Adding ports under the seats for more bass

I've seen a few pics of some people who have cut 4 inch holes (or some variation of that) in order to create an outlet for some air movement for a sub that is under the observer's seat, or under any seat for that matter.

Can you post some pics of what you did? I'm interested in doing this in the area under my observer seat, but don't know exactly how to proceed.

My understanding you need some vents or ports to create more air movement if you have your sub in an enclosed area. It will depend if you have a wood base or a fiberglass base. My guess is you can buy a port like you would use on a sub box and drill out a hole in seat base and insert the plastic sleeve. Many of the subs I have seen under rear seats on performance boats are built with a 1-2 opening at the bottom of the seat base with pedestal bases on the sides and in the middle for support.

Check out this thread it might help some

http://www.hotboat.com/forums/showthread.php?t=105472

You definitely need to know what you are doing. You are essentially tuning an enclosure when you add ports to it and creating a bandpass style sub. That is, unless you can get a ton of air out of the enclosure. I tried to do that with my old Sanger and got no benefit from it. I ran 4, 4" ports with a sealed box 15". So, just an FYI..... Most likely not worthwhile.