We actually have the same method of testing as Mitch (in the video) although we have a power supply that is four times larger so the voltage will not sag when testing larger amplifiers. And, we are doing regular amp clinics where at designated times anyone can come in off the street and have their own amplifier tested. But you really need to have more than a DVM to do the testing. It also requires a distortion measurement tool, such as a distortion analyzer or an O-Scope. We have both. We like to stay with the CEA2006 standards (not WLS or JBF). Believe me, it can be very revealing. We have also had amplifiers sent off to an independent lab with 50K worth of test equipment and 3-phase supply, to confirm our findings. Like Mitch, we have begun showing the test results on products in the store as well as on the on-line store.
Consumers deserve to know the undistorted truth.

David
Earmark Marine