Quote Originally Posted by Alpha_One View Post
33MHz is ultrasound. Even bats can only hear up to 100KHz.

I think the original claim is 33Hz. 33MHz is a million times that. If my 8 units (so far) of the relevant EE are not wrong, it would be impossible to produce a 33MHz signal with the subwoofer (which are usually lowpassed to produce bass frequencies only). Ultrasound equipment, maybe, car stereos, no. I've never heard a woman squeal while having an ultrasound...

EDIT: http://en.wikipedia.org/wiki/Brown_note related stuff...
HZ it is!