Re: OT Create your own Impulse models for freeware Convolution Reverbs

[andy butler <akbutler@tiscali.co.uk>]

Rainer Straschill wrote:

> A very good application is to model a specific good-sounding room at 
> sensible SPL levels, simply by recording the impulse response of that 
> room [4]. But what can be done for actual rooms can also be done for 
> things which model rooms - e.g. you could simply take your treasured 
> Lexicon 480 effector, load a patch and record its impulse response (and 
> this is actually done; 

The Lexicon algorithms aren't representable by their impulse.
>From an article by "the Lexicon guy" (which I don't have to hand)
it's explained thus:
When you record a choir in an acoustic space, each voice is
a distinct sound source, emanating from a specific place.
So the reverberant sound is equivalent to each voice being treated
by a slightly different impulse. This is why the overall sound
avoids obvious comb filtering. If take the sound
of the whole choir, and put it through a single impulse, then
the comb filtering returns, it doesn't sound like the choir
singing in the samples acoustic space.
So, Lexicon algorithms have a method to randomise the phase
of the reflections which compensates for that.

So...convolution based reverbs can give convincing results 
on a small solo instrument or voice.
Use them on a mix, or on a drum kit, and the result 
won't match the popular expectation.

If you had a set of impulses corresponding to the location
of the individual elements of the kit then you could run
the close mic'ed signals through their respective convolution
....that could work.

andy