Rerurn to Romy the Cat's Site
In the Forum: Playback Listening
In the Thread: Time Alignment : Live Performances vs Audio
Post Subject: Timing discrepancies and room decay.Posted by Romy the Cat on: 3/8/2007
 be wrote: |
The paradox of the orchestra sound would be resolved if we asume that the audience (in the good seats) mostly hear the reflected sound, primarily from the wall behind the stage and that the players at the front follow the visual lead of the conductor and the players behind, play accordingly to the audible lead of the front players, the sound would then be time aligned, when reflected from the back.
This would obviously only function if the orchesetra is not to widely spaced and the the listener is not to much to the side.
That it is indeed the reflected sound and the reveberation that is dominating seems to be correct since it is imposible to pinpoint the instruments at least from a seat that is not to close to the stage. |
|
What "be" said is valid and goes along very well with the theory of phase randominization. However, what "be" said also made me to think in the following direction….
The reverberation radius usually is very small, I believe in Carnegie Hall what it is 3.2M reverberation radios is a distance at witch the ratio between direct sound is reflected sound is 50%:50%) Also, the live performances usually take place in the lager rooms where RT-60 is very long. (RT-60 is a test that indicted how long time a given frequency decays in a give space for 60dB).
So, what I would be very interested to learn is how RT-60 affects the timing discrepancies in playback stage. Let pretend that we have for instance an arrival miss-alignment between drivers measured in half-wavelength. We recognize some subjective auditable negative consequences of that miss-alignment listening it in a room that has RT-60 = 0.6 second at 60Hz (it means that 60Hz reach a point of minus 60dB at 0.6 second - a typical number for a good size audio room). So, would our “subjective auditable negative consequences” be at identical amplitude if we listen the same playback at the same distance but in the room that would have RT-60 = 1.3 seconds at 60Hz? (A larger room)
In a larger room that reverberation radius is smaller, phases get randominized faster and therefore I would presume that our negative reaction to time discrepancies in a large room would be way less annoying to us…
Rgs,
Romy the CatRerurn to Romy the Cat's Site