Both the D500 LCR and SUR measure 450 (w) x 260(h) x 130(d)mm, which is very compact and manageable as THX-certified speakers go. The front of each speaker is covered by a cloth grille, but tug the little tag on the right and it comes away, revealing the driver arrangement behind it. On the rear, you’ll find robust gold-plated binding posts.
The three D500 LCRs in the system can be used interchangeably across the front soundstage and each one is a three-way closed design, sporting two 140mm woofers, two 76mm midrange drivers and a 25mm tweeter. They’re arranged in a sort of cross, with the tweeter sitting in the centre, the woofers on either side and the midrange drivers sitting above and below. Their frequency range is 80Hz up to 20kHz, with the sub handling everything below 80Hz as specified by THX.
As for the D500 SUR, it’s a three-way closed dipole design, THX’s preferred method of reproducing surround sound effects. They have the ability to spread rear effects and ambience along the back of the room so that the soundstage is a little more integrated. Take off the cloth grille and you’ll see a single forward-facing 140mm woofer, while at either end is a 76mm midrange driver and 25mm tweeter.
As we mentioned before, the SUB650 isn’t the monster you might have expected from a THX Select 2 system, although it’s not exactly a matchbox either. This immensely solid and sturdy closed-box design measures 400(w) x 419(h) x 418(d)mm and weighs a hefty 48.9kg, plus it’s fashioned in a delicious Dark Apple or Black Ash finish. The only detail on the front is a volume dial that glows blue when activated, but there’s all manner of knobs and sockets on the back.
These include stereo line input and output, speaker-level binding post inputs and dials controlling phase (between 0 and 180 degrees), crossover point (between 40 and 150Hz) and Boundary Gain, which lets you fine-tune the sub’s performance when it’s in a corner or against the wall.
On the inside is a 305mm long-throw woofer and it’s able to muster a phenomenal 650W from its built-in BASH amplifier. Frequency range is quoted as 24Hz to 200Hz.