Surround Sound Speaker Systems

Kef IQ Series Speakers and HTBSE-W Wireless Subwoofer

ARTICLE INDEX

Design

Let's talk subs, shall we? One look tells you that the HTB2SE-W is not your father's subwoofer. The HTB2SE-W has a ten-inch driver set opposite a matching passive radiator. The driver and passive radiator are housed in an open flying saucer-shaped shell. The sub can be mounted on its side, with the driver in a down-firing position, or attached to a supplied stand in a side-firing configuration. If you use the side-firing configuration (as I did), the control panel is located somewhat inconveniently at the bottom of the unit.

The panel has a power button (which is "standby" rather than always-on), detachable power cord and a single line-level input. There are also three switches: One switch flips phase from zero to 180 degrees; a second contains a three-stage "bass boost" that provides an EQ boost at 40Hz (I left it off), and a third switch to run the sub wired or wireless (hence the "W" designation).

Wireless subs are becoming more popular, as they allow for flexible placement without worrying about running a line-level cable between the sub and the receiver (or processor). KEF's wireless transmitter operates at the ISM-band spectrum (2.4-2.4835GHz). Like other wireless sub solutions, KEF's transmitter connects from the subwoofer-out jack of the receiver/processor to the base unit via RCA cable, powered by its own wall wart. Setting the sub to operate on wireless is a simple process: Set the switch on the sub to "wireless," plug in the base unit, connect the RCA cable to the receiver, then turn the base unit so that faces the subwoofer and displays a solid blue light.

Regular readers know that subwoofer output is the primarily dictated by three factors: Amplifier power, speaker size/excursion, and cabinet volume. Judging by those criteria, one would think that KEF had modest expectations for the HTB2SE-W. The KEF sub has a 250 watt Class D amp, which sounds like a lot of power, but the last two subs in my listening room had 1,000 and 3,000 watts RMS, respectively. Moreover, the KEF's ten-inch driver and matching passive radiator are housed in a smallish housing that has minimal internal cabinet volume (15 liters). Nonetheless, KEF's specifications state that the HTB2SE-W has a frequency range down to 30Hz, and maximum SPL of 110 dB. Really? Spoiler Alert!: Towards the end of this review is a graph from my bench tests, showing the KEF's maximum output is over 112dB at 31.5 Hz. They weren't kidding, were they?