STAX SR-007S: an advanced electrostatic earspeaker with 007 heritage

The STAX SR-007S is an open-back electrostatic earspeaker developed as the latest continuation of the SR-007 family, a series that began with the original SR-007 in 1998. Rather than abandoning the established circular form and distinctive wearing concept, STAX has refined the underlying transducer, headband assembly, earpads and cable connection. The result is designed for dedicated music listeners who want to hear fine recording information, tonal relationships and spatial positioning without an exaggerated presentation. Its large round sound elements and open-air enclosure make it especially suitable for focused home listening, where acoustic recordings, orchestral works, voices, ambient detail and layered studio productions can benefit from a spacious and clearly organised soundstage.

A revised push-pull electrostatic element sits at the centre of the SR-007S. STAX has updated both the diaphragms and the fixed electrodes, while reducing the diameter of the air vent holes in the large circular electrodes by twenty percent compared with earlier models. A high-precision etching process is used to control this structure and further optimise the acoustic profile. The specified frequency response is 6 to 41,000 Hz, accompanied by 110 pF electrostatic capacitance, 145 kΩ impedance, 101 dB sound-pressure sensitivity and a 580 V DC bias requirement. The new Anti Resonance Structure draws inspiration from the SR-X9000 and incorporates a seamless stainless-steel plate to increase rigidity and reduce unwanted vibration within the supporting assembly.

Comfort and system longevity have also received practical attention. A movable hinge allows the earcups to adapt more naturally to the listener, while the rubber head-pad attachment maintains the close, adjustment-free fit associated with the SR-007 line. The rotating earpads use genuine sheepskin on the surfaces that touch the skin and artificial leather around the surrounding sections. Their redesigned internal shape is intended to manage absorption and reflections, helping preserve perspective and image definition. A detachable 2.5-metre cable with OFC conductors, six parallel strands and a low-capacitance wide format simplifies maintenance and future replacement. The 430-gram, Japan-made SR-007S should be paired with a compatible 580 V electrostatic driver unit; keep its leather clean and dry, and consider it for a carefully matched reference listening system.

Review:

Headphones n’ Stuff