I have 2 100 watt paging amps in large factory envirment. Coming out of phone system to anti feedback interface and on to phone input of amp. Also there is a nite ring over page and an alarm input from security system going into aux inputs. I'm using tape out of the first amp into aux 2 of 2nt amp. Ther is no more than 70 watts of speakers on each amp. Now the problem...Every month or 2 they loose 2 to 3 speakers. These are 15 watt bogen horns. This has been going on for some time now. No pattern in loosing speakers. Is there any way to test what might be causing this or any protection that can be put on outputs. This is a lot of heavy machinery there & was wondering if some outside interference could cause problems. It's a 2 hour drive tomorrow & any suggestions would be appriciated.