smaller, and more three-dimensionally accurate than ever. Images are now perceived outside the physical plane, not just in between the loudspeakers. And rarely, I’ve detected instruments and voices behind me. I’m not going to say I enjoy hearing something at my listening seat, but it does prove startling. I’ve read that the BACCH is even more impressive on live recordings than on those done in the studio. I agree with that assessment due to all the ambient sounds located on live tracks. However, I stand here one year later, more amazed at how the BACCH 4Mac can offer a new experience listening to both old and new studio recordings.

If there is one thing I want to emphasize, it is the word PURIFIER. That is what I hear and appreciate the most from the BACCH 4Mac. My brain doesn’t have to figure out what’s going on as much as it used to, thanks to the crosstalk cancellation filter. Therefore, the music comes across as less stressed and convoluted. Everything sounds so much freer and alive. I’ve concluded that Professor Edgar Choueiri has optimized the BACCH 4Mac in a very neatly designed package that needs to be heard to be believed. I am now a believer. So much, in fact, that I decided to upgrade to the complete chassis $32k BACCH-SP.