DO NOT confuse Lou Franklins DSP with the MUCH better SP-1A! CB City's processor is more or less a clipper circuit with user-defined filtering on the output. The idea is ok IF selective real-time filtering was practically possible, but that takes digital processing to accomplish, and is way out of the league of the average CB-er, or even ham operator for that matter. The SP-1A on the other hand is basically a glorified mic preamp and compressor/limiter, just like you find in any modern (last 30 years or so) CB radio from the factory. Its not EXACTLY like those built-in circuits, but it does the same exact job. It just does it MUCH, MUCH better.