Feedback Frequency
Find the standing-wave frequencies where sound will peak or howl.
About Feedback Frequency
Sound bouncing between parallel surfaces builds up at half-wavelength spacings, and those exact frequencies are prone to howl. Locating the feedback peaks for a given mic-to-speaker gap lets you notch or damp the problem frequencies in advance.
Formula
Feedback Frequency
Fundamental = speed of sound / (2 x distance)
- standing wave
- A wave reflecting between two surfaces that reinforces itself
Worked example
With the default values below, Feedback Frequency returns Fundamental of 171.5. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Distance between surfacesminimum 0.01 m
- 1 m
Results
- Fundamental
- 171.5 Hz
- Second Harmonic
- 343.0 Hz
- Third Harmonic
- 514.5 Hz
Step by step
- 1Values used
- 2Feedback Frequency
- 3Fundamental= 171.5 Hz
- 4Second Harmonic= 343.0 Hz
- 5Third Harmonic= 514.5 Hz
Assumptions and limits
- The result is derived only from the single input listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Feedback Frequency calculated?
Fundamental = speed of sound / (2 x distance) Sound bouncing between parallel surfaces builds up at half-wavelength spacings, and those exact frequencies are prone to howl.
Why does Feedback Frequency matter?
Locating the feedback peaks for a given mic-to-speaker gap lets you notch or damp the problem frequencies in advance.
What values do I need to enter?
This calculator takes 1 input: Distance between surfaces. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.