from collo's experimental port site and built into flareit, we know that ports go turbulent (i.e. completely fail to any longer act like ports) when the air speed in m/s is 5 times the port diameter in inches. in this case, that is 10 m/s.
i have attached your simulation with red dashed lines matching up the 10 m/s air speed to the three charts.
in the bottom chart, 10 m/s occurs at 7hz.
moving up to the middle chart, 7hz is right where the port is expected to help lower cone motion. but because below 7hz, the port will completely go turbulent and completely fail, the cone motion will just proceed up as though it were a sealed cab. so no benefit there.
moving to the top chart. again, the port provides less than 1db of gain above 7hz and because the port will completely fail below 7hz, there will be no spl advantage there.
so overall, no advantage to either spl or cone motion vs. sealed.
noah, by transition frequency, i meant the point where the air transitions from behaving like a compressible gas to more like an incompressible gas. that is the only thought that i had on why there would be a cutoff frequency where turbulence is no longer a function of frequency in the port.Edited by LTD02 - 12/11/12 at 3:54am