Thank you for the open and lively discussion on BACCH. I thought I could allow myself to add to It by offering an answer to the valid question “
How does BACCH enhance the spatial imaging of "studio-mixed" recordings without altering the sound intended by the mixing engineer?” This is a fair question, and an important one given that the majority of commercial recordings are of the “studio-mixed” type, as opposed to stereo recordings done acoustically in real acoustic spaces.
To better appreciate the arguments I make in my answer to that question, I suggest that you first read the answer to the less controversial question “
How does BACCH enhance the spatial realism in the reproduction of acoustical recordings made in real acoustical environments?” which is Q&A # 14 on
Theoretica’s FAQ webpage. The answer to this question is a bit extensive as it covers the cases of acoustical recordings made with various stereo microphone techniques: binaural (dummy head mic), coincident (ORTF, XY, Blumlein, etc.), time-based (spaced omni or A-B pair, Decca tree, Jecklin disk, etc…). While extensive, the discussion eschews math and too much jargon in favor of intuitive arguments, “thought experiments,” measurements and illustrative plots.
The question regarding “studio-mixed” recording is then addressed in FAQ #15, in light of the previous answer, to argue why playback through BACCH, except in some rare extreme situations, does not betray the intent of the mixing engineer – a fact well appreciated by most of those who have listened carefully to BACCH, but sometimes questioned, fairly, by those who have not.
Instead of cutting and pasting text from the FAQ page, and for the sake of saving space on this ASR discussion page, I hope that those of you interested in these questions could read the detailed answers there.
Regards,
Edgar Choueiri