Abhay and Akshay here.
It's been a long time since we have published a full step tutorial, so today we are going to make an awesome speaker that sounds good and it can distort sound if given high voltage or extra power.
We haven't made any audio amplifier project before, so let us see how it comes out.
- Loudness- >95dB
- Battery - 20 hrs
- Can charge other 5v devices
- Charges in approx 1 Hour from 0 to 8v
- LM386 Audio Amplifer
- Aux Input
So let's start making this awesome speaker.
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Step 1: Watch the Videos...
If you don't want to read the full tutorial, you can just watch our video and get cool tips and a special bonus in the video. And you can even know some little tips to make your work faster. And you also don't have to just scroll down below to see more 20+ steps.
Step 2: Here Are the Things You Will Need-
- 10 ohm Resistor (x1)
- 10K ohm Potentiometer (x2) (one with on/off function)
- 220uf Polarized Capacitor (x1)
- 100uf Polarized Capacitor (x1)
- 10uf Polarized Capacitor (x3)
- .01uf Ceramic Disc Capacitor (x1)
- .047uf Ceramic Disc Capacitor (x1)
- .033uf Ceramic Disc Capacitor (x1)
ICs and MOSFETs
- LM386 IC (x1)
- 7805 Voltage Regulator (x1)
- 4v 1Ah Sealed Lead Acid Battery (x2)
- 4 ohm 3W 40mm Speakers (x2)
- 3.5mm Audio Female Port (x1)
- Female USB Port (x1)
- Female Power Adapter Port (x1)
- Some wires
For speaker enclosure
- PVC Pipe 3/2 inches diameter and 19 cm in length (Diameter is affected by speaker's diameter. Our speakers were 40mm that is nearly equal to 3/2 inches (i.e. 38.1mm) so use appropriate pipe.)
- Red fabric (We used a torn off vest cotton cloth for this purpose and painted or dyed it in red acrylic color. You may use any other piece of cloth like denim or any other.)
- Soldering Iron
- Glue Gun
- Super Glue
- Drill Machine
- Rotary Tool
After gathering all these materials, we started by first building the basic circuit and then adding some more thing like bass boost and 5v regulator.
So let's start making this speaker.
Step 3: Circuit
This project is inspired by HackAWeek's Dean Sergovis' LM386 Mono Amplifier. We will start by first making his basic circuit. You can see the circuit diagram above for making his circuit.
Step 4: Bass Boost (optional)
To make bass boost just connect a 10K ohm potentiometer and a .033uf Ceramic Disc Capacitor in series with pin 1 and 5 of LM386 IC. It is fully optional to do this step and you may not follow this step.
Step 5: Let's Take a Look at the Batteries-
We are going to use two 4v 1Ah batteries. We will convert them into 8v 1Ah battery pack by connecting them in series. We will charge them will 12v as they need to be charged by a higher voltage than that of their output. They are not as sensitive as lithium batteries towards higher voltage input. So if you will use lithium batteries please use a balance charger or PSU to charge them or they will blast off.
Step 6: Connect the Batteries in Series.
Just connect them in series with the help of soldering iron.
Step 7: Hot Glue Them in This Shape.
Now hot glue them in this cuboid shape as in the last photo of this step.
Step 8: Securing Them.
Now we will secure them with some masking tape.
Step 9: Completed
As you can see we have completed the battery pack so now let's make our speaker enclosure.
Step 10: Speaker Enclosure
We will make our enclosure from a PVC pipe having diameter 3/2 inches and length 19 cm. You can also use any other enclosure for your speaker but remember it must be airtight or your speaker will sound like crap :P.
Note- We have used a pipe of diameter 3/2 inches as our speaker drivers are also of diameter 3/2 inches.
Step 11: Drilling the Holes
Okay, first of all mark holes for your components and them drill them out. We need holes for potentiometer, USB port, Audio port and power adapter port. Actually, we forgot to drill a hole for 12v charging input for the batteries. we did this later.
Step 12: Wrapping the Pipe
Now we will cover the pipe with red fabric torn off from old vest. We used super glue to stick it to the PVC pipe.
Step 13: Drilling Holes in the Fabric
We have also used our soldering iron to make holes in the fabric, you can also use a hobby knife to cut them out.
Step 14: Let's Take a Look at the Speakers
These are 2x 4 ohm 3W speakers recycled from old 1$ Speakers from Ebay.com. As you know that cheap Chinese products don't last long, so in a month or so we were ready to use them in a project as the speaker was already malfunctioned. Moreover, you get a rechargeable battery, some ports, components and an enclosure for free. These speakers are >95dB loud and can be used with PAM8403 IC too.
Step 15: Schematic
Here's the schematic and now we will connect everything according to it. We also made a 5v regulator from the above circuit.
Step 16: Completed Electronics
Here's an explanation of the circuit.
Battery is connected to LM386 Amplifier as well as 5v Regulator which has USB output. Then we have connected 12v input for battery charging. We will use 12 v 1A adapter for charging but you can use any other 12 v adapter. We have connected a on/off switch potentiometer to the LM386 circuit for volume control as well as on/off functionality.
Step 17: Assembling the Speaker
After completing the electronics you can put everything in the speaker enclosure. It took us 1.5 hours to do so.And even we had to put the battery pack outside due to lack of space. We also hot glued some wire mesh from old garden fence to the speakers. At last it was looking very nice and sounds very great.
Step 18: How to Use the Speaker...
Now to use the speaker to play music, just connect audio or auxiliary cable to speaker and to your sound playing device like say phones or computers. Then just turn the potentiometer to max and you are ready to party.
Step 19: Charging 5v Devices...
Now to charge any 5v device like phones or power banks or Ipods, just connect USB cable to the speaker and then to your device. You don't need to turn the speaker on as there is no switch connected between this 5v regulator.
Step 20: Charging the Speaker...
Now to charge the speaker just connect a 12v power adapter to it. Current may change according to your adapter but we may recommend using a 12v 1.5A adapter.
Step 21: Sound Control...
To control sound just turn the potentiometer clockwise or anti-clockwise depending on what you want. This potentiometer is also used to turn the speaker on and off. We didn't connected bass boost with a potentiometer, we just used a 2K ohm resistor as it sounded ample and nice and the speaker would not look good with two pots.
Step 22: Our Next Project...
Yes, we are going to post a video instructable soon on how to make a swivelable, tiltable and very powerful table saw that can cut anything ranging from PCBs to wood to plastic to styrofoam.
Step 23: Thanks for Reading...
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