Nice to see I've stirred up a hornets' nest. "Muahaha. My work here is done!"
If a sound occurs in a room e.g. a note from a loudspeaker, the brain is able to distinguish the directly radiated sound from the reflection *if they arrive at sufficiently different times*. This is one reason why moving speakers away from walls makes them sound better. The reflections from rear and side walls don't "muddle" the sound in the same way because the path of reflected sounds is sufficiently longer than the direct path. This causes echos to arrive late enough for the brain to realise they are, well, echos. Now, if you do RC on the original sound...a pre-echo to cancel a reflection...well that corrects the response neatly for a microphone (which doesn't have a brain) but doesn't work so well for a human (who does). This is because - if the speakers are set in space - the brain already knows the echo is an echo. There is already DSP going on - in the grey cells! And your RC is messing with the brain DSP. Knowing the echo is an echo, the brain can filter through it to hear the direct sound "echo-less"...a bit like listening to a conversation in a loud pub. But if the direct sound has been DRC'd...what happens? Maybe the brain filters through the room echos and hears an unnatural sound. So I am saying DRC might work better for speakers which are near walls (not the ideal set up anyway, I note). Another way of looking at it... The IDEAL room is anechoic i.e. no sound of any frequency is reflected, all you hear is direct sound. Such a room doesn't exist and certainly not domestically. So another strategy is required which admits "reflections happen" and make the best of it in concert with the brain. 1. A "normal room" acoustic is fine. Any more damping will result in gross differences in damping at certain frequencies (an "unfamiliar or unnatural acoustic"). 2. Now here is part of the theory behind omnipole and dipole speakers. They spread sound in all directions, which aids in creating a sound field which the brain is used to. After all, normal real sounds spread out in all directions. With natural sounds their reflections - albeit arriving later and attenuated - have a similar quality to the original. In contrast box speakers, which have a directional output, naturally cause reflections to have a different quality to the direct sound. (Stand behind your box speaker. Even *before* the sound bounces off the back wall it has a different quality from the sound in front!) Omnipole and dipole advocates work on the above premise, namely "reflections happen" so work with it not against it. I think a really short Executive Summary would be "by creating natural and familiar acoustic conditions in the listening space, the brain can do its DSP magic to re-create an illusion of the RECORDED acoustic space (which could be quite different)". This might sound counter-intuitive, but I have read a lot of listening reports which say that it works! I am listening to some very good dipole speakers soon (Linkwitz Orion) so I will report on what I hear. Opaqueice, can you chip in since you've already heard them? The DRC approach is a contrast to this. However I think DRC in the bass is OK ;-) Darren -- darrenyeats SB3 / Inguz -> Sony DAS-703ES DAC -> Krell KAV-300i -> PMC AB-1 Dell laptop -> JVC UX-C30 mini system (old, cheap, loved) ------------------------------------------------------------------------ darrenyeats's Profile: http://forums.slimdevices.com/member.php?userid=10799 View this thread: http://forums.slimdevices.com/showthread.php?t=35615 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
