4th order for 2 18 btl

[elastic 1]

i want to build a 4th order bp for 2 18 btl and im pretty unsure about how to calculate the port.

the sealed chamber is 2* 3,3 cft and the ported one 1* 10 cft.

how do i design the port? does 40 hz work well or is that too low?

shall i make the port for 5 cft @ 40 hz and then double port area (because both woofers will play in one ported chamber)?

[BILTD 60]

I wouldnt do it. You are still running the BTLs sealed. SPL, you would get away with it. For music, I'd look at a 6th order Quasi bandpass.

Pretty sure G'Monk did a 4th order in his Avalanche and ripped it out in all but a few weeks.

[Duran 387]

They will perform well in a 4th order.

[///M5 2,833]

They will perform well in a 4th order.

4th order ported >> 4th order BP for the BTL