Re: Specific Port v. Sealed question
For the flattest response curve (assuming cabin gain doesn't provide massive dB gains) the box needs to be aligned at a Qtc value of 0.707.
An easier way to explain this is that the net volume of the sealed box needs to be:
Vb = Vas / [(0.499849)/(Qts^2) - 1]
Vb = net volume of sealed enclosure
Vas and Qts are T/S parameters for your driver. You can probably find these variables in your owner's manual or by contacting the manufacturer.
Vehicle: 1996 Honda Civic EX
Head-Unit: Alpine CDA-9856
Subwoofer: 2 12" Fi SSD
Box: Sealed: approx 1.1ft^3 per chamber
Sub amp: Kicker ZX1000.1
Components: JL XR650-CSi
Comp amp: Profile AP1000
Before you accuse me, take a look at yourself.
Refs: phrozen5100, 1meanGTA, famous_78