How did you figure out about this?? I bet you tried it many times till find out about where to place the cassette.
I don't know how I figured it out, really. And the first time I tried, it just worked! Then I pulled out my phone to record it and didn't work, but after 3-4 tries it worked finally. That's all!
I don't even know how this idea came to my mind, and this won't change my life, though but, hey, it's funny huh?