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.
Sharyn