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.

Mounted just above the audio system interface, the CSA is comprised of several small, powerful speakers using dedicated amplifiers and Digital Signal Processing (DSP) technology. In English, its job is to widen the sound image before distributing it throughout the car. It's all about controlling the directivity of the sound image, in order to create a spacious sound stage throughout the cabin. The end result is an auditory impression of your favorite band playing to you right from the centre of the dashboard.

Unlike an aftermarket system, the Lincoln / THX stereo is customized and optimized for each vehicle application. Specific speaker selections and placements are chosen alongside custom digital signal processing parameters to ensure a perfect aural fit.

That's important, as a vehicle isn't really an ideal listening environment. Acoustics can vary between models, and driving conditions, vibrations and exterior noise often have dramatic, negative effects on the way music is experienced. THX and Lincoln worked on items from acoustic performance to exterior noise management in the name of duplicating music exactly how it was recorded.

Throughout the lengthy development process, THX provided specifications for how the final system should perform. Detailed specifications for each component helped enable the system to reach THX performance expectations, and prototypes were tested by engineers from both companies in a laboratory setting under a variety of road conditions.

With the twist of a knob, it can transform your next ride into a rolling concert hall.

A lot of work went into this stereo system, and needless to say, THX would love to serenade you on your next test drive. You may be thinking of cranking the bass, treble or both- depending on the type of music you're bringing along for the ride. The sound gurus at THX have taken some of the guess-work out of tuning for you.

THX says that all THX II certified systems in Lincoln vehicles come programmed with presets for optimized bass, treble, balance and other settings. The system interface does let the driver select Digital Sound Processing (DSP), bass and treble individually as well, and THX says there is no right or wrong way to adjust the settings. It all boils down to personal taste- but using the presets can ensure a more accurate duplication of sound.

If you're planning to check out a new Lincoln, be sure to head to the dealership with a selection of CD's in hand and give the THX stereo a spin. With the twist of a knob, it can transform your next ride into a rolling concert hall- and no one's likely to ask you to turn it down.