Port Velocity Graph

How to read front and rear port air velocity, warning thresholds, and ported-enclosure applicability.

Direct answer

The port velocity graph shows simulated air speed in a vent over frequency for ported alignments.

What it measures

• Front port velocity in meters per second for vented and bandpass designs.
• Rear port velocity separately for sixth-order bandpass designs.
• A configurable warning threshold reference line.

Why it matters

• It reveals air-speed problems that the SPL graph cannot show.
• It helps evaluate port diameter, port count, tuning, and input power together.
• It is a practical check before committing to a vented enclosure geometry.

How to read it in 00 Simulator

• Check peak velocity near the tuning region and across the intended playback band.
• Raise port area or reduce power when velocity remains high where output matters.
• Use enclosure configuration values to confirm that a lower velocity fix has not created an impractical port length.

What good, warning, and bad usually look like

Good

Velocity remains below the chosen warning threshold for the intended power.

Warning

Velocity crosses the threshold narrowly and may depend on flare design or program material.

Bad

Velocity stays high through useful bass frequencies or forces an unrealistic port geometry.

Common false conclusions

• The graph does not directly model every audible turbulence or compression detail.
• A bigger port lowers velocity but usually lengthens the required vent.
• Passive radiator designs should be checked with PR excursion instead.

App behavior notes

• The main UI graph id is `port`; the internal API key is `portVelocity`.
• A separate rear-chamber graph exists for bandpass rear port velocity.