Boxplot and other cabinet software

[GM]

The program keeps making the port 3" round and I forget what depth.

Actually, BP doesn't calculate a vent suggestion, so you need to find one with an area that has a < 5% vent mach for the max desired power it's likely to 'feel' to ensure a minimal amount of vent compression and once the vent length exceeds ~ SoS/(20*Fb), then it should be loaded with some form of TL.

GM

[airboss]

Yeah, the crudely expanding 'port' between the chambers introduces a phase inversion around its ~180 Hz upper mass corner as well as modestly 'pumps up' its vent gain, though considering how leaky the originals are, it may just offset vent losses. Personally, I'd rather have a well sealed cab and the entire area in the coupling chamber cut out to get a nice smooth response once the bottom side of the horn/driver is damped against spurious woofer reflections. This should make for a subjectively 'tighter'. more accurate bass line which some folks consider too 'dry' sounding though.

GM

But still cut the port same size right? Not sealed?

Dan

[GM]

For an otherwise stock tuning, yes.

GM