This tutorial will answer many questions on building a bluetooth speaker and/or headphones. including unavoidable problems.
This is a partial recycled scavanger project. a lot of the jumper wires came from my old computers, if you look at the ends the labels are a dead giveaway.
I must warn you about the power consumption.
If you put 7.4v to one or three devices at the same time, electronic Logic says each one must be a 7.4v item.
Because they are not splitting the volts (7.4 divided by 3), they are sharing the volt's (7.4 three times) capacity, now you add capacity and amps.
I am going to try a 4xAA test, since the Chargers max is 5v?
Step 1: First Off, Here Is My Setup Diagram
This is what I did to setup a two way using four speakers for my Tahoe's mid and back area.
These are the supplies you would need:
All Items I bought from dxsoul.com because I wanted it in two weeks not 1 month from dx.com. going to Hawaii.
1) a couple of capacitors for the amps or amp (10uf) and 0.1uf for the bluetooth output (must be attached to the bluetooth's module spkrp and spklp).
2) rosin core solder (makes the wire dirty after admission) if you miss, you'll have to clean the wire or leads and re-solder. :::::::Personally, I used the solder and 183 flux pen from my solar panel project that was a success.
easy: first you press the pen's tip down a few times and mark the area you want to solder, add solder to your iron's tip and touch the soldering parts; this will clean and heat the area at the same time without frying your wires.
3) micro usb charger (TP4056) max 5v. Instead, buy a mini usb charger (TP4056) 4v-8v. The amp (PAM8403) asks for 3.6-5.5v per. and bluetooth (blk-md-spk-b) asks for 3.3v. I think you add em up and you need about 7v for all three items (2 amps, 1 BL).
4) Amplifier PAM8403 (another option might be one with leads and wires:
http://www.dx.com/p/mini-digital-3w-3w-amplifier-m... this is the one I wanted.
5) Speakers (50MM=2") 4ohms 3watts, they make some nice crisp sounds, a little on the high side though. but still drives.
6) bluetooth module (blk-md-spk-b), although you might consider a stereo audio bluetooth usb that's about 5 to 10 bucks just as this BL module will cost ($7), and then hack the music audio usb bluetooth.
7) you should get some leads and terminal pins as shown.
8) Wires, someone said 1mm dia. I used my old computer's jumper wires from the HDD led, usb and disk drive cables, which were probably almost 1mm dia.
9) and of course a cell phone battery, it seems to be the easiest way to go.
10) finally I used a plastic junction box cover (electrical receptical where house wires are connected) that cost about $1 at any hardware store.
Step 2: Pull Leads, Melt in and Solder
So, I basically had a hard time because I sliced the lines where I wanted the lead wire run. BAD IDEA, as you can see it gave me a hard time, the leads didn't sit flat.
draw with a pen first and what I would do differently is: ensure those leads coming off of the BL module will extend so the output ends line up with the lead pins, drill pin size hole and place the lead pins from the underside so they stick up to touch the BL's lead ends.
You need to make sure that the lead ends have solder that will not break off, poke it or dig at it and it should not flake off otherwise your solder is no good.
NOTE: this is important because you will be soldering your other lead wire that pokes out from the other side.. If you want to do it like me same thing, the wire needs to stick to the lead.
TIP:: pre-solder all ends before soldering together; that means wires and lead tips. this will guarantee an easy application.
Step 3: Solder Lead Pins to Where Needed
I soldered lead pins everywhere; battery, speaker, and the amp, BL and charger modules so it would be easy to disconnect if I had to. and I have to say I did.
Pic one shows headers all lined up ready to plug in speakers.
Pic 2 and 4 show pins broken off of the headers to use individually for easy connect / disconnect application.
Pic 3 is more pictures to see.
by the way, the red and blue lose wires are for the charging led, I don't know were to connect the other end of the led to. The 2 black wires are the ground incase I have to ground the module, which I don't think I need to.
Step 4: A Really Tight Setup
I wanted a very tiny component so I could hide it in my car's cealing panel, I must say that it was very difficult to measure and connect in such a tight little space without damaging something.
I did run into many problems, such as bluetooth connections and found that I kept soldering the vbat wire to the lead itself and kept missing the solder bead I left, once I took a closer look, I saw it an made the solder stick; now the bluetooth works
I also ran into problems with the speaker wires being lose as you will see in the video I added.
I just pushed them in farther and the sound stayed with me.
I have to say, that with a lot of patients and some vulgarity, I succeeded.
I showed you how I did it and advised a better way to accomplish this that will be cleaner and easier.
WARNING: this bluetooth's frequency connection is dynamic and spiratic causing a soft connection humm or buzz and a low soft thumping sound.
Step 5: Audio Test for Four Speakers
one video shows the bluetooth unit working and losing speaker connection, that is my speaker connection at the headers.
After pushing the jumpers in farther making better connection, the next video shows clean sound, but lack of power at the end when it just shuts off.
I can run all of it on the charger plug, but I am going to run two separate battery sources for the amps and bluetooth. or 7.4v battery configuration that will require the 4v-8v charger I advised you to get.
see, problem solved. Not really.
UPDATE: I ran 3-5v charger powered to max volume was good.
I ran 7.4v to my system, ran OK for a few seconds and batteries died. I think this is the wrong configuration, as explained in the intro. Should be just 5v or 5.5v. Larger mah or capacity like 2500mah or more, this is the run time.
EXPERIMENTS: I am going to run 4xAA setup to test series (neg to pos) = 4.8 or 6v depends if the battery is a 1.5 or1.2. It should power for at least one minute. You know, mah is low.
SOLUTIONS: maybe we rip open a 5v charger adapter and instead of a wall plug, we use 7.4 (2x3.7 in series) that down regulates the 7.4 to a5v. OR someone here showed how to build a charger that plugs into a car 's cigarette lighter.
P.S. this is the bluetooth module I am getting and should have gotten since it is for my car.
Step 6: Finally, the Headphones Recycled Project
I took a wired headphone that wasn't working and turned it into a wireless headphone by adding a charging module and bluetooth module in one ear and the battery and switch and led in the other ear to balance it out.
I used the broken headphone wires to run power and speaker wire from one side to the other.
it works except for that damn buzzing or static sound.
check this out, when I put the headphones bluetooth side next the ipad or kindle the irritating sound disappears and when I move the headphones away, the irritant comes back. You can hear it when you turn the volume down. If you don't hear it, your bluetooth is not connected and you'll get no audio.
do you still want to use this BL module or the audio usb bluetooth and crack it open and connect your amp to that without the static buzz?