Re: [LAD] stereospread.lv2 - Stereo spreading plugin (conjugate random phase all-pass filter pair)
Fons Adriaensen <[email protected]>
| Newsgroups | gmane.linux.audio.devel |
|---|---|
| Message-ID | <[email protected]> |
On Wed, Nov 16, 2022 at 12:51:44PM +0100, Florian Paul Schmidt wrote: > This ensures that what is a phase theta in the first filter becomes a > phase of -theta in the second filter, and summed that just gives a phase > of 0. 1. If I understand this correctly the L and R outputs have opposite phase shifts. That means they will not sum to the input. Just assume the L shift is 90 degrees. then R is -90, and they will just cancel. 2. If you measure this, you will also note amplitude differences between L and R outputs. This is to be expected. Even if the two filters have exact unity gain (and just a phase shift) at each frequency corresponding to an FFT bin, the resulting filter will not be all-pass. 3. At high frequencies (above 1 kHz or so), it's actually the amplitude differences and not the phase shifts that create the stereo effect. Ciao, -- FA _______________________________________________ Linux-audio-dev mailing list [email protected] https://lists.linuxaudio.org/listinfo/linux-audio-dev