Since we have so much talk about how dynamic, ortho, and electrostat headphones work, I thought... how about a place we can condense all that information so that future generations (or ourselves) can read up and learn?

Let's do it! 

Someone asked about this recently: why is it that a thinner diaphragm is desirable in orthodynamic and electrostatic headphones?

My answer to that is... well, it isn't always the case.

A thinner diaphragm has the benefit of having less overall mass, so with the same amount of force applied (same power supplied by the amplifier), the thinner diaphragm will be accelerated more, thus it will displace a more significant amount of air. Potentially, this means that low amplitude vibrations are possible (reproduction of higher frequencies), and also that smaller signals that are low in amplitude but may not be necessarily related to high frequency vibrations can be reproduced on a thinner diaphragm. Effectively, what that means is that it will pull out more details from any given recording. Also, since the diaphragm is more affected by signals, it will respond to start and stop signals easier, and thus the movement of the diaphragm would become more precise. Oh, and by "more precise", I mean... no significant excess ringing/decay, so better separation/blackground/quiet passages... Note: this "no decay" only applies to the diaphragm. The enclosure and elements attached to it may still continue ringing/vibrating beyond the diaphragm's control.

However, a thinner diaphragm with big surface area tends to be more affected by air friction. Notice how Fang Bian's video of his new diaphragm for the HE-1000 has it floating around? That's what I'm saying here. Since air friction becomes a problem at gravitational pull, at higher accelerations, typically low frequencies with an audio signal, air friction becomes a huge problem here, and the diaphragm may end up not moving as far as it was supposed to. Meaning... bass will be anemic, as the diaphragm is not able to push air as far. Unfortunately, I think the only remedy for this problem is to apply a greater force at lower frequencies. For orthodynamic (planar magnetic) headphones, this means... bigger, stronger and much heavier magnets (Abyss??). For electrostatic, this means higher voltage at lower frequencies, but this may also potentially melt the diaphragm... so it's a crazy balancing act in order to achieve realistic sound. Unfortunately, this is a case where I don't think we can have our cake and eat it too... or at least not with current technology.

And that's how I understand it. Please comment, dissect, and criticize my stupidity.