[Scott Dorsey]

wrote:
Scott Dorsey wrote:

Actually the acoustic space within headphone earcups do cause problems
too. Even the space within your ear canal!

The interesting thing is that because the volume (AND the volume of your
ear canal) are much smaller than a room, the chamber resonances that were
bass problems get moved up and turn into upper midrange problems. The bass
becomes easy since the volume is too small to have resonance issues, but
other things get harder.

** There is no problem, other than how to sensibly measure the response of a headphone.
Using an imitation head with a tiny measurement mic buried inside the ear hole is ********.

This is true, but there are standard methods to measure them. There are a
bunch of standard ear simulators which might not emulate my ear or your ear.
But if I see a plot made with a Zwislocki coupler or a Keller coupler, I know
I can compare it with other measurements made with the same coupler.

But... headphones are designed with those resonances in mind. And it's hard
for headphone designers to work around some of those resonances.. if it were
easy, there woudn't be so many different-sounding headphones out there.

The outer ear and ear canal does NOT create response anomalies for the * owner * of that ear.
The person's brain tunes them out so we hear sounds correctly.

Right. That's the problem. When you put on headphones, it's like putting
on someone else's ears and all of that brain training goes out the window.

For example, you're used to having a notch caused by reflections off your
shoulders. You use that to some extent to judge height of a sound source.
Where that notch is depends on your shoulder and neck geometry. So if you
try to emulate it in headphones to make the headphones sound more natural,
the place to put it is different for you and for me because our brains are
adapted for different bodies.

ES headphones are almost acoustically transparent, creating no trapped space for resonance to exist.
Other types having a weak air seal are not very different.

Yes, it's MUCH easier to do if you can go with an open-back design. This
leads to much more consistent measured response from person to person.
But it also kind of defeats much of the purpose of headphones.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."