Avoid Over Powering:
Overpowering occurs when your amplifier puts out too much power relative to what the speaker is rated for. The solution is preemptive – when buying the pieces that will make up your sound system, make sure everything in your sound system can "handle" each other. But of course, it's not an ideal world and we can't always be preemptive. You can modify your system to even out the power load – we at Galaxie can recommend the best way to do that, maybe an amplifier change or a tweak to speaker hardware. As always, we are always here to advise you towards your best sound!
Over powering is the speaker issue that gets the most attention, but interestingly, is not the one that causes the most problems. You have to exceed a speaker's rated power for an extended period of time to cause it to fail. It happens, but it doesn't cause as many failures as people think it does. If your amplifier puts out an amount of power similar to what your speakers are rated for (even if it is somewhat more), its not too detrimental.
Bad music can literally ruin your speakers!
Yes, you read it right – bad music can destroy a speaker. In fact, it is a very common cause for speakers failing!
When a speaker receives power from your amplifier, it converts most of the power into sound by moving back and forth and causing the air to vibrate. However, it is not 100% efficient and some of the energy is converted into heat. The higher the power, the higher the heat. Your speaker is literally pulsing out the soundwave that it is being told to play by your vinyl, cd or other media.
A normal soundwave looks like, well, a wave. "Clipping" is a sound issue that occurs on the recording/producing and renerdering side of music. Clipping is when the sound being recorded or rendered exceeds the decibel level that the recording device or format can handle. Low quality mp3s often and inproperly rendered "home studio" files unfortunately can have this problem.
When a speaker is given a signal that is clipped, it actually receives far more continuous power (as it is reading the chopped part of the wave) than it would when it is given a normal not clipped signal. This is converted into more heat than the speaker was designed to handle and the coil literally burns. It can, in extreme situations, actually catch on fire (remember, the cone is made of paper)!
So, you can use a power amplifier that puts out considerably less power than the speaker is rated for, and yet, because the sound wave it is trying to play has clipping, the speaker will blow. The harder the amplifier is clipped (the louder the distortion), the greater the chance of this happening. Tweeters are particularly sensitive to clipping because a clipped signal generally has lots of extra high harmonics (high frequencies) and tweeters are normally able to handle only small amounts of power. However, woofers can be blown due to clipping as well. It's not the under powering that causes the problem, it's the distortion that often occurs as a result of under powering that is the culprit.
This is just a fancy name to describe sudden loud sounds. One of Isaac Newton's famous laws states that a body in motion wants to stay in motion. Just like a car wants to keep going forward unless you apply the brakes, a speaker wants to keep going forward (or backward) when it is given an amplified signal. If it goes from a low volume (or no volume) to a very loud volume (especially if this sound exceeds the power handling of the speaker), the cone wants to go farther than it was originally designed to go. In the forward motion, it can extend so far that it rips, and in the backward motion it can go back so far that it either rips or hits the magnet assembly and breaks.
Common transients include turning on something that goes "pop" when the amplifier is at full volume (always turn the amplifier on last and off first), dropping a microphone when it is on, or plugging and/or unplugging a cable into/out of a P.A. component when the amplifier is on.
Feedback is the loud squeal that is often heard in a P.A. system when a microphone is pointed too close to a speaker cabinet or the volume gets too loud. A squeal lasting less than a second is generally harmless (although it can act like a transient sometimes and cause failure – see above). However, keep feeding back for very long (more than a second is often all it takes) and the tweeters and/or horns will get so hot that their coils burn and they stop working.
Most speakers can take a degree of rough handling. However, if a cabinet takes a hard enough impact, it is possible that internal parts of the speaker can shift. Speakers have heavy magnets hanging off the back of them and momentum on a hard enough drop will cause the magnet to shift. Remember, the way a speaker creates sound is by vibrating hundreds and even thousands of times per second – it doesn't take much of a shift to throw the alignment of the various parts of a speaker out enough that they will rub. When a moving part on a speaker rubs, the part receiving the friction eventually rubs through and causes the speaker to fail. Usually it is the wire in the coil that is rubbing and it eventually rubs so thin that it breaks or shorts, thereby causing the speaker to stop moving.
Bad cables can cause is oscillations. Oscillations can occur in a sound system when the ground has come off in a cable. Everything may seem to be working alright, but a missing ground can cause a high frequency (high pitched) sound that is so high that you cannot hear it (maybe your dog will), but it is, nonetheless, causing the tweeter to burn out. A high quality cable is much less likely to have a bad ground connection than a lower quality one, and one blown tweeter can pay for a significant number of good cables.