System shutting down due to clipping?

Just to stir the pot a bit more.

The OP may be able to keep his current AVR and IF it has pre-outs, he could add an external amp.

Couple of choices:
1) 2-channel ext amp for Front L/R speakers - which may 'offload' the AVR enough to drive the remain speakers
2) multi-channel ext amp: 3 or even 5 channel and completely offload the AVR from driving any speakers.

Would be helpful to know which Yammie AVR model the OP has.

I still have my Yamaha RX-V1800 as my AVR for a 5.1 setup. At one point I had my old Carver M-1.0t hooked up via the AVR pres for Front L/R ext amplification, and could go "stupid loud" for all channels.

Erikt
I have the Yamaha RX 1000. Not sure if it has pre outs as you mentioned. The Sonic Frontiers preamp has a bypass switch so the mains are running off 2 Aragon Palladium monoblocs. The Sub is self powered and the Yammy is also running the center.

Your AVR does have preouts ("Main outs"):
http://www.son-video.com/images/static/Rayons/HomeCinema/AmpliAV/Yamaha/RXV1000bg.gif

It sounds from your above system setup description that you are using the main outs from the AVR, connected to your Sonic Frontier/Aragons to drive your Front L/R speakers.

If so, then your V1000 is only driving the center and surrounds.

How long have you had this setup? Is the AVR shutting down recent?

I have had this setup about a year. The shut down has only started in the last 2 months and only when I have things cranking ...like a concert dvd. The Snell center is also 4 ohms. The AVR is rated at 105 watts @ 8 ohms. The center is
rated at 90 db sensis. and 50 watt min, 250 w max. Not sure about the Canton surrounds but I do know they are 4 ohm.

I just got off the phone with Yamaha....was only on hold for 50 minutes !! yipeeee. The tech said this AVR can be reset to 6 ohm by holding down the power button and the Straight button during power up. I will try that tonight after work.
This should help and would be cheaper than any other option
if it works.