The NHT Evolution A1 amplifier ($400) is a 250watt, mono Class G amplifier with balanced and unbalanced inputs. The Class G operation of the amp is very efficient, allowing stacking of multiple units. The X1 bass manager and active crossover ($350) has balanced and unbalanced inputs, with variable high-pass and low-pass filters for active management of bass. The X1 also has a bass phase control for sub integration, boundary control for different placements of the sub and an LFE input with its own gain control, allowing easier integration of older receivers and surround decoders with limited or poor bass management, which is apparently quite common in NHT's experience.

Filling out the line are two new subwoofer systems, the U1 ($1,300) and U2 ($1,400) are identical in quality, response (-3 dB at 26Hz) and output levels (108dB at 1 meter) but they differ in driver packaging, each being optimized for different placement requirements. Both woofers come with an A1 amp and X1 bass manager. The U1 is a single-cabinet with two opposing 12-inch woofers, and is designed to be placed in the room, instead of in a cabinet or near a wall. NHT claim the opposing woofers eliminate cabinet vibrations, so decorations such as lamps and plants may be safely placed on the top.

The U2 consists of two 14-inch cubical cabinets, each with one 12-inch woofer. Because of its single-woofer design, the U2 can be placed in cabinets in, or near walls. For advanced audiophiles, the two separate woofers may be placed separately in a room to reduce standing wave effects. Drivers in both systems are driven in parallel by the single-channel A1. []

Evolution Loudspeakers Theory & Design...