Most internal amplifiers clip around 2/3 of full volume with 0dB information, most pre-amps clip (if at all) at about 9/10s.

 

I realize you are new, "hi...i'm new" So I will tell you some usefull info that will serve you well in the future. Never look at the volume numbers on your deck. It is too arbitrary a "measurement scale" to provide any usefull info. In fact on some JVC decks you can adjust the sclae from 0-50 to 0-30. I would be more worried about if the speakers are distorting before they are as loud as you want to listen. And if they are get an amplifier. If you have any speakers running off a head unit (factory or aftermarket) most of the distortion is from the amplifier section in the head unit, not the speakers. Some people say upgrading the speakers is the biggest bang for the buck soundwise in a system, and I would agree. But you will still be limited to pretty much the same overall volume with aftermarket speakers. Adding an amp will not only aloow you to have better SQ, it will also increase the overall volume capability of the system.