I have been working out my box calculations for my Le14H-3 project. I am planning build a 3.5 ft^3 box tuned to 30Hz. I was planning to use a single 4" port that is flared at both ends. When I calculate the length in WinISD I see that the first resonance falls below the crossover point I would like to use of 1000-1200 Hz.
I could step down to a 3" port which would raise the resonance, but than my vent mach goes up.
I have also tried a few multi port variations but run into the same problems.
I read some where in my google searches, that I don't have to worry about resonance, until my port length reaches several times the diameter. Is this true? In my case my port length will be around 8" for the 4" dia port.
I know a few of you have built 2 way projects based on the LE14 variants. Did anyone have to make a similar compromise in box design? Or did you find the resonance or vent mach was not significant enough to become a factor? Which would be the better direction to go, step down the diameter and raise vent mach or keep 4" and potentially have resonance?