I discovered this technique when I was home alone one day after school. I have a stereo system that has two fairly good-sized speakers and when you turn the volume up on the speakers they vibrate like crazy. I don't even need to take off my underwear to cum. Basically I just put some song on that has a lot of bass and put the speaker on the floor so the cone is facing up. And I sit on it so that my pussy is on the cone. I can make myself cum in seconds if the volume is high. You can fool with the volume to make the intensity whatever you like ranging from a gentle tickle to INSANE!
Anyway, just though I would share because I haven't seen this technique before.