No silicone?

analogluvr

No silicone?
I remember reading another post a while back where F1nut said never to use silicone in the speaker. Why is this? I am wondering as when I read that I had already plugged the connecter hole in the back with a lot of silicone.

mhardy6647

Just to be clear, I don't know -- but that wouldn't stop me from offering an opinion.

Well, the normal "acid cure" RTV silicone wouldn't be a good choice, I'd opine -- since the acetic acid in it would be (could be) pretty corrosive to the metal innards of a (sealed) loudspeaker.

There is also "neutral cure" RTV, but I am not sure what the curing agent (catalyst) is in that stuff.

Jstas

Silicone off-gases fumes that will actually degrade the glues used in driver assemblies. It can also degrade the butyl-rubber surround structures used in many modern subwoofers.

It's ok to use but you need to use the stuff that will cure completely because it will eventually stop off-gasing in a few days.

When I used to build sub boxes for cars, I would seal a box with silicone and then leave it sit for at least a week, two if I could. That would usually give the silicone plenty of time to cure and not be a problem.

There are silicones that do not cure and remain pliable and those are not a good idea to use in speaker enclosures.

Also, RTV sealant is not a good idea because not only is the acid damaging but they are loaded with solvents to keep them squishy until they cure. Most RTV sealants will not cure or seal properly without being under pressure (like torquing down a valve cover or differential cover). Others need heat so just squirting RTV into a box corner is not enough for it to work.

I used an interior caulking to seal boxes because it was typically water based so no oils or solvent fumes and it would cure completely within a half hour and within a week, it'd be done doing anything bad.

pitdogg2

analogluvr wrote: »

No silicone?
I remember reading another post a while back where F1nut said never to use silicone in the speaker. Why is this? I am wondering as when I read that I had already plugged the connecter hole in the back with a lot of silicone.

hot glue would be much better for what you did

Jstas is correct

analogluvr

Aaah ok. Live and learn.

Jstas

Actually, if you have to plug a hole, the best thing to do is us an actual plug.

Silicone and hot glue can actually lose their grip over time because they pull moisture out of whatever they are stuck to. So stuff like MDF or particleboard or even plywood, the wood fibers dry out and as the glue and silicone contract with age and harden, they can pull the fibers away from the materials they are supposed to be sticking together. They will eventually fail on unsealed wood/paper/pulp materials.

However, if you have a jig saw, some wood, some screws, a tape measure and some sand paper you can make a plug without fancy tools.

What you do is measure the size and depth of your hole you need to plug. So if you have a 3 inch hole to plug and the speaker wall is 3/4 of an inch deep then you'll need to take your jigsaw and cut a round piece of wood 3" wide. Test fit it to the hole. It doesn't have to be super snug, just no huge gaps.

Next, since you have a 3 inch hole, you want to make a backing plate that is around 50% bigger. So, now, take your jig saw and cut a square piece of wood that is 5" square. This piece does not have to be 3/4 of an inch thick. It can be something as small as 1/4 inch plywood or something too.

Once you have that square cut out, find the center of it with you tape measure and mark it. Now, if you have a drill and a set of bits, I would predrill holes in both the plate and the plug. You want to center the hole in the plug as well. The reason you are going to pre-drill the holes is because you don't want excessive stress on this hole. As the speaker vibrates, it will loosen the fastener in that hole and it could squeak over time.

Once you have your holes drilled, put a bit of your silicone between the plug and the plate and screw them together. Clean up anything that oozes out. You should have a piece that looks like an odd top hat.

Now, from the inside, test fit your top hat so that the plate is is flush against the inside wall of the speaker cabinet. This is why using the thinnest piece of wood you can for your plug is a good idea. At this point, you should cut notches in your backing plat to clear anything like bracing or or electronic components in the case. Once you get that plate fitting flat against the speaker enclosure wall, pull it out.

