I fiddle around with portable speakers and also DIY high end audio for music at home from time to time.
That´s one of my latest builds. It´s a stereo bluetooth speaker, with dimensions of roughly 30x20x6cm.
Left and right are the two channels (two way) from these Philips tv speaker, which are incredibly powerful for this price. For a little extra bass i added a third woofer in the middle (upper driver), the ND91 from dayton.
Below it is a passive membrane. Everything is powered by a TDA 7492 class D amp
I rounded over the holes in the front plate with a router.
Front and back are multiplex, the front is coated multiplex (epoxy rasin). The sides are covered with a robust red cloth, it is glued to them as well. On the bottom i used an aluminum strip in a deepening to fix/lock (i can´t find a good translation) the cloth into place. On the back there is a DC jack. I moved the battery to the outside.
This has two advantages: using a simple converter cable like this you can power that thing with any powerbank, laptop, usb charger or whatever you have lying around. Or just power it directly with a 12v dc charger (like most laptops use).
With my 20mah powerbank (they always calculate this for 3,7v, so that would be 20:12x3,7 = 6,17mah for 12v) i get around 20-27 hours of playtime depending on volume (medium or high).
Secondly it was easier to build an the box weighs less.
All in all it cost me about 50€, which could have significantly been reduced, but i wanted to test out and try new things (passive membrane was expensive, didn´t know you could get these things so cheap on AliExpress when i bought them).
If you´re further interestet - tell me (e.g. via e-mail: firstname.lastname@example.org) or here, if that´s possible.
I´m thinking about uploading a sound demo to YouTube.
Have a lovely weekand - Jacques from Germany.
Step 1: Sound Demos
Distance speaker to back wall: about 50cm
Distance camrea to speaker: about 1m (it´s zoomed in)
Sadly my camera seamingly is primarely a photo-camera, which it does excellent.
The Videos however lack a bit in sound and image quality.
The base is not as mushy, the sound - especially the highs are clearer/more vibrant in reality.