Hi all I would like to know are there any simple tests that can be carried out on speakers to test them. I have a multimeter and I ain't afraid to use it! I have an AV speaker pack (Infinity), and have had a faulty speaker repaired already, I found the other day when playing a dvd that there was a shrill from the other front speaker at certain pitches of music/sound. The company said that they would like to get to bottom of this and find it strange that two speakers have gone down. They said maybe the amp is sending a DC current to the speakers. I checked dc voltage while system was running and found it to be the same on all speakers 0.02v. I 'presume' that there must be some kind of DC output from the amp, otherwise how would the speakers work? Other than this, these speakers sound great. Any help/advice would be greatly appreciated.