This is how many manufacturers get away with telling consumers their receivers are 100x5.

"The FTC requirement is based entirely on measurements derived from an 8-ohm resistive load, with only two "adjacent" channels driven. To further undermine the issue of real amplifier performance, manufacturers are only mandated to sample their measurements at an easy 1 kHz frequency- no distortion specification required."

http://www.hometoys.com/wrap.php4?/htinews/oct02/articles/nad/defuria.htm