Summary: The pioneer name stands for excellence in the car audio world and this amp does nothing to tarnish their name. This is a great little mono amp that does what it suppose to do. I've had this amp very effectively power an Alpine type R and a RF P3. This amp is light weight and small enough to be mounted in various areas of your vehicle. It stays cool for the long drives, and the blue light looks good at night while not over doing it.
Summary: Monoblock Class D, small and powerful enough to push 2 fosgate 12's at 2 ohm. Works great, looks good, stays cool. No complaints. The remote bass enhance knob is pretty useless. Would have been nice if it was a gain knob. Paid about $62 for refurb and quite happy with purchase from worldsbestdeals.
Summary: Very tight bass! Not enough power alone to drive 2 woofers (12") cleanly, so I use one woofer in passive mode in my bandpass setup. The result is a very, very clean bass that doesn't overshadow the mid-range and treble, yet visibly vibrates the rear view mirror in my Dodge Stratus! Perfect, by my standards!
Summary: The Pioneer GM-D8400M is an amazing amp. I have it pushing two 10" subs in my Chevy Avalanche. The remote for it is great. I can keep the bass at the perfect level and not over power the music. Love it.