My neighbors are setting up outdoor movies with a few groups of people sitting 6-10 feet apart. The setup is a a smart projector and multiple Bluetooth speakers - one at each group, and the group members will bring their own speakers. It is analogous to a drive-in movie with a single large screen and multiple small speakers.

Let’s assume there are 4 Bluetooth speakers that were mostly made circa-2015 and we are trying to use what people currently have wherever possible. How might we keep the multiple Bluetooth speakers reasonably in sync so that there is not so much out-of-sync audio that it becomes distracting?

I am thinking of plugging in a 3.5mm splitter to the smart projector and then attaching multiple Bluetooth transmitters to the 3.5mm jack.

Would it perform better to use a 4 or 5 way 3.5mm splitter like this 5 way splitter

And plug in 4 simple Bluetooth transmitters to it?


Use a 2-way 3.5mm splitter like this 2-way splitter

And plug in 2 Bluetooth 5 transmitters like this bluetooth transmitter

...which can pair simultaneously with two speakers each



4 BT transmitters talking to 4 receivers is a setup liable to cause delay problems.

If all of the receivers support Bluetooth LE, you should be able to run one transmitter for all receivers, which will improve things. You still have some uncertainty in the amount of delay introduced by each speaker.

Some BT speakers also have a 3.5mm input jack. That's easier to set up and will guarantee there are no delay issues.

  • How might I find a transmitter that will stream to four receivers? In searching for “multistream bluetooth le transmitter” I am only finding devices that stream wirelessly to up to 2 receivers. Wired connections would be tripping hazards in this setup (dark with people scattered about), so thanks for the tip, but trying to avoid that. – Mike Eng Jul 26 '20 at 11:14

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