From: Ross Vandegrift (ross_at_willow.seitz.com)
Date: 11/25/03 11:16 EST
From: Ross Vandegrift <ross@willow.seitz.com> Subject: Re: [Ardour-users] Re: good quality reverb - brutefir! Message-ID: <20031125161656.GA22372@willow.seitz.com> Date: Tue, 25 Nov 2003 11:16:56 -0500 On Tue, Nov 25, 2003 at 03:03:45PM +0000, Carl Hetherington wrote: > Now of course having a church in your cellar presents certain practical > issues. Yes indeed ::-) > 1. Use something that is "good enough" --- e.g. a gun shot (probably > best not to use this in a church) or a high-quality loudspeaker. I was thinking about this earlier today - I'm a drummer so I've got lots of things that could be used to produce such sharp, noisy signals. Seems like that'd be a fun thing to play with. > 2. Swept sines --- you can make a good stab at measuring the impulse > response by measuring the response of the room to a varying sine wave and > doing some jiggery-pokery. Do you really need the jiggery-pokery? The nice thing about the delta function is that it captures *all* the frequencies and the IRs will capture the rooms response to all of them. But of course we can't actually generate a delta function. So it occurs to me sweeping from 0Hz to 24kHz will capture the response of all the frequencies people will be able to hear. So, if we apply the reverb filter to audio, and we miss frequencies that are inaudible, who really cares? > 3. Pseudo-random binary sequences / Golay codes --- a bit complicated to > go into here but essentially you use a pre-defined but noise-like signal > and do some maths. Hmmm, not an application of coding theory I'd have guessed... What does this approach win us? It seems to me that the sine-sweep is really where it's at for audio. Using Golay codes seems like a lot of work. > One commercial gadget that uses these principles is the Yamaha SREV > http://www.soundcorp.com.au/html/yamaha_srev.htm > I'm sure there are others. I seem to recall a discussion on lau recently about sine-wave sweep generation. I'll dig into the archives and try to find some free software to do things like this. -- Ross Vandegrift ross@willow.seitz.com A Pope has a Water Cannon. It is a Water Cannon. He fires Holy-Water from it. It is a Holy-Water Cannon. He Blesses it. It is a Holy Holy-Water Cannon. He Blesses the Hell out of it. It is a Wholly Holy Holy-Water Cannon. He has it pierced. It is a Holey Wholly Holy Holy-Water Cannon. He makes it official. It is a Canon Holey Wholly Holy Holy-Water Cannon. Batman and Robin arrive. He shoots them. ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/ _______________________________________________ Ardour-users mailing list Ardour-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ardour-users
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