[sdiy] [OT] plate reverb impulse responses?

[Seb Francis]

Hi Amos,

I'm sure that many people, including JH and I, would be very grateful if 
you were to make some IRs of a real plate!

Although it does work to record a reverbed click, a much better way is 
to feed a sine wave sweep through the reverb and the 'deconvolve' the 
result to make an impulse response.  When sampling real spaces it is 
arguably better to use a click or starter pistol because then you don't 
have to contend with the inadequacies of the speaker system playing back 
the sine sweep.  But for sampling hardware, the sine sweep method is the 
way to go - all professional IRs are made this way.

You need some software to deconvolve the result ..
http://www.voxengo.com/product/deconvolver/
The demo version of this will not work in batch mode and is limited to 3 
deconvolutions per session (then you have to restart the program), but 
this should be fine for sampling a plate reverb that doesn't have very 
many settings.  You can also use this software to create a suitable sine 
sweep file.

Regarding bitrate & sampling frequency: yes 24/96 recording is the way 
to go if your hardware supports it.  You can then create IRs up to 32bit 
with Voxengo Deconvolver, but probably 24bit is good enough.

I do hope you manage to do this :)
Seb

P.S. Here's a good place to post your impulses to make them available to 
the masses..
http://www.noisevault.com


Amos wrote:

> I have a good friend with an enormous old plate reverb that came out 
> of a Nashville recording studio... shall I try to get some impulse 
> responses for you?
>
> what would be the best impulse to feed it... starter pistol?  
> single-sample digital "pop?"  advice appreciated... I can record the 
> response as a 24bit/96kHz .wav, no problems.
>
> Cheers,
>
> Amos
>
> On 10/29/05, *Seb Francis* <seb at burnit.co.uk 
> <mailto:seb at burnit.co.uk>> wrote:
>
>     That's a shame.  I guess they could be converted to WAV (if only by
>     taking an impulse sample of the Altiverb itself), but this is
>     probably a
>     lot of work (and of questionable legality)
>
>     Let us hope that one day someone samples an EMT 140 and puts the IRs
>     into the public domain !
>
>     By the way, Jay, how do the Altiverb IRs of the EMT 140 sound?
>
>     Seb
>
>
>     Jay wrote:
>
>     > Seb Francis wrote:
>     >
>     >> I don't suppose someone on the list who
>     >> is a registered Altiverb use could let me and JH know their email
>     >> address so we can download these IRs? :)
>     >
>     >
>     > I have it, but I'm pretty sure that they're not WAV files. They're
>     > some kind of specially processed ones propriety to AltiVerb
>     (which is
>     > Mac only). I bought AltiVerb specifically for that EMT 140 response.
>     >
>     >
>
>