Nov 16, 2008 at 7:48 AM Thread Starter

#### tintin47

I have tried hard to find a thread on this, but to no avail. If there is one, point me in the right direction and sorry for taking the space. I am trying to get answers to exactly what all of the specs for headphones and amps mean. Specifically output resistance on amps and sensitivity on phones. I know the basic principles but I'd like to be able to understand it better.

What exactly to the specs all mean and how do they relate to the sound that you hear? I am a pretty advanced physics student, so I have no problem with relatively complicated equations/ideas, and I know basic circuits and electricity physics, but nothing I've found has done a very good job explaining the answer to my question.

Nov 23, 2008 at 8:35 AM

#### iamlistening

i fall in the same category as well....please enlighten us

Nov 23, 2008 at 9:18 AM

#### Uncle Erik

##### Uncle Exotic
Headphone impedance has to be considered in light of the amp's output impedance. The closer the two values match, the better the power transfers from the amp to the headphones. Keep in mind that the headphones' impedance changes as it is being driven.

The sensitivity shows how loud the headphones will get depending on how much power it is given.

You can figure out the loss from an impedance mismatch (if any) to see how much power is being transferred from the amp to the headphones. Once you know how much power is getting through, you can use the sensitivity to find how loud the headphones will get with the amount of power coming through.

There's more to it, and I'm still learning how all this works together, but I hope that can get you started.

If you want to read more, there's a wonderful library here:

Technical books online

A great tutorial on building an amp is here:

Boozhound Laboratories

I also highly recommend the books by Morgan Jones and Bruce Rozenblit.

Nov 23, 2008 at 10:00 AM