Subwoofers — Psb Alpha S10

The Alpha S10 is the 10 inch powered subwoofer of the Alpha series from the Canadian brand PSB Speakers, created to accompany the Alpha loudspeaker line that the company had just renewed. PSB introduced it at the Rocky Mountain Audio Fest, held on 5 to 8 September 2019, began deliveries in October 2019 and put out a shipping announcement on 11 March 2020. The US launch MSRP was USD 549. Company founder Paul Barton was responsible for the overall design and the final voicing, and those listening sessions were held, as for every PSB speaker, in the facilities of the National Research Council of Canada.

Key specs that matter

A custom long-throw woofer of 10 inches (254 mm) uses a polypropylene cone held by a rubber surround. Its digital amplifier carries ratings of 150 W continuous and 210 W dynamic. PSB specifies an on-axis response of 28 to 150 Hz within plus or minus 3 dB, with output falling to -10 dB at 22 Hz. The vented cabinet has 41 litres of internal volume. External dimensions are 356 mm wide, 359 mm high and 445 mm deep. The cabinet is finished in a black woodgrain veneer.

Engineering and use context

PSB's stated aim for the series was bass that blends with the main speakers rather than calling attention to the subwoofer, which is why the company put its effort into the crossover filter design and tuning. Digital signal processing is used to flatten the frequency response and stretch low-frequency extension from a relatively compact box, and PSB specified the high-efficiency amplifier so that deep bass peaks are reproduced without constraint. The rear-facing reflex opening takes the form of a slot, shaped to avoid audible port noise and chuffing when the driver works hard. On the back panel sit the volume and crossover controls, a phase switch, an LFE setting, gold-plated RCA line inputs and a switch choosing between Auto On and Standby. There is also a USB power jack intended for PSB's RT100 wireless accessory. Rubber bumpers and spikes are packed with the subwoofer to suit hard floors and carpet.

Pairing

The low-pass crossover is variable and follows a B2 alignment, and the LFE setting leaves filtering to an AV receiver or processor when the S10 is fed from a dedicated subwoofer output. PSB positions it for both music and film systems and says it will work with any quality loudspeakers, not only its own. Connection is by line-level RCA only, so a source or amplifier needs a subwoofer or preamp output to drive it.

Alternatives

The PSB Alpha S8 is the smaller model of the pair, built around an 8 inch woofer and launched at USD 449.