To the Concept D 500s' credit is their use of binding posts, in preference to spring clips, for the cable attachments between the sub woofer and satellites. The Sub Woofer also sports a power input, a connector for the systems controller, a microphone pass-through and a coaxial line-in. Bearing in mind that the Concept D 500 THX speakers are intended to be used with a PC, you'll want a half-decent sound card to drive them, but if you're spending £449 on a set of speakers you can't be surprised that driving them from the headphone output on a netbook isn't going to cut it.
Speaking of that power button, we have to question just why Teufel felt that it was a good idea to make it stick out from the sub woofer's frame so much. Not only is this totally unnecessary, it's also likely to be bumped into and broken off - it just doesn't sit right with the rest of the Concept D 500s' build quality.
As you might expect from a system with such a sizeable sub woofer, the remote for the Concept D 500s has a dedicated bass adjustment in addition to the volume control. These dials rotate without any limit, which has the benefit of giving a very fine level of volume control, but does mean you've no way to know how loud the system will be when turned on. We particularly like that Teufel resisted the temptation to have an LED lit on the remote when the speakers are in standby - the secondary standby button on the subwoofer does glow all the time, however.
Explaining the presence of that microphone output at the back of the Concept D 500's sub woofer is a microphone input on the cabled remote control. In addition to a headphone output, this saves the effort of crawling around behind your PC to attach a headset should you want to use one. Arguably lacking, however, is a second audio input - almost all rival speaker sets let you easily connect an MP3 player if you don't want the hassle of turning on your PC.