The wharfedales are 6ohm and the receivers power ratings are Continuous Average Power (FTC) not RMS, it's FTC into 6ohms is probley around 130watts thats FTC not RMS the speakers power ratings are RMS not FTC.
I don't understand the abbreviations you are using.
I've just been thinking, if the Edifier R1600Ts were amped, could their max volume succeed that of the Soundsticks? Or are the Edifiers just not suitable for being amped? Its no good just being loud, they have to be punchy as well.
You can't amp the edifiers any more, you would have to replace there interal amp or take it out and bulid a passive cross-over and run them from an extenal amp both require a good knowledge of eletronics and speaker d.i.y.
Ok, so I really do need a bookshelf upgrade then.
The Wharfedale Diamond 10.2s and SW150 look fantastic, but I need to keep the total cost (bookshelves + sub + amp) under £500. I am going to have to downgrade somewhere.
What about this amp http://www.amazon.co.uk/Sony-STRDH100-Receiver-2-Channel/dp/B002CU0N2G/ref=sr_1_1?ie=UTF8&qid=1321481735&sr=8-1 , you can have the Wharfedale Diamond 10.2 and SW150 and still be in budget.