Use this calculation for a first-order acoustics estimate when the stated geometry, propagation model, averaging convention, reference quantity, and SI units match the measurement or design problem.

Pipe Radius Meters

A finite measured or assumed value greater than or equal to 0, expressed in m.

The implemented rule is: Approximate unflanged open-pipe end correction 0.61 times the pipe radius, per open end.^[1]

Correction Meters

The calculated correction meters, expressed in m.

This is an idealized calculation rather than a complete acoustic simulation or measurement. Reflections, boundary conditions, directivity, damping, frequency dependence, near-field behavior, background noise, transducer response, temperature, humidity, and geometry can change a real result.

Confirm important results with calibrated measurements or a model that includes the actual geometry, materials, boundaries, source directivity, and frequency-dependent losses. Preserve the reference quantity and weighting whenever a result is expressed in decibels.

• Open Pipe Fundamental

  Ideal first resonance of a pipe open at both ends, neglecting end corrections.

• Stopped Pipe Fundamental

  Ideal first resonance of a pipe stopped at one end, neglecting end corrections.

• Half Wave Resonator Length

  Ideal half-wave resonator length from sound speed and fundamental frequency, before end correction.