Portable Sound System

From a few items I picked up at the Goodwill Store, I built a pair of loud, excellent quality computer speakers. This instructable will show you how to modify those crappy computer speakers that usually come with computers. The total amount I spent on this was 9 dollars. It will also show you how to power them off 8 AA batteries for a couple of hours. (The batteries didn't die on mine after running them for 2.5 hours on full volume!) If you're only going to use them as computer speakers, you don't really need to run them on batteries, but it isn't hard to turn them into a portable sound system.  The Goodwill Store is an excellent place to look for stuff you need, though you may need to check a couple of times to get all the right stuff. This is my first instructable, so please comment!

Step 1 Getting the Parts

You will need:
a pair of computer speakers
a pair of nice speakers you wish to upgrade to
spare speaker wire

If you want them to be battery powered, you also need:
an 8 AA battery holder
an extra power supply (it needs to fit in the power input, but doesn't have to be the same voltage)
a 12 volt regulator (or whatever voltage yours are)

Here are some things to look out for when you're buying stuff:

Computer speakers:
Look for a set that comes with a power supply, unless you know you have a spare power supply at home. For some reason Goodwill has a habit of separating the speakers from the power supplies. I don't know why. But you may need to look through the bin of tangled cords for a power supply with the same voltage as your speakers. Also if you want to power them on batteries, you MUST get speakers that are rated for DC power, preferably ones that run at 9 or 12 volts. You may be able to work with other voltages, like 15, but that might get tricky. They really don't need to be nice speakers. Mine are stock Dell speakers that probably came with a computer. The only control is a volume knob. They cost me $3.

Upgrade speakers:
You may need to check Goodwill a couple of times before you find an appropriate pair. Look for speakers with a name brand like Sony or Panasonic. These are usually nicer. You should also check the power rating. A pair of 50 watt speakers usually sound a lot better than a 5 watt pair of speakers, even if you aren't going to power them at anything higher than 5 watts.

Comments

[tecneeq]

BTW, i'm planning on building something like this myself. I have bought a Philips SBA 3000 speaker set, wich is basically a D-Class amp that runs on 4 AA batteries for about 25 hours while putting out 2x2 watts peak. The builtin speakers are tiny, so i guess a bigger speaker would not only have more power at low frequencies but a higher efficiency. I'm thinking about car speakers in a wooden box that i can use at the beach (of the river rhine, for it is the only beach for several hundred km ;) ).

[zvillesurfer]

I thought of something just like that. Car speakers would be perfect because you can get coaxial ones that have a woofer and tweeter built together. You might need a bigger amp though. The amp would be plenty loud enough for taking to the beach or whatever, but i'm not sure how many watts it is.

I was thinking of building something like this instructable, but super-downsized.
http://www.instructables.com/id/Outdoor-3-Way-Speaker-Sound-System-12V/

[tecneeq]

Well done, Sire, well done indeed.

I recommend to listen closely to avoid any distortion, for the distortion of even a 1 Watt amp is able to kill your 60 Watt speakers. This is why you buy a powerfull 100 Watt Yamaha Amp, even tho your speakers are only rated for 80. You can listen with high volume, without distortion.

Also you should consider that your big speakers might look to the amp like a 4 Ohm resitor, the builtin speakers might be 16 Ohm. Wich could mean your amp has to deliver more ampere (or rather milliampere i suspect ;) ). More ampere means more heat. More heat could mean fire hazard.

The amp is probably rated for a wide range of incoming volts, this is good for the manufacturer, since he can basically use a trafo that he can aquire cheaply, without the need to look for a special voltage.

I'm not a pro when it comes to electronics. I'm just thinking loud.

[zvillesurfer]

I did check the impedance of the speakers. I don't remember what they were though. I thought about putting that in the instructable, but I figured most speakers should work with most amps. I think the original speakers were pretty low.

[tecneeq]

Yes, i suppose most speakers work with most amps at low volumes.