Полочная акустика — PMC MB2-A SE (Active)

The MB2-A SE is the active edition of the middle model of the PMC SE series, made by the British loudspeaker company formally called The Professional Monitor Company. PMC presents the MB2 as keeping the character of the smaller IB2 while resolving more bass detail. The active package combines the speaker with PMC's own analogue amplification and active crossovers, matched to the power needs of each driver.

Key specs that matter

Drive units are a PMC 310 mm (12 inch) Radial bass unit, a PMC75 75 mm soft dome midrange and a 34 mm tweeter designed for the active SE models. The crossover splits the signal at 380 Hz and 3.8 kHz, and the frequency range runs from 20 Hz to 25 kHz. Sensitivity is 89 dB at 1 W and 1 m. Amplifier power per channel is 325 W for the bass unit and 150 W each for the midrange and the tweeter. Effective ATL (Advanced Transmission Line) length is 3 m. Inputs are balanced XLR plus a Neutrik NL8 connector. Each speaker measures 870 mm in height, 380 mm in width and 535 mm in depth and weighs 58 kg, while the dedicated stand weighs 17 kg. Veneers are Grand Walnut, Amarone, Natural Oak and Jet Black.

Engineering and use context

The Radial bass driver is built around a large exo-skeleton frame that gives it physical and thermal stability. Its cone is rigid enough to allow very long excursions, and exposed fins on the unit act as a heat sink that keeps the voice coil cool during long high-level sessions. Loading this driver with a transmission line lets the rear wave of the cone travel through a damped internal path and reinforce the bottom octave at the front vent, which is how a stand-mounted cabinet reaches the bottom octave. PMC says its active electronics are hand-built to purist analogue principles and wired directly to the drive units, removing the passive crossover between amplifier and driver. The tweeter was engineered for the power demands of the active range and uses an acoustic lens whose development took 18 months. A 20-year warranty applies after registration within 10 days of purchase.

Pairing

With amplification included, the MB2-A SE requires just an upstream component that controls volume, for example a preamplifier or a streaming DAC with adjustable balanced outputs. The passive MB2 SE shares the drivers and cabinet but has three pairs of 4 mm terminals for tri-wiring or tri-amping, an 8 ohm nominal impedance and a 10 W to 500 W amplifier recommendation, and a dedicated MB2-C SE centre channel exists for home cinema systems.

Alternatives

The PMC BB5-A SE is the larger active SE model, with a 15 inch Radial bass unit driven by 900 W and a 4 m transmission line.