I am upgrading the crappy stereo in my 2013 JK. I bought a double din Pioneer and Polk DB651s and DB6501s for speakers. What are you guys doing for bass? I want 2 10s probably?? Tell me about your subs and where you put them
The Alpine PDX-V9 5-Channel amp(100x4+500watts/sub) is an excellent choice for the subwoofer, just not for the 60wattRMS Polk651. The Alpine puts out 100wattsRMS, and will blow out the Polk 651, although the Polk 6501's can handle it. I would never have recommended Polks for a powerful subwoofer. You will definitely want 100watt speakers to compliment the subwoofer. Unfortunately, Crutchfield sells the PDX-V9 for two hundred dollars more than everyone else. I paid like 350 for mine brand new.
I have the JL audio stealth box designed for the jeep wrangler JK. It has 1 10" sub and I'm running off a bridged JL amp. I'm happy with the sound. I listen to mostly country and it is more than enough for me.
When i upgraded my system i simply added an 8" Kicker sub and took out the piece of crap factory Alpine sub. I then had the installer Polyfill and Dynamat the sub enclosure. Now that my sub is powered properly my system absolutely booms. If i were you, i would spend my money on upgrading the factory speakers, installing a quality 5 channel 500w amp and then getting a new subwoofer.
The kicker sub i bought was $70 shipped from amazon.
If you don't want to change out your head unit and did the install yourself, you could do it all for less than $1000.