I do not have access to a computer or modeling software.
I've exhausted myself searching thru pages of "enclosure calculators" and "port formulas" on my not-so-smartphone.
Also, had difficulty regarding dramatically different answers on port length, between different websites..
I have 5cuft gross box. 4.46cuft net. Desired tuning, 32hz. Sub xmax 23mm, 18" diameter, F(s)30.4hz... What is proper amount of port area? And what is the port length if PD= 4" × 18.5"?
Length? PD= 6.25" × 18.5"?
Any help is appreciated!! Also, stupid ?... For a recommended enclosure size (manufacturer recommends 5.5cuft for ported) is that including port displacement, or excluding? As in do I need a 5.5cuft box, then to tune I add on a specific length of port to the 5.5? Or is it 5.5cuft including PD? As in 5.5cuft total, regardless of Port displacement? Don't know why I'm confusing myself. . ..
Lastly, if anyone wants to model my box in winisd or similar... How much response is lost or how is the response curve affected by losing 1cuft tuned to 32hz?
Recommended 5.5cuft ported
DC Level 3 18" dvc
Clean power from 500w - 1500w (doesn't matter)
But my box is roughly 30"×20"×20" external, .75" MDF. More accurate would be 4.9cuft gross.