How does Impedance work?

[TotallyNotABsName]

Just trying to understand something I know little about. So ignore my ignorance.

How does Impedance work?
Why do some amps have higher Impedance, as well as headphones? Also, how do you "power match" your headphones/Iems to your amp?
Thank you

 

[dunring]

Just match them that the output impedence of the amp has to be 1/8th of your headphones. If it's too high, I've heard firsthand how it changes the sound for the worse.
10ohm IEMs need a source with less than 1.2 ohm output impedance for example. It's one of the reasons you'll see two opposite reviews that love or hate something. One of them has a source that's too high and sounds bad to them.

 

[TotallyNotABsName]

Just match them that the output impedence of the amp has to be 1/8th of your headphones. If it's too high, I've heard firsthand how it changes the sound for the worse.
10ohm IEMs need a source with less than 1.2 ohm output impedance for example. It's one of the reasons you'll see two opposite reviews that love or hate something. One of them has a source that's too high and sounds bad to them.

Ah ok, thank you. I never knew
Is there a book over this you would suggest, so I could learn? Because I have many questions.

 

[bigshot]

Ah ok, thank you. I never knew
Is there a book over this you would suggest, so I could learn? Because I have many questions.

https://www.head-fi.org/threads/headphone-amp-impedance-questions-find-the-answers-here.607282/

 

[71 dB]

Just match them that the output impedence of the amp has to be 1/8th of your headphones.

This is the "rule of thumb", but in reality the properties of the headphones dictate how low amp output impedance they require. If the impedance is flat in all frequencies, the output impedance can be very high and vice versa.

10 ohm IEMs need a source with less than 1.2 ohm output impedance for example. It's one of the reasons you'll see two opposite reviews that love or hate something. One of them has a source that's too high and sounds bad to them.

Again, if the 10 Ω IEMs have very flat impedance curve, the amp output impedance can be high. Also, I don't think opposite reviews can be contributed to output impedances only in such a simple way.

Is there a book over this you would suggest, so I could learn? Because I have many questions.

https://en.wikipedia.org/wiki/Electrical_impedance