My wonderful wife is getting me a Boston Acoustics SPG555 sub for Christmas and I want to install it in the factory location in our Centurion Typhoon. There is all ready a fiberglass enclosure built into the floor but it is 2-3 cubic feet in size and the 555 needs exactly 1 cubic feet. I have done a lot of fiberglass work in the past and I feel very confident that I can build a new enclosure floor and sidewalls INSIDE the current enclosure to make it exactly 1 cubic feet. Once I get the new box built inside using the original front, back and top wall then it should be pretty easy to lay enough fiberglass in there to make it as thick as I want so here are my questions:
If ¾ MDF would be considered the minimum thickness, what would be considered the equivalent thickness in fiberglass taking into consideration that the box is very small. Seems like ¾ inch fiberglass would be overkill in such a small box.
My main question is will it be strong enough screwing the sub straight into the fiberglass. I plan on making the fiberglass very thick at the sub mounting surface so there will be plenty of fiberglass for the screws to bite into but I see most enclosures have MDF mounting rings. I can’t figure out if they use the mounting rings to make the enclosures easier to build or if it is necessary to get the sub mounted securely without the screws coming loose. The original sub was just mounted into the fiberglass and it isn’t near as thick as what I will make it but this sub is much better and I will be putting 1000 watts RMS to it and I just want to make sure that I do it right.
Any advice will be greatly appreciated, I really don’t want to cut the whole thing out and build a new enclosure like I have seen some do.
(Message edited by scott76310 on December 16, 2009)