Headphones — Stax SR-009S

The SR-009S is Stax's flagship-tier electrostatic over-ear headphone, sitting above the SR-007MK2 with a substantial maximum sound pressure level. The SR-009S represents Stax's most ambitious current statement in electrostatic headphone engineering.

Key specs that matter

Frequency response spans an exceptionally wide 5Hz to 42,000Hz within plus-or-minus 10dB. Maximum sound pressure level is a substantial 118dB SPL at 1kHz at 5% THD. Sensitivity is 101dB SPL at 1kHz/1mW, with impedance at an extraordinary 145,000 ohms, characteristic of electrostatic driver technology. Weight is 583g.

Sound and use context

Expect the exceptionally fast, detailed character Stax's legendary electrostatic driver technology is broadly celebrated for, with the substantial 118dB maximum SPL combined with the exceptionally wide 5Hz-42kHz bandwidth representing Stax's absolute current flagship electrostatic engineering ambition.

Pairing

The SR-009S requires a dedicated electrostatic headphone amplifier such as the SRM-D50 rather than a conventional headphone output.

Alternatives

Stax's own SR-007MK2 offers a somewhat more accessible alternative within the same broader flagship electrostatic catalogue.