Though there are a growing number of planar magnetic headphones in its price range, the PM - 3 are more functional in everyday environments than many other options. (digitaltrends.com)
Removing the ear cups reveals the headphones planar magnetic drivers. (techhive.com)
The very design of planar magnetic drivers, which use a thin membrane excited by a magnetic coil to produce sound, is part of why they're generally so big. (digitaltrends.com)