In addition to a large venting port, the back panel includes the Sub-12's ample connectivity options: stereo RCA line-level inputs and stereo speaker-level inputs and outputs. The subwoofer's crossover is continuously adjustable from 40Hz to 120Hz. The LED on the front baffle of the subwoofer glows red when the amp is in standby mode and blue when the amp is turned on.
We listened to the Sub-12 first with a set of five Klipsch Quintet III satellite speakers. The blend wasn't perfect, but while watching the House of Flying Daggers DVD, the big, pounding drums were reproduced with exceptional clarity and definition. Switching to music, the Quintet III/Sub-12 combo delivered a refined sound on Tony Bennett's lush Sings Ellington CD, and the spread of the orchestral backing wasn't inhibited by the speakers' stature. On our Barry White CDs, the Quintet III subtracted more than a few pounds from his weighty presence, but we regained some heft by turning up the Sub-12's volume. We finished our listening test of the Quintet III/Sub-12 with the Led Zeppelin II CD. Switching back and forth between stereo and Dolby Pro Logic II surround, the sound was equally enjoyable.
After packing up the Quintet III speakers, we paired the Klipsch Synergy Sub-12 with our much larger reference Dynaudio Contour speakers. Once again, the Sub-12's low-down authority--especially the superdeep, room-quaking frequencies--won us over. Compact 8- or 10-inch subs simply can't plumb the depths the way a mighty 12-inch sub can. One downside to 12-inchers is that they can sometimes soften definition compared to that of smaller subs, but the Sub-12 was surprisingly taut. Stand-up bass instruments sound quite detailed and pitch accurate. The Sub-12 provides notable oomph over its smaller 10-inch sibling, the Sub-10, while also meshing better with speaker systems. As with the Aperion Intimus S-10 and the Infinity CSW-10, the Sub-12 is a pleasure to the ears, even if it's not a treat to the eyes.