I always wanted to have a bluetooth speaker. I thought, why not design and build one. So here it is.

This bluetooth speaker contains two rechargeable 18650 battery's, so you have lots of listening fun without plugging it in your walloutlet. The front, back and body need support. I printed these parts with PLA and 0.2mm with 15% infill. The seal rings (you need two of them) have i printed with ninjafex.

Update 19-12-2017: I've noticed, when playing on high volume (above in the red region of your phone volume) the connection will be lost or the device will shut down. (failsave) I think this has to do with the step up module. The step up module can't keep up stepping up the power for the amplifier board. I'm convinced the device can be much louder! Does anyone have a idea?

Parts you need for the build:

Brass inserts 24 pieces
https://www.aliexpress.com/item/100Pcs-M3x5mm-L-5mm-OD-Metric-Threaded-Brass-Knurl-Round-Insert-Nuts-LXM/32693221350.html?spm=a2g0s.9042311.0.0.CsvCxE

LED base holder 3 pieces
https://www.aliexpress.com/item/Hot-Sale-10pcs-3MM-Round-Chrome-Metal-LED-Light-Lamp-Emitting-Diode-Bezel-Lamp-Base-Holder/32808747894.html?spm=a2g0s.9042311.0.0.CsvCxE

1Pair Black 78x41mm Bass Speaker Passive Radiator Auxiliary Bass Rubber Vibration Plate
https://www.aliexpress.com/item/1Pair-Black-78x41mm-Bass-Speaker-Passive-Radiator-Auxiliary-Bass-Rubber-Vibration-Plate/32785907739.html?spm=a2g0s.9042311.0.0.M8oXrZ

m3x10 24 pieces
https://www.aliexpress.com/item/160PC-Metric-Thread-M3-Stainless-Steel-Hex-Bolt-Kit-304-Cap-Nut-Washer-Set-Screw/32794842281.html?spm=a2g0s.9042311.0.0.EMQ1jk

Electical parts:

Wire
https://www.aliexpress.com/item/Free-shipping-5M-10M-20M-2-Pin-18-20-22-AWG-Electric-Red-Black-Extension-Wire/32806955753.html?spm=a2g0s.9042311.0.0.pmSp9d

https://www.aliexpress.com/item/100m-UL-1007-28AWG-10-color-Mix-box-package-Electrical-Wire-Cable-Line-Airline-Copper-PCB/32740101895.html?spm=a2g0s.9042311.0.0.pmSp9d

Speaker drivers 2 pieces
https://www.aliexpress.com/item/2pcs-40mm-5W-10W-Full-frequency-bass-Bluetooth-wifi-Speaker-neodymium-hifi-free-shipping/32579541437.html?spm=a2g0s.9042311.0.0.pmSp9d

Amplifier board 1 piece
https://www.aliexpress.com/item/DC-5V-3-7V-6W-6W-Stereo-Bluetooth-Receiver-Amplifier-Board-Lithium-Battery-Powered-For-Speakers/32807976635.html?spm=a2g0s.9042311.0.0.kBgoBF

Power switch 5V 1 piece
https://www.aliexpress.com/item/5V-12V-220V-Latching-push-button-switch-locked-16mm-flat-head-fixed-Push-Button-waterproof-LED/32789351190.html?spm=a2g0s.9042311.0.0.CsvCxE

Bluetooth/charging and charging ready 3mm LED 3 pieces (blue, red, green)
https://www.aliexpress.com/item/New-Arrival-300pcs-Five-Colors-3mm-Round-Bright-Light-LED-Diode-Lamp-Assortment-kit-Red-Convenient/32725226668.html?spm=a2g0s.9042311.0.0.CsvCxE

Battery case holder 1 piece
https://www.aliexpress.com/item/EDT-2-piece-battery-storage-box-case-holder-for-2-x-18650-parallel-lithium-batteries/32716650716.html?spm=a2g0s.9042311.0.0.5KfgS2

LM2587 DC-DC Boost Converter 3-30V to 4-35V Step up Module 1 piece
https://www.aliexpress.com/item/LM2587-DC-DC-Boost-Converter-3-30V-to-4-35V-Step-up-Power-Supply-Module-5A/32612862664.html?spm=a2g0s.9042311.0.0.5KfgS2

5V 1A Micro USB 18650 Lithium Battery Charger 1 piece
https://www.aliexpress.com/item/20Pcs-lot-5V-1A-Micro-USB-18650-Lithium-Battery-Charging-Board-Charger-Module-Protection-Dual-Functions/32469596060.html?spm=a2g0s.9042311.0.0.5KfgS2

Power Socket DC Block 2-Pin Wire With Nut 5.5X2.1 1 piece
https://www.aliexpress.com/item/Quality-Copper-DC-022B-DC-Power-Socket-DC-Block-2-Pin-Wire-With-Nut-5-5X2/32762835561.html?spm=a2g0s.9042311.0.0.dgxm8s

5V 2A Power Supply EU plug AC 100V-240V Converter Adapter 1 piece
https://www.aliexpress.com/item/5V-2A-Power-Supply-EU-plug-AC-100V-240V-Converter-Adapter/1059369926.html?spm=a2g0s.9042311.0.0.M8oXrZ

18650 rechargeable battery 2 pieces and some rubber feet

Good luck building!