[Tsujigiri]

Most headphone companies have some kind of a feature prominent in some of their products that is unique to the brand or relegated to just a few brands. These features are interesting from a headphone geek's perspective, and help each company build a niche for themselves and distinguish their products from others. Let's see how many of them we can come up with, for those headphone collectors who see something unique and just have to have it. I'll start:
 
Beyerdynamic's highly efficient Tesla driver
 
Audio Technica's "wing" headband
 
Ultrasone's electromagnetic shielding and "S-logic" for soundstage
 
Sleek Audio and Phonak's use of filters to adjust the sound signature
 
What else can you guys think of?

 

[obobskivich]

Not just contemporary, but also historic innovations (and I'm not saying all of these are as important as one another):

Audio-Technica:
- DADS
- Variations on 3D Wing
- Woodies (partially)
- Angled drivers (I don't know if AT has a marketing brand for this)


Ultrasone:
- S-LOGIC and S-LOGIC Plus
- MuMetal Shielding
- ULE

Beyerdynamic:
- First dynamic principle stereo headphones
- Tesla
- Variable porting (the COP)

Sennheiser:
- First open-back headphones
- Ring-radiator
- EAR (Ergonomic Acoustic Refinement)



Koss:
- First dynamic principle full-range stereo headphones (and they're also more or less responsible for stereo headphones as a consumer item as well; they did a lot to promote stereo headphone listening in the 1950s and 1960s)
- First electrostatic headphone (disputed; I think Koss can definitively claim to have produced the first CLOSED electrostatic headphones though)
- First noise-canceling headphone (I've seen counter-claims, but none are as old as Koss' claim)
- Adjustable IEMs (CC_01)
- Folding headphones (not certain on this, but I'm assuming PortaPro are the first)
- First celebrity endorsed headphones (I am not kidding; the original BeatlePhone)
- First (and currently only) WiFi headphones

STAX:
- First electrostatic headphone (disputed)
- First (only?) electrostatic IEM

Sony:
- First woodies (afaik)
- Various advances in diaphragm material over the years (bio-cellulose, LCP, nano-composite, etc)
- Magnesium-alloy frames for their headphones (very few other manufacturers do this (AT does on their TOTL), especially at a reasonable price point)
- Zobel networks in headphones
- "Personal ear speakers" (the PFR-V1; its unique, whatever it is)
- Open-air headphones
- Auranomic driver alignment (this is Sony's marketing brand for angled drivers)

AKG:
- Varimotion diaphragm
- Open-air headphones
- ESP/dynamic hybrid
- Flat-wire voicecoil

Denon(/Foster):
- Free-edge driver
- Nano-fiber driver (afaik this is unique)

Grado:
- Vented Air Chamber (basically the overall design of the Grado enclosure is unique; I'm not sure "Vented Air Chamber" is accurately how they would describe the entire thing though)

Bose:
- "Acoustic Noise Cancellation" (they're probably the only legitimate claimant to be first to ANC, over Koss, that I'd believe as well)
- TriPort design


That's all I got, off the top of my head.

EDIT:

Oh yeah, and this is a cool idea for a thread!

 

[Tsujigiri]

Wow, that's quite a list!

 

[obobskivich]

I want to add the Parrot Zik onto there somehow, but don't even know where to begin. Like with Koss (and the Striva) it's easy to just say "WiFi Headphones" - but the Zik are so unique (so are Striva, but they're easier to explain). These two (Striva and Zik) both came to mind based on the "future of headphones" thread - both are quite innovative/advanced (in terms of the tech behind them) compared to the majority of modern headphones.