I have noticed from time to time clipping coming from my rear side QS8's I believe its the side ones. It doesn't happen very often but it happens.
I am running a Pioneer SC-27 for my Center Channel and my four QS8. The amp is rated at 140 watts a channel. My front M80 i have hooked up to a separate amp so they are fine. 140 watts is more than enough for these speakers as they max at 400 watts right? I have a 7.1 set up and I think I am hearing the clipping coming from the side QS8's. Anyone have a ideal what could be causing this? I have checked the wiring and everything is good. My M80 towers fronts were clipping time to time before I purchased a separate amp for them and I have never heard them clip since. Do you think I need a separate amp for the remaining 5 speakers in my set up?

I wouldn't base it on the wattage ratings; those don't mean much. What dB level are you listening at?

I usually like to crank it loud. It is in a dedicated theater room. My receiver is set on 4.5 to 5db. I would say 90 to 100. not sure.

Sounds like AVR clipping to me.

I run my medium grade Denon AVR (5.2) at -10 Db for most movies as it is just too loud for my medium size room. I can't imagine what +5 Db would be like & I would expect clipping up that high as well...

TAM

are you running them on the "small" setting and a crossover around 80-90Hz?

I believe they are set to small and 80hz correct. I will double check tonight. Should they be on large?

nope, small is the correct setting so low freq's go to the sub. do you hear the sound from both speakers?

I believe I do here it coming from both the left and the right side not the rears. I use to get it from my M80 until I put them on a separate amp. What gives what could it be? Wiring? Receiver

I know all my surrounds should be set to small how about my M80's? set them to large or small?

Small if you are using a sub woofer. This will divert the lower end bass (basically below your crossover setting) to your sub and free up your M80s for the rest of the frequencies.

If you don't have a sub, set them to large so they can do full range, including bass.

If you set your M80 fronts to large and also have a sub, they both will do the lower bass frequencies which is not considered desirable by most people.

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