T- nuts or wood screws

7928 Views 28 Replies 21 Participants Last post by monomer, Jan 29, 2013

Code Red

Discussion Starter · Dec 19, 2012

Hey all, I'm in the cabinet design phase for a SI HT 18 I pre-ordered yesterday. Its going in a sealed box. Im planning on a thick baffle, at least double thick maybe thicker. Im using MDF throughout but have been reading some comments on the use of t-nuts and bolts for the driver. I have used them them in a 2 way build with a 6.5" woofer and thought they were a pain as I didnt have a drill press and had some alignment problems. I was thinking instead of using MDF sandwiched to 3/4" hardwood plywood and using heavy duty wood screws into the plywood. I was just wondering if that would be strong enough for a big heavy high excursion woofer in a sealed box with a big amp on it.

1 - 20 of 29 Posts

Kal Rubinson

· #2 · Dec 19, 2012

IMHO, the wood screws will be strong enough...................the first time. If you expect to have to remove/replace the driver, think T-nuts.

chrapladm

· #3 · Dec 19, 2012

I have 21" subwoofers with Mdf as the face and plywood as the inner baffle. I used 2" screws and have removed the drivers plenty of times. So I think you will be fine with MDF/plywood baffle.

Wardsweb

· #4 · Dec 19, 2012

As long as you have something other than MDF for the screw to bite into, you should be fine.

theJman

· #5 · Dec 19, 2012

I'd opt for threaded inserts for t-nuts myself. MDF doesn't grab screw threads all that well. You're going to be using a big, heavy driver in a sealed enclosure -- meaning lots of weight and lots of force -- so for peace of mind you might want to consider something a bit sturdier then just wood screws biting into compressed sawdust.

Mike P.

· #6 · Dec 19, 2012

If you're going to use MDF sandwiched to 3/4" hardwood plywood then screws will be fine.

Stereodude

· #7 · Dec 19, 2012

If you're careful when taking them in and out screws are fine. When I say careful I mean make sure the screws reuse the same threads by turning them counterclockwise until they drop and then tightening 'em.

That said I've generally used some sort of metal threaded insert in my various projects.

vann_d

· #8 · Dec 19, 2012

I would not recommend T-nuts to anyone. If you aren't comfortable with wood screws, go with a real threaded insert.

randyc1

· #9 · Dec 20, 2012

Predrill holes a bit smaller, add a little white glue and screw in and out a few times , let dry without screws .
I tested this method with 1" of threads amd was able to drive head of screw in mdf If wanted,... plenty strong!!

lsiberian

· #10 · Dec 20, 2012

I recommend hex heads and manually tighten them. You don't want an electric spinning sharp point hitting your Subs surround. I've come very close to taking out a driver before with a phillips it's not something I suggest repeating.

Sonnie

· #11 · Jan 2, 2013

I am using the hex head screws on my Audiopulse drivers firing down and it is all MDF (triple baffle). Had to take one driver out the other day to repair a terminal connection that vibrated loose. I did shift the driver slightly so that I did not use the same holes, but the screws tightened up very well and I have never had a problem. I also have all four of my Q18's mounted with screws into MDF (double baffle).

Those screws came with the driver... same as the TC Sounds Driver Mounting Screws from Parts Express (I believe).

dougc

· #12 · Jan 3, 2013

I am a fan of t-nuts epoxy'd in to place, manually tightened. The trick is to thread them several times before installing them and then again after the epoxy so that you don't have them binding up on you. I have had to take out my drivers several times and thanked myself for taking the extra time to set myself up.

lucasa.miller

· #13 · Jan 3, 2013

I'm a fan of the t nuts you nail into place with brad nails. Nails and epoxy and they won't spin loose on you.

Prof.

· #14 · Jan 3, 2013

randyc1 said:
Predrill holes a bit smaller, add a little white glue and screw in and out a few times , let dry without screws .
I tested this method with 1" of threads amd was able to drive head of screw in mdf If wanted,... plenty strong!!

That sounds like a good idea!. The sub driver that I'm planning to use in a new horn build has the mounting screws very close to the cut out, which wouldn't leave enough room for T nuts and the driver will be mounted to MDF..Strengthening the screw holes with glue should do the trick! :T

Code Red

Discussion Starter · #15 · Jan 3, 2013

The wood glue idea sounds good, I might have to try that. Thanks for all the replies everyone. My SI HT 18 will be here the 8th, so I'll start a build thread here soon.

sub_crazy

· #16 · Jan 3, 2013

I have a bunch of bags if T-nuts if you want to buy some :whistling:

Seriously though I will never use T-nuts or even hurricane nuts again as they are truly not worth the trouble. Wood screws have been great to use in either MDF of better yet plywood, you just have to be careful not to overtighten and strip the wood. Even if you do happen to strip the wood there is a great wood repair epoxy they carry at most hardware stores called kwikwood by jb weld or Quickwood by PSI. I have used both and they dry fast and then can be drilled and the screw takes to it like magic.

andy_c

· #17 · Jan 3, 2013

Another option that I've read about but not tried yet is these drywall anchors that I first saw mentioned in this thread.

lucasa.miller

· #18 · Jan 4, 2013

The drywall anchor link you posted didn't work. Can you provide a new link?

I'm very interested in this solution.

andy_c

· #19 · Jan 4, 2013 (Edited)

lucasa.miller said:
The drywall anchor link you posted didn't work. Can you provide a new link?

I'm very interested in this solution.

I'm not sure what is going on with the link. I just tried it and it worked fine. You might try looking for it this way:

site: lowes.com
item number: 169762
model number: 25316

I just tried a search by item number at Lowe's, and it found the item.

Edit: Here's a revised link. Maybe it will work?
http://www.lowes.com/pd_169762-2191-25316_0__?Ntt=169762&UserSearch=169762&productId=1042133&rpp=32

Edit 2: The product is called "E-Z Ancor Stud Solver". The odd spelling of "anchor" is apparently deliberate. The manufacturer's web page is here. Home Depot also has them here.

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lucasa.miller

· #20 · Jan 4, 2013

I've used those to hang a mirror.

It looks like you have to screw the anchors into the baffle and then mount the speaker and sandwich the speaker between the anchor and screw.

I'm going to have to test it out on MDF. I'd be worried the anchor would rip out when screwing it in since its so close to the edge.

1 - 20 of 29 Posts

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