Sub install questions

I'm about to install a pair of 8's and I was wondering, how did you guys seal and secure the board?

 

Step 1: Put some speakers in it...

 

That would be step 3 or 4

 

Step 1: Purchase appropriate subs

Step 2: Acquire stainless steel self-tapping fasteners to secure subs to carpeted board

Step 3: Tilt board on its side so cardboard box doesn't impede speaker install

Step 4: Insert subs (preferably one at a time to minimize chace of them falling out during step 5)

Step 5: Secure subs to carpeted board with stainless steel self-tapping fasteners (an extra pair of hands during this step is recommended)

 

I guess my original question is not detailed enough, securing the board in the truck and achieving an air tight seal is what I'm curious about. Considering many have used these boards for their setups, what materials have they used. At the moment I'm leaning towards using a thick bead of silicone to try and seal the compartment.

 

Is this for your AC or the DC? Assuming the DC, but they know what you say about when you ASS-U-ME...

 

DC
Sounds like someone has experience with assumptions

 

One could assume that, yeah?

Some people you may be able to ask are here and here.

Ultimately, some people would saying, with this being carpet+metal, you'll never get completely sealed without using something like a bead of paint-friendly sealant around the lip of the opening, and fastening the board down. There are different opinions on that, and just like assumptions have cliches attached, you know what they say about opinions...

I'd remind them, though, your subwoofer basket is made of metal also, so you're not getting a perfect seal where it meets the carpet of your baffleboard either.

The reality is, you just need to fasten it tightly to the lip of the hole it's going over. "Fastening" has different meanings to different people. Some people would use sheetmetal screws every 4-6 inches to lock the baffle board down. Some would probably be content just laying a thick beat of paint-frendly sealant or even a rope of butyl around the lip of the sheetmetal, laying the baffle board on top, and putting 200-300lbs on it to lock it down into place.

What would I do?

If there are existing holes around the perimeter of the storage cubby, I'd probably try to utilize those with a panhead fastener and nut, and predrill the baffle board in appropriate spots to accept the hardware (I hate drilling sheet metal).

I'd drill with a hole saw from the back of the board in the approximate location shown (to keep the front carpet intact), slit the carpet, and install a terminal cup as shown here. I'd then pre-wire my subs for my desired load (either in parallel or in series), terminate my cable ends (if needed) for the sub I chose, then I'd fasten the wire to the board where the yellow boxes show, and tape down the wire between the cup and clamp to prevent rattles. Finally, I'd install the board over the cubby, then install my subs. I prefer using a flat rubber ring gasket for my subs when I screw them down.

PS/EDIT - Reason I'd go with the terminal cup. I'd seen so many people in my life run a speaker wire up under a baffle board, then silicone the board to the metal. No gasket/grommet. And what happenes to that wire casing, touching metal, after it vibrates for thousands of miles? Not only that but it looks and seals like shit. Using a terminal cup will make for easy and clean looking install, and also a way to easily disconnect. And doing things the way I described, you can prewire things enough that you'll just clip on two wires, drop the speakers in, and screw them down. I'd also put some polyfill inside the hole!

​

 

Thanks for the response. I did a little reading and ultimately there's no really great solution. A thick bead of silicone is going to do just fine, I will have to make a trip to the depot to get better screws.
This started as some simple radio install and now look what dumb shit I'm doing, new door speakers, new door handles and trim, amp and appropriate wiring yada yada WTF

 

Totally get it, that's kinda the way it goes with this stuff.

I also just realized how unclear that pic I scribbled together was. Those red/black wires would be on the inside of the box. I can't tell if that's clear or not to someone just glancing over, so ... I'm mentioning it.

Honestly, before you get OCD and lay sealants in your truck that will be a bitch to scrape off later, I'd skip the silicone and button it up without any sealant... Again, the seal between that baffle board and the sheet metal of your truck is going to be no worse off than the seal between your speaker basket and the baffle board. Low-pile carpet does come with some semblance of air-prohibitive-ness to it when compressed. It's why you virtually never see anyone using silicone around the subwoofer holes on boxes etc.

As far as screws go, if you're just gonna go ballszdeep on this one and start drilling, use self tappers. C clamp the baffle board in place using the speaker openings, pre-drill pilot holes through the wood and into the metal, lift your baffle board off to confirm you've got good spacing, and use a #8 self-tapper, probably in 1¼" like this: https://www.grainger.com/product/Self-Drilling-Screw-8-Size-4HJX9

On a #8 fastener, I believe 1/8" drill bit will be your pilot hole size. Go 7/64" if you're concerned. Yes, I know, "self tappers don't need pilots", but in this case, with a baffle board, you're going to get far more control over how/where things pull into place.

I'd screw all the self-taps into the board so the nubs are just barely poking out 1mm-2mm (enough you can easily center the self tappers over their pilot holes), then clamp the baffle board down again, then drive your self tappers home.

Wire and position the subs. Drill pilots suitable for your mounting hardware. Fasten the subs.

Test drive.