Aphex Systems LTD Original Compellor 1988

A Compellor is the first and only product designed specifically for the transparent control of audio levels. While other audio processors are designed simply to compress and limit audio signals, a Compellor is designed to intelligently manage the dynamic range of audio without causing noticeable changes to the character and feeling of the sound. Contained within the Compellor are three gain controllers: a frequency discriminate leveler, a compressor, and a limiter, all working interactively. In addition, a dynamic verification gate, silence gate, and dynamic release computer intelligently guide the operation of the gain controllers to assure the least noticeable processing effects will be generated.

The name “Compellor” is a combination of “Compressor-Leveler-Limiter”.

Simply stated, a Compellor automatically evens out the varying levels in an audio system without making itself noticed. It may seem odd to have a processor you wouldn’t notice work- ing, but imagine being able to keep a wandering vocal track just right in the mix as if the talent were using perfect voice techniques. Imagine a TV show that always sounded just the right level even though scene changes were wide ranging. Now imagine these things without any background swells, pinched voices, or holes punched by a transient hitting the limiter. If you can, then you realize just a few things the Compellor can accomplish.

Without a Compellor, it is usual to insert a compressor or limiter in the line to control varying levels. That always results in degraded sound due to the processing by-products. Lost punch, overly fat backgrounds, inversion (when a loud sound gets lower than average), suck-down by transients, and noise swell ups are typical problems encountered with usual processing. The Compellor was designed specifically to avoid all of these problems and more.