What is headphone impedance & why do you care?
Headphone impedance is another one of those audiophile glossary terms that goes right over people's heads who ask about headphones.
And finding out what it is and why it affects you can be almost as confusing.
So we've done our best to compile the best answers into this post that should convey what it is and why you should care. At least that's the goal, anyway.
What is impedance
impedance is the resistance that an electrical current faces when being driven from a power source through a circuit. Much like when you have a hose that has water coming out of it, but then you put your thumb over the hole, this would be considered impedance, which is measured in Ohms. source
Hopefully that makes some sense.
When measuring impedance in the context of sound though, the lower the Ohms means the resistance is higher. Which also means that there's a higher need for energy to force the current through the circuits.
And impedance in headphones in regards to performance means that the lower the impedance of the headphones, the louder/clearer sound you'll get. Because there's more power needed to make the sound happen.
What does impedance have to do with headphones?
Well if you're using high impedance headphones on a mobile device, you're going to be able to listen to them a lot longer, because there won't be as much juice required to make them work. However, if you're using low impedance headphones, you'll burn through your battery pretty fast.
And if you're using a amp with your headphones, you'll have to take into account that the impedance of your amp plays a role with your headphones as well. If you have low impedance headphones with a high impedance amp, you'll likely run out of battery quickly. (source)
So pairing high impedance amps with high impedance headphones is your best bet for power usage/conservation.