Understanding Speaker Impedance and Why Does it Matters?
Speaker impedance is a measure of the degree of opposition to the flow of current in an electrical circuit. Speaker impedance is usually measured in ohms and is essential for amplifiers, AV receivers, or interconnected speakers, as mismatched impedances will cause distortion.
It's probably easiest to understand speaker impedance if we compared it to water pressure. For example, if you have two garden hoses connected to opposite ends of your house, and one has a higher pressure rating than the other, connecting is like trying to get more water through the lower-pressure hose than before. Being originally there complicates things and reduces the water pressure as a whole.
To avoid speaker impedance, speaker manufacturers have designed speaker wires of various materials and sizes to more easily match the speaker output of the receiver.
Some of these speaker wires are made of copper or silver coils wound around an aluminized steel core. Others wrap two strands of thinner wire together and then create a larger muscle wire around it to help offset speaker distortion because the speaker itself doesn't have to work hard.
What is the difference between resistance and impedance?
Resistance is the flow of electrons across a resistance. Producers make a potential difference. Without resistance, the current would flow in a straight line through the circuit without impeding the flow, and there would be no restrictions on how fast and in which direction it can go.
A resistor causes an increased voltage drop across the resistor, changing the amount of power dissipated in the resistor. Also, introducing an inductor into the circuit makes the electron flow more complicated as it converts the kinetic energy into a magnetic field that opposes the electron flow. This creates a magnetizing current that decreases the current level over time.
This magnetizing effect provides an analogy to how exercise makes your muscles stronger. This is because, without this dissipation process, the magnet maintains its magnetic field indefinitely.
The term "impedance" is often used synonymously with the term "resistance". It is the opposite measure of a component to alternating current.
When AC power passes through an unconnected circuit, this resistance develops and becomes less powerful. Impedance is measured in ohms, kOhms, or MOhms (for mega ohms) and is usually connected in series or parallel to increase or decrease the effect it has on something.
Why is speaker impedance important?
For speaker impedance to be an issue, the speaker and amplifier must not match. For example, if the amplifier is designed for an 8-ohm speaker load, it will only produce maximum power. Connecting a speaker impedance that is not ideal will reduce the effectiveness of the speaker and may cause distortion in the speaker itself
A speaker connected to an amplifier that is a low load impedance (less than 4 ohms) but can only handle high impedance speaker loads (8 ohms or 16 ohms or more) puts more stress on the speaker as it works harder than usual when tried. It pushes the music signal through higher impedance boundaries.
In this case, the speaker "works harder" by generating more heat to produce sound. This extra heat generated by the difference in speaker impedance can damage the speaker itself and, if it gets too hot, it can even cause speaker failure. Speaker impedance issues can be avoided by paying attention to detail.