Edgar Choueiri of Theoretica Applied Physics discusses Spatial Audio and the BACCH SP products

Dr. Edgar Choueiri, founder of Theoretica Applied Physics joins the Audiophile Foundation to explain how his BACCH (Band-Assembled Crosstalk Cancellation Hierarchy) cross-talk cancellation technology solves a fundamental flaw in two-channel stereo: the "phantom image" effect, where everything sounds like it's coming from between your speakers instead of from actual locations in 3D space. He walks through the science of how we actually hear in three dimensions—using interaural time differences, level differences, and spectral cues—and shows why standard stereo recordings capture all the right information but then destroy it through speaker crosstalk. The key insight? BACCH mathematically eliminates crosstalk between channels, so your ears receive the correct spatial information, letting you hear instruments as they were recorded. Audiophile Foundation member Todd Sitrin, who also moderated this event, briefly discussed Theoretica's range of products, from the software-based BACCH for Mac (starting at $980) to their high-end hardware solutions like the BACCH-SP (approx. $24k), all designed to deliver genuinely three-dimensional imaging from ordinary stereo recordings without requiring specialized room treatment or changing the tonal balance of your music. In the last half of the video, Dr. Choueiri answered questions from Todd and the audience. He announced the upcoming release of a breakthrough product, made possible by the recent advent of AI. He also discussed how BACCH addresses reverberation and imaging, and touched on room correction and headphones, using other BACCH modules. https://www.theoretica.us/ About Us The Audiophile Foundation is a 501c3 organization completely run by volunteers and supported by donations and membership. If you like our publications, events and/or content we provide, please consider becoming a member and/or donating so we can continue our mission to provide non-biased information and preserve the legacy of high end audio. Hyperlink Links Becoming a member - https://audiophilefoundation.org/cont... Donating - https://audiophilefoundation.org/cont... _ Disclaimer: The information and views expressed in the multimedia content (“Video Content”) posted represents the views and opinions of the presenters and participants of such Video Content and does not necessarily represent the views or opinions of the Audiophile Foundation (“AF”). The mere appearance of Video Content on the Site does not constitute an endorsement by AF or its affiliates of such Video Content. The Video Content has been made available for informational and educational purposes only. AF does not make any representation or warranties with respect to the accuracy, applicability, fitness, or completeness of the Video Content. AF does not warrant the performance, effectiveness or applicability of any sites listed or linked to in any Video Content. AF hereby disclaims any and all liability to any party for any direct, indirect, implied, punitive, special, incidental or other consequential damages arising directly or indirectly from any use of the Video Content, which is provided as is, and without warranties. This presentation is protected by U.S. and international copyright laws. Reproduction or distribution in any form without written permission from the Audiophile Foundation is strictly prohibited. © 2026 Audiophile Foundation. All rights reserved. Chapters: 00:00 - Intro 10:57 - What is Spatial Audio? 21:00 - How We Hear in 3D 39:30 - Cancelling Crosstalk 44:18 - How does the BACCH filter work? 1:07:56 - The BACCH Products Explained 1:12:19 - Will BACCH work in my room? 1:18:08 - Does BACCH work with any speakers? 1:23:11 - Will BACCH work with other corrective technologies? 1:26:46 - Will BACCH work for multiple listeners? 1:35:55 - Does BACCH work with analog sources? 1:41:11 - Does BACCH improve height and depth perception? 1:45:13 - BACCH Room Correction (ORC) 1:53:40 - BACCH in a home theater system 1:54:20 - When to Recalibrate BACCH? 1:56:38 - BACCH Headphone Module 1:59:31 - Connecting BACCH to your system 2:01:20 - Future Enhancements 2:07:36 - Wrap-up