XTL2500 audio into vehicle stereo system?

[MatRat80109]

I am helping a friend find a installation solution. They have gotten in some 2013 Ford Interceptor SUVs and are going to install Motorola mid power 700/800 MHz XTL 2500s in them. I believe it is a single XTL in each vehicle. They are looking for a way to have the XTL 2500 audio play through the front vehicle built-in speakers without disabling the ability to hear warning tones/beeps from the vehicle or the built in stereo. I see combiners for multiple radios into single speakers but think this is a bit different. I have strongly warned them not to ground either leg of the XTL audio output of the radio in any way.

Anyone have experience with this?

Tks,
Jacob

[jim202]

Originally Posted by MatRat80109

I am helping a friend find a installation solution. They have gotten in some 2013 Ford Interceptor SUVs and are going to install Motorola mid power 700/800 MHz XTL 2500s in them. I believe it is a single XTL in each vehicle. They are looking for a way to have the XTL 2500 audio play through the front vehicle built-in speakers without disabling the ability to hear warning tones/beeps from the vehicle or the built in stereo. I see combiners for multiple radios into single speakers but think this is a bit different. I have strongly warned them not to ground either leg of the XTL audio output of the radio in any way.

Anyone have experience with this?

Tks,
Jacob

One major point to keep in mind is that you can NOT GROUND EITHER SIDE of the speaker wires from most of the Motorola radios. Doing so will blow the audio output section and the radio will have to be repaired.

You could find a 1:1 transformer for 3.2 ohms to the same or 8 ohms. Anything to isolate the radio from grounding either speaker wire.

[W2NJS]

Here's a sidenote for what it's worth. In the past I've successfully run the audio from an XTS5000 through my Subaru's 400 watt Harmon Kardon audio system via the system's aux input. The source was taken from the earphone jack on the speaker/microphone.

[DOC_ET]

Agreed on the "no ground" principle...

It sounds like you have two separate goals to accomplish. 1) to route the audio through to the existing speakers and 2) prevent any other audio from interfering with the radio traffic to be heard.

For quite a while, I would route the speaker audio into the driver door speaker of a car. I would completely disconnect that speaker from the system, remount it in the door using plastic washers to prevent it from making contact with the door and then connect it to the radio. This worked very well for me and the several cars I did it to.

The audio from the car's OBD computer can come from a variety of locations, but these days they tend to route through the radio and emitted from the driver door. I'm not sure I see the harm in keeping those sounds as they to tend to be relevant to the operation of the vehicle (not judging, just one man's opinion).

I have recently begun using the audio mute feature in the car radio. This is fantastic when you get it working right. Many cars now are prepped for a bluetooth add on. The bluetooth usually has an output that grounds when a call comes through to mute audio. The radio is often prepared for this input (i have found this to be particularly true in Ford) and is only a matter of connection. If you use a COR or TOR signal from the radio to provide a ground or drive a relay to ground, you could allow the operator to use the car radio normally but when the xtl receives audio it will mute the car audio for the duration of the call. You could get really fancy and use DPDT relays to shift the audio back and forth.

Like I said... Just my two cent, but I hope it is helpful. Good Luck!

[Skypilot007]

Why not just mount the motorola external speaker somehwere and keep it simple. These vehicles have plenty of room in there for one spreaker.

[MatRat80109]

Thanks for the ideas all. I have since heard that the bluetooth is also tied into the front speakers and can not be interfered with. They also can not spend any money on this change the end-user wants. So it is a dead issue.

Tks,
Jacob

[W2NJS]

MatRat,

Don't give up so easily. First, your friends should ask why they want to use the SUV's built-in speakers for the PS radio system. It's probably a much better idea to keep the systems separated for any number of reasons. Second, any seasoned radio installer can figure out a way to use simple 1:1, for example, isolation transformers on the "no ground" XTL audio output. Then they can have AM/FM audio, or XTL audio, but using the same speakers they'll find it hard to devise a system that will give them both at the same time. But again, who would really want such a horrible mish mash of sound when trying to hear the dispatcher. Just doesn't make sense.