Need help with aero port tuning!!!!!!!!!!!!!!

[Daniel Winkler]

I have a fourth order bandpass, approx 11 cubes, 5 sealed and 6 ported. 15" AB HD D2 w/ soundstream dtr3400.1 in a walled 96 accord. Using a 6" aero, how long should my port be, and how do I get that measurement? do i use total airspace, or just ported area?

[Hugh G. Rection]

so let me make sure i understand what your doing here. your doing a bandpass for 1 15" sub, in a 1-1.2 ratio, with the sub sitting in 5ft^3 sealed, and only using a single 6" aero port on the ported side?

first things first, for a 6ft^3 ported side, you want alot more than a single 6 inch aero. bandpasses are generally figured with more port area per cube than a standard ported box, though even for a standard ported your single 6" aero is still epically inadequate. i usually figure bandpasses at 16in^2 of port area per cube, which for 6" aeroes in 6 cubes would come out to 3.4 ports, or just say 3 or 4 depending if you want to cheat for a little output or cheat low for a slightly wider audible band.

also, your ratio is off. people tend to like that 1:2 ratio, though the most damn impressive bandpass ive ever seen was a black dodge neon at sbn with 4 12's in a 4th order and it was doin 158.2 on the termlab, with a 1:3.25 ratio.

and most importantly, i wouldnt run a single 15 in 5 cubes sealed. thats a really good way to get rid of a woofer you dont want.

[Daniel Winkler]

See, thats why I am askin for help. I do not know all the technicals.....The box was originally built for a single 18" and had an 8" port, so I figured if I was dropping sub size, I would need to drop port size as well. The guy I got this box off of was doin a 152 / 153 at the headrest at 31hz playin music, not burps. All i done was put in a faceplate for a 15" and hit a 149.8, made a port plate with 4 x 4"s and hit a 149.3, so I did not know if I should go smaller on the port or not, so I came here to get some more informed opinions.