First of all, I would buy this active subwoofer at any time. At first I wanted to take up a more favorable speakers, but too often annoyed about apparent bargains. The subwoofer will last many years, the 50 - to 100, - More investment worthwhile. The magnate Betasub 30A is processed very clean and solid. Since wobbles and rattles nothing. I opted for the 30 A, because to me a clean low bass is important. Other "authors" report here from a hum and clunk when turning, I can not confirm. Probably there is not properly connected or not shielded cable has been used. For me, the subwoofer to my very old Yamaha RX-V44RDS is "digital RCA audio cables" connected with and works flawlessly. Even the stand by mode works without big Kawum, a light clack can be heard during the automatic switching on of course. In principle, however no noise for a rich, clean bass. The bass level (crossover) I have as dictated by Yamaha set with 90 Hz and positioned the volume at 3/4. Plug the power supply I have leg amplifier plugged to not stand by power consumption to have. For Betasub 30 A but you should have space. With free space around it approximately 0.75 square meters are needed. In conclusion: a great device with great sound / bass that also in the Subwoofer category 600, - + can compete.
