The Behringer Europower EPQ304 300-watt 4 channel power amp offers the power of Accelerated Transient Response (ATR) technology into an exceptionally lightweight package. Ample power and high-tech efficiency combine to give you a feather-light supercharged workhorse that will keep your rig kicking for years to come. The Behringer Europower EPQ304 300 Watt Power Amp was built for the working musician. They are exceptionally light, they pack massive power and they are built to last through all the rigors of the road. Plus its light price tag will leave you with enough cash left over to acquire more stuff to amplify. The simple front panel controls of these amps give you all of your sound's vital signs at a glance. After pressing the Power Button, the power LED will light when the amp is ready for action. Both channels have independent gain dials as well as clip LEDs that indicate when the signal is distorted and you need to reduce the gain. There are also signal LEDs that light up when a signal is present at the input. The back panels of the EPQ304 accept balanced XLR. The EPQ304 has an MONO On/Off switch for INPUTS 1 AND 2, and another MONO On/Off switch for INPUTs 3 and 4. It takes huge pulses of energy (current and voltage) to propel a woofer cone out fast enough to match a bass beat. That's called Transient Response and it's the holy grail of amp designers. By carefully selecting transistors with extremely high slew rates and optimizing other proprietary parts of our circuitry, Behringer amps are able to react instantly to even the most demanding electronic bass impulses. If the woofers in your PA system can keep up, your audience will hear a tighter, crisper, more natural sound.