We've reviewed a bunch of headphones over the years, and what they all had in common were traditional, commonly used voice coil dynamic drivers as a means of producing sound. But very few headphones use a driver technology that's called "planar magnetic drivers", which are large thin diaphragms sandwiched between magnetic grids that use all of their surface to produce sound, don't have two moving parts like dynamic drivers, and have an ultra-fast transient response. You'll only see these being used on high-end, expensive headphones from companies like Audeze and HiFiMan. Another brand that prides itself in using planar magnetic drivers is Oppo, a company you may not immediately recognize or associate with audio at all. Oppo's PM-3 are the company's entry-level over-ear headphones which use planar magnetic drivers to produce high quality sound that's more accurate and has less distortion than other similarly priced headphones with typical dynamic drivers. So how does a $400 pair of planar magnetic headphones sound like? You can check out our full review down below to find out!