I bought the MM6501's and Infinty Kappa 60.9cs at the same time, hooked them up to my kicker zx350.4 amp , and wow these MM's blew the Kappa's away!Apples and oranges. Twice as loud, much cleaner, better highs mids, after a month while the MM kept banging the infinty kappa's both fizzled out . (Note one of the MM 6.5 drivers failed after about a month or two , polk replaced no questions asked. I just payed shipping to the company. Infinty is sending back tweeters as we speak but im ordering a 2nd set of these today)
I upgraded from the fullrange db series to the MM6501's and these are absolutely amazing!! The sound is very full and bright. I am running two sets of them off an MB Quart 4.80 that is 160wrms @2ohms x4. Polk has done a great job on the MM6501 and I have had infinity, focal, and JL audio and IMO these are hands down the best sounding speaker on all types of music.
Sounds good great price