Hello,
I thought it would be nice to show everyone my inexpensive helmet speaker set up with a few pictures and blurbs on what I did and how I installed them. I am using a Icon Airmada and they fit superb!
Here are the speakers I have purchase at work from NCIX
Wicked Chill Stereo Headphones - Black
*note; This may not work on all helmets but if it does for yours, great!
*note2; Some application of disassembling headphone will not be the same if you do not buy the same set (duh!)
*note3; WARNING THERE ARE A LOT OF PHOTOs.
*note4; If I broke any rules, please tell me so I can fix them.
1) This is all you need, maybe replace the stuff animal with a glue gun and you will be set!

2) The unit itself; It sounds pretty decent for $5 but the overall product as a headphone was complete garbage.

3) Use the screwdriver to remove head rest from the driver enclosure. These were very cheap so it was super easy.
4) Unit after removal
5) Remove earpieces from the driver enclosure by simply tugging/ripping it off.
6) Unit after earpiece removal
7) Using a screw driver; remove the enclosure so in the end you'll be left with the speaker mounted on a plate.
8) Unit with enclosure removed.
*Note : This is also a good time to remove extra trim around the speaker to make it fit into your helmet. I also plan to trim mine down a little.
9) Some hot glue to prevent the wires being pulled out from the speaker!
10) Where I mounted them..
11) Speakers mounted and the cheek pads clipped back on. They fit really well without any distortion or discomfort.
Velcro can easily be used to seat them if you weren't as lucky as I was !
12) Wiring out from the back, down the inner of my jacket and in the change pocket where my MP3/Phone/idevice is located.
13) Finally here is a quick clip of the finished results, please excuse the slightly loud ending.