Cody, I am researching the same thing right now. I don't think there is really any difference in the db650 and db651's as far as function is concerned. The only thing different I can spot is the slightly different grills that each speaker has, and the db651's come in a shallow/slim version as well. My advice would be get the db650's...they are all on closeout now. I talked to tech's at Crutchfield and they highly recommended them.
About the amp...
Now, I don't know too much, but I've just been listening to others. The speakers would work without and amp, but for best sound, you really need an amp for them. When comparing powers, I think you need to pay more attention to the RMS watts than the peak watts. Those db650's are rated at 60W RMS. I think with your 50Wx4 Kenwood, the RMS that it would push through each channel would only be about 20-22? As you can see, you are not truly getting the power to your speakers that they can handle. Therefore, a 4-channel amp that pushes 60W RMS through each would be ideal.
If you take a look at the thread I started on here (it should be below somewhere, entitled "Need help with stereo selection/install", or something like that), 54 gives some pretty good advice on everything. A good amp for that setup will start out at about $100 or so. Let me give you some suggestions of ones I was looking at! (credit to 54 for most of this info!)
54 thought this was a very good amplifier for the money to run the 4-Polk db650 setup like you described. Compared to the original price, it seems a great deal!
http://www.sonicelectronix.com/item_1702_Phoenix+Gold+R5.0-4.html I spoke to a technician at Crutchfield, and he recommended this amp for that setup. However, 54, who knows much more than I about audio things, pointed out that this amp's original price was much lower than the Phoenix Gold's, which might therefore mean it is of inferior quality? Who knows though...
http://www.crutchfield.com/S-jOubKKXtJd2/cgi-bin/ProdView.asp?g=120&I=489AP740 Now, as you see, that Profile amp is $129.99 at Crutchfield with free shipping. However, 54 sent me this link, where it is on sale for $91.95, but it is about $15 to ship it to me in Texas.
http://www.audio-warehouse.com/web/mdl/AP740/detail.asp Best deal I found on it was Ebay. It is $90 shipped to you.
http://cgi.ebay.com/Brand-New-Profile-AP740-480-Watt-4-Channel-Amp-Low_W0QQitemZ330120315704QQihZ014QQcategoryZ39739Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem Also, if you are considering one day adding a sub to your system, you might want to opt for a 5-channel amp, or you could always just add another amp and run 2 of them. If you are interested, here is a 5-channel amp I found that would work for not only your db650's, but also a sub. Cheaper than buying 2 amps probably.
http://www.sonicelectronix.com/item_1613_Phoenix+Gold+R9.0-5.html Please let me know what you decide to do, because I am currently in the same situation you are!
(Message edited by whtlghtn49 on May 18, 2007)
Linear Mode
