I did the Chet thing as posted above, but without the amp or the sonys.
The alpines make the CD changer sound better than a motorcycle has a right to. And the OEM fronts put in the rear with the EC harness fill the space just fine. I usually run the volume at 20 and it ROCKS! Many times folks have rolled up the windows in their cages, the wimps!!! If I'd just put that 10" woofer in the trunk, I could rattle the lowriders!
There is a bit better(?) way to mount the Alpines I read about here last year, but haven't changed mine (yet). It was told that you can just simply remove more speaker frame with your tin snips and wallow out the holes allowing the use of the stock mounting nuts and dash clips.
I installed the Diamond Audio M341i 4 1/2" speakers in the front.
The speakers are a little pricey at around $110.00 but well worth it.
I have Alpines in the rear and will replace them soon with the Diamonds.
I have tried the BigBike speakers, Alpines, and a few others.
I'll tell ya, I blew a lot of cash trying to find a good speaker for my bike.
The Diamonds are the way to go.
Visit my webpage for pictures and a review on them.
Just click on the Speaker Install link on the left side of the page.
I also have a link to the Diamond Audio site there. http://www.angelfire.com/in3/rumblepipe
I installed the Polk's from Electrical Connection front and rear and I'm not happy with them. They really don't sound any better than the stock Honda ones I had front and rear. They do absorb more power and therefore the volumn control doesn't respond as fast as the stock speakers did. I guess I'll give the Diamondaudio M341's a try. I also don't have nor want to install an amp.