Bad mics and Blown Speakers


Well-Known Member
Sep 3, 2006
In most cases the cause of a blown speaker or horn driver, is either feeding the amp a distorted signal, or over driving the amp. Extensive feedback blows out the system more because it drives the amp to distortion, than actual power level.

Many people think if they have a speaker rated say at 300 watts that they should only attach a 300 watt amp to drive it. In actual practice, using an amp with 1.5 times the peak rating for the speaker will REDUCE the chances of blowing the amp. So the 300 watt speaker for instance at rms might be rated for 500 watts program, and 800 peak. So in a pro setup it would not be unusual to have a 1000 to 1200 watt amp driving it. It is when the amp is over driven that the distorted signal causes too much CONTINUOUS energy to be sent to the speaker, which causes the voice coil to over heat, and burn out.

If you have a active cross over system there is also the possibility that someone altered the cross over points so that a signal below the operating level of the speaker or driver (usually driver on horn) in this case, many time the voice coil is not blown out, but rather ripped out as the diaphragm ans over extended its travel.

When or sub woofer blow out, in addition to any of the above, sometimes a poorly designed cabinet will not properly "load the Speaker" and so the cone over travels and gets damaged.

As counter intuitive as it may seem, having a significantly more powerful amp driving the speaker will usually cause LESS speaker failures.

Putting an improper load on an amp (for instance operating in bridged mode at 4 ohms or below for an amp only rated for 8 ohms bridged) rarely blows the speaker, but it does quite often blow the amp.



Active Member
Apr 1, 2006
North Carolina
we recently got all of the monitors fixed.

we got a quote and he said 400 dollars originally for all 4, but then after he fixed them, he said it was 400 each!

He kept them for 3 months and the principal called and we got them back free of charge. so 4 brand new monitors for free.