Now, you can use silicone on the backing plate between the speaker enclosure wall and the plate but personally, especially if this isn't a permanent solution, I'd go to a car parts store and get a sheet of thin cork gasket material and cut a square out that will cover the entirety of of the backing plate and cut my 3 inch hole in it. But that's me. You can use silicone or even Dynamat or similar products here too.

Once you get what you are sealing the backing plate to the speaker in place, slide that plug back into that hole and screw the backing plate to the inside of the speaker.

You have plugged your hole with a non-permanent but very effective solution. This is good for plugging port holes so that you can restore the speakers to original form by removing the plug and reinstalling the port tube. You can also use this to plug speaker terminal cup holes or certain kinds of damage. It is strong so nobody like a 3 year old can poke it into the enclosure. You can paint it to match the outside or just paint it black. It won't leak and even if it does, a bead of silicone on the outside of the plug between the plug edge and the speaker cabinet wall will solve the issue without causing damage to the speaker or drivers.

Jstas

If you have a set of speakers where someone did something stupid like drill a half inch hole for "bi-amping" into the case on each one and you want to fix their stoopit, do this:

- Find out how big the hole is
- Go to a home improvement store and look for wood dowel
- Buy a wood dowel that is the same size as the hole that was drilled (you want this snug)
- While you are there, buy wood glue, wood filler, sand paper and a hand saw of some type if you don't have one (a coping saw will be about $15 and do just fine for this)
- Get a hammer if you don't have one of those too
- When you get home, check how snug the dowel is in the hole. You want it tight, you should need the hammer to be able to gently tap it in to place, if it's not, go back and get the next dowel size up. If the next size up is too big, then you can enlarge the holes to get a good fit, just make sure you get a drill bit the same size as the dowel when you get the dowel
- If everything is good, cut a few inches off the end of the dowel. Do that twice so you have two pieces, maybe 4 inches long or so, you'll need enough length to hold on to it
- Now squirt a bit of wood glue in the holes, you don't need a lot so no drips
- Now cover enough of the two dowels you cut in glue so that they will have glue for the entire depth of the hole in the speaker wall
- Now tap those dowels into those holes far enough that a little bit will stick into the speaker enclosure.
- Let the glue dry over night.
- Now that it's dry, take your saw and notch the dowel that is sticking out as close to the outside of the speaker box as you can. Make the notch go all the way around the dowel.
- Once you have that notch, hit the end with the hammer. It should snap off at the notch
- Alternatively, you can choose to saw through it completely, it's up to you, depends on how much sanding you want to do.
- Once the extra dowel is gone, sand what's left flush with the speaker box surface.
- Any pieces that came out that left a hole in the dowel you can fill with wood glue but glue contracts when it dries so the wood filler would be the better option here. Once the wood filler dries, sand that smooth and flush too.

You plugged your hole. You can paint it or stain it to match it's surroundings by using a q-tip.

For paint, get a can of spray paint, shake it and spray a puddle in a cup or on some cardboard, dip your q-tip in and dab it on the dowel. (if you use a plastic cup, be aware that the propellant and solvent in spray paint will melt your typical plastic cup)

If it's flat black, you can likely get away with a black Sharpie marker.

For stain, get a small can of stain that is close, stir it up so it's mixed properly, stick your Q-tip in and dab it on the dowel.

If you need to do finish work, that's more involved and I don't want to get into that right now.

pitdogg2

Yep was thinking dowel rod my self. I was thinking it was in the plastic cup or something.
I have plugged mamy a hole with an hardwood dowel rod and wood glue.

Jstas

Well, if it's a big hole, a dowel wouldn't be the best idea.

Also, I hope it doesn't need mentioning but I will mention it anyway.

If you are going to make a plug and your hole is square, make a square plug the same shape and size as the hole.

A round peg in a square hole is just....yeah, use you're head for more than a hat rack.

VSAT88

Just plug it with a Nathans Hot Dog.