I noticed that the horn in one of my SWR Goliath 3's is not as crispy as the other. I took out the tweeter to examine and it looks fine. I also did the crank the highs and master, rotate the attenuator and you can hear the highs increase, but not very much. I'm wondering if the L-Pad is going out. I have continuity between all connections in the circuit and everything seems to measure as it should, fuse is good. How can I test L-Pad?