Amp and Speaker wattage

 Many people misunderstand how you can blow a speaker most thing its all about too much power and so they buy amps that are less than their speakers Watts rating. Although this is true its not the most common way people blow their speakers.

The ways to blow your speakers are:

  • Under powered: When a speaker is under powered and the amp is turned up it can "clip" which is a square sound wave that will melt the speakers coil apart.
  • Over powered: There is a fine balance of speaker power to amp power that you want. It is best to get an amp that is more powerful then the speakers and turn down the output at the amp level this way it will not distort or clip and the lowered level at the amp level will stop the amp from sending too much power to the speaker.
  • Age and heavy use:  Just as with anything else in this world if you use it to its limits too often it will wear out speakers are no exception.
  • Plugging inputs while the system is on:  Always make sure when you plug in any inputs the power to the amp/receiver is off, this can cause a nasty sound and usually nasty popping sounds are not good for your speakers.

Matching amp power and speaker power: If your speaker is 150 W RMS get an amp that does 150W RMS per channel. You are best to go over than under but try to keep as close as possible to each other. You want to make sure the amp you choose is capable of supplying from 75% to 150% of the speakers /sub woofers total RMS rating. So add up all the RMS Watts for the speakers and or sub woofers you are going to attach to the amp and make sure the amps total RMS wattage is within 25% up or down from that number.

RMS and Max Watts  You want to pay more attention to the RMS but also make sure the max of the amp doesn't exceed the speakers max.

  • RMS = what a speaker/Amp can do all day long
  • Max = the max output a amp can do or max input a speaker can take.

Ohms:  Just to complicate things some more make sure you match the ohms of the speaker to the ohms of the amp as well. Most run 4 ohms until you get into bridging and well we will leave that to another day and a later article. Here is a link to a great wizard to hep you wire your sub woofers correctly. The 12 Volt Subwoofer Wiring Wizard