Billy, in my bench testing with a Zapco ST SQ 2X in blind testing the Zapco did ok but not as good as amps such as a Pioneer d8604 which is an inexpensive class D design. To be fair the pioneer has twice the power but I kept everything under clipping and levels were matched exactly using a microphone in identical conditions. The Zapco sounded good but not as good as all the hype about these amplifiers led me to believe.