Using Bluetooth and cabin speaker

I don't really want to permanently mount a cabin speaker

There are sometimes I just don't want to wear the headset. I've got a great Bluetooth portable speaker that really throws out the sound. What I'm looking for is a Bluetooth transmitter that has a male plug that plugs into an aircraft headset jack. This Bluetooth device would broadcast to my portable speaker everything it hears. I've seen these with 3.5mm jacks for conventional devices, but I'm looking for one compatible with aviation systems.

Anyone seen anything like this?

Thanks,
David

Buy one of those little bluetooth transmitters with the 3.5mm plug and also by a 3.5mm to 1/4 adapter.

But, I think that device is going to be looking for around 32 ohms impedance. Aviation headsets are 150 ohms total (300 ohms in parallel). It might attenuate audio for other positions (pilot/pax). It won't harm anything to try though.