Hi,
I'd say the power is a real issue with this one as well as the Fosi ZA3. I tried them both in my home cinema setup. The avr is a Marantz Cinema 70s. I'm running preout for LR to a Mcintosh MA8000 integrated amp. I tried both the A70 and ZA3 preout to surround and front heights. Volume cranked to max on the A70 and ZA3. Very underwhelming. Audyssey suggested +7 and +8 dB correction. When running direct from avr to speakers, correction was -6 and -5. The surround speakers are Dynavoice Magic Around 5 (4-8 ohm, sensitivity 90) and the heights are Dali Spektor 2 (6 ohm, sensitivity 84.5). For both speaker pairs, with each amp, the results were awful. Thought I missed something, so tried and old crappy Nobsound 01G Pro and that worked flawlessly. I know, the Nobsound surely doesn't test well etc, but for surrounds and heights for movies, it matters less, at least for me. For music I only use stereo or front with subwoofers. Note, I did not use the highest end power supply. It was the 48v 5a version. Also, at full volumes these guys both hum. So, here I voted poor. Don't know what's up.