How to test and measure your amplifier outputs - avoid blowing up speakers
explaining off set measurement
I wonder how your amplifier/receiver is balanced. you hear the words from Simon...don't worry if there is a difference but do not connect speakers above a certain output level.
You can do the same test when you go score a amplifier and there are no speakers to test there, just take your multi meter and headphone with when going out scoring. MEASURING IS KNOWING