Vent Air Speed Calculator

This calculator is to help you determine the speed of the air in a port. This will help you decide if a particular port is too small for your application, which will cause noise at high volume levels. This is not intended for use on bandpass designs. The answer is in percentage of the speed of sound.

Try to keep port air speed 10 percent or less to prevent port choof.
The results show 1.00 is 100%, so your want 0.10 or less to remove port noise.


Speaker Reference Efficiency


Explanation of Terms
W is the acoustic power output of the speaker in Watts.
Fb is the tuning frequency of the enclosure.
R is the radius of the port.
Mach is the speed of sound in air (344.8 m/sec or 1131.2 ft/sec).
 To use this form, enter the values for W, Fb, and port radius. Then click the "Calculate Values" button, and the answer will appear in the empty text box.
Enter W
Enter Fb Hz
Enter Radius  inches
 percentage of Mach