I was probably the only person on the planet without a Bluetooth speaker. Rectifying the situation was made easy by a colleague who spotted a great deal for the Canz 808 Bluetooth speaker. The speaker itself is surprisingly capable for something this small and a handsdown winner for portability, but I do like the sound produced by my home theater receiver a lot better. I have a smartphone capable of streaming whatever music I want, and a speaker that can connect wirelessly to my smartphone, and I'm still thinking..... "wouldn't it be great if this speaker had a line-out jack that I could plug into my home theater system?" A quick bit of googling came up with commercial products that would enable Bluetooth streaming to my home theater system for reasonable money. But, I already had the speaker and I don't need 2 different products. So I hacked the speaker apart to create a line-out connection to my home theater receiver. Now I can use the Bluetooth speaker either as small standalone speaker like the manufacturer intended, or connect it to my home theater system for those times when I need a little more wall rattling ooomph.
And it just feels like magic being able to change the music selection in real-time from the phone in your hand.
This is guaranteed to void your warranty! The modification is neatly concealed on the underside of the speaker so that the final hack looks like the original product.
Step 1: Stuff You'll Need
- Bluetooth speaker - Canz 808. Mine came from Sams for $20. Also available at Amazon.com
- RCA cables for connecting to the home theater receiver. I hacked ones I had in my project box. If you need to buy a set, Radioshack has them - 6ft Stereo Patch Cable with RCA ends
- USB cable that is included in the speaker box
- Small flickering LED tealight. I hacked the latching pushbutton out of it. If you have another source for a small latching pushbutton, that will work fine. Improvisation encouraged!
- 26 Gauge hookup wire. 28 Gauge would be better as the 26 gauge is a little on the thick side but 26 gauge was all I had available.
- Soldering Iron and solder. Your choice of leaded or unleaded. Radioshack has both types. I use their standard 60/40 Rosin core.
- Side cutters and wire strippers
- #0 philips screwdriver
- Heat shrink - 3/8" and 1/16". For the smaller wire you can try 1/8" if that's all you have available. Radioshack has a variety pack that will work just fine: http://www.radioshack.com/product/index.jsp?productId=12515232#
- Dremel rotary tool with a small metal burr for removing plastic from the inner edge of the speaker enclosure.
- Drill with 3/16" drill bit
- Small round file for fine-tuning hole made with the 3/16" drill bit.
- Small punch for punching through the rubber base ring on the speaker to allow access to your installed pushbutton - this will make sense later!
Step 2: Speaker Dissasembly
There are two small screws that attach the PCB to the black base. Remove these screws to free the PCB as you will need access to the underside of the PCB later for wiring in the audio signal to the USB connector.
Step 3: Mounting the Switch
The switch will be mounted to the Bluetooth PCB. One of the PCB holes will be sacrificed as shown in the picture. Enlarge the hole with the 3/16" drill bit so that the switch button fits though it. I used a small file to adjust the hole as needed.
Step 4: Wiring the Switch
Run the extension to the middle of the switch. Cut the extension wire long enough to reach the switch in the switches mounted position and ensure you have a little slack int he wire. Strip the wire that is still attached to the PCB and attach it to either of the remaining switch terminals. THe switch will be used to enable or diable the internal speaker. When streaming through the home theater system, you want the switch to disable the sound out of the Canz speaker. When used as a standalone Bluetooth speaker, the switch is used to enable the sound from the speaker module.
Now hot glue the switch into position. Minimise hot glue that extends past the edge of the PCB as this will need to be trimmed off to get the PCB back into the housing.
Step 5: Connecting the Line-out
Step 6: Reassembly
We sacrificed one of the base mounting screw positions for the switch. Now drill out the mounting hole with the 3/16" drill bit and test for fit. You may need to make some small adjustments to get everything lined up properly. I used a small round file for this.
Reassemble the PCB to the base and then screw the base to the speaker. Punch a hole in the rubber ring to lineup with the switch and glue the rubber ring back to the speaker using a touch of contact adhesive if necessary.
Step 7: Line-out Cable
First cut the supplied USB cable connector off at about 3 inches from the back of the connector. Strip and tin the wire ends with solder. This needs to be done on the USB A and B connector sides. ON the A side, we don't need the Green and White wire as these now carry audio for the mini-B connector. Insulate the ends of these 2 wires so that they are electrically isolated from the cable. Make sure not to create a short circuit.
Cut the RCA connectors off one end of the cable. I normally cut so that I have enough cable left so that the connectors are usable on future projects. Strip and tin the wire and then connect the two grounds together and the 2 signal wires together. The output of the speaker is mono and the home theater receiver input is stereo so we feed the same signal into the left and right terminals of the home theater receiver.
Now solder everything as follows:
- USB White connects to RCA joined Red/White
- USB Green connects to RCA joined shield
- USB Black connects to the the USB cable "A" black (GND)
- USB Red connects to the USB cable "A" red (5V)
Before soldering, cut heatshrink as needed to insulate the connections after soldering. To give overall strength, a heatshrinked a couple of pieces over the entire connection area of the cable.
Step 8: Test and Enjoy
So if you got an unexpected bluetooth speaker as a gift for the holidays, you now have options to increase it's utility. Enjoy!