Transmit FROM a car radio as source to BT headphones

[Odysseus42]

Noobie/beginner here

I want a transmitter device which will broadcast car radio sound to a BLUETOOTH receiver, such as BT headphones, NOT TO THE CAR RADIO, BUT FROM THE CAR RADIO USING BLUETOOTH and allow the car's speakers to be turned off?

I understand the reason (safety) why auto manufacturers do not include an output (e.g. 1/8" pin) from the car radio, but if the person listening is not the driver, then (like screens in the back seat) there is no reason not to have this capability.

The ideal device would be one that plugs into the cigarette lighter socket, or a USB port, but that requires somehow routing the car radio output to one of those, and this is well beyond my tech capabilities.

Is there a socket, ideally accessible without taking the dash (or any part thereof), that will plug in between one of the existing male/female wiring connectors to provide the car radio source for such a device which will then broadcast over BT.

As is probably evident, I don't know much, if any, car audio terminology, so please be patient. I am happy to try to clarify any confusion above, but please include an explanation for any industry terminology (e.g. head unit, etc.) that you might use.

And if this post should go into another category, can a mod transfer it to the correct subforum? Tks

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[Jimi77 5,000+ posts]

Why, to what end? That said, I'm sure there are bluetooth transmitters that can take your preamp outputs and transmit it over bluetooth. Something like this could work.

https://www.bhphotovideo.com/c/product/1706524-REG/sennheiser_508258_bt_audio_transmitter_4_2_compliance_aptx.html/?ap=y&ap=y&smp=y&smp=y&lsft=BI%3A6879&gclid=EAIaIQobChMIk_imz6bkgQMV5RitBh3NXwG0EAQYBCABEgKQ3vD_BwE

 

[Doxquzme Premium Member]

Noobie/beginner here

I want a transmitter device which will broadcast car radio sound to a BLUETOOTH receiver, such as BT headphones, NOT TO THE CAR RADIO, BUT FROM THE CAR RADIO USING BLUETOOTH and allow the car's speakers to be turned off?

I understand the reason (safety) why auto manufacturers do not include an output (e.g. 1/8" pin) from the car radio, but if the person listening is not the driver, then (like screens in the back seat) there is no reason not to have this capability.

The ideal device would be one that plugs into the cigarette lighter socket, or a USB port, but that requires somehow routing the car radio output to one of those, and this is well beyond my tech capabilities.

Is there a socket, ideally accessible without taking the dash (or any part thereof), that will plug in between one of the existing male/female wiring connectors to provide the car radio source for such a device which will then broadcast over BT.

As is probably evident, I don't know much, if any, car audio terminology, so please be patient. I am happy to try to clarify any confusion above, but please include an explanation for any industry terminology (e.g. head unit, etc.) that you might use.

And if this post should go into another category, can a mod transfer it to the correct subforum? Tks

Sometimes good ideas just seem good but in reality, they don't make any practical sense use in the day-to-day reality of things. That said, I'm always open to new ideas. Why is this needed, or wanted? Your BT car audio HU's are already transmitting to speakers or BT audio in the car, not following here. When are you in the car that you are not with your phone (a BT transmitter in itself)?

 

[Odysseus42]

When my wife and I are on trips, we share driving. Whoever is driving chooses whether or not to have the radio on. I like to listen to XM radio, but my wife does not. In some areas, there is no cell signal so cannot use phone.

 

[Odysseus42]

Sometimes good ideas just seem good but in reality, they don't make any practical sense use in the day-to-day reality of things. That said, I'm always open to new ideas. Why is this needed, or wanted? Your BT car audio HU's are already transmitting to speakers or BT audio in the car, not following here. When are you in the car that you are not with your phone (a BT transmitter in itself)?

Are you saying that the car radio connects with the car's speakers over BT instead of wire? If so, can the transmission be intercepted by headphones?

 

[Odysseus42]

Why, to what end? That said, I'm sure there are bluetooth transmitters that can take your preamp outputs and transmit it over bluetooth. Something like this could work.

https://www.bhphotovideo.com/c/product/1706524-REG/sennheiser_508258_bt_audio_transmitter_4_2_compliance_aptx.html/?ap=y&ap=y&smp=y&smp=y&lsft=BI%3A6879&gclid=EAIaIQobChMIk_imz6bkgQMV5RitBh3NXwG0EAQYBCABEgKQ3vD_BwE

The link reads: "The BT T100 Bluetooth Audio Transmitter from Sennheiser acts as a bridge between your existing wireless Bluetooth headphones and your wired audio sources. You can use it with TVs, computers, or any other audio device that outputs audio via 3.5mm or optical audio cables." My Subaru Forester does not have a 3.5mm or, AFAIK, optical audio cables. If it does have the latter, how would I access them?

