Karaoke by carolclarinet via Flickr

Guys, have you ever heard of this? Once in the mid-70s I heard someone play a pop song in stereo in a way that supressed the main vocals until they were almost gone.

The reason this happens is phase cancellation. During the show we use some audio examples and here are links to the specific clips as WAV files:

Example 1 Sine Wave 1 – Reference: Two sine waves mixed into a mono file
Example 1 Sine Wave 2 – Two sine waves, one of them 180 degrees out of phase

Example 2 Brad Sucks 1 – Reference: Brad Sucks‘ Understood by Your Dad
Example 2 Brad Sucks 2 – Understood by Your Dad, with the right channel 180 degrees out of phase
Example 2 Brad Sucks 3 – Understood by Your Dad, 1 and 2 with a switch between the two in the middle

Example 3 Brad Sucks 1 – Understood by Your Dad, mono mix
Example 3 Brad Sucks 2 – Understood by Your Dad, mono mix with phase cancellation