The Symetrix Model 544 is a professional, quad-channel dynamics processor that combines the functions of a noise gate and an expander in a single 1U rack-mount unit. It provides four independent channels of processing, each capable of operating as either a downward expander or a full noise gate, making it a versatile tool for cleaning up audio signals in live sound, broadcast, and studio recording applications. As an expander, it reduces the gain of signals that fall below a user-set threshold, gently lowering the noise floor between vocal phrases or musical notes. In gate mode, it acts more aggressively, muting the signal entirely when below the threshold, which is ideal for shutting off microphones on unused drum kits or eliminating bleed and hum from inactive channels during a mix.

Engineered with the precision and reliability expected from Symetrix, the Model 544 features comprehensive controls for each channel, including threshold, range, attack, release, and hold. These parameters allow the user to tailor the response of the gate/expander to the dynamic characteristics of the source material, ensuring musical and transparent operation. A unique "key listen" function allows the engineer to solo the sidechain signal for precise threshold setting. The unit utilizes high-quality, low-noise VCAs (Voltage-Controlled Amplifiers) for smooth gain reduction. Its balanced inputs and outputs, via XLR and 1/4" TRS connectors, ensure compatibility with professional audio systems, while its robust steel chassis is built for the rigors of touring and installed use.

The value of the Symetrix 544 lies in its ability to deliver clean, controlled audio by effectively managing noise and unwanted signals across multiple channels. It is a staple in front-of-house racks for managing drum microphones, in broadcast consoles for cleaning up commentator mics, and in recording studios for tightening up recordings during mixdown. By offering four channels of high-quality, adjustable gating/expanding in a compact package, it provides an efficient solution for a common audio challenge, helping engineers achieve a polished, professional mix with greater clarity and less clutter.