Convolution reverb

It’s weird. All these years of writing music with technology and I’d never heard of convolution reverb or impulse responses until last weekend. I’m sure I’ve used it at one time or another without knowing, but never really knew what it was or how it worked. I was looking for a way to record my amp using the line out and not have it sound like complete crap when I came across some forums about cab impulses.

A couple freeware suggestions for trying this out:

Voxengo Boogex: this is intended as an amp sim, so it also has other features like drive and dynamics, but the speaker sim uses impulse responses. It comes with some default impulses, but it also allows you to load your own. If you turn of all the “preamp” stuff you could use it for reverbs too, although it’s mono.


Freeverb Impulser: the UI is not much to look at but it allows you to chain multiple impulses together, each with independent levels, filters, etc. This would be useful if you were trying to simulate a complex reverb scenario like say, a fly in a jar sitting on a windowsill beside a forest…


Speaking of which, I came across some impulse responses for small spaces like jars (“Claustrofobia”) . Check out these Impulse Responses by Fokke van Saane. I’m not sure what one would do with these exactly, but they sound pretty cool.

The more useful impulses I came across were the more typical ones – natural spaces, guitar cabs and the like. These are some of the nicer ones I found but there are tons more out there.

Update: in action

Here’s an A/B comparison of a direct recording with and without a cab impulse.

The signal chain is as follows:

  1. Fender Strat
  2. EH Memory Man (short delay with mod and low cut)
  3. Fender Vibro Champ XD (Blackface voice, mild reverb)
  4. DI box
  5. Mackie 1202 VLZ mixer
  6. Delta Audiophile 2496

Note: my DI has a speaker level switch so I was using the amp’s speaker out and not the line out.

The second sample was run through Voxengo Boogex with the “Fender SuperChamp AT4050” impulse from Beamsonic. Both samples were run through the Ultrafunk Sonitus compressor.