Drive-In Theater Speaker Rebuilt with Bluetooth

The first drive-in movie theater was opened in 1933 in Camden, New Jersey. In the subsequent nine decades their popularity has varied, but even today in 2023 there are still around 300 such theaters left in operation. Besides the common central screen, an interesting feature of these theaters is their iconic window clip-on speakers, used to provide the audio portion of the entertainment.

While simple – typically just a speaker, plus a potentiometer for volume control – these devices are built like tanks, featuring a metal shell that could stand up to all kinds of abuse (maybe even being run over). As such, creator CodeMakesItGo decided to enhance such a unit with a Bluetooth receiver, along with an LM386 audio amplifier circuit and a new speaker to make it pump out the tunes.

To ensure the new parts fit correctly, the whole device was 3D scanned, generating an accurate model of the tank-like case. This was then input into Fusion 360, where CodeMakesItGo virtually inserted the new speaker and even the driver PCB, exported from EasyEDA. The results, as seen in the video below playing a song streamed from a smartphone, look extremely good.

What’s not really shown in the video is how well things are organized inside, a far cry from the stuff-it-in-and-see-if-it-works methodology that would satisfy many creators. While either would probably be acceptable, this design and the process used here would facilitate duplication, plus straightforward troubleshooting as needed.