I've had Polk MM's, Infinities, and Biketronics. I'm still running Biketronics 6.5's in my lowers. They're guaranteed for life, that's pretty hard to argue with. All of them sounded good though. I had a tweeter stalk failure on the Polks, a common problem at the time. Got the Infinities and liked them, but when I added lids I needed 4 ohm speakers so I could run them in parallel. IMO you'll be happy with any of them.

 

So I narrowed it down to the mbquarts NA2-400.2 amp, it's small and puts out POWER @ 4-OHMS 2 x 100W, which is plenty to drive the 6.5 speakers. I found a spot that I think it will fit ( behind the right side battery cover). My question to you is what's the difference (impact on sound) between using 2ohm or 4ohm? This amp is capable of either...

 

Impact on sound? I couldn't say. Impact on wattage? Twice as much with 2 ohm.

 

So since the amp can run either, will running it in 2ohm make it run hotter?
Or, will depend on the speakers I choose?

 

Sorry, I don't know the answer to that

 

heat should not be an issue if you stay with specs of that amp. i have the pn 1000d and and pushed it very hard with 4 speaks at 2 ohm each. didnt flinch

 

You may want to consider potential heat issues with that under seat location combined with engine heat and restricted ventilation.


Just a thought.....

 

The amp will always like 4 ohm better than 2 ohm and yes the amp will run a little warmer with 2 ohm speakers. Again. The amps is happier with a 4 ohm load.