Royer Labs SF-24

Stereo Ribbon Microphone

The Royer SF-24 active stereo coincident ribbon microphone is the only microphone of its kind available, combining high quality audio performance with outstanding stereo separation
and imaging. It is a modern ribbon design with no audible diffraction effects or cavity resonance. The SF-24’s active electronics produce an output comparable to studio condenser microphones and provide an optimum impedance to the ribbon elements, preventing overdamping of the elements and assuring consistent microphone performance.
The high gain and low output impedance of the SF-24 allow it to operate with any microphone preamplifier with phantom power, including those of nominal gain and input impedance characteristics.

The SF-24 is actually two matched ribbon microphones placed one above the other and fixed at a 90° angle. This arrangement allows for Blumlein and M-S recording with one microphone, as well as excellent monaural compatibility when summing the two elements to mono. The frequency response is excellent regardless of the angle of sound striking the ribbons, and off-axis coloration is negligible. The SF-24’s extension cable comes with an adapter which splits into two separate left and right XLR connectors, labeled “upper” and “lower.”

The SF-24’s two 1.8-micron ribbons are of pure (99.99%) aluminum and provide superb transient response due to their low mass. The SF-24’s transducers incorporate “cross-field” motor assemblies (patent pending) which are comprised of four powerful Neodymium magnets and Permendur iron pole-pieces. This cross-field design delivers excellent high frequency response due to the extremely short path between the front and rear sides of the ribbon elements. The microphone’s case is ingot iron and forms part of the magnetic return circuit, an effective system with low leakage flux which contributes to the mic’s high sensitivity.

SF-24 FEATURES

• True stereophonic (Blumlein and M-S) recording from one microphone
• Operates on standard 48-volt phantom power
• Active electronics provide high output capability
• Absence of high frequency peaks, “ringing” and phase shifts
• Extremely low self noise
• Ribbon elements unaffected by impedance/load, heat or humidity
• Equal sensitivity from front and back of elements
• Very low magnetic leakage

RECOMMENDED APPLICATIONS

• Stereo & distance miking
• Choir, orchestra, string sections
• Overhead drums & percussion instruments
• Room miking, distance & ambience miking
• Brass instruments, horn sections
• Woodwinds, flute & other reed instruments
• Stereo acoustic piano, harp
• Acoustic guitar, mandolin, stringed instruments

Technical Specifications

• Acoustic Operating Principle: Electrodynamic pressure gradient with active electronics.
• Polar Pattern: Symmetrical figure-8
• Generating Element: 1.8-micron aluminum ribbon
• Magnets: Rare Earth Neodymium
• Frequency Response: 40-15000 HZ  ±2dB
• Sensitivity: -40dB (re. 1v/pa ±1dB)
• Self-Noise: < 18 dB
• Output Impedance: 200 Ohms
• Output Connector: Male XLR 5-Pin (Stereo)
• Rated Load Impedance: 1K-Ohm
• Maximum SPL: 130dB
• Power Requirements: 48-Volt Phantom Only
• Supply Current: 4 mA per channel
• Dimensions: 10 5/8” X 1.5” wide (base) X 1” wide (top) (270mm X 39mm X 25mm)
• Weight: 20.5 OZ (583 grams)
• Finish: Optical Black, 18K Gold (optional)
• Accessories: 25’ Cable (XLR5 to 2 standard 3-pin XLR male), shock mount, protective case, mic sock
• Optional Accessories: Wind screen, 50 or 100 foot extension cables