Subwoofers — Wharfedale SW-150

The SW-150 is a compact powered subwoofer from Wharfedale, the British speaker company, and is also sold under the name Diamond SW150 as the bass partner for the brand's Diamond loudspeakers. Wharfedale places it in its SW series, which it presents for both hi-fi and home cinema use, and it sits at the entry point of the company's subwoofer offer. The cabinet is a squat box of 330 mm high, 330 mm wide and 370 mm deep.

Key specs that matter

Amplifier power is 150 W RMS, and it drives a single 250 mm woofer. The quoted frequency range runs from 35 Hz to 110 Hz, and Wharfedale gives a maximum level of 107 dB measured at 1 m. Low-pass filtering is adjustable from 35 Hz to 85 Hz in 10 Hz steps with a slope of 12 dB per octave. Input impedance is 10 kohm, and the phase switch offers 0 or 180 degrees. Three cabinet finishes are listed - black, cherry and walnut.

Engineering and use context

The cone uses a tri-laminate construction, and the motor has an elongated voice coil that allows up to 24 mm of maximum excursion, which gives the 10-inch driver a longer stroke to move air at low frequencies from a small enclosure. Wharfedale builds the filter section from six discrete circuits rather than a single stepped control, and the unit can also run with the internal filter bypassed. That bypass matters when an AV receiver already applies its own crossover to the subwoofer feed, since two low-pass filters in series would roll off the top of the band too early. The enclosure is reflex ported, which lets a compact box reach lower than a sealed design of the same volume would allow. Because the crossover moves in fixed steps rather than on a continuous dial, settings are easy to note and repeat after moving the unit. The company backs the SW-150 with a 3-year standard warranty.

Pairing

Both line-level and high-level connections are provided. Line inputs suit a stereo preamplifier, an integrated amplifier with a sub or pre output, or the LFE output of a surround receiver. The high-level input lets the sub take its signal from the speaker terminals of an amplifier that has no preamp output, so the main speakers stay connected to the amplifier as before. The crossover span fits small bookshelf speakers whose own bass rolls off somewhere in that region, such as compact models from the Diamond range.

Alternatives

The Wharfedale WH-D8 is a smaller alternative built around an 8-inch long-throw driver in a vented box.