[sugarkang]

Wow.
 
First, I would love to hear your thoughts on that beast.
 
Second, I think the way those are split between 30mm high /90mm low,
it confirms my suspicion that the larger the driver is,
the less it is able to provide clarity at the high treble end. 
Therefore, drivers rarely go above 50mm. 
 
That's my theory for now. 
It's also complementary to the Sennheiser employee's comments about stability.
 
 
Quote:

i just picked up a pair of these this week, 
apparently they have 2 speakers per earcup, a 30mm tweeter and a.................wait for it.................  90mm subwoofer
may need a bigger amp to actually get these to work

 

[buffalowings]

fanny wangz? I remember they were advertised with 60mm drivers

 

[Landis]

Quote:

I have a feeling that when you get huge drivers you're just gonna hear bass...

Not true in the slightest! That very much depends how the manufacturer decided to tune the actual driver. My HE-5 has larger drivers than my old DT770s and the DT770s had far heavier bass.
 
However, I'm assuming, with the right tuning, you could very much take advantage of those big drivers and create a really interesting headstage/soundstage out of them. However, once advanced tuning/modding comes into play, you may just have something the size of a Jeklin Float on your head.

 

[Argyris]

The responses so far seem reasonable. I'll add another one that was touched on but not fully explored: mass. The driver needs to overcome its own inertia in order to produce sound. The heavier the driver (or, more importantly, the more mass it has), the greater the inertia. A lightweight driver is quicker and can therefore reproduce quick transients with greater ease than a heavier one. This translates into a more coherent and "quicker" sound. I imagine at some point a driver has too much mass and starts to lose agility. That point is likely around 50mm.

 

[wywern209]

i think the fact that trebel is harder to produce w/ giant drivers is true
just imagine the energy draw of trying to vibrate something of that mass a such a high frequency. 
E= mv^2 so if the velocity of the driver's vibration increases then more and more energy is required.

 

[IPodPJ]

I think the HE90 has a very large diaphragm, from what I can remember.  Not a dynamic driver, obviously, but still large.

 

[chrisbrock]

Fun topic! Ill jump in on this one as well.  The size of the driver is only one factor in the speed or quickness.  Really the most important factor is the motor structure that is driving diaphram, the "power to weight ratio" if you will.  Think of it like this.  Lets put a base Ford Mustang V6 against a base Ford F150.  Of course the mustang will win hands down in every way.  Now lets drop the Shelby GT500 motor, transmission and suspension in the F150 and run them again.  Even though the F150 would still far outweigh the mustang it would stand to blow the doors of the lighter mustang.  Power to weight ratio is a major facotr in the ability of a driver to be quick.

 

[sugarkang]

You're saying that we need a 10 pound floater on our heads.
 
 
Quote:

Fun topic! Ill jump in on this one as well.  The size of the driver is only one factor in the speed or quickness.  Really the most important factor is the motor structure that is driving diaphram, the "power to weight ratio" if you will.  Think of it like this.  Lets put a base Ford Mustang V6 against a base Ford F150.  Of course the mustang will win hands down in every way.  Now lets drop the Shelby GT500 motor, transmission and suspension in the F150 and run them again.  Even though the F150 would still far outweigh the mustang it would stand to blow the doors of the lighter mustang.  Power to weight ratio is a major facotr in the ability of a driver to be quick.

 

[Bilavideo]

 

Im pretyt sure the HD800 have got 56mm drivers. But i would say 56 mm seems to be the max because a typical ear is like 70mm? diameter? So any bigger and it would just be way to heavy and uncomfortable. Imagine a headphone that covers your whole head! That would be bad.

The HD800's 56mm driver also bears some scrutiny.  If that whole area were covered in Mylar, you'd have a bit more driver.  Instead, the center of the driver doesn't exactly exist; it's a hole.  To avoid cone breakup, the HD800 avoids having a cone.  The result is a 56mm driver with an actual driver real-estate significantly smaller than 56mm.

