Hello all, I am building a ported box to hold two 10" Alpine Type R's (dont ask about the size...thats what I have to work with already) that will sit on the middle of the back seat of a crewcaband rest on the transmission hump on the floor. My question is what frequency do I need to tune it for - the resonant frequency of the sub (31 Hz) or the frequency given by alpine in their specs of their "ideal" box which lists two frequencies: Fb=35Hz and F3=30Hz? I am still a little fresh to building a ported box and all the frequency numbers has kinda confused me. The formula im using off of JL's website leads me to believe I need to use the Fb=35Hz number. Thanks in advance.

 

Fb - is frequency of the box. (Use for sealed boxes)
F3 - is the 3dB downpoint of the port. ( ported)

Grab a portacalc. If you arent understanding this go sealed. Otherwise you REALLY run the risk of damaging the drivers.

 

so according to your signature i want to solve for port length by using 33Hz for the box frequency?

 

How much does your woman weigh?

 

wtf is that supposed to mean? given the time you wrote it i can only imagine what state of mind you were in....or werent in.

 

just build it to the specs that the manual says...it tells you how deep, wide and tall the port should be

 

I was serious. Again answer the question.

 

I have seen many "factory specs" that are not okay for the driver and/or reach max potential. Tuned to your vehicle or woman is the way to be.