Have you ever thought of making your own portable speaker in a CD case? Here is how you do it.
Step 1: Components Required
- 8W speaker with 4 ohms impedance (Make sure the speaker's impedance must match your amp's specification or you would damage your amp!!)
- CD case ( Use the one with a zip would be good)
- 18W Amplifier module (I used the Kemo #M033, you can use other amplifiers as long as the Watts are not 2.5 times larger than your speaker's power level)
- Rocker switch
- 3.5mm stereo adapter
- Battery snap and a 9V battery
- Solder iron and some solder
- Glue gun
- Cutting knife
If you choose an amp that is supplying too much power to your speakers, then its clear that there is a chance that you will damage them. It may cause the voice coil to overheat, or the speaker could move back and forth too much (known as exceeding its Xmax).
However if you have a smaller amplifier you may have to run it all the way up full to provide enough power to your speakers. When running at full blast, there will be lots of stress on the components of the amps and it can introduce a significant amount of distortion into your signal, which is often called 'clipping'.
As well as sounding very bad, trying to reproduce a clipping signal can potentially do far more damage to your speakers that a little too much power.
Therefore the unwritten rule is that you should have an amplifier that is capable of 1.5 to 2 times the power rating of your speaker system, and only turn it up part way. The extra power available is called the headroom, and means that your amplifier should never been running at full tilt and therefore producing a distorted, or clipped, signal.
Step 2: Cut Some Holes
Use a cutting knife to cut out some holes in order to fit the rocker switch and the speaker. Drill a hole for the stereo adapter.
Step 3: Connecting the Components Together
Solder two wires on the stereo adapter, one in the front (ground) and one at the very left /right back (it doesn't better which side since it is a mono speaker).
Solder other components together as shown in the 2nd diagram. Remember to leave out red wire of the battery snap for the rocker switch.
Solder the red wire of the battery snap to the rocker switch. Solder another wire that connects the rocker switch and the positive terminal of the amp module.
If you don't understand the steps above . Look at the next step to see how the circuit is connected.
Step 4: How the Components Are Connected
Step 5: Fix the Speaker, Switch and Stereo Adapter in Place
Use a glue gun to fix the main components in place. Don't glue the battery though!! Leave the glue to dry up for 15 mins. Connect the 9V battery, ipod and then switch it on!
Now you can carry this portable speaker anywhere you like. You can even put your ipod inside the cd case when it is not in use!!