From martin wood Sent Tue, Aug 31st 1999, 15:59
>>the speaker moves in the most uncanny ways. sometimes >>breathing (>1hz), sometimes 'jelly-fishing' (1 hz saw wave), sometimes >>beating (1-3hz), sometimes even downright waggling (low frequency noise >>centered at 10hz) etc. EI> If the lowest frequency you can get out of a CD is 20 Hz, how did you EI> achieve the lower frequencies? EI> curious EI> ernie i dont know about this, but id have thought you could do it by using the beat frequency generated from 2 high(er) frequency tones interfering with each other...