Shure SM81-LC Cardioid Condenser Instrument Microphone

The Shure SM81-LC is a cardioid condenser instrument microphone for capturing acoustic instruments in studio, broadcast, and sound-reinforcement setups. Its wide 20 Hz to 20 kHz response and flat-response character are designed for accurate reproduction of the source. It is a practical choice for close or stand-mounted use on acoustic guitar, piano, cymbals, and other detailed sound sources.

This microphone uses an electret condenser element and requires external phantom power from a mixer, audio interface, or dedicated microphone preamp. It operates from 11 to 52 V DC phantom power, with 48 V DC providing its intended performance. A balanced XLR microphone cable is required and is not included with the SM81-LC.

The cardioid pickup pattern concentrates capture toward the front of the microphone while reducing pickup from the rear and sides. This can help place more attention on the intended instrument in rooms, on stages, or in multi-microphone sessions. Its frequency response is uniform and symmetrical around the microphone axis for controlled off-axis pickup.

Three selectable low-frequency settings provide useful source and room control without external processing. Choose the flat setting for the most natural response, a 6 dB-per-octave rolloff below 100 Hz to manage proximity effect, or an 18 dB-per-octave cutoff below 80 Hz to reduce rumble and low-frequency room noise. A lockable 0 dB/-10 dB attenuator helps accommodate louder sources such as drums or guitar cabinets.

The SM81-LC is built for regular studio and live production use with a steel body, stainless-steel screens, and a vinyl metallic paint finish. Its low self-noise, high maximum SPL capability, and low RF susceptibility support use across a broad range of acoustic recording and reinforcement tasks. Included mounting and protective accessories make it ready to add to an existing XLR microphone system.

Key Features

• Cardioid Condenser Capsule: Captures the intended source while reducing surrounding sound pickup.
• 20 Hz to 20 kHz Response: Covers a wide range for detailed instrument capture.
• Selectable Low-Frequency Filtering: Helps control rumble, room noise, and proximity effect.
• Lockable -10 dB Pad: Adds headroom for louder close-miked sound sources.
• Phantom-Powered Operation: Connects to compatible mixers and interfaces using balanced XLR.
• Steel Microphone Housing: Supports dependable use in studio and sound-reinforcement environments.

Design & Installation

The SM81-LC has a slim steel housing with a vinyl metallic paint finish and stainless-steel screens. It measures 212 mm long by 23.5 mm in diameter and weighs 230 g. The microphone is supplied with an A57F swivel adapter, 10 dB attenuator lock, foam windscreen, and carrying/storage bag.

Mount the microphone to a compatible stand or boom with the included swivel adapter, then connect its male three-pin XLR output to a balanced XLR cable. Enable phantom power on the connected mixer, interface, or preamp; the microphone accepts 11 to 52 V DC and performs best from a 48 V DC supply. Select the low-frequency switch and 0 dB or -10 dB attenuator setting for the source, placement, and sound-pressure level.