Pink noise is all frequencies of sound at the same amplitude. Actually, wiki says it has the same "power".

http://en.wikipedia.org/wiki/Pink_noise

This was commonly used to adjust graphic equalizers. You would adjust the sliders until the display showed all bands at the same strength. You could, of course, adjust in other ways if you wanted (for example) more bass. But the intent was to help adjust the equalizer to compensate for the room. Modern amps have YPAO (or similar) features built-in now, and they appear to be more precise. So pink noise doesn't even seem to be a feature anymore.

If you can run wires in your attic you can put your surrounds wherever you want. Surrounds are generally above and behind the listener(s). Your Yamaha manual (when it arrives) will have a diagram with suggestions for placement.

1poorguy