I have been listening to binaural recordings made with a pair of omnies usually in croakies for 15 years, and has been making them myself for 11. I have always played them on speakers in regular stereo position. If there is a problem in this premise I had to assume that it’s negligible and that I have to live with it. (Please don’t tell me to use headphones.)
^^^
That's not actually binaural, but rather head-baffled omnis*. Binaural requires the microphones to be placed
within the ear, at the opening of the ear-canal at a minimum, which is the easiest way to do it and what I'd recommend for anyone wanting to try it. That is necessary to achieve the complex 3-dimensional spatial high frequency response imparted by the shape of the outer ear, which is a core aspect of 'binaural' recording and playback.
David Griesinger argues that binaural is not actually truly accurate unless microphone probes are placed deep within the ear canal. However doing that requires special equipment and equalization and Griesinger goal is the careful study, categorization and quantization of acoustic phenomena, rather than music recording with the simpler goal of listener enjoyment. For most, binaural-recording means either placing miniature omnis at the opening of one's own ear canals, or recording with a relatively anatomically accurate dummy head with head and ear shapes based on those of humans.
*(Around TS, you'll also commonly find the head-baffled omni technique - typically mounted with 'croakies' - refered to as "HRTF", which like binaural isn't a strictly accurate usage, as the Head-Related-Transfer-Function [shorthand = HRTF] includes the response imparted by the fleshy portion of the ears as well as the head between them)
I don't know what plugin your friend is using, so I can't be certain about what the stereo expander is doing, but it is likely making a simple Mid/Side adjustment. The Left/Right signals are first converted to Mid/Side signals, the Mid/Side ratio is then adjusted, and the signals converted back to Left/Right stereo again. The basic technique is to increase the Side signal with respect to the Mid signal, which increases the "width" of the resulting recording. You can do that without a plugin by setting up some signal routing in your DAW, or with an analog mixer, but there are many plugins which make it very simple. Some are free and work just as well as others that are not. It's is a simple thing for a plugin to do.
A more advanced technique is to equalize the Mid and Side signals differently when doing the above, which changes the ratio by frequency instead of by the same amount across all frequencies. That can, for example, widen the bass frequencies more than the higher frequencies, which is appropriate for adapting head-baffled omnis for loudspeaker playback. That can be done by signal routing combined with an equalizer, but again, plugins do it easily. Some stereo width adjustment plugins will allow independent adjustment across several frequency bands. Alternately many EQ plugins now offer a Mid/Side mode. That mode does an L/R>M/S conversion before the EQ and M/S>L/R conversion afterwards for you. Once channel of the EQ controls the Mid signal and the other the Side signal.
In other words it recreates exactly what you hear from your seat. Here is the proof that all you need to recreate what you hear live is a pair of omnis, contrary to what many sound engineers say.
Nah, it's just a somewhat better, more-convincing illusion! It does not recreate what you actually experience live- your brain is doing most of that for you, in combination with your willing suspension of disbelief, and a slightly more convincing playback experience. To actually get as close as possible, you'd need to record using Griesinger's in-ear-probes, equalise to accommodate for the ear-canal resonance, and playback over a headphone system calibrated to accurately match the HRTF response of your head and ears. At that point the signal at the each ear-drum would be as accurately reproduced as possible, but that still would not completely recreate what is experienced at the live event. The low frequency sensation would not be the same as it would be lacking tactile "body feel" and bone conduction present at the live event.
To recreate that "signal at each eardrums" with the same degree of accuracy using loudspeakers is far, far more complicated and error prone. Regular stereo doesn't even come close. Fortunately we're gullible, and a not very technically accurate reproduction can be good enough for our brains to trick us into thinking it sounds exactly like it did live, you from your seat.
Topic: Convert Binaural recording to Stereo? (Read 17299 times)