Triangular Logic
With the RT-12d, Klipsch aims to outgun the biggest and baddest of 12-inch subs with a design that's highly capable, visually striking, and feature-laden. Its 12-inch front-firing ceramic-aluminum driver is driven by an 800-watt digital amplifier and "vented" via matching passive radiators on the other two sides of its triangular form, making this, technically, a bass-reflex design. Though clearly optimized for corner positioning, the RT-12d looked quite natural in my left-front wall placement.
Klipsch packed in some sophisticated electronics for tweaking the sub, though you wouldn't know. Its only controls are a five-button navigation pad and one-line display on top; all crossover, level, phase, EQ, and other settings are reached here, menu-driven. Unfortunately there's no supplied remote control, so a certain amount of back-and-forthing is inevitable to get it tuned if you're working alone, as I was. However, the RT-12d does have an IR sensor (and a USB port) on its rear panel for connection to custom remote systems. The USB port is also said to allow some advanced room-correction features through optional Klipsch software intended for professionals.
The sub relies on digital signal processing for its filtering and EQ and includes an automatic room-compensation routine accomplished with a supplied test mike. There are three recallable EQ modes ("Punch," "Depth," and "Flat") and five user memories for saving combinations of filter/crossover settings, EQ, and level. Of course, if you use the crossover in your receiver or preamp/processor and set the sub to its LFE (bypass) mode, most of this is moot.
The RT-12d performed brilliantly in my space, taking its place among the best subs I've ever tested (see the above RF-83 system review). Unless you're in a very large room, getting enough deep bass from it is unlikely to be a problem; finding the location that yields the smoothest bass should be your paramount concern. But get help: Because of its unusual shape and integral, carpet-grabbing feet, moving the 71-pound Klipsch about on your own is an invitation to back trouble.
