Stairwell @ Keystone - Vancouver BC

Impulse Response A/B Test

One of the greatest features of the convolution reverb is recreating the natural acoustics of a space and that’s what I’m going to prove in the following test. This can be achieved by simply downloading Impulse Responses (IR) online, or recording your own (IR)  by following the Altiverb manual, this will help you to set up your playback rig and understand the process.

Stairwell @ Keystone - Vancouver BC


In 2009, I decided to make an A/B test between the voice of (Foley mixer and editor) Craig George, recorded in a big stairwell and the same voice recorded in an ADR booth with the same mic and convoluted with the impulse response of the same stairwell and at the same position were the voice was initially recorded.




Our technical supervisor Peter Sartwell quickly set up a dolly cart with a mounted Tannoy speaker and a DVD player that allowed me to playback 30 sec of sweep tone. I placed the speaker exactly where Craig was located (top of the stairs), I adjusted the loundness of the DVD amplifier so that it matched Craig’s voice and then placed the mic two floors lower to get a significant reflection effect.


A/B Test 1 : Stairwell  /  ADR Booth

A/B Test 2 : Stairwell  /  ADR Booth processed thru the Altiverb Stairwell IR with no parameter changed, 100% Reverb Time, 100% size and 100% Mix, Mute direct ON).

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(TOP: Sweep tone, BOTTOM: Impulse Response)

Frequency domain comparison
Time domain comparison