adamdea wrote: > I'm intrigued as to why the echo only appears with the sweep in the > example and not with the castanets or impulse. I wonder whether there's > more energy in the sweep as it does seem to glow brightly.
That is it! By definition an impulse being infinitesimally narrow but with the same maximum amplitude as any other kind of test signal, contains less energy. The castanets being a natural sound can pick up some duration over the impulse, but by their nature their energy content is limited. The sine sweep being a continuous tone has duration on its side. We've been through this same progression with speaker measurements. Back in the day we knew we wanted the frequency response whose theoretical synonym is Impulse Response, so we actually set up spark gaps and there was your impulse signal to test with. But the amplitude of the test signal is limited by the max SPL capabilities of the microphone. And people have to be in the room and ear plugs are a hassle so really loud noises are less practical. Then we tried pink noise and the like, which drove up the energy levels by being more of a continuous signal, but the average energy in noise is still less than it is with the sine wave. Today, most of the speaker measurement systems are based on a swept sine wave test signals. ------------------------------------------------------------------------ arnyk's Profile: http://forums.slimdevices.com/member.php?userid=64365 View this thread: http://forums.slimdevices.com/showthread.php?t=103537 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
