I bought this head unit 4 years ago. It's currently installed in a '99 Honda Civic Coupe, which the four speakers where changes for a higher quality than the stock Pioneer speakers, made with paper cone and a 15 watts rms magnet. The head unit is rated for 18 rms watts on a 4 ohms speakers, I measured 20 rms watts without audible distortion at 80 hz, maybe the unit is underrated, but it is CEA-2006 certified (don't even know if it is more accurate than other head unit ratings, I guess it should). My head unit was hardly used, and show only a few minor problems described below:

I was considering a Clarion head unit and this Alpine. My choice was the Alpine because I do not know someone that had an Alpine head unit, so I guessed it was time for me to try one...

I live in Canada, where temperature changes from -25 to 35 degrees, which I think is a hard test for a head unit. After 4 years of non-stop work and so much cd's that went into the device, I need to say that de CDA-9831 was a good purchase. The head unit main features are a large range of color for the four main buttons and a green or orange back color for the smaller buttons, a customizable equalizer with two "user's eq" memory and a few presets, mp3, wma, XM ready, etc.

About the color customization, Clarion head units features a color customization that changes the entire panel's color. The Alpine changes only the main buttons (source (power), band, previous and next button).
About the built-in amplifier, it delivers a great sound quality, best of all head units I've tried; It's a great balance of power and quality, pioneer's mosfet circuit is more powerful but has a poor sound quality when directly compared to the CDA-9831.
The alpine features a sound correction that allows user to changes the speaker time correction, so that the sound comes to driver's ears at the same time for four speakers. This feature is cool when it's set correctly, but like in most cars, the distance of each speakers from the driver's head doesn't shows a huge difference, and the time correction is set only for one people in the car, I mean that I've tried to set the time correction like if the driver's head was between the two front passenger: The setting of the time correction was nearly the same as when it was turned off, so since the last 4 years, this setting is turned of. It might be really great in a bus, when the rear speakers are far away from the driver's head, but not in a compact car.
The display show only one line of text: It can shows a lot of the mp3's ID3 values or cd-text like the name of the song, band, album, file name, folder name, folder and file number (files on the root of the cd are in folder 0) and the clock. Clock is only shown whit the file and folder number; It would be great to have the clock and the song's title at the same time... :(
The volume knob is used to navigate in the menu, for example, when customizing the equalizer, you can't turn up/down the volume. You need to exit the setup menu and the main menu, turn up/down the volume, and get back into the menu once again...
When compared to other head units, when a cd full of mp3 files is loaded into the device, the display shows "loading" during a huge 15 to 30 seconds, while you hear the laser lens seeking from one end to another on the cd a few times. The head unit show also the same delay when seeking from the last song of the cd or the last file of the last folder to the first song.
On a mp3 cd, the first 1/4 of the first second of each file is not played at all. Which is annoying when the music starts at the very beginning of the file.
When playing large mp3 files, it get stuck somewhere at the 230th minute, this is not something that most users will try, but I did ;)
The swing tray mechanism is a little to slow, it's working great and hide the loading tray, but it's a little too slow and noisy. It also get slower in cold conditions.
When loading a mp3 cd, now and then, device shows "error". Eject and load once again solve the problem in most cases. But it sometimes doesn't want to load a particular cd, 5, 6, 7 time in a row, and than it works on the 8th try... And if the displays shows the track number, it doesn't show "error" then it should, it shows "T--" during the loading and after the error should appear.
The head unit also changed the equalizer to fully higher eq bands... the sound was audible at 1, loud at 2 and distorted at 3. Thanks to the reset button.
The head unit sometimes doesn't light the four main buttons.
But has I wrote at the beginning of this review, the head unit had to work in deep cold and extreme high temperature, also during a 11 000 km trip that lasts 5 days of non-stop cd and mp3 playing...

If you don't have any problem using some complicated devices with non-user-friendly menu, you can use the CDA-9831 and enjoy the sound quality.

Recommended: Yes

Amount Paid (US$): 380