Get a high-end car system! They are designed to run of 12V DC from the start, and it will greatly expand your options!


Watch out for the loudspeaker impedance. Most car speakers will be 4 ohms, and most high-end indoor speaker will be 8 ohms. I'm certain you won't break anything trying to run 8 ohms speakers on a amplifier designed for 4 ohms - at worst you'll only be able to play at low volumes - but you'll have to actually try it to hear how good or bad it sounds. Or consult someone more knowledgeable than me on the subject. Anyway, finding 4 ohms speakers is probably easier than finding high-end systems that run of 12V and are NOT designed for use in a car or a boat.


You even get DVD systems for a car... You'll probably want to invest in a system with an external amplifier, which will put you in the same range quality wise and power wise (play it LOUD) as many indoor systems.


If you want to use car speakers, building a box for them is really not that difficult: Get some good car speakers and build as solid a box as you can using MDF boards. Smaller boxes are easier to do properly and get absolutely rigid. Bigger boxes will give more base (low frequency tones) but may have more resonance to the higher frequencies). If base is important to you, you may overcome these shortcomings by building a small pair of satellites for the high frequencies and a sub woofer for the base. Search for it and you'll find plenty of DIY material about how to build your own speaker system.

Oh, and by the way: Don't believe any of the power ratings they use on car systems! They are absolutely ridiculous! 25w "quality watt" for a domestic system with a conservative rating may translate to 100-200 w for hyper-inflated RMS watt ratings. Go with the car audiophile crowd and you'll find what's good and what's not.