DO NOT BUY EITHER ONE!!!!!!!!!
lets start with the dual...they are a terrible company with the worst products EVER!!! i bought an amp and 2 12" subs from them. The subs sound terrible and my amp was fried within a few months. The company literally fell off the face of the planet. After 6 months and multiple threatening letters sent to them, i recieved a new amp. This one broke within 6 months. I took that one back to best buy and they told me they didn't even carry the brand anymore!!! i managed to get it replaced for a sony. They are a very cheap company.
Now JVC...I bought a JVC head unit for my first car. Had it professionally installed. It lasted about six months before it started skipping all the time. I would put in BRAND NEW cds and it would skip!! my dad bought one as well ( before mine started screwing up) and his cd player did the same thing and then just wouldnt eject cds. He took it back to the store and they replaced it. it started skipping again he just left it in the car when he sold it.
I just bought an alpine for my new car. It is wonderful. it has tons of sound options, multiple ports for amps, never skips even when i hit massive bumps/holes in the road. It came with a plug for MP3 players. The face plate folds down to reveal the cd player so the actual face plate is big and easy to see. I have lots of friends with alpines and have had them for multiple years. Mine was only 180 for a low end one. Or pioneer and sony are good ones.
just don't buy either one of those brands...they are both a waste of money