Shure SM27 Pro Large Diaphragm Condenser Microphone

The Shure SM27 is a versatile, side-address, large-diaphragm cardioid condenser microphone built for both critical studio recording and demanding live stage applications. It combines an ultra-thin Mylar diaphragm with rugged all-metal construction to capture detailed vocals and acoustic or amplified instruments while withstanding high sound pressure levels.

It features a uniform cardioid polar pattern that isolates the primary sound source directly in front of the capsule while rejecting off-axis room ambiance and stage bleed from the rear. The cardioid pattern remains consistent across the frequency spectrum, minimizing off-axis coloration.

It utilizes a low-mass, 1-inch externally biased, ultra-thin (2.5-micron) 24-karat gold-layered Mylar diaphragm. The low mass allows the diaphragm to react quickly to rapid audio transients—such as acoustic guitar plucks, snare drum hits, and vocal sibilance—delivering a natural, flat frequency response (20 Hz to 20 kHz).

Two recessed toggle switches are located on the body of the microphone:

• 3-Position Low-Frequency Filter: Offers a flat response, a gentle low-frequency roll-off (-6 dB/octave below 115 Hz) to tame vocal proximity effect, or a steep low-cut (-18 dB/octave below 80 Hz) to eliminate stage rumble and HVAC noise.
• Switchable Attenuation Pad: A -15 dB pad that prevents preamplifier overload when miking extremely loud sources.

In standard operation, it handles up to 138 dB SPL (with a 2.5 kΩ load). Engaging the built-in -15 dB attenuation pad raises the maximum SPL handling to 153 dB SPL, making it suitable for close-miking screaming guitar cabinets, snare drums, brass sections, and kick drums.

Because it is an externally biased true condenser microphone with Class-A discrete transformerless preamplifier circuitry, it requires standard +48V DC phantom power supplied by an audio interface, mixing console, or external mic preamp via a balanced XLR cable.

Yes, the capsule is suspended inside the housing by an internal shock mount that isolates it from handling noise and mechanical stand vibrations. Additionally, three separate mesh grille layers act as an integrated pop filter to reduce wind noise and vocal plosives without requiring an external screen for moderate use.

The SM27 is essentially the direct successor to the discontinued KSM27, retaining the exact same acoustic capsule, internal shock mount, and electronics while adopting the rugged matte-black finish of the SM series. Compared to the entry-level PGA27, the SM27 features a much lower self-noise floor (9.5 dBA vs. 14 dBA), higher SPL capability, internal shock mounting, and a 3-position low-cut filter.