Older post that went off topic a little.

It's not the QS8 clipping, it's the amp. OP said their running at 4.5 to 5 db ( assume they mean + 4.5 to +5 ) Thats well into a possible distortion and/or clipping zone.

If it helps, think of O db on your dial as the MAX volume. Anything above that (in the + ) is like overdriving the amp.
(Not really overdrive just a lack of better words....)

Here are two excellent articles:
http://www.axiomaudio.com/understandingdb
&
http://www.axiomaudio.com/power

To help answer the Original Posters question: Lower your loudness (volume) setting to avoid clipping or get a more powerfull amp(s) that can handle your desired loudness :-)

More info here:
http://www.axiomaudio.com/aboutamplifiers


Glenn.
M22,M3,VP150,QS4,EP175,EP125
Carver M1.5t,NR828/BDT330,60VT60