What is Speaker Impedance?
Impedance is the electrical characteristic of a speaker that regulates the flow of power from the speaker and the amplifier. To get more technical, it is the combination of the resistance of a speaker plus is reactance. The impedance value is expressed in Ohms. Speaker Impedance is essentially a number that quantifies how difficult a speaker is to operate and how compatible is can be with various amplifiers.
Why Impedance Matters
An amplifier is made to work with multiple speakers. However, when connecting multiple speakers to an amplifier, you have to make sure that the amp isn’t overloaded. As you add more speakers to the amp, the impedance it uses gets lower causing the amp to work harder. This is fine because amplifiers are built for heavy duty use provided they are used within the parameters specified. Overloading the amplifier can severely damage it.
Higher or Lower?
As mentioned earlier, impedance restricts and regulates the flow of power between the receiver and amplifier. This might lead people to assume that the lower the impedance the higher the power and hence the better the performance. In reality it’s quite the opposite. Lowering the impedance increases the amount of current forcing the amp to work harder to maintain the desired voltage. A low impedance load will stress an amplifier to put out more current and if this value is more than what the amp can provide, it can cause the amp to overheat.
For example, 4 Ohm speakers will work with a low power amplifier, as long as the user does not increase the volume all the way up. Doing so, puts too much strain on the amplifier and it will find itself short on power. This is why low impedance speakers demand more power than high Ohm speakers when the volume is turned up.
One solution to this problem is to use a very strong amplifier that can handle such a load. Some amps are built to putout high current flows and can drive virtually any speaker without with no issues whatsoever. However these amplifiers also come with a hefty price tag.
So then is high impedance the answer? Afraid not. Impedance that is too high restricts the flow of current. If the speakers aren’t getting the right current they need, they speakers will provide poor quality sound or might crash altogether.
Desired Impedance Range
So too low and the amplifier can get damaged. Too high and the speaker can fry. The ideal solution is to find a middle ground; meaning an impedance range that don’t stress neither the speakers nor the amplifier. For most people and most electronic devices a speaker impedance specification in the 6-8 Ohm range represents a good compromise between current and voltage flow. Most of today’s amplifiers and receivers can safely drive speakers that fall within this range.
The new generation is more tech savvy, more keen to ask questions and very inclined to know more about the product they purchased or are about to purchase. Understanding speaker impedance is integral to knowing how well your speakers and amplifier will be performing. Knowing the capabilities as well as the limitations makes for a good sound experience. It will also help audio shoppers in their quest for a good quality entertainment system.