View Full Version : Mounting a sub + baffle/ring into a fiberglass box; which way?

02-01-2010, 02:34 PM
I'm trying to mount a sub in a fiberglass box (designed for the car) however the sub is slightly too deep for the box. The mouting ring on the box is recessed as well (a sub less deep woudl sit flush) so I've had to use two rings, one to sit in the recess and get to the level of the rest of the box and then another one on top of that because I still need just a little bit more depth to get the driver in there.

So what I did was I drilled the 8 holes through the two rings and then glued them together with Liquid Nails. To set the ring I put screws through the 8 holes to hold them together. My initial intention was to do that, remove the screws, and then drive the 8 screws for the sub straight through the rings, and then into the ring that the box has to hold the sub. However I then thought with my screws all in there I might as well leave those to hold the two spacer rings together permanently and then make new holes by offsetting the ring and driving through the screws for sub like that.

Then I got to thinking again, lol. What's the better way to do this?

Should I

a. Leave the ring as is with the screws, then drive 8 more screws through there and through the ring in the box which will hold the sub and the spacer rings to the box? (This is what I mentioned last above.)


b. Should I instead mount the rings to the box with 8 screws (going through the two rings plus the box) and then mount the sub to the top spacer rings (without the sub-securing screws going through the box)?

I thought about doing both but then I'm not sure I want to make 16 holes through the ring built into the box so it should be one way or the other. What does everyone think? Rings secured together and then sub driven through all the rings; or rings secured to the box and then sub secured to the rings?

Is there even a difference?

02-01-2010, 08:26 PM
kinda confusing but I say go ahead and drill those rings on to the box then drill the sub onto those rings

since you already got screws in the rings just leave them there just make sure they are countersunk

I just did this a couple days ago actually and I just used liquid nails to attatch the mdf rings to the fiberglass box and clamped it no screws

def predill into the fiberglass or else it will crack and drill the screws in to the fiberglass either with a drill really slow or hand tighten them cause for some reason the fiberglass heats up the screw and can cause the whole screw to just snap off or break the fiberglass

02-01-2010, 08:27 PM
I'm not even really sure what you were asking maybe some pictures of what your talking about

02-02-2010, 01:14 PM
Thanks for the reply

I think you got it right to begin with though there's no attaching to fiberglass directly...

The sub box already has an MDF ring built into it, though I will definitely mark and predrill the pilot holes in the ring in the box. I just had to use more rings (to sit on top of the ring in the box that's there to mount the sub) because of a depth issue.

In option A my screws would secure the sub, go through the two rings, then through the mount ring in the box (one set of screws goes through everything and holds everything together). In option B the additional rings are secured to the box [only] with one set of screws and then the sub is screwed into only those top rings (two sets of screws--one which secures the rings to the ring in the box, the other which goes through the sub and the rings).

I decided to do it the way you said yesterday anyway (option B), seemed to make the most sense to me too. If I ever have to remove the sub for anything it should be easier to do just pulling it out instead of having to remove the sub and spacer rings like I would with option A.

Seems to be good now