Phil Leigh;348711 Wrote: > ah...oh... (sound of penny dropping) so it must be a pretty good > approximation given what comes out of the DAC!
The math is not so hard to understand. What it says is that -any- signal can be decomposed into a sum of sin waves. In principle, if you had enough pure-tone signal generators, you could start them off (only being careful they all have the right phase) and they would play a perfect rendition of Beethoven's 5th for you. So anyway, a square wave can be represented by a sum of sin waves - but the trick is you need an infinite sum of them going up to infinite frequency. If you only have a finite number available, you end up rounding off the edges and/or introducing Gibbs overshoot. When you digitize something you band-limit it to frequencies below Nyquist (otherwise you get lots of nasty aliasing artifacts). So that means you only have a finite range of tones available, and therefore you get plots like that. A 1kHz square wave can be represented reasonably well. Here's a picture: +-------------------------------------------------------------------+ |Filename: square.jpg | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=6009| +-------------------------------------------------------------------+ -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=53345 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
