All pass filters?

[John Speth]

As I undertstand, in an all-pass filter, essentially no frequency bands are
attenuated nor boosted but rather frequency band phase is changed.  A phase
shifter is a perfect example and to make it interesting, the phase shifts
are usually cyclic to give the sound some motion.

John Speth
Object Engineering, Inc
mailto:johns at oei.com


> -----Original Message-----
> From: owner-synth-diy at mailhost.bpa.nl
> [mailto:owner-synth-diy at mailhost.bpa.nl]On Behalf Of BuDWeiSeR
> Sent: Thursday, September 03, 1998 5:01 PM
> To: Synth DIY
> Subject: All pass filters?
>
>
> This is something i just don't understand. I'm studying computer systems
> engineering 2nd year, and i'm doing a lot of analogue electronics
> subjects including filter design etc, but what the hell is an all pass
> filter used for? If it passes everything then its not really
> filtering is it?
>
>
> <bUd>
>
>