The Matrix MP150 amplifier is a proprietary switching amplifier It uses a unique pulse control scheme that takes feedback only from the speaker terminals. No feedback loop from the switching output is used. The result is extremely low output impedance over the entire bandwidth. Damping factor is >400 up to 2kHz and >100 at 20kHz. The frequency response is DC-50kHz (+0,-3dB) and is completely independent of the load impedance. THD and IMD are very low (<0.02%) and completely independent of frequency, like a good zero-feedback amplifier.