i installed 4 polk coaxial db651 with a alpine f300. something was missing in the front that did not sound right and i thought it was the tweeters. i replace the tweeters with a lanza 100rms (yes i know lanza sucks) 4ohm it sounded better but still wasn't right.

now after some reading i notice that the front speakers and tweeters are conected parallela which means that if my polks are 4ohm and tweeters 4ohm my resistant would go down to 2ohm. i figure that my problem was distortion front the tweeters and front speakers. This is why my rear speakers were cleaner and much louder at the same amp gain.

Today i disconnected the tweeter and of course my front speakers came back at full force 4ohm clean 50rms watts to them. Now my system sound much better. i really think that if you are going coaxial 2/3 way, remove the oem tweeter on the dashboard.

 

interesting....

i have the 651s on all new speaker wire, and can just slightly hear that the rears a bit louder at the same gain...

but then it does balance out since the trunk bass hits pretty hard