Koss CM 1020 (late 1970s)
Almost everything documented about the CM 1020 comes from Koss's own advertising. No independent reviews turned up. The campaign was built around Koss's computerized "Theory of loudspeaker design," and it ran in several US audio magazines between March 1978 and May 1979. The ads call the CM 1020 a three-bandpass loudspeaker developed by computer modeling instead of trial and error. They claim a 3 dB gain in electrical efficiency, a 3 dB down point of 31 Hz, and maximally flat response across the low bandpass. A "performance synthesizer" was said to handle presence and musical energy from 300 Hz to 3.5 kHz.
High-Fidelity (March 1978, p.48) and HiFi/Stereo Review (May 1979, p.146) both carried the same Koss advertisement. So did the buying guide HI-Fi-Stereo-Buyers (March 1978, p.29). Past those pages, the Archive holds no independent measurements, no editorial review, no original price, and no production details for the CM 1020. If you have a pair, a manual, or a review we've missed, the Archive would like to hear about it.
- Type: three-bandpass loudspeaker
- Design: computerized ("Koss Theory of loudspeaker design")
- Advertised: 3 dB gain in electrical efficiency; 3 dB down point of 31 Hz
- Advertised: performance synthesizer covering 300 Hz to 3.5 kHz
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