Something never seen before (I think)...

[BrianG]

Before I get into this, I want to say that this is NOT a serious project by any means. It was just one of those whimsical things that grab me from time to time.

A while back, I was driving my Revo around the yard while listening to headphones when a car went by with a booming stereo. So, I figured: Why not install a stereo in the Revo? An idea was born.



And just in case you think you didn't read that right: Yes, a stereo in a Revo.



First, I started by tearing apart a set of old computer speakers that had a blown internal amplifier. So, now I had a 2.5" full-range driver. Not exactly deep bass material, but whatever.

Since the Revo doesn't have much room on the inside, I thought I'd make a speaker box that would sit in the rear "bed". After making a few measurements and a trip to Lowes for fiberglass resin and some thin wooden dowels, and a trip to Wal-Mart for some fleece, I started assembling the box. The pics below show some of the various stages of the fabrication.


The wooden frame made of 1/4" square dowels with fleece wrapped around it:



Several layers of fiberglass inside and out and a bit of sanding:



Test fitting the driver. Perfect fit!



After a little textured paint (to emulate speaker carpeting), a speaker gasket, and some port tubes:



I didn't have any Theille-Small parameters for the driver, but I figured I'd make the box as big as I could and then port it for a little extra 100Hz response. The result was adequate at best. Oh well. Can't make a hi-fi out of junk I guess.

So, now I need a car amp.... but to scale. So, an I found a small and cheap 7W mono amp circuit. The amp chip is really designed for low-power car headunits, but an amp is an amp right? The IC will work well from ~8v all the way up to 18v+, but needs at least 14v to get the rated 7W out on a 4ohm load. Easy enough on 14 NiMH cells I think. After some assembly and shoe-horning into a RadioShack enclosure fitted with appropriate connectors:


Internals. Pretty basic stuff. You like the blingy gold heatsink?



The amp all buttoned up:



The amp and "subwoofer" box together for size comparison:



So, a little velcro to hold down the box in the Revo truck bed, a little power wiring to my batteries, and hookup to a tiny flash-based MP3 player is all that is needed to have tunes while zooming around! Please don't mind the poor Crowdpleaser paintjob - artistic flair is not my strong suit!


A last pic showing the box mounted in the truck
:



Yeah, the sound isn't the best, but is surprisingly loud when running around. Of course, you wouldn't want to race or bash with this stuff on there, but it was a fun project nonetheless. :)

Maybe with a nicely painted hummer body, a true stereo would be an interesting project. Maybe even have a true subwoofer. :)