Royer Labs SF-2 Matched Pair consists of two factory-matched SF-2 active ribbon microphones selected for identical sensitivity and frequency response, assembled as a stereo set for classical recording, scoring, and acoustic instrument applications. Factory matching is critical in stereo configurations — ORTF, X-Y, wide ambient overhead — where any mismatch between the two microphones directly affects stereo imaging accuracy and channel balance. The technical specification is fully identical to the single SF-2: crossfield motor assembly with four Neodymium magnets and Permendur pole pieces, 1.8-micron aluminum ribbon, active electronics at -38 dB sensitivity, and self-noise below 18 dB. Twenty SF-2 prototypes circulated across major studios and scoring stages for years before commercial release, establishing the model's reputation in classical and film recording circles before it ever appeared in a catalog.
Crossfield motor and active electronics — two defining factors
The proprietary crossfield motor minimizes the front-to-rear acoustic path length inside the capsule: four Neodymium magnets surrounding the ribbon with Permendur iron pole pieces reduce this path to the shortest possible distance, enabling a flat response across 30 Hz – 15 kHz +/- 2 dB without artificial high-frequency boost. This distinguishes the SF-2 from most ribbon microphones in the same price bracket, where the upper frequency limit is often a practical constraint, not a design achievement. The 1.8-micron aluminum ribbon's low mass delivers fast transient response — audible and measurable on strings, woodwinds, piano, and percussion. Active electronics — a hand-wired FET circuit with a custom toroidal transformer — provide 14 dB of free gain with no added noise and maintain constant optimal impedance loading on the ribbon regardless of what preamp follows in the chain. The 200-ohm output supports long cable runs without HF degradation.
Matched pair — stereo and M/S without level adjustment
Factory matching eliminates the need to calibrate levels or correct tonal character between channels when setting up stereo configurations. The symmetrical figure-eight pattern makes each microphone usable as the Side element in an M/S array, where sensitivity matching between Mid and Side has a direct impact on stereo width after matrixing. The SF-2 operates as a complete, self-sufficient microphone — requiring no high-gain specialist preamp and no impedance matching considerations from the console. The ribbon element is fully protected against phantom power, miswired cables, and electrical transients. Primary applications: choir and orchestra, classical piano, strings, woodwinds, harp, acoustic guitar and other plucked instruments, voice-over, ambient miking, room recording. Lifetime warranty to original owner; first ribbon replacement free.
KEY FEATURES
- Two factory-matched SF-2 microphones with identical sensitivity and frequency response
- Proprietary crossfield motor: 4x Neodymium magnets + Permendur pole pieces — minimal acoustic path, maximum HF extension
- 1.8-micron aluminum ribbon — low mass, fast transient response
- Active Ribbon electronics: -38 dB sensitivity — condenser microphone output level
- 14 dB free gain from toroidal transformer — zero added noise from active circuit
- Self-noise below 18 dB
- Constant optimal ribbon load impedance regardless of preamp characteristics
- 200-ohm output — long cable runs without HF loss
- Flat frequency response: 30 Hz – 15 kHz +/- 2 dB
- Negligible off-axis coloration; consistent response regardless of incidence angle
- Symmetrical figure-eight — each microphone usable as Side element in M/S
- Stainless steel body with internal baffle and damper; low external magnetic leakage
- Gold-plated XLR output connectors
- Ribbon elements protected from phantom power, miswired cables, and electrical transients
- Lifetime warranty to original owner; first ribbon replacement free
TECHNICAL SPECIFICATIONS
- Acoustic operating principle: electrodynamic pressure gradient with active electronics
- Polar pattern: figure-8
- Generating element: 1.8-micron aluminum ribbon
- Motor assembly: crossfield — 4x Neodymium magnets + Permendur iron pole pieces
- Frequency response: 30–15,000 Hz +/- 2 dB
- Sensitivity: -38 dBv re. 1V/Pa
- Self-noise: below 18 dB
- Output impedance: 200 ohms @ 1 kHz
- Rated load impedance: above 1,500 ohms
- Maximum SPL: above 130 dB
- Output connector: XLR 3-pin (Pin 2 Hot), gold-plated
- Power requirements: 48V phantom, 4 mA per microphone
- Dimensions: 142 mm (L) x 39 mm (base) x 25 mm (top)
- Weight: 448 g (15.8 oz) per microphone
- Finish: Matte Black
- Includes: two SF-2 microphones, SFS-2 shockmounts, mic socks, aluminum carrying case
