high power pa amplifier, professional power amplifier, stereo amplifier, audio amplifier, sound amplifier, power amplifier. stereo amplifier, audio amplifier, professional power amplifier, pa amplifier, professional amplifier, power amplifie The I series ( ... installations and touring applications that demand the finest audio quality.ModelI1I2I3I4Input ImpedanceBalanced:20KΩ, Unbalanced:10KΩFrequency ...