Help with port measurements?
 

I am building a box for 4 powerbass m124 subs.
can anyone show me a diagram or tell me how to port and tune it???
box measurements are as follows:
34in. wide.
26 in. long.
14&1/4in. tall.


meaurements from hatch on a 1999 mercury cougar.

most people use a program. One I recommend is Torres.

Heres a little to get you started with.
1. Make sure that size will fit in your car. In a regular trunk style car I see a lot of people measure, build, then try to fit and realize its not going to. Get some card board and make a box of the size you want and see if you can fit it though the openings.
2. In general its best to buy subs that fit your space/desired result instead of trying to make a particular set of speakers perform in the space you have and give you the results you want.

With that said powerbass recommends 1.25 cu ft per sub that you have for sealed and 1.9 cu ft net for ported. So doing the math your going to need 5 cu ft sealed and about 7.6 cu ft net ported which is about 8-10 gross depending on what types of ports and tuning you are shooting for.

So long story short you don't have the room to port those 4 12's, you do have the room for a sealed enclosure as the measurements you gave give you 5.88 feet before sub and brassing displacement.

Now... with all that said, do you already own the subs? Maybe I can help you make a better choice that will help you achieve your desired results easier. What is your desired result? What power do you have?