Here's what Behringer have to say...
The EPQ Series
uses Accelerated Transient Response (ATR) technology to produce high power from a lightweight package. Instead of operating relatively continuously, the EPQ power amps feature rail tracking for effectively modulating the power supply rails with only the peaks of the input signal. When combined with switch-mode power supplies that do away with heavy toroid transformers, our new designs provide more dynamic punch and, because they are so much more efficient, run cooler and don't require huge, heavy heat sinks. EPQ power amplifiers also feature built-in crossovers (low pass filters) for use with subwoofers and switchable limiters.
EPQ304: 300 Watts, 4 kg / 8.8 lbs
EPQ450: 460 Watts, 4.7 kg / 10.3 lbs
EPQ1000: 1,060 Watts, 4.7 kg / 10.3 lbs
EPQ1200: 1,200 Watts, 6.7 kg / 14.8 lbs
EPQ2000: 2,000 Watts, 7 kg / 15.4 lbs
Pricing and Availability:
See Behringer website