Myrison,
I don't know what to suggest. You have witnessed exactly what I've been complaining about for some time. Including the rattle.
I actually have two rattle sources. The first is from the amp. I've removed and replaced the amp too many times and that has caused at least one of the bolt holes to widen since the bolts go into MDF and nothing else. The other rattle source is the driver itself. I replaced the driver, the driver noise was gone but now it's back again. Both of these issues however are not noticeable during regular listening; only when I put on sine waves and white noise.
My biggest complaint however is the lack of "thump", "punch"...whatever you want to call it. I expected a lot better for the $2K I paid over a year ago now. Do you have the 150Hz firmware and is that what you've dialed the 600 to?
Now having said all that, I haven't heard anything better for my 4,000 cubic foot space. Maybe the SVS that Jason has coming will fix that. I do have to admit however that the $160 Sony sub that I have paired up with audiobytes in my 1,000 cubic foot office gives me more musical pleasure than the 600
.
Some have said that it has to do with my room. But my Sony thumps in my big space. It just doesn't go as deep or play as loud.
