[LAD] Is there an LV2 plugin that can add echo like echo added by large cathedrals?

[Gordonjcp]

On Tue, Apr 06, 2021 at 01:00:53PM -0700, Yuri wrote:
> I remember listening to the talk of researchers who were traveling to
> different old cathedrals, particularly to Hagia Sophia in Turkey, and
> measuring echo in these cathedrals. Such buildings add a lot of deep and
> very prolonged echo which depends on the building's shape and materials.
> They were quantifying the noise response too.
> 
> 
> Are there LV2 plugins that can add same or similar echo as cathedrals add?
> 

It sounds like what you're looking for is a "convolution reverb", if you want to get the exact sound of a space, or just any reverb plugin if you're not too fussed.

Normal digital reverbs use combinations of different sized delays to provide a dense "wash" of sound.  By twatting about with the phase through allpass filters and having combinations of very long and very short delays that don't sync up - at least one has to be modulated to stop it sounding "pingy", you can get a very realistic reverb effect.

Convolution reverbs effectively multiply each individual sample of the incoming audio with every individual sample of an "impulse" which is a recording of a loud bang in a reverberant space.  So, for each input sample you've got an output a few seconds long.  One single pulse - just a one-sample click - would play out the impulse, and a sustained sound would sound like it was being played in that space.  There are tricks to make it less insanely computationally expensive, but that's basically the size of it.

Now even if you don't have exactly the answer, you've got the right words to put into Google :-)

-- 
Gordonjcp