For 1 year and a half. I had 2 other amps sound. I liked the sound quality, very clean, I used some time to sort Hifi active amplification (to feed 30 cm). Today it amplifies in parallel mode, a subwoofer diy on my home theater. I chose a guy says hp heavy (car audio) with a titanium diaphragm driven by two coils enclosing 2 ohms 2000 w RMS each (it seems according to the manufacturer Caliber Us) is a 12 "24 kg naked. I send low (more precisely, infra) until the speaker heels (you can hear it and it shows) yet the amp never clipped. SMi The 1500 is sold into 2x 1Kw Rms in 2 ohm. Honestly I do not know if I would recommend this amp because ultimately I've never used PA speakers. on the other hand I am very happy. has what I need: great power operation in 2x8, 2x4 and 2x2 ohm stereo modes, parallel and bridged is very clean 8 ohms (compared to a stereo amp) and it is reliable.