Subwoofers — Polk Audio Monitor XT12

Polk Audio's Monitor XT12 is the larger powered model at the top of the Monitor XT subwoofer pair, a range the company traces back to the original Monitor loudspeakers of 1974. It was introduced as the bass unit for the current generation of that line, but Polk also presents it as a stand-alone subwoofer for other systems. The US list price is USD 399, while Polk's Signature Elite ES12 occupies a higher price level at USD 899.

Key specs that matter

Its driver is a 12 inch long-throw, high-excursion unit using a bi-laminate paper diaphragm on a foam surround, powered by a 100 W amplifier working in Class AB. The ported enclosure has a quoted response of 24 Hz to 160 Hz within 3 dB. A continuously variable low-pass filter covers 80 Hz to 160 Hz, with an LFE position for receivers that handle bass management themselves, and phase switches between 0 and 180 degrees. The cabinet is 407 mm wide, 418 mm high and 456 mm deep, weighs 17.7 kg and comes in black vinyl.

Engineering and use context

Polk describes the woofer, amplifier and cabinet as new designs developed for this generation, and the XT12 is the only model in the pair to use a Class AB output stage rather than Class D. The MDF enclosure is critically braced to lower resonance, and a removable grille shaped to fit the front baffle keeps the woofer protected when the cover is in place. The feet are fixed to the cabinet rather than supplied as optional spikes. The woofer carries Polk's Dynamic Balance designation. The rear panel provides volume, crossover and polarity controls. Warranty cover runs five years on the woofer and three years on the amplifier, both limited.

Pairing

Unlike the XT10, this model accepts speaker-level signals through left and right pairs of nickel-plated 5-way binding posts, in addition to stereo line-level RCA inputs and a single RCA LFE socket. That makes it usable with older stereo amplifiers and receivers that lack a subwoofer output, as well as with current AV receivers supporting Dolby Atmos and DTS:X. Polk matches its voicing to the other Monitor XT models, and Polk proposes a second XT12 for higher output and smoother low-frequency coverage.

Alternatives

The Polk Monitor XT10 is the compact subwoofer in the same series, using a 10 inch woofer, a 50 W Class D amplifier and a down-firing port in a 10.4 kg cabinet.