Shure SE30 Gated Compressor/Mixer

A broadcast remote box that solved the "pumping problem" by remembering where the gain was supposed to be.

Overview

The SE30 is one of those pieces of broadcast gear that never got famous because it did its job too well to complain about. Shure built it as a Gated Compressor/Mixer — a three-input mixer with a built-in compressor, a 600-ohm line output, and a battery-backed standby supply, all packed into one portable package aimed squarely at field remotes. The pitch, repeated across Shure's own advertising in the pages of DB (August 1974, p.11) and elsewhere, was "hands-free gain riding": the engineer sets a level, and the box holds it while the announcer talks, then holds it again during the pauses.

That last part is the whole trick. Conventional compressors release during silence, so the gain creeps back up — and when the announcer starts talking again over a crowd, the compressor has to clamp down hard, producing the audible "pumping" that anyone who has ridden a remote knows too well. Shure's fix was the Gated Memory circuit: it holds the compression level constant through program pauses and only releases when the signal returns. Shure's advertising claimed this eliminated crowd-noise build-up between words and sentences, and in practice that's exactly the kind of problem the circuit was designed around. For news, sports, and special-events remotes, the SE30 compressed in the field so the signal-to-noise ratio going down the phone line stayed optimized — no manual gain riding required.

The physical package was built for the truck, not the rack. Shure's own copy describes it as "functionally engineered" with a self-contained standby battery power supply, a built-in tone oscillator, and a VU/dB compression meter — the tone oscillator being the practical detail that lets an engineer send a reference level down a line before the feed starts. The three-input mixer section means a couple of mics and a line source can be blended without dragging a separate console along, and the 600-ohm line output is the standard broadcast interface for a phone line or a house feed.

Pricing puts it in context. Either way, it was never a consumer toy; it was a working tool bought by stations and remote crews.

The SE30 turns up in period broadcast literature in exactly that role. In one account of a multi-site remote setup, a Shure SE30 was held at the studios as the reserve mixer — the unit you reach for when something in the field fails. That's a telling detail: it was the spare, not the star, but the spare you kept close because you trusted it. It also appears in Shure's own modular-component advertising alongside the M67 and M68 mixers, the M610 Feedback Controller, the M63 Audio Master, and the M675 Broadcast Production Master, positioned as the compression piece in a system of small boxes meant to replace a big console.

Collectors should note that documentation is thin and the SE30 is not a commonly traded piece — it's a broadcast utility box, not a hi-fi icon, and it tends to surface through professional-gear channels rather than the audiophile market. The battery-backed standby supply is the thing to check on any survivor: batteries left in a stored unit are the usual source of corrosion, and the tone oscillator and meter are the functions worth verifying before trusting it on a live feed. Values are not well established in the available record; buyers should treat pricing as a matter of what a working broadcast spare is worth to them.