After having built some prototypes I am now finally able to show you my first self-designed and self-build proper Bluetooth speaker.
The inside of the enclosure is divided into two chambers by a small piece of MDF, to create a real stereo image. These chambers are both ported, in order to improve the bass response. This is necessary because each chamber has a volume of only 3 Liters, which isn’t really enough to employ a closed design and still get a decent bass response.
Amplifier/Battery
The Amplifier/Bluetooth receiver I used is a Dayton Audio KAB250 together with some of the available accessories like the volume control knob and the LEDs. I used the same drill battery I already used in my first speaker because it has proven to be a great choice in terms of weight and energy density.
Drivers/Crossover
The woofer is a Dayton Audio Nd105-4, and the tweeter is a Peerless DX20BF00-08. I crossed them over at roundabout 2.7khz with a second order filter design.
On the back, there are the ports and the second way to play music, an aux input jack. I added a regular drawer handle on top, but the final speaker is not as lightweight as I wanted it to be in the first place.
All in all the amazing sound quality compromises for the weight, and I already have some ideas on how I could improve the speaker even further.
PS: Sometime in the future I may post the build plans on Instructables.