Talkin' 'bout a Convolution

Although the technology has existed for quite some time, it is only relatively recently that the average studio computer has had the processing power to take full advantage of Convolution Reverbs in real time. If you're unfamiliar with the concept, you can think of a convolution reverb as a 'reverb sampler'. Ever been in a cathedral and wished you could apply the magnificent reverb it had onto your home recordings? Convolution allows you to do just that. There are a couple different methods of doing this, but the most common one is to make a recording of a very short, sharp sound (think starter pistol) in the environment in question. This is known as an 'Impulse Response'. That sound is loaded into your convolution reverb of choice, and the software uses the recording to apply the characteristics of the reverb to whatever sound you apply it to. It's an extremely powerful technique that has put otherwise impossible to get reverbs at the fingertips of computer musicians everywhere. But you can also use it for some unusual special effects that might not necessarily fall under the traditional definition of a reverb. Because this technique uses a sound recording to create its effect, one not need restrict themselves to the short, sharp sounds traditionally used for impulse responses. Have a go at loading in a bit of speech, a drum loop, or anything with a rhythmic quality to it, and you get effects somewhere between reverb and creative gating. Different convolution reverbs have different restrictions, but in Logic this is quite easy to achieve in the included Space Designer plug-in. Simply apply the reverb to the track in question, click on the IR Sample menu (on the left) and select 'load IR sample'. Select your audio, and you're off! It may take some experimentation to get the ideal results, but that's part of the fun. Below is quick example where I loaded a drum loop as the IR sample and applied it to a piano.