Im a really cheap bastard and I enjoy getting found stuff that doesnt go together working. In this case I have 2 things. These cheap Kinyo TW-527 5.1 speaker set, pc style .. specs:
labeled 3 watts, 4 Ohms on back. geeks dot com specs claim

# Satellite Speakers:
# 2.5 Watts RMS per channel
# 3" 8Ohm full range drive; frequency response 30Hz - 20 kHz

# Center Speaker:
# 2.5 Watts RMS
# 4" 4Ohm full range drive; frequency response 120Hz - 20 kHz

A friend recently handed down Sony STR-DE925 specs:
back says in surround mode use 8 Ohm or higher speakers.
only use 4 ohm or higher in stereo mode.

So I have two main questions relating to could this possibly work at all...
o first the speaker set is hardwired in the back of the speakers to rca style male cables. and the sony obvisouly has seperate wire posts. in theory I could cut the rca ends off or get wire to female rca adapters i think. right?

o second is assuming the speakers get connected somehow am I guarenteed to blow the receiver? would it even drive these speakers?

I actually have a decent center and two side channel speakers as well from same friend .. so a third potential would be to use those KLM speakers and two of my kinyo set for rears.

I know you guys mostly deal with real audio equipment but I sure would appreciate any advice on my frankenstein idea. Remember I am cheaper than you can imagine so telling me to spend more than say $5 derails the point of the project :)

Last thought. I additionally have a couple of aiwa bookshelf systems lying around. Any thoughts on the impedance of those speakers, could they serve ?

I don't think you will hurt the receiver any as it has built in circuit protection. Your not going to get 30hz out of the 3 inch driver. cut & strip would be the easy and cheap hook up. I don't think they were designed for much more than background volumes, but it's worth a try. I would compare the klm & aiwa and use the better ones as mains and the others as surrounds. Pick the next best sounding speaker for the center. If your as cheap as you say you are I would go to a dozen yard sales over the next weekend & you might be surprised. you mostly see junk, but I have found JBL 4311b studio monitors for ten bucks, and a nice marantz 2270 receiver for 5 bucks. I got some speakers from a guy that was moving and he asked if I was interested in the amp & preamp, I said no & he just gave it all to me saying he had no room to move it. Anyway as you upgrade you can sell the old stuff and make some money. As long as you are patient there are killer deals out there!

Yes, you can cut off the RCAs and hook them up.

The receiver doesn't want 4 Ohms for surround, but that's likely only if you're going to play loudly. Given the specs of those speakers, you probably won't make it past quarter on the volume dial before you blow the speakers (rather than the receiver).