Your car is probably something of a sound-proof spousal safe-haven where you can listen to any type of music at any volume you like. Motorists are relying on their vehicles for entertainment duty more than ever- and in the premium segment, a selection of stereo systems are available from the world's most well known audio manufacturers.

THX is one example. The company was originally started by maverick filmmaker George Lucas as an effort to bring top-notch audio to movie theatres. The company has since become a big name in home audio as well- and a few years back they teamed up with Lincoln to create an in-car stereo system with some serious firepower.

The collaboration was intended to bring engineering innovation from home theater into the luxury automotive market, recognizing the growing trend of owners using their vehicle as a primary listening environment.

THX II Certified is now optionally available in the Lincoln MKX.

The resulting THX II Certified Audio system debuted on Lincoln's LS model, and is now optionally available for 2008 in the Lincoln MKX, MKZ, Navigator and Navigator L. The 2009 Lincoln MKS will feature the THX II Certified 5.1 Surround Sound system, which adds discrete 5.1 surround sound playback of DVD-Audio and DVD movies.

When not bundled with other features, the THX audio system is a $1,000 option- but you don't need to be an audiophile to enjoy it. THX says that while listening to CD or MP3 music on their system, vehicle occupants will detect subtle details they wouldn't notice on a lesser stereo system. Music on CDs and MP3 files will feel very natural, and the system won't distort when playing at very high volume levels.

For Lincoln and THX, it's all about reproducing music to sound exactly the way it was recorded- and the system won't be offended if you throw in a little alternative or rap either. High-quality audio systems are generally designed to play all music genres loud and clear with very little distortion. For THX, that's enabled by 600 watts of power channeled through up to 16 speakers and a 10-inch subwoofer.

Special technologies like the THX Configurable Speaker Array (CSA) and THX Slot Speaker enable sound to be distributed precisely from the center of the vehicle dashboard too.