Im putting two 15” in my Tahoe. My max dimensions are 48” x 20” x 20”. That puts me around 10cu ft gross. The guy at the shop says it going to be hard to keep it above 6cu net after baffling, bracing etc. i want to tune to 30hz but it will be hard since the port will have to be longer than the 20” box and take up more volume. Any suggestions ? Thanks