This project is something I have wanted to do for quite some time. Several years ago I did manage to get a hard drive to produce “sound” but have since revisited the project and greatly improved it.
I decided to put the assembly inside a small case I have for portability. Using the sound amplifier out of an old set of pc speakers, I am able to have a stereo setup with two hard drives. The right channel hdd speaker has a single platter and the left channel has 3. It was interesting to watch how the different sized r/w heads responded to different frequencies and volume levels.
It is a lot easier to make this work than you are probably thinking. It is as easy as hooking up the speaker or headphone cables from your computer straight to the two wires that move the read/write head back and fourth. With the read/write arms having coiled wire between two strong magnets (opposite side of the read/write heads), they act just like speakers do. Just less efficient. Sound is created by the arm moving back and fourth, that’s it, no movement of the platter at all. After looking at one of my hard drives I easily traced the two wires that controlled the arm. They are pin’s 5 and 6 in this picture.
Those pins continue on through the hard drive case to the circuitry underneath. I pulled off the original circuit board and cut down a floppy drive connector to easily connect to the hard drive. Cutting off all of the wires except for pins 5 and 6 was my last step in preparing the hard drive, those wires went to the positive and negative from the pc speaker amp.
The triple platter drive produces quite a bit more sound but is less responsive. Since it is getting the same power as the other arm but weighs more that does make sense. The tricky part was to get the arm out from the platters so that I could bend the heads to prevent vibrations.
The single platter arm moves more through songs and other tone tests. However, it produces maybe 65% the amount of sound that the larger arm does. Neither arm preform well with deep sounds. High tones or what I call 8-bit tunes sound great, I’d dare say better than regular speakers.
The single platter drive is on the left and the triple platter is on the right. It is amazing to me how fingerprints seem to magically appear on open hard drives.
Here is the triple platter hard drive playing a RadioHead Nude hardware remix (original video after mine)