Wayne Parham Messages: 18787 Registered: January 2001
Illuminati (33rd Degree)
Most prefer to keep airspeed under 75mph, and the airspeed you've calculated is 125mph. Remember, however, that maximum airspeed is only realized at frequencies near fb, and only at high power. You can use a steep high-pass filter to reduce excursion below cutoff if necessary, but for home theater and hifi subwoofer applications, I don't think you'll need it, either for port "chuffing" or for protection against over-excursion. You can also reduce turbulence using ports with radiused ends.