The new innovative QX MK2 Series Amplifiers QX-2500 MK2 are a technological tour-de-force. From the input stage to the output stage the QX MK2 Series has precise and comprehensive protection systems with enough power rest, Moreover, the sensitivity of QX-MK2 series is 1V. which provides very safe working condition to the amp. All four models are usually sold in pairs as they are equipped with high and low pass filters, so you can optimize output for subwoofer or full range systems to provide peak audio quality and performance from any speaker system you may be using. The patented aluminum heat sink is of special tooling which has 60% higher cooling than regular heat sinks and much lighter than normal heatsink to boot . Perfect LXTM input overload limiter protection. The input is well controlled by this thoughtful feature. It is dynamic in nature, which means that it works differently over varying frequencies and temperatures. This will ensure clean distortion-less sound that will protect both the amplifier and the loudspeaker. Special LRSTM short circuit protection. When the output stage sees a short circuit, this advanced circuit can mute the input signal and switch off the relay. At the same time, it locks the amp by another circuit.