Just a (not at all) simple Bluetooth speaker

[PeterDHabermehl]

A long time ago a co-worker told me: "If it's worth doing - it's worth overdoing!"

So I wanted to share the results of my efforts with you and say a big, big "thank you" to Phil. For the library and his support.

I just wanted a simple bluetooth speaker for my smartphone. Heck, I could have used the surround system in the living room. Actually I just wanted to "make" something:

So meet the DL Acoustics DL-BB8 Mono bluetooth speaker system:

It features one JVC 4" wide band chassis, a 3D-printed spherical housing and ... well ... that sounded a little flat, so ... I added a low frequency transducer, also 3D printed, almost five kg of PET-G, fitted with two 5.25" Dynavox chassis (the cheapest stuff I could find) in an isobaric face-to-face arrangement.
We do have some chinese amps (1x 60W for the JVC, 1x150W for the Dynavoxes), a pilot (5V) and a main (24V) power supply, of which the main power supply is switched by the ESP, for standby power saving, and, well, a SD card with some audio samples to confirm the rather complex operation of the device via one single button.

All electronics are contained in the socket of the 4" speaker, thus it's rather huge but it stands stable. Of course the electronics compartment has also a main switch and a 40mm fan for cooling of the electronics.

I had to apply two notch filters at 80 Hz and 125 Hz because of terrible resonances on the "woofer" (i don't like that word since the device is not a classical boom effects woofer), but in the end I can listen to my favourite blues songs at a rather low volume and bass still tickles my soles...
Downside is that now, as I significantly lowered the overall volume when listening music, my wife still complains that the bass can be heard in the whole house... Well, mission accomplished, if it's worth doing, it's worth overdoing.

I will upload my code to GitHub later and link it here.

[PeterDHabermehl]

Find the code here:
https://github.com/PeterDHabermehl/ESP32_bt_mono_speaker

[pschatzmann]

Cool !