 

[Odysseus42]

Are you saying that the car radio connects with the car's speakers over BT instead of wire? If so, can the transmission be intercepted by headphones?

In some areas, there is no cell signal so cannot use phone.

 

[Jimi77 5,000+ posts]

The link reads: "The BT T100 Bluetooth Audio Transmitter from Sennheiser acts as a bridge between your existing wireless Bluetooth headphones and your wired audio sources. You can use it with TVs, computers, or any other audio device that outputs audio via 3.5mm or optical audio cables." My Subaru Forester does not have a 3.5mm or, AFAIK, optical audio cables. If it does have the latter, how would I access them?

I doubt you have optical audio cables. Assuming you have a base audio system, you need to tap into the speaker outputs with a line out converter and feed that into the Bluetooth audio transmitter. You'll also need to build a switch/relay system to shut off power to the car speakers.

 

[Odysseus42]

Jimi, that sounds promising. If something like that could be done, do I understand that the car radio volume control will also control the volume on the BT headphones so that it is not just a simple matter of turning down the volume to the car speakers and using the BT headphones to adjust volume?

Also this setup sounds complicated to me. What $ range would you expect a car sound shop would charge for such an undertaking?

 

[Doxquzme Premium Member]

Are you saying that the car radio connects with the car's speakers over BT instead of wire? If so, can the transmission be intercepted by headphones?

No, it reproduces signals through the system's speakers that are being transmitted from your BT source, a phone in this reference. That said, the phone is the transmitter. What would you need a separate transmitter for? Is it not possible to get any source you would get on a HU to a transmitter over the phone anyway? I'm not understanding why you could not just use your phone. Guess I'm missing any practical application.

 

[Doxquzme Premium Member]

In some areas, there is no cell signal so cannot use phone.

In those areas, it's also possible that your radio signals are compromised too. For everything else, SSD digital music devices are a practical option. Again, not seeing any practical application for your idea.

 

[Doxquzme Premium Member]

Noobie/beginner here

I want a transmitter device which will broadcast car radio sound to a BLUETOOTH receiver, such as BT headphones, NOT TO THE CAR RADIO, BUT FROM THE CAR RADIO USING BLUETOOTH and allow the car's speakers to be turned off?

I understand the reason (safety) why auto manufacturers do not include an output (e.g. 1/8" pin) from the car radio, but if the person listening is not the driver, then (like screens in the back seat) there is no reason not to have this capability.

The ideal device would be one that plugs into the cigarette lighter socket, or a USB port, but that requires somehow routing the car radio output to one of those, and this is well beyond my tech capabilities.

Is there a socket, ideally accessible without taking the dash (or any part thereof), that will plug in between one of the existing male/female wiring connectors to provide the car radio source for such a device which will then broadcast over BT.

As is probably evident, I don't know much, if any, car audio terminology, so please be patient. I am happy to try to clarify any confusion above, but please include an explanation for any industry terminology (e.g. head unit, etc.) that you might use.

And if this post should go into another category, can a mod transfer it to the correct subforum? Tks

Just saw the post about XM and sharing the radio when out of reception areas. Get a satellite phone, one that has BT that is - problem solved!

 

[Jimi77 5,000+ posts]

Jimi, that sounds promising. If something like that could be done, do I understand that the car radio volume control will also control the volume on the BT headphones so that it is not just a simple matter of turning down the volume to the car speakers and using the BT headphones to adjust volume?

Also this setup sounds complicated to me. What $ range would you expect a car sound shop would charge for such an undertaking?

I have no idea what they'd charge. TBH, I'd call it a simple install, but I have a lot of installs under my belt. A simple solution and free solution would be to just download music to your phone and switch to downloaded music/content when you're out of cell range. Alot music services will allow you to download music for a small fee.

 

[metalheadjoe 10+ year member]

There's no reason for that feature to exist.

 

[1aespinoza 10+ year member]

When my wife and I are on trips, we share driving. Whoever is driving chooses whether or not to have the radio on. I like to listen to XM radio, but my wife does not. In some areas, there is no cell signal so cannot use phone.

Portable XM player.