Subject: Re: [linux-audio-dev] Reverbs
From: Paul Winkler (slinkp23_AT_yahoo.com)
Date: Fri Sep 15 2000 - 04:25:36 EEST
Juhana Sadeharju wrote:
>
> >Hans Mikelson's reverb.orc (but NOT the gardverb.orc) from
> [ ... ]
> >http://media.dr.rhbnc.ac.uk/csound/list/msg03983.html
>
> I have not tested Gardner's reverbs myself but I'm surprised to hear
> if they sound bad. Well, I'll give a report when I have implemented them
> (small, mid, large versions in his thesis). I have got an impression
> that Gardner worked for Lexicon at the time...
Well, my impression is that with reverb, the details of
implementation can make a big difference, so maybe Mikelson
didn't get it quite right.
> >Freeverb is fast and sounds *very* nice. I wish somebody would
> >figure out how to hack freeverb into a csound opcode. I tried but
> >had to face the fact that I had no idea what I was doing. I'm amazed
> >that I got an opcode that actually runs - but it didn't sound
> >anything like the ladspa freeverb!
> >If anyone wants to give it a try, you can see my crude attempts at
> >http://www.slinkp.com/pw_linux/code.html
>
> The freeverb binary Ladspa release sounded ok, but when I reimplemented
> it and close-listened, it didn't sound that good. Or my implementation
> is not exactly the same
That's my guess. Or you have more discerning taste!
> (plus/minus 1 sample in delay line lengths?).
> If you can easily make an impulse response of the late reverberation
> only (no direct sound), please do put the response available at your page.
OK, it's up:
http://www.slinkp.com/pw_linux/impulse-test-freeverb.wav.gz
Also, I looked at my impulse source in snd to make sure it
was as you described. Yup, full scale at sample 0, zero at
sample 1.
> Impulse response is got by feeding an audiofile with one sample having
> value 1 and all others having value 0. You should use stereo impulse
> because Freeverb is stereo, and don't forget report the parameters
> so that I may duplicate the setup.
applyplugin -s 8 ~/Sounds/Test-signals/impulse2.wav
./impulse-test-freeverb.wav jlpl freeverb1 0.99 1 0 1
(that's roomsize = 0.99, damping=1, dry=0, wet=1.
analyseplugin will tell you the wrong order for wet &
dry...)
I trimmed a bit of silence off the end.
> I have also written Smith's waveguide reverb but it is patented.
> Because it is already released I guess it doesn't make harm if I too
> release one...
I think this is the waveguide reverb Sean Costello
implemented in csound. It sounds quite nice in that version.
> My reverb system has nothing to with Csound opcodes, by the way, but
> little birds have told me that you will soon have one very good reverb
> as a Csound opcode. Its implementation can be a realtime even its present
> implementation is not. The same algorithm is used in a few commercial
> plug-in reverbs.
Interesting. What's your algorithm like?
--
................. paul winkler ..................
slinkP arts: music, sound, illustration, design, etc.
web page: http://www.slinkp.com
A member of ARMS: http://www.reacharms.com
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