Hello. I recently got a Velodyne CHT-10 subwoofer. It works well. But i noticed yesterday that the 'cooling ribs' on the back where hot, even though the sub hadn't been used for several hours. It was in standby. They weren't red hot, but a little above body temperature. Is this normal? I always thought they cooled down when the sub wasn't used. Apprecieta any respons. regards, jørn.