Spare tire speaker box

I wouldn't think that having separate chambers would help, atleast not from my experience. I would think that any gaps in the seams that let air leak would be ur major problem, also the internal volume of the box, although not so much a problem with sealed boxes.

So when I seal the gaps will I notice the difference

No way I sealead it with foam  but the part where the top connects to my base is where it leaks I can easily seal it with silicone or any gap sealer but I was wondering if there was anything else that I could use that is not permanent like a gasket

Yeah, you will notice a difference when you seal the gaps, i had some screw sized holes once in one of my older boxes and it made a difference when i sealed even those, crazy ain't it.

You might wanna try some rubber stripping (weather stripping and the such). I think that will give you the effect ur lookin for. It comes on a role and in different lengths and width so you have a lot of options. Your local hardware store will have it. If you went with a liquid sealer like an engine liquid gasket type thing i'm not a 100% sure that it wouldn't stick to the porousness of the wood or foam.

Hope that helped.