FM Wired Modulator

A good friend of mine recently got one of those neat little iPods.  He made me a deal on his not very old 30 GB Creative Labs Zen Xtra MP3 player that I simply could not refuse.  I had always wanted a portable MP3 player that could serve double duty as a music source in the TJ.  The travel time to Moab and California would go quicker with some of my favorite tunes playing in the vehicle.  Since my factory radio doesn’t have audio input jacks, I decided to try an FM modulator and see if I could get my MP3 player running in the TJ.  And so the search started.

After spending several hours reading user feedback on various FM modulators, I decided to give the Scosche FM-Mod01 unit a try.  I got it from Buy.com for just over $25 (including shipping). 

The Scosche modulator is not a wireless unit like so many of the FM modulators.  The vehicle’s antenna cable is unplugged and the modulator’s two antenna connectors are hooked up to the car antenna and radio.  +12V and a ground are all that are required to power the unit and complete the installation wiring.

The modulator comes with a short stereo patch cable (about 3 ft).  A pair of RCA jacks on the modulator accept the audio signal.  The patch cable as a standard 1/8″ stereo plug to connect to your MP3 player.

When turned on, the FM signal, now carrying the MP3 player music, is fed directly into the radio’s antenna port.  The result is a fairly good sounding signal.  I compared it to a number of local FM stations here in the Phoenix area.  The music from my MP3 player didn’t sound as good as that coming from the FM station I normally listen to.  However, it sounded better than several other “less popular” stations in the area.  Compared to some of the reviews I read concerning other FM modulators, I would say this one ranks fairly high.  It does take about 5 seconds to energize once the power switch is enabled.  That seems to be the one major issue that some folks complained about.  While waiting for the transmitter to come on, you hear static from the vehicle’s radio.

I removed the glove box from the dash to get to the antenna cable.  It is located right near the fuse box and mine had a foam sleeve on it (easy to spot it that way).  With the antenna cable unplugged, I connected the matching connectors on the modulator to the TJ’s antenna connectors.  Easy to do and I was already half way done with the installation! 

I crimped a ring terminal onto the ground lead and found a screw that I could slip the terminal under.  I used a switched ignition wire (turns on and off with the ignition key) to supply power to the unit.  Since I had an unused switch on my center console, I opted to route the power for the modulator through that switch.  (I tossed the switch that came wired to the modulator). 

A couple of zip ties were used to secure the modulator.  I plugged the stereo audio connectors into the two RCA jacks and routed the cable through the dash so that it came out at the center console to plug into the MP3 player.

With power applied and the MP3 player plugged in to the audio cable, I tuned the TJ’s FM radio to one of the two frequencies the modulator operates on.  I was treated to the sound of one of my favorite songs.  The audio was a little low so I adjusted the level control (on the modulator) with a small screw driver.  That brought the sound up so that it was about even with the audio on the other radio stations.  I had the MP3 player at about 3/4 volume.

BradW, a good friend of mine, stopped by the next day to take a look at another project I was working on.  Brad is pretty much into the world of audio (tube amps and all).  He listened to the MP3 player and thought it sounded very good.  Given Brad’s critical ear, I took that as a pretty good indication that the setup was working OK.  He left and came back a bit later with his iPod in hand.  Before he ordered one, he wanted to hear what it sounded like with his iPod plugged into the modulator.  He had not see a wired modulator before and was impressed with the performance and solid signal it fed to the TJ’s radio.  I passed along the information needed so he could order one for his Rubicon. 

As I mentioned earlier, I researched a few different brands of modulators and without a doubt, this one came up with very good comments, especially when you consider the low cost of the unit.  With any luck, it will give several years of good performance.  If it does, it will have been a bargain for sure.