4'' Dash Speakers, '05 Durango

I have an '05 Durango which had the stock cd radio. There are the two spots on the dash which I assume would have held 4" speakers if I had the Infinity system. I recently upgraded to the Jensen VM9511TS for all of it's cool features. My questionis as follows: Can 4" speakers be added to this system even though they were not present before? I am currently using three sets of preamps to run speakers in both doors and a sub box. If I am able to add speakers to the dash how might it be done? Use another amp and hook it up to the center channel preamps? Any info is greatly appreciated.

Sorry, BTW the speakersin both doors are Polk dB6500s. Also, would adding tweets make much of a difference or would I get just slightly better separation ?

While you "could" possibly add some 4" speakers (or additional tweeters) up front to your current setup, I would highly advise against it. Placing additional speakers in the dash, especially while playing the same frequencies as the other front (door) speakers will cause you phasing problems. Tonal characteristics will most certainly be different as well, as they're not part of a 3-way set. It will not sound right. My advice to you if you're unhappy with the sound produced by your current speakers is to listen to others at a local dealer, and buy something you like. You can experiment with different tweeter positions until you find the spot that works best for you. I suggest you also read Stephen's sticky about front speaker system setup.My ex once told me I have a perfect face for radio.

OK. Thank you for the input. Much appreciated

OK, one more question(for now).  If I wanted to use the 4" spots,might I go with just a 6.5" woofer in the front door,4s in the dash(actingl ike tweets?) and the 6.5" two ways in the rear doors? would this help or should I just deal with the two ways o rinvest in some components?

I don't recommend puting 4's in the dash while you have 6.5's polk's in the front door. If you want to keep a stock look and still would like to add tweaters, then I personally would put the tweaters in the dash. An adapter would need to be fabricated (which is a super easy job). Or you can always install components (woofer in door, tweater in dash). But if u don't like the tweater in the dash, then get 'em installed on your door panel. Might sound better than on the dash, but you'll lose the "stock" look.

I agree with the above. 4" speakers were not designed as part of the set, and would sound awkward if you tried to simply use them in place of the tweeters. However, IF you like how the tweeters sound in the dash locations, more power to you. Build a couple panels to house them in those locations.My ex once told me I have a perfect face for radio.