Features: ATRAC 2. Wireless remote. (No Amplifier).

Links: Sony Page info. Comments from an owner. Crutchfield sells this unit and has further info on it. MiniDiscussion has collected user reviews for this unit.

User comments: The MDX-400 is really nice. It has two parts - the in dash 4MD changer, and a separate tuner/preamp unit. This makes it much easier to install, since all of the connections are made on the preamp unit, which doesn't have to be crammed into the dash where the stereo goes. There are connections for power, Sub, Front, Rear, Unilink, 2 antennas, wired remote, and MD changer. There's also a wired remote included, which is necessary because the display is so big that they couldn't fit all of the buttons onto the front panel.

The MD changer function works great - there's a cartridge which holds 4 MDs, and it changes between discs in a few seconds. The 2-line display shows the disc or track name on the top line, and the elapsed time on the bottom. The LCD is backlit in a blue-green color, and the buttons can be switched between green and red illumination.

It has a diversity antenna system, which constantly samples two antennas to determine which has the best signal. This gives improved radio reception in areas with weak signals.

It controls an optional TV in the car, and you can see the disc name and track names on the TV. It also controls an optional DSP module which lets you set your seat position and then it digitally delays the signals from each spkr by different amounts so that they all reach the specified position at the same time. The DSP has 10 DSP modes which you can link to your CDs, so that you can have your classical CD play in the concert hall DSP mode, and the disco CD play in disco DSP mode automatically.

The only mis-features that the MDX-400 has are:

• It does not have the "source tone memory" function (independent bass/treble settings for FM, AM, MD, and CD) that most sony ES car receivers have. This is instead implemented with as the "Last Sound Memory" function of the optional DSP. So, you have to have the DSP if you want this feature.
• The "Loudness" function is disabled if you have the DSP connected. Without the DSP, the loudness function works fine.

Reviews:

User Manual: MDX-400