[riker1384]

Why aren't there any active headphone designs? That is, a headphone with a matching equalizer, and probably an amp.
 
I am not an engineer, but it seems to me that active design would be even more useful in headphones than in speakers. Headphones are like single-driver speakers, there is no crossover. The only way to change the response is to make mechanical tweaks, or electromechanical tweaks in the motor. That must be a difficult and arcane process; every time you try to fix one problem, you probably introduce others. In EQ circuits, on the other hand, it's straightforward to alter the response in a particular way. Also, headphones aren't even designed for flat response. You're trying to create a certain curve with peaks and dips through tweaking the driver.
 
It seems like it would be much easier to design active phones. Got a great phone that's light on bass? Boost the bass. Need a peak at a particular frequency in order to get to your target curve? EQ a peak. And so on. Why don't they do that? Does anybody do this, or do any headphones have passive EQ circuits built in?

 

[leeperry]

the MDR-F1 has some of that: http://www.sonystyle.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10151&catalogId=10551&langId=-1&productId=11035332
 
"the MDR-F1 requires no amplifier impedance matching; built-in equalization circuitry eliminates the variations in sound quality caused by amplifier impedance differences"

 

[Drubbing]

These used to be available. They're not anymore. That speaks volumes for the interest in them.
 
1 they'd cost too much
2 they'll sound crap for the money
3 the EQs will be cheap and dirty
4 EQs are already available in media player software, and most are cheap and dirty
 
It makes more sense to let an engineer build a phone for a certain sound and do it well for a decent price, and if you don't like it, buy something else.

 

[vvanrij]

I tried strapping my SPL Phonitor on my head today, but... it was not a succes.

 

[soundaddicted]

I agree with Drubbing post, number 1 and 4. 
 
1- Hard to afford headphones (specially for people on budget)
4- Thats why we have software, and eq hardware. 

 

[Argyris]

 There is another reason as well, and it's probably the dominant concern among the audiophile set. This is that every element you add to the signal chain is another chance to introduce distortion or otherwise negatively effect the purity of the signal. Audiophiles strive to eliminate as many things from the signal path as possible in order to create the most faithful and direct reproduction achievable. Loading a headphone with an amp and EQ would introduce a lot of inescapable variables into the equation, and it would also be yet one more thing that can break/get flaky and require a good contact cleaning in order to restore the unit to properly working condition.
 
Essentially, what others have already said is just as true: a jack of all trades is never going to be as good in any one area as a simple, well-engineered design. It would be kind of complex and flaky for the mainstream market, and the audiophile market wouldn't bite at all. So it's a non starter.

 

[ear8dmg]

All Active Noise Cancellation headphones are also active in the sense that you mean, in that they have an onboard amp.  They all only have battery powered amps though and usually no EQ.