Bookshelf Speakers — Evolution Acoustics MicroOne

The MicroOne is a two-way Evolution Acoustics monitor for stand mounting, from a company that designs, engineers, hand-builds and assembles its speakers in San Diego, California. It was also sold as the MMMicroOne and belongs to the Micro series, which the maker now lists among its discontinued legacy lines next to the Mini and MM ranges. Evolution Acoustics states that the MicroOne is made entirely from custom tooled parts, with no off-the-shelf components anywhere in the build.

Key specs that matter

A 2 inch Pleated Diaphragm Air Velocity (PDAV) tweeter handles the treble, and a 4 inch Ceramic Matrix mid-woofer (CMAT) covers the rest of the band. The quoted response is 35 Hz to 30 kHz within plus or minus 3 dB and 30 Hz to 35 kHz at the 6 dB points, both measured in-room rather than anechoic. Sensitivity is 87 dB and nominal impedance is 6 ohm with a deviation of plus or minus 2 ohm. The maker lists a minimum amplifier power of 10 W RMS and maximum power handling of 250 W RMS. Each cabinet measures about 457 mm high, 178 mm wide and 305 mm deep and weighs about 13.6 kg.

Engineering and use context

Signal division is handled by a 2-way constant voltage design with time and phase alignment between the two drivers. Its parts list includes reference grade film foil capacitors, oversized high purity copper air core inductors and ultra high current wire wound precision resistors. The enclosure uses glue laminated, double braced curved side walls 25 mm thick, while the baffle and the plates closing the top and bottom of the box each measure 50 mm. Every cabinet is hand-finished in several polished layers to a high gloss surface. Connection is through 5-way precision machined binding posts, and the drive units are the proprietary PDAV and CMAT types developed in-house.

Pairing

The low minimum power figure and a nominal load that varies little let the MicroOne run from low-powered amplifiers, while the high power handling leaves room for considerably larger designs. A single pair of binding posts per cabinet means one amplifier channel per speaker.

Alternatives

The Evolution Acoustics MODEL ONE is the brand's current stand-mount monitor, pairing a soft-pleat AMT tweeter with a 5.5 inch ceramic matrix mid-woofer.