KEF HTB2SE-W Wireless Subwoofer

Most people conjure up the image of a square box when thinking about a subwoofer, but KEF has changed that image with the HTB2SE-W wireless subwoofer. Far from a boring, unattractive box that sits in the corner and thumps, the KEF sub delivers style, performance and wireless connectivity for home entertainment systems. KEF is known for their innovative, even radical-looking speaker designs, and the HTB2SE-W takes subwoofer style to new levels. It also offers good bass performance with stereo and home theater systems that have subwoofer control features.

The KEF HTB2SE-W is a high-gloss black donut or ring-shaped subwoofer that can be placed upright (like sitting a donut on its edge), or laying flat so it can be concealed under a table or chair. When sitting upright, the sub rests on a stand and when placed flat, four short legs are attached on the bottom to raise it about 2" inches off the floor.

The center of the donut is outfitted with a 10" woofer on one side and a 10" passive radiator on the other and powered by a built-in 250-watt Class-D digital amplifier.

But there is a caveat: The KEF sub is designed to be used with receivers and processors that have a built-in crossover and a continuously variable level control. The subwoofer's level control is a three-position switch labeled 0 dB, +6 dB and +12 dB, which offers limited level control and it does not have a built-in crossover. The lack of these controls doesn't matter if the receiver includes them and many receivers have very sophisticated subwoofer controls anyway. It also lacks high-level speaker inputs often used with a satellite/subwoofer system. But, I don't recommend the KEF for use with systems that don't have LFE or low frequency crossovers and subwoofer level controls.

The KEF sub is wireless, meaning that the only connection needed is a wall socket and a wireless signal transmitter. The audio signal is sent wirelessly from a receiver or processor's Sub Out or LFE Out to the subwoofer via a small transmitter that sits on a shelf. KEF uses the ISM frequency band to transmit the audio signal, the same frequencies used in your microwave oven, cordless phones and Bluetooth devices, which might lead to concern over interference or signal dropouts. To prevent this, KEF employs additional technology to constantly monitor and change frequency instantaneously to find the strongest, cleanest wireless signal, thus preventing potential signal reception problems.

The advantages of a wireless subwoofer cannot be overlooked. The obvious benefit is the elimination of the subwoofer cable(s) from the receiver to the sub, often as long as 25' that snakes around the walls or across the floor. But the real plus is flexibility of placement. Arguably, a subwoofer is the most difficult speaker to place accurately in any room. Improper placement can lead to very lean or exceptionally heavy bass that can thwart a good listening experience and even a small difference in placement location can make a huge difference in sound quality. Placement options are greatly expanded when the subwoofer is freed from the receiver, allowing it to be placed where it sounds best.

Another plus is KEF provides an extra-long AC cord for the subwoofer, making the best placement even easier.

I tested the KEF HTB2SE-W in my home theater system with an Anthem AVM-50v pre-amp processor with very sophisticated crossover and subwoofer level controls for music and movie sources. I set the crossover at 80 Hz, which is the recommended frequency for THX and most other systems.

I ran the KEF through a few tests using some of the most dynamic bass content in my collection and I found it had surprisingly robust bass performance. It exceeded my expectations for a modestly sized 10" subwoofer. It rocked when needed and hit the low notes when required. The best example was Toy Matinee's "Remember My Name", a multichannel DTS CD with lots of rockin' bass and aggressive use of the kick drum. This disc (and track) is a tough test for any subwoofer and sounds especially good when played loud. The KEF sailed through the test, but my dog left the room when I turned it up.

"Dirty Laundry", one of the best tracks on The Eagles "Farewell Tour 1 from Melbourne" disc (DVD Video) in DTS 5.1 channel sound has a solid, pounding bass track that sounded clean and articulate on the KEF subwoofer.

The combination of the woofer and opposite-facing passive radiator helped distribute the bass evenly throughout the room. The two drivers working in conjunction prevent peaks and dips in the bass and result in smoother response.

I have to evaluate the KEF HTB2SE-W on two levels: features and performance. On one hand, it doesn’t have a crossover, continuously variable level control or speaker-level inputs, which prevents its use with systems that don't have these controls, such as many two-channel receivers and processors and some home theater components. When considering features, I rate it at 3.5 stars out of 5.

On the other hand, the KEF offers solid bass performance and its interference-free wireless operation offers a lot of flexible placement options. In this area, I rate it 4.5 stars. Considering both factors and its $1,200 price tag, I'll split the difference and rate the KEF HTB2SE-W overall at 4.0 stars.