Peavey M-400
A monitor system built around a 400-watt stereo amp and twenty-seven bands of EQ. Peavey advertised it hard.
Overview
The M-400 is a complete portable monitor package, not a single box. The heart of the system paired the new EQ-27 graphic equalizer with the field-proven CS-400 stereo power amp. Peavey billed the pair as producing 400 watts RMS across twenty-seven bands of equalization. That was the pitch: enough sound pressure on stage to get vocals above a loud band while virtually eliminating feedback.
Peavey added the pieces that made the M-400 a system rather than a rack of parts. DDT compression was included to maximize apparent headroom (that's Peavey's phrasing), along with transformer-balanced inputs, an electronic crossover, and bi-amp capability. In the company's own words the result was "a highly versatile package with more than enough punch to get your vocals above even the loudest stage situations." That is marketing copy, not an independent verdict. It does lay out the feature set clearly.
To deliver the punch, Peavey designed a new series of enclosures with bi-amp capability, built around its Black Widow speaker and the 22A high-frequency driver/horn combination. The 1245 and 2445 monitor enclosures were made for onstage monitoring. Peavey claimed tremendous clarity, projection, and wide frequency response from them. Kick-proof grills and flight-case-type covers came with the package to protect the units from damage and road abuse.
The M-400 turns up repeatedly in Sound Arts through 1980, where Peavey ran the "Perfect Harmony" advertisement describing the system's transducer technology working in conjunction with the CS Series power amp program. Sound Arts (August 1980, p.15) carried the same description of the package - the EQ-27 and CS-400 core, the 400 watts RMS and twenty-seven bands, and the DDT compression, transformer-balanced inputs, electronic crossover, and bi-amp capability - that appeared in the May, June, July, September, and October 1980 issues.
The surviving documentation does not settle the production span, the original price, or detailed measured specs beyond the headline 400 watts RMS and twenty-seven EQ bands. Those figures come from Peavey's own advertising, and no period review in the available record puts the M-400 through measured tests. Treat the wattage and band count as manufacturer claims. Check the condition of the CS-400 amp and the EQ-27 before buying, since the system's value is in that pairing.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.