[mvw2]

Um, that's it.  I'm curious if anybody has the answer to this.

 

[tomscy2000]

Hmm, no idea, but it's an interesting question. The way they're laid out, it's certainly in the realm of possibility for a planar design, but not many people have actually dissected armatures before.
 
The only contact I've ever had with an isobaric design is Klipsch's Promedia speaker series. The back-to-back woofers delivered great, tight bass for what it was.

 

[goodvibes]

No they are not.
 
Isobaric basically means constant pressure where one diaphram is mounted directly behind another to create a sealed unform cavity between them. As both are active and in phase, the front driver sees significantly less pressure change in excursion as the rear driver both compresses the air volume of the cabinet/housing and tries to maintains a constant volume between it and the front driver. It's actually not a constant pressure as between the drivers as the drivers will compress the volume between them slightly in a sealed system as limits are reached but in effect you get, a lowered resonance point and bass extention as the front driver thinks it's in a larger chamber by not having to compress one. It is under more controll as the bass isn't getting compressed and the small chamber of air allows the 2 drivers to help each other dynamically and linearly. This obviously only works as long as they're in piston mode and there are drawbacks. Generally the rear driver still plays mids like the front and can IM the front driver above the bass and there can actually be cancellation of frequency at, I think, a frequency 1/2 wavelength between the drivers if not worked around by damping, positioning and/or limiting the range of the rear driver which can have phase trade offs.
 
What happens in dual BAs when they're the same unit is that they simply fire into the same nozzle, There is an advantage though as they get positioned so that they exactly cancel each others vibration and can be both quieter and have theoretically better transients from a more stable platform.

 

[RADI0HEAD]

They look like two separate enclosures mated together but they share a single sound port. So no, they're not isobaric.

 

[SeEnCreaTive]

But close to it, if they are in a single tunnel, they should still have similarish properties to a full isobaric set up. (Cleaner sound, and double virtual cabinet size).


I'd be interested to see a pair of cans with an isobaric set up inside. Really they are the perfect candidate for it. Super confined space, and the need for sound cleansleyness is a bit more then speakers. Almost tempted to buy a few pair of cheap $8 Sonys to see what I can get them to do. Of course double cabnate size might be a bad thing, laat years models of Sonys are wwaaayyyy too bassy and a bit muddy even though it says "balanced sound". (The new models that just came out are actually insane amounts better, but sadly its hard to tell what model year you are buying)

 

[Mython]

But close to it, if they are in a single tunnel, they should still have similarish properties to a full isobaric set up. (Cleaner sound, and double virtual cabinet size).


I'd be interested to see a pair of cans with an isobaric set up inside. Really they are the perfect candidate for it. Super confined space, and the need for sound cleansleyness is a bit more then speakers. Almost tempted to buy a few pair of cheap $8 Sonys to see what I can get them to do. Of course double cabnate size might be a bad thing, laat years models of Sonys are wwaaayyyy too bassy and a bit muddy even though it says "balanced sound". (The new models that just came out are actually insane amounts better, but sadly its hard to tell what model year you are buying)

I'm 3 years late, posting this, but, for archival purposes, I'll go ahead and link this, as it's relevant:

https://www.head-fi.org/threads/grado-fan-club.530965/page-2364#post-13465899