The OPPO PM-1 Planar Magnetic headphone offers a different way of thinking about planar magnetic technology. The PM-1 is characterized by its natural, dynamic, and engaging sound quality with an emphasis on comfort and reduced weight. It is the result of many years of research led by a team comprised of passionate audio and acoustics engineers, chemical and materials scientists, and audiophiles. A number of technological breakthroughs have made their way into the PM-1, including the use of a unique 7-layer diaphragm, double-sided spiraling coils, and an FEM-optimized magnet system.
The advantages of planar magnetic technology are based on the fact that in a planar driver, sound is generated by a very thin and light diaphragm that is driven evenly over the entire radiating area. Sound, entering our ear, has a planar wave front at the so called ear reference point (ERP), with all spectrum components in phase. A typical dynamic headphone driver, due to its phase irregularity, disrupts that coherence, resulting in less than perfect signal peak reconstruction, especially of very short impulses. A planar magnetic driver has another advantage that relates to its purely resistive impedance. It has a flat conductor pattern that does not have any inductive component, which eliminates inductance related IM distortion, common in dynamic headphones. A resistive load also ensures that any amplifier will drive the headphones without any changes in spectral balance.