would i see much of an improvement using say a 200w p/c amp over the 130 watts my current reciever puts out? the woofers only get decent extension at levels just below clipping. they are rated at 300w, is this max input or an output measurement?
To answer your first question, going from 130 to 200 would only get marginal gains in absolute output. You would have to increase power substantially for any appreciable increase in spl. The 300w rating of your speaker is most likely it's peak suggested power handling capability, but provided you are sending unclipped signals, they should handle much more without a problem.
If you really need more output via increasing amp power, you will have to spend a bunch of ducats to get a noticeable increase in volume. If that Onkyo has pre-outs you could purchase a more powerful multichannel amp from, say, Emotiva (Their xpa5 is conservatively rated at 200w, but it can put out unclipped peaks far in excess of that; I strongly suspect the Emo's dynamic capabilities would far exceed those of the Onkyo.) This would be a pretty expensive solution to a seemingly minor shortcoming.
If you are going to spend a bunch of money on this percieved shortcoming in your system, I would suggest buying subs instead of new amp/reciever, and implementing the bass management in your Onkyo. If you send only signals above 80hz (only a suggested crossover point, experiment yourself for best settings) to your mains you will be optimizing the Onkyo's available power by relieving it from producing power-hungry bass signals, and resulting in more power available to those frequencies the Onkyo
is asked to push. You'll get better dynamics and louder overall output that way. Let the sub's drivers get the excursion and relieve that duty from your mains. That's what subs do best.
And don't overdo it to the point that you need to call Phonak in 10 years. (Phonak makes hearing aids, fyi.) CV's can get to concert sound pressure levels.