Custom Sub box question

[VesperZ]

I'm building a custom boot including custom sub boxes. I have 2 x Alpine SWR-1242D subs which came in the factory alpine sub boxes which are ported. According to the SWR-1242D manual, the optimum volume for a sealed box to house this sub is between 0.7 cubic foot to 1.0 cubic foot. My box has a total internal volume of 1 cubic foot.

When I took my sub out of the factory box, I saw there was like this foamy white stuff. So I went and bought some of this foamy white stuff to put in my box. After putting my subs into my custom boxes I connected them up and gave them a test. Basically it sounded like it wasn't as loud and punchy as in the factory boxes.

I'm not sure if everyone is familiar with the factory boxes from Alpine, however here is a link

My question is, do I need this foamy white stuff that I found in the original boxes or are they just for ported boxes. My other question is what purpose does this foamy white stuff actually have on subs.

Do I by any means have to retune my subs due to the changing of boxes or make any adjustments on my amp?

Before anyone questions whether I hooked them up right, the answer is yes I did hook them up right. The two voice coils of each driver are hooked up in series and the drivers in parallel.

Any help would be appreciated.

[Philthy]

Using a sealed box rather than the ported one they used to be in, they will be quieter.
I'll take a guess and say they seem less punchy because you built the box at the bigger end of the scale.
Dacron (the white stuff) hasn't even made THAT much of a difference from my own experience. I've always just experimented with different amounts though. I know there is a set amount you should use, but no idea how to figure it out

[acarmody]

I just half filled my box with Dacron, that's what Kicker recommend. Its cheap as piss anyway, I got mine from Spotlight (poly-fill) for about $10 for a massive bag.