Subwoofers — Velodyne SPL-X 15

The SPL-X 15 is the 15 inch member of the SPL-X range from Velodyne Acoustics, a set of four closed-box active subwoofers sold in 10, 12, 15 and 18 inch sizes. The Hamburg-based subwoofer maker presents SPL-X as a relaunch of its SPL line aimed at home cinema, studio and living room use. Only the SPL-X 18 sits above it in size. British pricing is GBP 4,999, and the US price is USD 6,499.

Key specs that matter

The woofer gets 1500 W RMS and 2000 W peak from an internal Class D amplifier. Velodyne quotes a response of 22 Hz to 180 Hz within 3 dB and 15 Hz to 250 Hz within 10 dB. The low-pass filter runs from 30 Hz to 200 Hz with a choice of 12, 24, 36 or 48 dB per octave slopes, and a delay can be set anywhere from 0 to 500 ms. The enclosure is 470 mm wide, 470 mm high and 580 mm deep, and the subwoofer weighs 45 kg, or 50 kg packed. The mains supply accepts 115 V to 230 V.

Engineering and use context

Its driver uses a carbon fibre cone held by a dual spider, which Velodyne pairs with vented baskets to keep the cone under control even at extreme levels. Its basket carries three ventilation channels that cool the motor and keep the structure stable under heavy load. The voice coil is a four-layer design of 102 mm and sits in a triple ferrite magnet system. The cabinet is sealed and built from reinforced HDF, with no port anywhere in the enclosure. A DSP handles filtering and equalisation, and the free app sets volume, crossover frequency, phase and a fully parametric 6-band EQ from the listening seat, with subsonic and high-pass filters and stored presets. The auto power-on circuit has adjustable sensitivity, and a black fabric mesh grille covers the driver.

Pairing

Inputs cover RCA stereo and LFE, XLR stereo and LFE and a high-level stereo connection, so the SPL-X 15 can accept the LFE channel of a surround receiver, a balanced line from a studio preamplifier, or the speaker outputs of a stereo integrated amplifier with no sub output. Matching RCA and XLR outputs allow a second SPL-X or other powered sub to be chained. The high-pass filter in the app can take the lowest bass away from the main speakers when they are run through the sub, and the slope choice lets the crossover blend with small satellites or full-range towers.

Alternatives

The Velodyne SPL-X 18 moves up to a larger carbon fibre driver with an 1800 W RMS amplifier, a rated 20 Hz lower limit and a 550 x 560 x 620 mm cabinet weighing 55 kg.