Contact mic impulse responses are custom convolution reverb textures created by capturing physical object vibrations using piezo microphones. Unlike traditional mics, contact mics exclude ambient noise and isolate the tonal fingerprint of solid materials like metal poles, paper bags, guitars, glass, plastic.
These recordings become impulse responses when excited with a sharp sound, trimmed, and loaded into convolution plugins like Hybrid Reverb. The result is a reverb that reflects the resonant behavior of the object, not the acoustic space. This method enables the creation of raw, distinctive IR libraries, expanding sonic identity beyond presets. Pitch shifting, EQ, and post-processing add further sculpting control.
Introduction
A few weeks ago, I began experimenting with contact mic impulse responses after picking up a cheap little contact mic, a tiny transducer that captures the physical vibrations of an object rather than the sound in the air. My original plan was to use it for field recordings, but that quickly spiraled into a different question: what if I use those contact-mic recordings as impulse responses?
That idea led to an afternoon of poking metal, scraping paper bags, and slapping a guitar in the name of sound design. Here’s how I did it, what came out of it, and how you can start building your own IR library using everyday objects and a bit of curiosity. If you want unusual source material to stress-test your custom IRs, grab a few textures from my YouTube Sample Packs.
What is a contact mic and why use it for this?
A contact mic (aka piezo) picks up mechanical vibrations directly from the surface it’s attached to. Stick it on a metal fence, and you’ll hear its deep metallic ring, without all the city noise around it.
Why this matters for sound design:
- Noise-free recordings in noisy environments, perfect for clean field recordings
- Rich resonances you’d never catch with a standard mic
- Unique impulse responses, because it doesn’t pick up the room, just the object’s “voice”
Those qualities make contact mic impulse responses an instant source of new textures.
Recording Contact Mic Impulse Responses: My Process
- Pick your objects
I started with three simple sources: a sturdy metal microphone arm, my semi-hollow guitar, and a crinkly paper bag for something dry and textured. - Attach the mic
A dab of poster tack or a strip of gaffer tape usually works. The tighter the bond, the richer the tone. - Excite the object
Impulse responses need a short, sharp exciter: a hand clap or stick hit. You’re aiming for one clear, decaying sound that represents the object’s natural response. - Trim, fade, normalize
After recording, trim silence, fade the tail, normalize to 0 dBFS, and you’re ready to load the file into your reverb.
Using Hybrid Reverb in Ableton Live as your test lab
Drop your IR into Ableton’s Hybrid Reverb (or any convolution plugin) and change Size, Decay, and Predelay. With contact mic impulse responses, automating the dry/wet can keep grooves from washing out.
Creative tricks: pitch, delay & grainy goodness
- Pitch your IR – Transpose the IR down an octave for deeper, cinematic tails.
- EQ before the reverb – Boost a narrow band at the IR’s fundamental to help it cut through.
- Add a granular delay after – Feedback ≈ 30 %, spread ≈ 20 ms, small grain size = glitchy cloud. If you need extra sub weight beneath that pitched IR, layer in lows from Rumble.
Take it further: everything is an IR
Anything can become an impulse response, coat hangers, bike spokes, even a cracked mug. Organize recordings by vibe (“Short Metallics,” “Organic Bodies,” “Crunchy Foley”) and name files clearly. The more contact mic impulse responses you catalogue, the faster you’ll find the perfect tone later.
Wrap-up & your next experiment
Contact mics open a creative doorway into impulse-response sound design. It is a way to create and experiment with differerent ways of sculpting sounds. With a bit of curiosity and no fancy studio, you’ll collect:
- Clean, characterful reverb tails drawn from everyday objects
- Sound-design tools far beyond factory presets
- A personal IR library that stamps instant identity onto your tracks
Start capturing contact mic impulse responses today, swap them with friends, and see how radically they transform your mixes.