Re: Designing a burp box
Run a sweep with a sealed box. Find what frequency you are loudest at. Tune your new box about 4 hz below your peak. Build the box stout, smooth, and air tight.
I don't think 2x 8" subs will load up very well with too much port, so keep it under 30 cubic inches of port per cubic foot of box.
--My truck: 2007 GMC 1500 crew cab, Kenwood DNX570HD, DLS front stage, SQ3500.1, 3x RD Alpha Max 15"s in 6th order blow through, Second Skin deadening.
--Wife's car: 2013 Chevrolet Impala LTZ, Kenwood DNX470, GermanMAESTRO components on CT125.2, 2x AT10"s on an AT800.1, RF Deadskin deadening.
--Work truck: 2014 GMC 2500 crew cab, Kenwood DNX470, Kenwood front stage, DD M1A on a pair of American Bass XD10s.