[LAU] headphones

[Fons Adriaensen]

On Sun, Jul 20, 2008 at 12:26:05PM +0200, Arnold Krille wrote:

> I think truly flat responses is impossible with headphones.

Depends on what you call 'the response'. For a headphone
this would be ratio of the acoustic signal produced at
the entry of the ear canal to the driving voltage.
Now this must not be flat, at least not if you want
to use the headphone with signals that sound good
when reproduced by a speaker. The simple reason is
that the response from the speaker to the entry of
the ear canal is not flat, even if the free field
response of the speaker is.

More generally, expecting a headphone to work well
with signals that are intended for speakers is sort
of wanting the impossible. There should be a lot of
processing between the two. In practice headphones
are designed to be reasonable flat without any such
processing, which means they are some pragmatic 
compromise.

> Just compare the 
> sizes of your more-or-less flat response studio 
> speakers and the size of the average headphone.
> A speaker with a diameter of only a couple of
> cm has its  resonance never in the range the
> bass-driver of your studio-speakers.

Nor does it have to move large quantities of air.
But the most obvious difference that you listen
to the near field over most of the frequency range,
which is fundamentally different from a speaker.

Ciao,

-- 
FA

Laboratorio di Acustica ed Elettroacustica
Parma, Italia

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