Well, I haven't got my digital room correction going yet, but will report on it once I do. In the meantime, I've realized that there is a bit of a problem with the whole concept, at least in the lower registers. Actually this is pretty basic physics, but I hadn't appreciated quite how much it matters.
If I play a low pure tone, say at 60 Hz or so, I generate a standing wave in the room. That means if I walk around the volume of the sound varies enormously depending on where I go. The variation is enhanced if the frequency is a multiple of one of the resonant frequencies in the room (340.3 divided by the length or height or width of the room, in meters), but it's always there. There are spots where the tone is totally inaudible, and others where it's very loud. Typically the volume is loudest closest to walls and floor and ceiling, which surprised me at first but makes sense after some thought. The location(s) of the speaker(s) really don't matter much - they're just providing the juice to keep the standing wave going. So the upshot is, the room correction filter you generate - and its effect - will depend tremendously on where you put the mic when you record the reponse. Of course if you always listen to music from that one spot, no problem, but how many people really do that? Certainly I don't. Now, I'm not saying forget the whole thing - on the contrary, you can still fix the response at one location at least, you can damp out speaker crossover or system response badness, and in the upper registers the distance between your ears probably averages out any node/antinode effects (although I wonder about the mic) and this isn't an issue. In any case, it's a pretty fun physics experiment to try... and incidentally along the way I recorded a sharp pulse and measured the speed of sound to about 2%, which was satisfying :-). -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=25436 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
