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Placid Audio Resonator A

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  • MSRP: $300


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Resonator A Documentation

CardioidPlacid Audio Resonator A

Cardioid Dynamic Microphone

The Placid Audio Resonator A is essentially a high-SPL variation of the company’s signature Copperphone. Both are dynamic “effect” microphones with a Cardioid pattern and moving-coil dynamic cartridge.

An “effect microphone” is a microphone that heavily colors and modifies the sound at the source. Placid Audio was the first company we know of to create and market professional-level effect mics.

The Resonator A is the first of Placid Audio’s Resonator series, and its creation was the result of Placid Audio founder Mark Pirro being contacted by the band Green Day. The band wanted a microphone that could deliver the “AM radio sound” of the Copperphone but could better handle the higher sound pressure level of guitar amplifiers.

Though the Copperphone cannot be damaged by high SPL, its transducer can go into squarewave clipping, which is usable but outside the boundaries of what the mic was designed to do. So Pirro began prototyping a high-SPL effect microphone, which resulted in the creation of the Resonator A.

The Resonator A and Resonator B microphones employ a 1-inch diameter Mylar diaphragm with a broader bandwidth than that found in the Copperphone, which uses an aluminum diaphragm with 1.75-inch diameter. Where the Copperphone’s capsule responds from 200Hz–3,000Hz, the Resonator A responds from 115Hz–10,000Hz.

The “effect” part of the Resonator A’s sonic response comes from heavy mechanical acoustic filtering in the form of a tuned, ported, and baffled resonant chamber. As in the Copperphone, all filtering is mechanical; no electronic filtering is used.

While prototyping the Resonator A, Pirro discovered a variation in the tuning of the chamber that was met with positive response from associates, so he released the variation as Resonator B. The Resonator A can be visually identified by the vertical lines on the grill. The Resonator B has horizontal lines.

Mark Pirro, Placid Audio

The resonant chamber in the Resonator A imparts a “music box” like quality on the signal along with a hint of “micro-reverb” and is not subject to a noticeable proximity effect.

The Resonator mics use the same outer chassis and capsule but employ different baffled chambers to achieve a similar sound with two distinct voicings. Which one is better? Hard to say - I suppose the difference is the sonic equivalent to that classic candy: Almond Joy vs. Mounds.

Finally, as with the Copperphone, the Resonator A can be used as a blend mic, alongside a “standard” studio microphone.

The Resonator A is built into a durable, machined copper housing and is fitted with a Switchcraft XLR connector. It comes with an adjustable aircraft aluminum mounting bracket.

Permalink: Placid Audio ResonatorA

The mic was released in 2016.


Pickup Patterns Pads & Filters
Cardioid (115 - 10,000 Hz)
Coil Diameter Impedance SPL/Noise
n/a 150 Ohms (Low) SPL n/a
Weight Length Max Diameter Interface(s)
794g (28.01oz) 152mm (5.98'') n/a
  • 3-pin XLR male (1)
Power Specifications

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