[Pianist]

Dynamic driver IEMs have been around for years, but there are still no planar IEMs. Why? Is it because planar drivers cannot be shrunk to such a small size, or is it because manufacturers are simply being lazy and don't want to take risks because of possibly high costs of designing such drivers? Any thoughts?

 

[KamijoIsMyHero]

Vsonic focus in the portable headphones section is apparently a planar magnetic

 

[Pianist]

Ok, so nobody on here knows anything about this? Really? How about some ideas? Bump!

 

[ab initio]

What are the benefits of planar magnetic drivers? If I understand correctly, the advantage is derived from a nearly uniform magnetic flux over the driver, which, combined with the etched "coil" pattern, allows the transducer to be forced uniformly across the entire surface. Regular dynamic drivers, on the other hand are forced only at their center, and are subject to the vibration modes of the speaker cone+added mass of the coil. Furthermore, part of their benefit of orthos stems from having a very large driving surface compared to standard dynamic drivers. The tradeoff is that the design of orthos is (necessarily) large and bulky.
 
Here is an innerfidelity post that discusses the principles of planar magnetic drivers
 
My guess is that IEMs, which are an order of magnitude smaller (linear dimensions) than the large ortho headphones, are in ear and driving a much different acoustical cavity, and are constrained to be very small, may not gain any of the advantages that orthos provide for full sized cans. It isn't clear to me the operating principals and advantages of the planar magnetic design scale to IEM size and operating conditions.
 
Perhaps somebody knows the ballpark figures for the various transducer designs that might shed some light on whether planar magnetic design has any benefits to offer IEMs?