Sony CDX-T70MX MP3 CD-changer install

[TomH]

A couple of weeks ago (before the recent unfortunate accident) I installed a Sony CDX-T70MX MP3-capable 6-disc CD changer in my MINI. I used the custom cradle designed by MINI specifically for Sony CD changers.

I have the Boost MiniDisc head unit with Harman Kardon, but I understand that the same instructions would apply to any MINI with CD-prep.

The cradle is a great piece of kit. It holds the changer neatly out of the way so that it takes up as little boot space as possible. It also fits using the existing screw holes so you don't have to drill any new holes in the metalwork. The cradle is an official MINI part. I got mine from Damon Hill MINI in Warwick. If you want one, the guy to contact is StevePSB.

The CD changer itself is not available from MINI. I got mine (together with the Connects2 box which allows you to connect the Sony changer to the BMW-protocol CD-prep cables) from Car Audio Discount in West London. They delivered it very quickly and I would recommend them to anyone.


Here are some pictures of the installed unit:



The changer is located on the right side of the boot, and fits under the lip with the boot light:


To change the cartridge, the unit tilts forward by about 10 degrees and can be locked into that position:


If you need to get to the access panel, the changer can be tilted through 90 degrees:


Installation

Installation is pretty simple.

Note: These instructions assume that you have CD-prep. If you don't, then you will need to run the cables to the front of the car, and find some way of connecting them to the head unit. I know this is possible, but I didn't do it, and don't know how to do it.

The first thing to do is to set the changer up for vertical installation (it came set for horizontal). There are two plastic things on either end of the unit which should be turned (using a coin in the slot) through 90 degrees to the vertical setting. Don't forget to do this before putting the changer into the cradle! (Sorry no pictures).

Next slide the changer into the cradle, and fix it in place with a few short machine screws (supplied). I found that there was only one way round that it would easily fit -- the leads emerge from the changer on one side, torwards the back corner; and because of this it would only slide into the cradle one way around (the cradle has a slot down one side to accomodate the leads). (Still no pictures).

You will need a hole in the plastic access panel for the leads to go through. The easiest thing to do is to use one of those large drill bits used for making holes in wood. It would look neater with a grommet, but I couldn't find one large enough. Besides the hole will be hidden behind the changer itself... This is the only drilling that is necessary!


Next you should sort out the cables. It is easiest to do this before you install the changer, since you will have slightly better access to the space behind the panel. Find your CD prep cable. In my car it was taped to the wiring loom under the Harman Kardon amplifier. If you don't have HK it should be a little easier to find. I carefully cut the (masking) tape to free the the cable. It should split into two near the end and has two rectangular connectors:


The most awkward thing here is what to do with all the cable that comes with the changer. There are two 5m cables -- one is a pretty standard stereo RCA-audio cable; the other is a Sony data cable with a strange proprietary connector. Since the CD-prep cables are already very near the changer there is lots of excess cable. If you don't have HK there should be plenty of room, but if you do then you will want to tuck the excess cable out of the way. Just free some cable at each end of each bundle -- enough at one end to reach the Connects2 box (which will live behind the access panel) and rather more at the other end to go through the hole to the changer. Put the rest of the bundled cable out of the way:

The double cable in the foreground is the audio cable which I put just next to the wheel arch. Behind that you can just see the thicker "uplink" cable which I put in the space behind the rear light cluster.

Now you are ready to install the changer and cradle in your MINI.

The cradle is held in place by a metal plate which fixes to the two screw holes underneath the right-side access panel:

There is also a small metal lip which protrudes backwards from the top of this plate and rests on the narrow "shelf" immediately below the access panel; this takes most of the weight -- the screws just hold it all in place.

Just remove the two screws that hold the plastic trim in place, position the changer and cradle, and fix it using the two slightly longer screws that came with the cradle.

Before making the electrical connections you should disconnect your battery. If you don't then the stereo won't recognize that the CD changer is there.

Plug the CD-prep leads into one side of the connects2 box, and the leads to the changer into the other side:


Position everything so that the access panel will fit back on, thread the cables through the new hole and put the access panel back into place, and connect the cables to the female connectors on the changer:


Now return the changer to the upright position, reconnect the battery, and everything should be working .


Recording Settings

The settings you use to rip CD's can make a lot of difference. I am no MP3 expert, but I understand that VBR (Variable Bit Rate) is supposed to sound better than Fixed Bit Rate, as well as taking up less space (unless you use a very low FBR, in which case the sound quality will not be good).

The problem with VBR is that it may confuse the player's display of elapsed track time. However the standard MINI head unit doesn't display elapsed time (only the CD and track number) so this is not a problem. If you are using an aftermarket head unit that does display elapsed time, then you must decide between seeing the correct time and the advantages of VBR.

According to the instructions the changer can handle up to 511 MP3 files on each disc. The standard head unit gets a bit confused after track 99 and doesn't display the track numbers correctly (it goes "CD 1-99" -> "CD 1- " -> "CD 1-01" for example). But you can still navigate between tracks properly so this is a small price to pay.

For my CD ripping, I use iTunes on the Macintosh with the following (custom) settings:

Stereo Bit Rate: 128 kbps (this is just a minimum bit rate for VBR)
VBR: Highest Quality
Sample Rate: Auto
Channels: Auto
Stereo Mode: Normal (as opposed to Joint Stereo)
Smart Encoding Adjustments: On
Filter Frequencies below 10Hz: On

This gives me an average bit rate of about 140 kbps (and 140 kbps with VBR should sound better than 192 kbps fixed rate), which lets me squeeze about a dozen CD's onto one 700MB CDR.

I did find that my first recordings (with 192 kbps fixed bit rate) sound very slightly less good than MiniDisc in LP2 mode (i.e. still pretty good...). I have since re-ripped all my CDs with VBR which I expect will be an improvement. But the unfortunate intervention of some b****** driving a (probably-stolen) BMW sent my MINI off to the bodyshop before I could do a proper sound comparison.

But I did cut a VBR test disc, so I do know that the changer is quite happy with VBR files.

I also read that the standard MP3 encoder in iTunes is not the very best, so I tried using the highly-regarded LAME encoder. But it was so slow (took about the same time to rip one track as the default encoder did to rip a whole CD!) and I couldn't really hear the difference...


I guess now that the 05 CD player can handle MP3 there will be less call for this changer but there are still loads of people out there with older MINI stereos for whom this might be useful.

Tom.

[Rich_IX]

Nice write-up I have the same Cradle and CD Changer as yourself, But when I got my CD Changer the converter was faulty and had to send me a new one.

Looks good

[miniXL]

TomH,

Thank you very much for this detailed installation guide and great photo's.
I have purchased all the part and will be following these instructions when my baby finally arrives!

Happy Motoring!