Subwoofers — Polk Audio Signature Elite ES12

The Signature Elite ES12 is the 12-inch subwoofer of the Polk Audio Signature Elite line, with a list price of USD 899. It combines a front-firing mineral-filled polypropylene woofer, a Class D amplifier with 32-bit floating-point DSP and two front ports, and it is intended as the bass unit for Signature Elite loudspeakers such as the ES55 and ES60, as well as for other home cinema systems.

Key specs that matter

The 12-inch high-excursion woofer has a mineral-filled polypropylene cone and fires forward. Amplification is 300 W in Class D, optimised by DSP with 32-bit floating-point processing. Frequency response is 22 Hz to 250 Hz at -3 dB and 18 Hz to 350 Hz at -10 dB. Its fourth-order low-pass filter can be set from 50 to 160 Hz, and Time-Smart Phase Control sets the phase from -135 to 180 degrees in 45 degree steps. Inputs are an LFE RCA socket and a stereo line-level input on two RCA sockets. Two Power Ports on the front vent the cabinet, which is braced according to FEA analysis. The black cabinet is 483 mm high, 362 mm wide and 483 mm deep, and it weighs 21.6 kg. A power-save mode and a detachable grille are included.

Engineering and use context

Mineral filling adds stiffness and damping to the polypropylene cone. The 32-bit floating-point DSP handles the filter and equalisation, and floating-point processing keeps precision across the wide range of signal levels a subwoofer handles. Finite element analysis, or FEA, is a computer method for modelling how the cabinet panels vibrate, and Polk used it to place the bracing. Placing both ports on the front means the bass output from the ports does not depend on space behind the cabinet. Phase in 45 degree steps, instead of a simple 0 or 180 degree switch, allows finer matching to the timing of the main speakers where their ranges overlap. The fourth-order low-pass filter rolls off at 24 dB per octave above the chosen frequency. Power-save mode reduces consumption when no signal is present.

Pairing

The LFE input connects to an AV receiver, and the stereo line input serves amplifiers with pre-outs. With Signature Elite towers, the crossover frequency can be placed near their lower limit. The large cabinet suits rooms of 20 m2 and more.

Alternatives

The Polk Audio Signature Elite ES10 is the smaller subwoofer of the series, with a 10-inch driver, priced at USD 699.