MC DJ Judge Afroman presents...
Afrotech's Hard-disk Sound System

Why pay 500$ for Klipsch's latest speaker
system? You can make something that looks way cooler for the price of a DIY
amplifier and some HDDs out of a dumpster. It doesn't sound quite as good but
who cares! There really isn't much to say about this project... It's fun as hell
to watch, easy to do, and impressed the crap out of everyone I've showed it to.
Just download the movies already. But first here are some
pictures:

The system, with woofer, midrange, and
tweeter harddisks, lying on my favourite stolen cafeteria tray:

The amplifer I made (and the transformer
powering it):

The overall system:

Movies that you MUST see to
appreciate the project
You will need the divx codec to play
them.

Cheesy porn
music

Bad song, but good sound and shows
great movement of all the heads. You can here me trying to stifle a laugh
when the heads move to the dude going 'oh yeah!'

The Matrix
theme

Nothing special to watch but I like
that movie damnit

The Star Wars
theme

Because I know that all the geeks
will want to see this. Good movement of all the heads. See the platter of
the tweeter spinning?

Porn music
2

Slow and funky, its cool to watch
the heads jerk about to the bassline.

Porn music
3

Fast and groovy, the sound quality
from the drives is excellent. Have you guessed that I like porn a lot
yet?

Synaesthesia
1

Not much movement that you can see,
but good sound and its probably my favourite trance song ever. Halfway
through the video I flip the camera around so you can hear the sound a
little better with the microphone closer to the drive.

Synaesthesia
2

The drives look a little more active
when the chick is singing. Btw, that scrap of paper I keep focusing on
says Afrotechmods.com but due to the high video compression you can't see
jack because I am an idiot.

Yatta
1

If you don't know this song by now,
you don't browse the internet enough. Q Q Q Q US US US US....
I!

Yatta
2

My! I have never seen hard drives
vibrate with such irrational exuberance
before!

Every sound you hear in these movies is
being produced by the harddisks and nothing else. The sound quality is in
fact much better than what you'll hear in these movies because the microphone of
a digital camera isnt exactly the best thing ever...

Im sure you are confused as hell by now.
Here's how it works:

First I got 3 dead harddisks. A small one
that used to be my Amiga's, a normal sized one, and a bigass ancient one. I did
this just for the fun of saying I have a harddisk sound system with woofer,
midrange, and tweeter drivers ;). I ripped the drives apart. I took sound (in
electrical signal form) from the output jack of my sound card. I fed it through
a Velleman 30 watt audio amplifier that I bought from Parts
Express here and soldered together. I took the amplified signals and fed
them through the coil that controls the movement of the HD drive heads. I also
connected the amplified signals to the platter motors of the 'midrange' and
'tweeter' drives, so you can actually see the platters spin sometimes. I
determined which places to connect the wires by studying the drives and poking
wires around in random places. Hey... they were dead anyway. Anyways, the sound
that is being produced is from the rapid vibrations of the heads/platters due to
the 'sound' signals passing through them. With lower frequency sounds being
passed through the drives, you can see the heads move quite a lot. For the high
frequency ones, its invisible to our inferior human eyes. This kind of fun isn't
just limited to harddisks... I also got low frequency sounds to come out of an
electric motor, and even standard cooling fans will make some sound. Girls can
try even making music come out of their vibr... *cough*... The 3 harddisks are
connected to the amp in parallel. It's like ghetto raid with groove
;)

To build your own: First find 1 or more
dead harddisks. Rip them apart so everything is showing. Look in the area near
the drive heads. There should be 2 little wires that lead into the induction
coil that controls the movement of the heads. The exact location of this will be
different for every drive. Either attach extension wires directly to those 2
little wires, or follow the circuit trace and look for a more convenient place
to make the connections. Jam amplified sound through the coil, and you will get
the sound you seek. The amplified signals can come from any amp - your home
stereo, car stereo, or one you make yourself like I did. From my experience,
when the signals are around 3V to 8V RMS out of the amplifier, you will get the
best sound so adjust the volume accordingly. If you want to get sound out of the
platters themselves, look for wires or traces etc. that lead to the area where
the motor that rotates the platters is. Connect the sound up to them. Poke
around - some points give louder sound than others! Wire all the little
'instuments' in parallel to the amplifiers outputs.

FastCounter sucks ;)