Motivation:
This project came as a natural evolution of the first Portable Speaker (check it out here LINK) I built in late 2014. That speaker was loud, and portable, but had no bluetooth and limited features (the only audio input was a 3.5mm connector). I really liked the pvc tube design, and wanted to see how well it would scale (spoiler alert, not great).
Tools:
- Soldering Iron
- Wire strippers
- Dremel w/plastic & metal cutting wheels
- PVC pipe cutter or saw/sandpaper
- 3D printer (not necessary, see explanation below)
- Needle nose pliers
- Drill
Parts:
- 2 x 5v 3 watt, two channel amplifier.
- Bluetooth/fm/usb/sd card audio control board
- 4 x 2” (52mm) 3 watt speakers
- 2 x 2” 3D printed audio diffuse & end cap. (explained below)
- Various low gauge wire
- 2000mah USB battery backup
- (alternatively a 3-5v battery and charge controller)
- Toggle switch
- 3.5mm audio jack (female)
- Electrical tape
- 2” PVC Pipe
Design:
After much trial and error I decided on the layout below. I was concerned about everything fitting, and in the end it really all didn’t. I had to cut a rectangular hole for the amps and they ended up sticking out about a centimeter or two out of the side of the pipe. The 3D printed end caps worked great and kept everything together. I had to use a metal cutting wheel to make some slots in the inner speakers to allow the wires from the speakers to run along the inside of the pipe to the middle. If I were to do it again I would definitely improve on measuring wires to length and cleaning them up in general. Surprisingly the wires inside were the biggest problems when trying to cram everything in there.
How it sounds:
My hopes were that the additional speakers would improve the sound volume without losing quality. Unfortunately, the decreased space inside of the speaker container caused the sound to be much less full and sound alot more like a little speaker. It did get very loud, but the sound was almost tinny.
Battery life:
With 2000 mah the battery never died on me and never failed to supply the amps with enough current. The battery life was not an issue at all.
Future iterations:
I am planning on building a third version which I have most of the plans for and just need to build. It is made out of wood as opposed to PVC and uses all of the same systems as the first, accept for the addition of 2 passive radiators that should hopefully bring some bass to the sound and excell where this version fell short. Even though the battery life was fantastic, I’m thinking about adding another 2000 mah battery just because they are so cheap. Check back after Christmas and it should be completed.