the infinity has a swivel tweeter that i dont believe the polks have just to screw up your decision. i needed a decent rear door speaker and just ordered infinity reference 5x7s for around $40 from ikesound on ebay. i checked on the polk db570 but the lack of swivel tweeter led me to the infinity. i used to have the kappa 5x7 (wish i had kept at least a set) but the rear fill will be run off the hu and and will be faded out most of the time so they'll do their job.
