Like most things in life the quality of a cars audio system is in the ear of those who listen to it. The THX II system found in most Lincoln's is not a brand say like Harmon/Kardon or Sony, but a specification of how the audio system is supposed to perform based upon certain design and objective criteria. There are no THX decoders or source material in THX format. Rather, the THX branding (including seeing the THX logo at a theater) is about making sure that the sound from mastering to reproduction meets a benchmark and in the case of the Lincoln's THX II sound system it dictates a certain number of speakers in certain positions and with an ability to produce a range of frequencies with limited roll-off on the low and high ends. A typical car stereo can be loud and make the windows rattle, but it is unlikely to reproduce music with a wide sound stage, good instrument placement on that sound stage, and reproduce the subtle details of what that instrument should sound like. Take for example, a drummer tapping on the bell of a cymbal, does it have a ring, a shimmer of the larger part of the cymbal? Or, does it sound like someone hitting a metal trash can lid and the sound is coming from everywhere?
I've had the Sony standard audio system in my previous Ford Fusion and it was pretty good. It got loud, it was fun, it sounded decent enough to make SiriusXM music sound flawed (which it is). It was a good sound system to have on in the background. I've also had a Mark Levinson premium sound system found in a Lexus LS400 which is amazing and makes the standard system in the Ford sound like one of those $299 boxed stereos you get at Best Buy. Now, I have the THX II system in my new 2014 MKZ. This system is amazing much like the Mark Levinson system and at 1/3 the cost. What admire most about this new system is that it can make well sourced (CD or High bit rate MP3/AAC) music sound more like my home audio system. The sound-stage is spread out from door to door and the music doesn't sound like its coming from the speakers, but is just coming from just in front of the car. When I crank something I like, I feel the drummer snapping the drum head. I can hear the bass players fingers on the strings and the singer sound like he/she is right there in the vehicle. I listen to Classic Rock, Jazz and some classical and they all sound great on this system.
As I said in the beginning what each person likes in a car audio system is up to that person's personal taste. Some people out there don't like the MKZ and think a MB C250 or BMW 3xx is great. The audio system in my MKZ (THX II) is worth the $995 I paid for it. But, I know what I like from my car audio system. For you, listen to each and buy what sounds best to you.
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