Thursday, November 17, 2011

MP3 FM Transmitter

Winter is coming, so I will be driving the Jaguar for the next few months.  Unfortunately, it does not have a CD changer--only a single in-dash CD player.  Installing the CD changer in the trunk is about $1000 if the dealer does it, and it is still an astonishing amount of money if you buy the changer and do it yourself.  I am thinking of getting one of the gadgets that transmits MP3 on an FM frequency.

This unit gets very favorable reviews--even some of the low-ranking reviews are still pretty favorable:

What I like about it includes:

1. Let's me use the various SDHC cards that I have lying around the house.

2. Transmits song information to the Jaguar's RDS system, so you get song title and performer on the stereo display.

3. While a wired input apparently provides excellent sound quality, some reviewers say that the FM connection rivals CD sound quality.  Since there is no external jack on the Jaguar stereo, this is attractive.

4. Cheap enough that if the unlikely were to happen, and someone broke into my car to steal it, it would not be a great hardship.

5. While it is limited to 500 files on SDHC or USB stick, that's roughly equivalent to more than 30 CDs.  If I have to switch media every few days on a long trip, I think I can handle that.

Any suggestions on such units?


  1. MP3 is a lossy compression system - it can't possibly match CD but obviously most people - and almost certainly anybody with normal frequency loss associated with aging - find good enough good enough. BUT I'd investigate a new head unit at today's prices with a wired maybe USB connection.

  2. I tried one of those "Jupiter Jack" dongles that connects to one's phone and broadcasts on one of two frequencies to one's car stereo. I can't report on how good it was because both channels had strong stations on them that the device couldn't overpower.

  3. I wasn't able to click on the link for some reason, but I have had very poor experience with various FM Transmitter devices for my ipod.

    Let me second Clark Myers (above), buy a new in-dash unit from an aftermarket brand (I like Alpine, lots of good brands out there). It will cost a couple hundred bucks, at most, for a very nice unit with a direct wired connection.

  4. This is not limited to two frequencies. Apparently you can pick which frequencies to use, and have as many as seven available at once (presumably if you travel in areas where many frequencies are in use).

    One of the reasons that I have not considered a new head unit is the integration with the steering wheel controls for the stereo. This is a very nice feature to have, and I would not want to give it up.

  5. Clark:

    Yes, MP3 is a lossy compression algorithm. The theory, as I understand it, was that it was intended for use in cars and other places where spectacular audio fidelity was likely not going to be a factor anyway.

    I can remember my first car with a CD player. I was playing a classical CD and I could actually hear what sounded like one of the musicians dropping something. It was so subtle that I might not have heard it in the previous audio media!

    My recollection is that FM is limited to 11 Khz bandwidth; the chances that I am losing much at my age by transmitting through FM is pretty small--not enough to spend $300+ for Jaguar to install the box that lets me wire this unit into the stereo.

    I have looked; I can't find any aftermarket stereos that can handle the steering wheel controls for the Jaguar. They might be out there, but the X-type seems to be a pretty small market, and that may be why I am not finding them advertised.

  6. This is a little off-topic, but my solution to this was to get an Archos tablet. I bought one with a large internal drive (~150GB) so it easily holds my entire MP3 collection (~40GB). It comes with a built-in FM transmitter - with selectable transmission frequency - and it works well.

    As for MP3 fidelity, two points: I had my hearing tested in my mid-20s and couldn't hear past 18.5 kHz *then*. So now, 3 decades later, I'm not too worried about missing the high notes; particularly while I'm traveling in a car.

    Second, a little attention to the compression settings you use when you generate the MP3 will go a long way to preserving fidelity. MP3s come in varying grades of fidelity. Some are horrible; some are pretty good.

  7. I also cannot see the ad at the moment.

    However, I use what is likely a much simpler device.

    It a little like this example, but with no built-in memory or card slot.

    One big advantage is that I can manually tune it to any FM channel (87.5 to 107.9 MHz). That is much better than varieties that come with a limited set of defaults. (Although a set of programmable defaults would be nicer...)

  8. Karrde:

    I saw this, but so many of the reviews were so negative, I decided spending an extra $30 made more sense. Also, the unit mentioned above (whose ad I can see just fine) provides RDS data as well, which for my stereo is useful.

  9. Check that your car radio can't play MP3 songs directly from a data-CD. You can burn quite an extensive collection of MP3s onto a CD, and many car stereos of the past decade will play them and let you navigate the menu to them easily

  10. I can play CDs with MP3s on the CD player just fine. But one CD at a time. It is a bit clumsy to do it that way instead of having dozens of CDs queued up.

  11. It sounds to me like you have tried using Audio CD's burned from MP3 files instead of making data-disks with MP3 files on them:

    But I've downloaded the Audio Systems manual for your car and it suggests nothing about being able to play MP3's directly, so this is probably a moot point in the case of your Jag.

    In my Ford, I can fit about 10 hours of downloaded MP3 files onto a single CD-R, and the car stereo plays this disk just fine and allows intuitive selection of tracks or random play. I don't much mind taking the time to swap CD's for my next 600 miles.

    According to Popular Mechanics, the FM units which connect directly into the car's antenna line give better quality:

    There is more hassle in installing them, however. Like others, my experience of Ipod FM units is long in the past when units weren't as good, and I suffered from lots of interference. I suspect the unit you have found will be just fine.

    BTW: FM broadcast audio bandwidth is 15kHz, most of us have been listening to it our whole lives and don't find it awful.
    MP3 was intended to save data-rate and data-storage capacity, and if encoded with Fraunhofer-Gesellshaft's "best" psychoacoustic model from a 24-bit source audio-file, it can have perceived dynamic range that exceeds a CD. The reason people hate MP3 is partly
    audiophile snobbery, and partly because so many of the MP3s that we hear are encoded with too-low a data-rate or encoded using inferior software encoders.

  12. It did not even occur to me that you might be referring to CD-Rs in data mode, not audio mode. It might be worth trying! I suspect that you are correct that it won't work.

  13. I went ahead and created a data CD-R, which let me put about seven albums on one disc. As expected, the Jaguar CD player does not know what it is; neither the 2007 Chevrolet TrailBlazer CD player. I am not even going to try it in the 2000 Corvette. Still, it is a useful trick for those who have a modern CD player--you can get a lot more CDs on one disc than you can in audio mode.