Previously I had a Yamaha Sub of the I always- subjective gefühlt- a slight hum / drone in film and music noted. For comparison, I ordered the Jamo and must say that it sound much better must be seen within our equipment. When I use the front speakers Jamo S604. Rear are the and the Jamo S602 and as the Center 6Cen. The sub now gives a total of absolutely harmonious sound. Even with music notes is an absolute "abundance and sound volume".