The OPPO PM-1 Planar Magnetic headphone offers a different way of thinking about planar magnetic technology. The PM-1 is characterised 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 of course... 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-optimised magnet system.
The OPPO PM-1 utilises a planar magnetic driver that sets it apart from the majority of headphones on the market. Sound is generated by a very thin and light diaphragm whose entire surface area is evenly driven. The diaphragm is driven in a symmetric pull-push manner, and the magnetic system and conductor patterns have been optimised for maximum sensitivity and consistency. This allows the diaphragm to generate very stable and linear piston-like vibrations, ensuring phase coherence and high resolution performance with minimal distortion.
Unique to the OPPO PM-1 is the use of a double-sided diaphragm, which allows us to place twice as many conductors within the magnetic field and eliminate any passive return zones where the conductors do not work. This results in the use of 100% of our conductor length, which in turn results in greater efficiency. In addition, our flat conductor pattern
The OPPO PM-1 combines high sensitivity with low weight, allowing it to be used freely with portable devices without requiring additional amplification. Its circumaural, open back design provides the best in sound quality and comfort, and the overall rugged construction ensures that the headphones can withstand mechanical and environmental stress.
These aspects of the OPPO PM-1’s design combine to provide a transparent, highly dynamic sound that exhibits well-balanced tonal qualities with very little distortion, resulting in a listening experience that is both free of fatigue and capable of communicating every nuance of your favourite music.
When sound enters our ear, it has a planar wave front with all spectrum components in phase. A typical dynamic headphone driver disrupts this coherence with its phase irregularity, resulting in less than perfect signal peak reconstructions. Our planar magnetic driver has much better phase coherency since all parts of the diaphragm are vibrating in concert without break up and delayed resonance.
Purely Resistive Impedance
OPPO’s planar magnetic driver has a flat conductor pattern that does not have any inductive components. This eliminates inductance related intermodulation distortion, which is especially common in dynamic drivers with high impedance and a high number of voice coil turns.
Double-Sided Spiralling Coils
The diaphragm utilises a spiralling pattern of flat aluminium conductors on either side of the driver. The double-sided design allows twice as many conductors to be placed within the magnetic field, which leads to higher sensitivity, better damping, and even drive force.
Many planar magnetic headphones have a sensitivity far below 100 dB and require very powerful amplifiers to drive. The OPPO PM-1 has a sensitivity of 102 dB, which allows it to pair well with both mobile devices and scale upwards when used with high end headphone amplifiers.
FEM-Optimised Magnet System
An FEM-optimised magnet system with very high energy Neodymium magnets is used to maximise sensitivity and consistency of the applied force over the driver area.
Easily Replaceable Components
The OPPO PM-1’s earpads are mounted on rubber inserts and can be easily cleaned or replaced. This design also makes switching between the leather and velour earpads nearly effortless. The headphone cable is detachable and uses 2.5 mm mono mini jacks to connect to the earcups, making it easy to switch between the longer, 6.35 mm terminated cable for home use, and a shorter, 3.5 mm terminated cable for portable use.
Stability, Consistency, Reliability
Many planar magnetic headphones have large balance deviations between the left and right channels, and accurate stereo reproduction is contingent on having a very close match between the left and right channels. During the OPPO PM-1’s manufacturing process, drivers are closely matched to ensure optimum stereo imaging and soundstage.
OPPO’s planar magnetic driver diaphragm has 7 layers of thin materials that provide excellent performance, reliability, and longevity. The construction of the diaphragm ensures that it is very stable under thermal stress and vibration.
The OPPO PM-1 is ruggedly constructed with an emphasis on long term use and maximum consistency from unit to unit. The headphones have been tested to very high standards to withstand mechanical and environmental stress in order to guarantee exceptional performance throughout its lifespan.
Many planar magnetic headphones weigh over 500 g and are often viewed as being uncomfortable. With a weight of 395 g, the OPPO PM-1 strikes a delicate balance between weight, comfort, and elegant industrial design.
The OPPO PM-1’s ear cushions are made out of the highest quality natural latex, which is superior and longer lasting to any chemically formulated foam. It is naturally hypoallergenic, retains its mechanical spring-like properties for much longer periods, and resists moisture build up from sweating. The headband and earpads are made of hand selected lambskin that provides a luxurious look and feel.
The 6.35 mm terminated headphone cable features Ohno Continuous Casting (OCC) construction wrapped in a black fabric sleeve. The selvedge denim carrying case transports and protects the headphones in style, and the alternative set of velour pads provides a slightly different sound signature.