[luckyseventh]

alright, so i've got a project about how different factors in headphones may affect the end sound, and how they do so. i currently have the construction and housing materials, the technology behind it (electrostat, planar, ortho, etc), and a mention of the amp/dac/source. anything i might be missing?

 

[luckyseventh]

a bump, since apparently people dont appreciate pms all that much

 

[xnor]

(I don't like PMs because nobody else can see it / comment on it then.)
 
 
A random thought on material choice:
 
Drivers have to be mounted rigidly, else the driver itself will move back/forward opposed to the movement of the diaphragm effectively reducing e.g. bass output and increasing distortion. A rattling cup may even be perceived as noise.
 
This is imho one of the main reasons we see so much hard plastic, and that plastic is cheap, easy to mold etc.

 

[xnor]

A problem however is when the headphone is a closed construction and the whole cup is made of hard plastic without additional materials. Rigid means reflections, so at high frequencies there usually will be some ringing at certain frequencies which show up in CSD (waterfall) plots.

 

[davidsh]

The tension and thickness of the e-stat diaphragm can be important.

 

[luckyseventh]

and just an question... how would resonance work? as in how do you determine the frequency at which a certain material will resonate?

 

[xnor]

There are so many different kinds of resonances.
 
The ear canal itself has a resonance around 3 kHz. There's the Helmholtz resonance of the concha due to its own cavity volume. The headphone drivers have resonant frequencies, usually making the diaphragm more rigid lowers the resonant frequency but it depends on the whole construction.
 
Take a look at this simple cavity resonance calculator:
http://hyperphysics.phy-astr.gsu.edu/hbase/waves/coke2.html#c4
 
You can also find many tables like this on the internet:
http://www.sae.edu/reference_material/pages/Coefficient%20Chart.htm