This was built for a camping trip - we needed a reasonably loud, portable MP3 player speaker which didn't cost a silly amount of money. This thing was slung together in about 2 hours the night before.

http://i33.tinypic.com/34hhtdw.jpg

It's a somewhat sturdy computer speaker box (5mm ABS walls), stuffed with a Fostex full-range driver, rated at 25w. This is powered by a 12w per channel TDA amplifier module, bridged to output 24w mono. Reasonably efficient, and requires minimal circuitry. The amp is powered by a 12v gel-cell battery duct-taped to the side, which seems to be good for about 10-15 hours of full-volume music.

Total cost was £0.00. Cabinet came from a bin, speaker driver was an orphan I had lying around for years, amp chip was from a dead car stereo and the battery came from a binned alarm system.

Oh, and since the system probably rolls off at about 200hz, I built a simple 12db high pass filter centred at 150hz on the input to squeeze a bit more power out of the amp and speaker. No use amplifying and attempting to reproduce a signal that won't be heard...

Best thing is that it's damn loud for such a small thing, and sound quality isn't too bad either. Not bad for nothing.


Post your quick and dirty projects which have been better than expected! The more ghetto the better.

That is something i would really like to reproduce, do you tihnk you could explain the process in more detail please? My electronics knowledge is pretty limited.

I made sweet headphones with some lawn mowing ear muffs kinda like these (http://ecx.images-amazon.com/images/I/4130WNNMA4L._SL500_AA280_.jpg), but then one of the headphones died [taken from these sonys (http://i2.iofferphoto.com/img/1158044400/_i/14129476/1.jpg)], and then the plastic bridge part of the headphones snapped when I was using them with earbuds in, so now I'm fucked. They canceled noise better than the bose quiet comforts [all of them], cost me $20 [only paid for the original phones], but the frame of those headphones was broken anyways so I was just recycling the speakers. I'm thinking of remaking them with some of these bad boys (http://ecx.images-amazon.com/images/I/51HL9fYX4mL._SL500_AA280_.jpg) and awesome speakers, if someone could recommend me some. I'll just rip the cord of the old phones, it was super long which is great when you're on the computer. Any fairly cheap headphones speakers you guys might recommend? I don't even know if anybody would sell anything like that. Google time.

And props on the speaker. How long do you think the batt lasts?

Great idea, using the speaker box is ingenius.

I had sorta the same idea.
I used a squareish wooded clothes draw & fitted 2 speakers.

Put two speakers into the base of the draw & cut out a hole for the car stereo.
Insted of the dry cell battery I just made a socket & make a cord that runs from a cig lighter plug in the car to the socket.
Nailed a peice of plywood to the top of the draw to seal it up.
There were a lot of teething problems due to bad wiring joints etc.
& I left the handle of the draw on it as a holder, the draw stands on its bottom end with the handle at the top.

I call it my "Ghetto blaster" (sic)

I do have a dry cell & old portable ghetto blaster & will fit another car stereo to it too.
I want to use a computer power supply to power the car stereo with 12V.
That can charge up the dry cell it it works right.

After looking at the many I have, theres a 12V+ & a 12V- not sure if its AC or DC, I'll check with my meter, but still not sure.

The other project was
using a old Casio keyboard with 100's of sounds built into it.

Put batterys in that, connect up a car amp to the headphone socket.
& connect up a Pa Hornspeaker to the amp.

The amp is powered off the cig lighter socket like before.

Its fun, goes in the car, the passenger can fool around with it, use it as a horn or warning devise.

Kudo's to you though.

Heh, I made something like that and then two of my friends also made them. They work quite well...

That's pretty fucking sweet dude...Any chance of a schematic or layout diagram? :)

As for my ghetto rigging...Shit...So many...But there was this one time I put Christmas tree lights in my computer case....

So munkey, could you reccomend speakers that I could buy to make awesome headphones? Or anyone? Please?