A shock mount only breaks mechanical paths into the microphone body; if the noise arrives through the air, the floor, or the cable, the mount is not the fix.
Shock mounts: which transmission path you are actually breaking
checked 2026-09-16responsible Room Tone Register (a named register, not a person)
The four paths
| Path | What it carries | Fixed by |
|---|---|---|
| Air | Room noise, HVAC, traffic | The room, not the mount |
| Floor and stand | Footsteps, traffic, building plant | Shock mount, or a heavier stand, or isolation pads |
| Cable | Handling noise, cable slap, tugging | A loose loop, a softer cable, or a cable isolator |
| Direct contact | Handling the mic body itself | Not a mount problem — this is technique |
Almost every complaint about 'the shock mount does not work' turns out to be path two or path three. Test by lifting the whole stand off the floor and holding it: if the noise disappears, the floor was the path. If it stays, the air was.
Why mounts amplify below their natural frequency
An isolation mount is a mass-spring system. Below its natural frequency it does not isolate, it resonates: the microphone moves more than the floor does. That is why a mount tuned for 8 Hz is excellent at 40 Hz and useless against a slow, heavy sway. Choosing a mount means choosing the band you want broken, and no single mount breaks every band.
The damping trade
Adding damping lowers the height of the resonance peak but also lowers the isolation at high frequency. A heavily damped mount is a compromise, not an upgrade. The honest specification for a mount is a transmissibility curve, and almost no manufacturer publishes one — which is why the register treats a claimed isolation figure in decibels, with no frequency stated, as marketing.
Near kin: pads, suspensions and cable isolators
An isolation pad under a stand breaks the same path as a mount but at a different point, and it is often the cheaper fix. A boom-pole suspension isolates the pole from the microphone. A cable isolator decouples the cable, which is a separate path again. A low-cut filter is not isolation at all: it removes low-frequency content from the signal after it has already been contaminated, and it removes the same band from the voice.
| Term | What it is | How it differs from a shock mount |
|---|---|---|
| Isolation pad | Decouples a stand from the floor | Same path, different point, often cheaper |
| Boom suspension | Isolates the pole from the microphone | Solves the same path for a different rig |
| Cable isolator | Decouples the cable from the body | Addresses the cable path, not the floor path |
| Low-cut filter | Removes low frequencies from the signal | Post-hoc, not isolation; removes voice too |
The common misread is expecting a mount to fix airborne noise. A mount is a mechanical device. If the room's residual is 40 dB(A) from an air handler, no mount changes it, and the session will still fail. Test by lifting the whole stand off the floor: if the noise stays, the mount was never the tool.
Source log
- 01The Dynamic Vibration Absorber, Penn State Acousticssupports the mass-spring behaviour that makes a mount worse below its natural frequency
- 02Damped Simple Harmonic Motion, Penn State Acousticssupports the damped-oscillator treatment behind the transmissibility trade
- 03Principles of microphone technology (DPA Microphones)supports the mechanical and acoustic coupling paths into a microphone
Each line points at one specific document. No line is a home page.
Leave this page Close this page if the noise is continuous rather than triggered by movement — that is a room problem and a mount will not help.