But this instructable shows you how simple it is to create helmet speakers on the cheap :)
What you'll need are:
1. Old Headphones - NOT earphones, those are too small, computer headphones have at least a 1W speaker inside them
2. iPod - the best for this would be the shuffle, the one with tactile controls and also the smallest
4. Wires - you can just use the wires from the headphones, that's what I did
5. Soldering skills
Step 1: What You Need
Step 2: Gut the Headphones and Get the Speakers
Step 3: Reconstruct the Wiring
Step 4: Place the Speakers
UPDATE: after a while, I inserted the speakers into the cheekpad to make it more permanent.
Also run the wires around the back and INSIDE of the helmet lining, always good to put some slack to prevent the wires being pulled for any reason
Step 5: Position the Player
Use Velcro to stick the iPod on the helmet, just remember to use the eye part (the smooth side) on the iPod, that way, if you remove the iPod from your helmet and put it in your pocket, it won't snag on the inside of the pocket.
It's a good idea to remove the player when leaving your helmet on your bike when you park, and just tuck in the jack inside.
That's it, crank up the volume and enjoy your tunes!
The good thing about this is when you park and remove your helmet, you don't have to fuss about removing anything since everything is self-contained on the helmet, just remove it and go!
Since the iPod is placed upside down, rain drizzle can't really affect it but nevertheless remove it when it does rain just to be safe :)
Friendly reminder, don't crank up the volume too much and remember to be a responsible rider, happy trails!