Subwoofers — Revel B10

The B10 is a powered 10 inch subwoofer from Revel, a brand active since 1996 within Harman International. It belongs to the Concerta2 series and was designed to complement the other Concerta2 loudspeakers in stereo music or home theatre systems. Its development drew on Harman engineering resources that include a multichannel listening lab for double-blind tests, laser interferometry for driver and cabinet analysis, several large anechoic chambers and finite-element modelling.

Key specs that matter

A built-in Class D amplifier rated at 800 W RMS drives the single woofer. Maximum output is specified from 20 Hz to 150 Hz at no more than 0.1% THD. Anechoic low-frequency extension reaches 35 Hz at -3 dB, 32 Hz at -6 dB and 29 Hz at -10 dB, and response within the pass-band holds to plus or minus 0.5 dB. A 24 dB per octave low-pass crossover is adjustable without steps over 50 Hz to 150 Hz. The enclosure measures 41.8 cm high including feet, 37.7 cm wide and 39.2 cm deep with the grille fitted. Mains operation covers 100-120 V or 220-240 V at 50/60 Hz, and standby draw is 0.5 W.

Engineering and use context

The woofer uses a coated fibre-composite cone in a cast frame. Its spider is made from a Corex and cotton blend with geometry chosen for linearity, and a large ceramic magnet drives a copper voice coil wound on a Kapton bobbin. A vented centre pole helps shed heat so the coil resists compression at high power. The cabinet is built from MDF with extensive internal bracing and vents through a rear-firing port based on Revel's Constant Pressure Gradient design. Rubber padded feet on the base keep it stable on hard or carpeted floors. A three-state LED shows green when active and red in standby, which the unit enters after 10 minutes without signal and leaves as soon as signal returns. A 0 or 180 degree phase switch sits on the rear panel, and paint finishes are offered in black or white, both high-gloss.

Pairing

Connection is through left and right RCA line inputs. With a stereo preamplifier or integrated amplifier, both main outputs feed the B10 and its own low-pass filter trims the upper bass. Revel suggests settings up to 100 Hz with larger main speakers and higher settings with small bookshelf models. When an AV receiver or processor supplies the subwoofer signal, the level control goes to its LFE position, which bypasses the internal crossover and leaves filtering to the processor.

Alternatives

The Revel B140 is a later 10 inch subwoofer from the Performa4 line, with a 750 W RMS amplifier and extension down to 26 Hz.