You basically just said all dynamic drivers are the same because they function the same. Would you say that all internal combustion engines are the same? Is the 1.0L engine out of a Nissan Versa the same as a 5.2L V8 out of a Shelby GT500? They function the same, right? Same technology. Fuel goes in, sparks and explosion, and drives the piston.

>But aren't the drivers on a cheap headphones and drivers on a costly headphones the same?

Does that mean that 2 cars with the same engine perform the same?
The driver material/type doesn't tell you anything about how a headphone would sound (with certainty).

>What determines the "Attack Speed" of the drivers?

this is a myth that can easily be debunked by looking at impulse response measurements of different headphones; those headphones who are said to be "fast" have similar results as those with "slow" drivers.

The diaphragm material, speaker size, speaker magnet, and speaker coil all contribute to the performance of a headphone's speaker.

It's difficult to say why a speaker has a specific design or uses a specific technology - audiophiles can only speculate.

Only an engineer or someone who studies the subject can make definitive statements, but explaining it also involves understanding the mathematics and physics of audio.

Acoustics also plays a part in the performance of the headphones and are related to the speakers.

Finally, the entire construction of a headphone is related to the acoustics of your ears, whether it's the acoustics of the outer part of your ears (pinna) or the acoustics of the inner part of your ears (auditory canal).

All of these factors are synthesized in what is called the headphone frequency response graph (the most useful information for us as consumers) and THD.

Regarding the analogy between headphone speakers and cars, it is not a perfect analogy. It is possible to make good headphones with speakers that can be considered inexpensive.

Regarding "speed" in headphones, mathematically speaking, the idea of speaker speed is not very interesting since the frequency response can be derived from an impulse response. So if the headphone can reproduce frequency X at Y dB with no distortion, that's what it does.

The idea of attack speed can only be understood as something derived from the auditory perception of the frequency response of the headphone in your ears. I recommend that you don't place too much importance on the term "speed or attack speed," as each audiophile may have a different interpretation of what it means. It's a language game.

If you want to know about some of these terms, I recommend this here.

Imagine you have a Suzuki Hayabusa engine (that's your HD800S driver) and a Renault Clio engine (that's your cheap headphone driver) they use the same technology, but they are completely different in what they are trying to do, there is no one thing that makes them different, the entire housing, driver shape etc... is completely different from another and everything affects sound in some way or another, look at the HD660S and the HD700 for example, both use the same driver, but the different housing makes them sound very different

A bit off topic, but there is a beautiful, free publication from Klippel about flaws in loudspeakers, called Loudspeaker Nonlinearities – Causes, Parameters, Symptoms . The measurement and analysis tech has gone a long way to have a lot of insight into inner workings of a driver. It is DEEP. The same tools are used to analyse headphone drivers and microspeakers so I guess it's not entirely irrelevant.

The best drivers are optimised with software and a ton of simulation of the magnetic circuit and the airflow around it. The experimental research is carried with simple and complex signals. Not as complex as the ones from Jerobeam Fenderson, but still it's more than what you see on ASR.

They dissect distortion into many parts : HID, IHD, IMD, AMD and some more. They scan the entire diaphragm with a laser and then split the recorded movement into discrete components so that you can see if your diaphragm is making sound or just rocking.

Generally the task of a headphone driver is to turn voltage into pressure just like a compressor in your fridge, except it needs to happen on time. When voltage changes by one unit, the pressure must change proportionally and under varying conditions. Some drivers do it well, some don't. The 70 page paper I mentioned describes the issues that transducers face. A lot of it comes down to quality control. The symmetry of the assembled driver is not always the same. This last thing will become less of a problem with MEMS microspeakers, but with a driver assembled by hand there are always rejects that end up on Aliexpress. You can buy a driver and see what's inside. You'll see that there are many different drivers, made with different materials, vents, rings, magnets. Their coils have various diameters and lengths. You'll also see their prices.
If you go on ASR, you'll see that they also measure differently.

I wasn't going to write, because I simply lack knowledge, but since you apparently got a lot of motoring replies instead of information, then I guess I might try and throw in something which could be (perhaps? maybe?) somewhat relevant or at least entertain more knowledgeable people with my foolery.

I don't know if those serrations are like that, but in loudspeakers membrane can be ribbed which is done in order to delay distortion on that specific part. With increase of power membrane will start distorting, but it is not distorting whole, rather certain areas which are responsible for different frequencies start distorting earlier while some later. As such you can increase power handling of the membrane by ribbing it, even just partially. Tonally ribbed membrane is usually darker, while straight/smooth of the same material and dimensions is brighter. However membranes can be made of different materials, for example paper or kapton, and aside size can have different thickness, density, stiffness, they can be soaked or coated in some additional substances, and all will affect both sound as well as power handling properties.

The diagonal angling of those serrations actually look like it might be used to stop the wave from traveling along the membrane, something like wing fences on Mig-15 :P If I recall it right the sound actually travels along the ridge of the speaker and even come to play with the baffle.

Headphone drivers are mystery for me as well, the fight is against the size limitations so there is a lot of witchery like this going on.

Music

No but it depends on the internal resonance of the housing, and the the "friction/resistance" of the rubber used etc etc. But a better driver is not necessarily visibly different from a worse one, buy the material and construction affects the behaviour at different frequencies

I do think different drivers can help accentuate sound. I mean, if I made a headphone using the driver that come with electival engineering kits and have it tuned bery similarly or exactly to an hd 600, its going to sound like shit conpared to an hd 600 because the driver will get everything loud enough but lack texture, bass will sound like simple thuds with no detail and high hats will sound blunted lacking any stayong power. Granted, the difference among actual headphones is smaller but still noticable.