If one were to set out on a quest to find the best headphones that money could buy, the chances are that one would zero in on an electrostatic earpiece. To be more specific, and going by the testimonies of audiophiles and experts around the world, one would be hard pressed to find anything better than the Stax SR-009 Electrostatic Earspeakers. “The pinnacle of headphone listening” and “sublime” are some of praise that has been showered upon these headphones, and owning these treasures have been likened to the Mercedes-Benz philosophy of having the “best or nothing”.

The name Stax ought to be familiar to audiophiles, a Japanese company (now owned by Edifier) regarded as being synonymous with high-end audio equipment. Their electrostatic headphones—which they call earspeakers—are known to be among the best in the world, with the SR-009 being their flagship product.

For the uninitiated, electrostatic speakers and headphones use a different technology compared to the conventional headphones we come across in our everyday existence. In these, an extremely thin conductive membrane-like diaphragm is placed between two mesh-like panels called stators or electrodes. A continuous high bias voltage—580 volts in this case—is applied to the membrane, while audio signals are applied to the electrodes, one of which takes on a positive and the other a negative charge. This generates a push–pull movement of the diaphragm, depending on the sound signal. The delicate, precise nature of the diaphragm’s movement and the absence of any moving metalwork (like those present in the dynamic coil drivers of conventional headphones) results in a much better range and quality of sound—in fact, extending well above the audible frequency of 20,000 Hz.

The SR-009 is widely touted as an exemplary example of electrostatic headphones. The diaphragm, made out of reinforced engineering plastics—which Stax calls “super engineering plastics”—is a mere 2 microns thick. The MLER electrodes are made out of unified metal plates that require ultra-precision processing. The open-back design features a lightweight aluminium frame, while the cables contain silver-plated 99.9999 per cent high-purity copper wires. As for wearing comfort, the head piece has a 10-step slider to fit comfortably over the head, and the ear pads are handcrafted with leather and appropriate cushioning.

As for the sound quality, it is, by all accounts, simply out of this world. One reviewer calls it “the most revealing, most captivating, most neutral, most outstanding transducer of any type…. With this headphone, you really will hear things, textures, air, details you hadn’t previously heard.” Delivering a neutral, high-clarity sound with low distortion doesn’t come cheap, as you might have guessed. At $5,250, the SR-009 Earspeakers were never going to be an impulse buy. Moreover, to really get the best out of these beauties, you are also advised to invest in a high-end amplifier, which could easily double that amount. But if you are an audiophile, who will not dream of compromising on sound quality, then you know what you need.