 

[MrJohnny]

Personally the bigger the ddriver the Better the sound staging because more of your Actual ear is being shot with sound.  so your ear lob  and upper and outer ear can get the sound too. But The voice could has to be Wide to support the hudge cone 

 

[Bilavideo]

 

Personally the bigger the ddriver the Better the sound staging because more of your Actual ear is being shot with sound.  so your ear lob  and upper and outer ear can get the sound too. But The voice could has to be Wide to support the hudge cone 

You're right.  There's talk - down at the watercooler - that larger drivers are slower, because they have more mass to move; they also have more mass to damp.  But the real culprit, slowing the development of 60mm drivers, is profit margin.  Mylar isn't the dominant diaphragm material because it's the best choice - from the narrow perspective of sound.  It has low mass, which makes it better than something stiff, which really would be slow.  But the real reason for going with Mylar - or any other plastic film - is cost.  These drivers are cheap to mass produce.  The industry is also surprisingly conservative.  Headphone manufacturers slavishly copy loudspeaker designs.  There are precious few visionaries.  Why take chances when the real money is in making a zillion units of something that's hard to screw up, and then packaging, pricing and distributing the thing with a certain efficiency.  
 
The idea that headphone makers are sitting around dreaming up new ways to improve the product is probably a bit doe eyed.  It's probably more realistic that the smart firms are watching developments in the loudspeaker world, with an eye toward exploiting a good gimmick before their neighbor does.  
 
As for the idea that a larger driver would just be too slow, I think the use of filter cloth - on so many "audiophile" cans - is a tip-off, a bit like ordering a filet mignon and then asking for some A1 steak sauce.  I've got nothing against this particular condiment.  It's just that if the meal tasted right, in the first place, you wouldn't have to drown it in an extra product afterwards.  If the driver were "properly tuned" in the first place, there'd be no reason to mask its high end with a filter cloth.  This is also inefficient.  If the driver had the right tone, extra power would not have to be spent trying to pump through a barrier.  Grado doesn't (except to the degree that the front grill cloth is throwing itself on the hand grenade) but so many of its competitors do.  I'm happy to vent the driver to get more bass, but if the driver were larger, it would provide more front-wave bass, without needing as much bass-reflex from behind it.
 
A larger voice coil means using up more copper, which cuts into the margin, but that's a spreadsheet problem, not a problem of engineering or acoustics.

 

[Xymordos]

Well lets hope the Fanny Wangs provide the headphone industry with new ideas

 

[Ham Sandwich]

 
Quote:

  But the real reason for going with Mylar - or any other plastic film - is cost.  These drivers are cheap to mass produce. 

 
Mylar is also easy to form using modern assembly tools.  You can watch how AKG forms and makes the driver for the K702 in an episode of How It's Made: Headphones.  Not much to it once you have the tools and tooling.
 
Some headphones use a microfiber or cellulose fiber or similar fiber material.  The Denon headphones use a 50 mm microfiber driver.  The Sony CD3000 uses a 50 mm bio-cellulose driver.
 
Something that would require a composite material that can't be so easily formed is not going to practical for a consumer headphone.  Could you imagine a driver that would require a custom carbon fiber weave with a different weave or density for different areas of the driver?  Yikes!

 

[Xymordos]

Actually, it seems to me that only Sony and Sennheiser is putting in the effort to develop new technologies, probably coz they're much larger companies than the others and actually have the resource to do so?

 

[sugarkang]

Well, if Wikipedia is to be trusted:
 
Beyerdynamic:  300 employees
Sennheiser:  2,100 employees
Sony:  167,900 employees
 
Now, if we wanted to be all apples-to-apples about it, we'd have to compare the headphone divisions exclusively. 
That said, Sennheiser and Sony are not remotely in the same league of "large."
Which also explains how Sony can create high quality headphones,
but only charge $80 due to huge economies of scale.
 
Of course, the irony is that Sony has shut down its Qualia division while Sennheiser seems to put out new product in a timely manner. 
Though, I suspect that has more to do with the strong Yen, deflation and Japan's aging population than mere technical capability.