Is this something common that happens to everybody? When I have a CD on it's say on volume 18, but when I switch it to radio the same 18 is not as loud it sounds as if it were in level 12 why???

 

check ur stereo audio settings.. u have your cd volume higher than the radio.. what kind of deck is it? Sounds like a pioneer.

 

That's actually happened to me in various decks I've had, (sony, kenwood...)

 

Since it's happening with different decks I'd check the antenna and wire.

Have you tried the deck in a different car?

 

i've had that problem with all my cars the cd and tape volume is always louder than the radio reception. makes it a biatch when listening to a game on the road and then turning on the cd player to have it scare the shiat out of you