Subwoofers — Audio Pro SW-10

The SW-10 is a powered subwoofer from Audio Pro of Sweden, intended to add low bass to the brand's active and wireless speakers, though its analogue input means it can also be used with other makes. The model sits above the smaller SW-5 in the company's subwoofer range, was listed at EUR 450, and comes in black or white. Accessories in the box are a power cable, a subwoofer cable and a manual.

Key specs that matter

A 200 W Class D amplifier under DSP control drives an 8 inch long throw woofer. Two passive radiators, listed by Audio Pro at 8 inches, work alongside it instead of a reflex port. The quoted frequency range is 33 Hz to 120 Hz, while the adjustable crossover can be set anywhere from 40 Hz to 120 Hz. Phase can be switched between 0 and 180 degrees. The cabinet measures 280 x 280 x 295 mm and weighs 9.65 kg. Connection is by an RCA subwoofer input only, and the unit has no WiFi, Bluetooth, Ethernet or digital inputs.

Engineering and use context

Each passive radiator lacks a magnet and voice coil, and its diaphragm is moved by the changing air pressure inside the closed box, so they extend bass output in a way similar to a port but without port noise or the need for a long tube in a small cabinet. Using two of them around a single active woofer lets Audio Pro keep the enclosure close to a cube of under 30 cm per side. DSP control of the amplifier lets the maker limit excursion and shape the response electronically. There are no bass or treble controls, virtual surround or night mode on the unit itself, so level, crossover and phase are the only adjustments. Audio Pro gives a standby consumption of less than 0.5 W and an operating figure of 7.4 W, and the subwoofer does not have a battery.

Pairing

The natural partners are Audio Pro speakers with a subwoofer output, such as the A38 W or A48 floorstanding pairs, where the sub connects by one RCA cable. It can also be driven from the sub or preamp output of a stereo amplifier, AV receiver or other active speakers, with the crossover chosen to match the point at which the main speakers lose output. Flipping phase by 180 degrees can be useful if the cabinet stands nearer or further from the seat than the two main cabinets. Its compact cabinet suits living rooms of about 20 m2 in which a bulkier enclosure may not fit beside the furniture.

Alternatives

The Audio Pro SW-5 is the more compact and lower priced subwoofer in the lineup, with an 8 inch long throw driver, a 150 W Class D amplifier and a 35 Hz to 130 Hz range.