put the meter to a ac voltage, then burp the amp, measure the ac voltage from the speaker outputs... If u have a current clamp u can measure the current.. or if u have a good meter, set it on high current input unfused, then series the meter with either postive or negative of the speaker wire, record the current flow at burp also.. now u should have the voltage and current recorded.. always remember u measure current in series.. divide your voltage by your current see what the resistance is at burp.. V/I=R P=V^2/R that will give you your power output..
