Princeton University  

1 What is BACCH™ 3D Sound ?

BACCH™ 3D Sound is a recent breakthrough in audio technology (licensed by Princeton University) that yields unprecedented spatial realism in loudspeakers-based audio playback allowing the listener to hear, through only two loudspeakers, a truly 3D reproduction of a recorded soundfield with uncanny accuracy and detail, and with a level of high tonal and spatial fidelity that is simply unapproachable by even the most expensive and advanced existing high-end audio systems.

BACCH™ 3D Sound can be implemented in any hi-fi system by adding a single component: a dedicated hi-end quality high-resolution (96 kHz, or 192 kHz, at 24 bits) digital processor that applies, in real time, a customized (see Question 11 ) digital filter (called a c-BACCH filter) to any stereo sound input. The processor filters out a fundamental impurity (thus the epithet “pure stereo”) that occurs whenever stereo sound is played through loudspeakers, thus allowing the 3D cues which the brain needs to hear in 3D, and which exist in abundance in practically all well-made stereo recordings, to naturally reach the brain of the listener.

One of the greatest advantages of BACCH™ 3D Sound is that it is fully compatible with all existing stereo recordings and does not require any additional playback hardware aside from the single digital processor. Pure Setreo (like standard stereo) requires only a single pair of loudspeakers.

Not only does BACCH™ 3D Sound provide a shocking improvement to the spatial realism of sound reproduction, but the same digital filter used in BACCH™ 3D Sound also corrects, in both the frequency and time domains, most non-idealities in the playback chain (including loudspeaker coloration and resonances, listening room modes, spatial comb filtering, balance differences between channels, etc…) so that the frequency and impulse responses at the listener’s ears are as close to ideal as possible for a given listening room and hi-fi system. This corrective property of BACCH™ 3D Sound , which by itself is a highly desirable enhancement to the fidelity of any audio system, is only the secondary feature of BACCH™ 3D Sound – the primary feature being 3D sound.

BACCH™ 3D Sound was developed by Prof. Edgar Choueiri and is licensed by Princeton University.

A detailed technical description of the basic method behind BACCH™ 3D Sound is described1 in detail in this technical paper. The following Q&A's address most aspects of BACCH™ 3D Sound without going into the mathematical details.