We manage a Pilatus PC-12 airplane in which the manufacturer certified a Sony car stereo as cabin entertainment. Totally state of the art… for 1995.
The speaker output of the car stereo is used to drive airliner-style six headphone outlets in the passenger cabin. They are all hooked up in parallel across the speaker outputs (100X the power required to drive modern noise-canceling headphones?).
Instead of trying to modernize this system, it would make sense to buy a stack of Monoprice Bluetooth noise-canceling over-the-ear headphones ($70 each) and drive them all from one smartphone. Except that the typical smartphone can drive only one Bluetooth audio device at a time.
How could the designers of this standard not have foreseen that people would want a broadcast mode?
This year-old Qualcomm web page says that the hardware for a lot of phones is now capable of broadcast audio via Bluetooth. The company publishes a page showing 7 headphones connected to one phone. Yet as far as I can tell, nobody is implementing this from software. Samsung offers “dual audio” on the S9 and S10 (two headphones). Apple offers nothing.
How did we get to the point that the latest and great technology makes it tougher to share music than it was with the original Sony Walkman (1979)?
[One idea for the airplane is to try to drive all six headphone jacks in parallel from an MP3 player or a Bluetooth headphone amp. The latest noise-canceling wired headphones have high impedance and sensitivity and therefore even six in parallel would be an easy load to drive. Or we could do nothing and wait for an Android implementation that actually enables the Qualcomm hardware capability?]
Entrepreneurs: A lot of aircraft now have USB power outlets. Owners would be happy to pay $1,000 or more for a little box that drives the Qualcomm hardware as intended. FAA certification shouldn’t be required since the device wouldn’t be permanently installed in the aircraft (no different than a passenger bringing a smartphone or tablet on board).
It’s pure speculation on my part, but I’d be shocked if the music industry has not had some significant influence on the physical device implementations of Bluetooth to specifically discourage use of the broadcast capability.
You’re the only one in the world with a family who could use such a thing. Everyone else is living alone or married to someone they don’t want within bluetooth range. The range would have to be increased for the married people, to the size of a courtroom.
Search Amazon.com for “silent disco headphones” or “silent dance party headphones” or “silent symphony headphones”. They broadcast on unregulated 900-915MHz, instead of a Bluetooth connection. Add some usb disco/dj lights and turn your dull cabin into a FL280 party!
Had been looking for something like this for my home theater system for a while. Will allow us parents to enjoy a movie when the children sleep. Please post here if you find anything useful.
Possible handwavey idea: Use one of the apps that syncs music across multiple phones (I think you need WiFi for this and don’t know if you have that on the plane). Instead of using them as an ad hoc Sonos system, plug in headphones.
Also google IR (infrared) headphones. A lot of car DVD players (as found in minivans) broadcast an IR signal. The headphones are cheap. For non-car use you can get an IR sending unit (also cheap) that plugs into a 3.5 mm headphone jack which will convert audio to IR.
This is a thing for motorcyclists, but from what I can tell they are up to 6-way intercoms with music. I’m not sure if the music is sent to all units or is personal to each headset (maybe a feature not a bug). Plus I only see them as complete headsets.
The closest I’ve seen for an intercom base station with BYOHeadset is these guys. I can’t tell if they support more than two headsets though.
https://www.sena.com/product-comparison-others
Might also try Alibaba. Lots of amazing stuff that could never hold it’s own on retail shelf-space is listed there. Good luck.
For $6, you can try a cheap experiment with this five-way splitter: https://www.amazon.com/dp/B01L7HX4XY
Also, a search for Bluetooth splitter brings up a number of devices in the $30 range that will output from TRS plug to two bluetooth headsets, but not more.