DIY
Speaker
Kit
 
Lay everything out on the table
1× Printed Circuit Board
2× 1.2K Ohm Resistors
2× 1 Ohm Resistors
1× 220 Ohm Resistor
1× 4.7 Ohm Resistor
2× LEDs
1× Power Switch
2× Diodes
1× Header Pins
2× 100nF Capacitors
1× Optocoupler
1× Integrated Circuit
1× Battery Holder
1× 2.2uF Electrolytic Capacitor
1× 22uF Electrolytic Capacitor
2× 470uF Electrolytic Capacitors
2× 100uF Electrolytic Capacitors
1× Potentiometer
1× Exciter
1× Exciter Cable
1× Stereo Jack Socket
1× Stereo Jack Cable
2× Double-Sided Tape
1× Terminal Block
1× Battery
Not included
Turn your soldering iron on at 300º (or 572ºF)
It can take up to 10 minutes for your iron to heat up.

A soldering iron can cause harm if not handled correctly, follow these rules and you’ll be safe.
If you get burnt, put your finger in cold water for 10 minutes
Tie long hair back to keep it out of the way
Use goggles to protect your eyes
Wet your sponge
Ignore this step if your soldering iron does not have a sponge.
Hold your iron like a pencil
When you're done using it, put it back in the cradle.
Find the hottest side of your iron by melting a little bit of solder
Try rotating it until you find the hottest part.
Find the Printed Circuit Board (PCB)
A PCB (Printed Circuit Board) has been specially designed with metal lines and pads that connect together.

When you connect components into them with solder, electrical connections are made.
Find the diodes
A diode is a component that allows current to flow in just one direction.

The diodes have a black stripe on one end, to show the negative leg.

This asymmetry means they have polarity and must be placed in the circuit the correct way.

If you can't find them, they're in the bag labelled 'Resistors'.
Bend the legs into a 'U' shape
Use a flat hard surface like a desk or table to bend the legs against. This will give you a nice crisp corner.
Place on the PCB
Polarity Alert!

Double check that the black bands on your diode match the ones on the PCB or your circuit will not work.
Flip the PCB and secure with tac
The tac stops the PCB from moving around while soldering.
Solder both diodes
Having trouble soldering?

Check out our how-to videos »
Check your solder joints
A good solder joint should look like a pyramid and the gold pad should be completely covered with solder.

Having trouble soldering?

Check out our how-to videos »
Snip legs
Hold the snips flat side down and snip just above the top of the hill of solder joint.

Remember to hold the leg to stop it pinging off.
Find the resistors
Resistors are used in a circuit to restrict the flow of electrical current. The resistance is measured in Ohms.

Some limit the flow more than others. The colour bands tell us their resistance value. The greater the number of ohms, the greater the resistance.

The equation below shows Ohm's law, which is the relationship between voltage, current and resistance:

potential difference (volt, V) = current (ampere, A) × resistance (ohm, Ω)
Bend the legs of all the resistors
Place on the PCB
The resistor is symmetrical with same length legs, the bands just indicate the value.

This symmetry means it has no polarity, so can be inserted into the circuit either way round.
Place on the PCB
Flip the PCB, solder and snip
Having trouble soldering?

Check out our how-to videos »
Find the ceramic capacitors
A capacitor is like a bucket, it stores up charge, waits until its full and then releases it all in one go.

How much charge depends on the size of the capacitor, which is measured in Farads (uF) after physicist Michael Faraday.

A ceramic capacitor is used for low charges and high frequencies. They are symmetrical, so have no polarity and can be placed in the circuit either way round.
Place on the PCB
Flip the PCB, solder and snip
Find the electrolytic capacitors
Electrolytic Capacitors are used for storing bigger charges.

The different Farad (uF) values are written down their side.

They are asymmetrical with a white stripe over the negative leg, so have polarity and must be placed in the circuit the right way round.
Place on the PCB
Check carefully: they are the same size, but very different values!
Place on the PCB
Flip the PCB, solder and snip
Find the LEDs
An LED is a basic electronic light that only allows current to flow in one direction.

This is called polarity, and is why it is asymmetrical with different lengths.
Bend their legs
Place on the PCB
Flip the PCB, solder and snip
Find the Integrated Circuit (IC)
An Integrated Circuit, also known as an IC, is a whole circuit in itself, but very very small and made of silicon.
Place on the PCB
Flip the PCB and solder
The legs are short already and will not need snipping.
Find the stereo jack socket
This is connection between the audio device and the circuit.
Place on the PCB
These legs are delicate and can be easily bent. Carefully place the Stereo Jack making sure all the legs pass through the PCB holes.
Flip the PCB and solder
Be generous with the solder on these joints!
Find the switch
A basic switch allows current to flow in one direction when it is switched on by completing the circuit.

When switched off it breaks the circuit stopping the flow of current.
Place on the PCB
Check the small black switch is facing outwards.
Flip the PCB and solder
Find the potentiometer
A potentiometer is a resistor that you can control!

Turning the knob on the potentiometer increases and decreases the amount of resistance a bit like a tap and the flow of water.
Place on the PCB
Make sure that the shaft is facing outwards and away from the PCB.
Flip the PCB and solder
Find the terminal block
This allows a connection for the Exciter cables.
Place on the PCB
Make sure that the red and black switches are facing outwards and away from the PCB when placing.

Notice the small black clips on either side of the pins. These will click when placed into the PCB.
Flip the PCB and solder
Be generous with the solder on these joints.
Find the optocoupler
The optocoupler is an integrated circuit that is used to vary the current flow of an electrical signal dependent on the control voltage sent. This means we can create our own automated volume controller.
Place on the PCB
Make sure that the small circular notch on the optocoupler is the top left hand corner.
Flip the PCB and solder
Find the header pins
This enables easy connection to an Arduino for prototyping.
Place on the PCB
Flip the PCB and solder
Find the grey speaker wire
1. Split the small end pieces and twist the copper wire beneath into a neat cable

2. Remove the small pieces of wire casing

3. Split the remaining wire by 5cm

4. Repeat with the other end

This allows the speaker wires enough space to stretch between both the speaker terminals and the terminal blocks.
Find the exciter
This converts amplified audio signal as electrical energy into vibrations.

It has a sticky back that can fix it to you final speaker housing when it is made. You can only do this once, but can be refixed with double sided tape.
Pass the wires through the exciter terminal holes
This is tricky. If the wires fray, retwist.

Avoid lengths of exposed copper cable that can touch and short the speaker.
Solder the wires to the exciter
A strong connection here is important.
Split the other end
This allows the speaker wires enough space to stretch between the terminal blocks.
Clamp the wires into the terminal block
Find the battery holder
Insert a 9V battery
Bend the legs up
Flip PCB and place the battery holder through the back
Don't solder it yet!
Before soldering, it's time to test your circuit!
Holding battery in place, connect your favourite music player and turn it on. The PWR LED should be on. If not:
- Check if your circuit matches the image on the right.
- Jiggle every component with your finger. If it moves, solder it again.
- Your battery can be flat.
If it sounds quiet, turn the volume dial, check the solder joints, especially on the audio jack, speaker sockets and optocoupler.
Stick double-sided tape on back of battery holder
Peel the film off the sticky tape.
Press the battery holder in place on the PCB
Firmly stick in place.
Flip PCB, solder and snip
Time to experiment with materials!
Experiment with different materials of all shapes and sizes and hear how the sound changes.
When you find the perfect sound, turn it into a portable speaker box!
Yeah! You built your kit!
But we’re just getting started. To complete your kit, we’re going to teach you how to make the most out of your kit.


Continue