Audio-Technica ATM350U Instrument Condenser Microphone

Cardioid Condenser Instrument Microphone for Discreet, Rock-Solid Mounting

The Audio-Technica ATM350U packages the high-SPL ATM350a cardioid condenser capsule into a complete clip-on mounting system aimed at players and engineers who want studio-grade sound without sacrificing stage mobility. Engineered to handle extreme sound pressure levels with a clear, well-balanced response, the system mounts directly to the instrument itself, keeping the microphone in a fixed position relative to the sound source no matter how expressive the playing style.

For fiddlers, percussionists, brass players, and acoustic guitarists who move while performing, this kind of mounted capture eliminates the repositioning problems of stand- or boom-mounted large-diaphragm condensers. Sound stays consistent across takes, the capsule stays out of the way of technique, and feedback stays predictable because the mic-to-source distance never changes.

What Sets the Universal Mount Apart

At the heart of the package is the AT8491U Universal Mount, a two-piece clip bracket designed to grip the body, rim, or surface of virtually any acoustic instrument. The microphone attaches via a flexible 127 mm AT8490 UniMount gooseneck, which bends to any angle and stays put, so the capsule can be aimed at the sweet spot of a cello, a saxophone bell, or a snare top with equal confidence. A switchable 80 Hz, 12 dB/octave roll-off on the in-line power module helps reject low-end rumble on stage without dulling the attack of plucked strings or struck skins.

Capsule Performance and SPL Headroom

The fixed-charge, permanently polarized condenser element is built for instruments that get genuinely loud, including brass, drums, and amplified acoustic guitar rigs.

• Polar Pattern: Cardioid — Rejects stage bleed and feedback off-axis so the source stays focused in the mix.
• Frequency Response: 40 – 20,000 Hz — Wide enough to capture both low-end string body and high-frequency attack without sounding thin.
• Reaching 159 dB SPL at 1 kHz, 1% THD headroom, the capsule absorbs snare hits, brass fortissimo, and acoustic guitar feedback bursts without breakup.

Power Module and Phantom Power Requirements

The AT8543 in-line power module supplies the capsule with stable phantom power and gives the engineer a hands-on switch for the low-frequency roll-off, no menu-diving required.

• Open Circuit Sensitivity: -49 dB (3.5 mV) re 1V at 1 Pa — Healthy output level keeps preamp gain manageable on quiet classical-to-loud stage transitions.
• Phantom Power Requirements: 11 – 52 V DC, 3.5 mA typical — Compatible with virtually any mixer, audio interface, or standalone preamp that supplies standard 48 V phantom power.
• Output uses an Integral 3-pin XLR-M type on the power module, so the cable drops straight into any standard microphone input on stage or in the studio.

Build, Cable, and Form Factor

The capsule itself is small enough to disappear on a violin, bass, or flute while staying durable enough for nightly gigging.

• Measuring 37.8 mm long with a 12.2 mm maximum body diameter, the capsule keeps a low visual profile on camera, on stage, and on acoustic instrument bodies.
• Microphone Weight: 14.5 g (0.5 oz) — Light enough that adding it to a delicate instrument headstock does not affect playability.
• Permanently Attached Cable: 4.0 m (13.1') long, 3.2 mm diameter, HIROSE HR10-type connector — Reaches from instrument to desk on small stages or to a floor box on larger ones.
• A 65 dB, 1 kHz at 1 Pa signal-to-noise ratio delivers a clean self-noise floor for capturing subtle classical finger noise or quiet arco bass passages.

Who the ATM350U Is Built For

The ATM350U is the right choice for live sound engineers, recording engineers, and touring classical or acoustic players who need the same tonal character from a clip-on mic across guitar, violin, wind, and percussion instruments. Solo acoustic performers get dependable on-axis sound no matter how much they move around on stage. Recording engineers dealing with a 20-piece drum kit or a horn section appreciate the consistent capture and road-tested mounting hardware. Fiddlers and double bass players running amplified acoustic setups benefit from a capsule positioned exactly at the bridge without getting in the way of bowing technique.

The Audio-Technica Approach to Instrument Capture

Audio-Technica designed the ATM350a line to give working musicians a single proven capsule platform that adapts to different instruments through purpose-built mounts, rather than requiring separate dedicated microphones for every application. The ATM350U Universal configuration is the most adaptable member of that family, serving players whose gig list spans strings, brass, and percussion in the same week.