I have always used regular wood screws, but Madisound sells a 6-32 x 1” Socket Head Cap Screw with T-Nut:
Opinions?
Thanks,
john
Opinions?
Thanks,
john
Those things look like crap to me. Surely you can get better threaded inserts? Screws are fine going into plywood, as long as it's reasonably thick.
jeff
jeff
It depends on what material the driver is being mounted on and also whether or not the driver opening will be used to get access to the inside of the box (necessitating removal of the driver and replacement) .
Would you even be able to fit the T-nut on the flange that holds the woofer?
I agree with Jeff that these look like they'd fall out at the lightest touch. Maybe you can find a boss of some sort either at a store that sells supplies for furniture builders or at McMaster-Carr: www.mcmaster.com
Tom
I agree with Jeff that these look like they'd fall out at the lightest touch. Maybe you can find a boss of some sort either at a store that sells supplies for furniture builders or at McMaster-Carr: www.mcmaster.com
Tom
I've honestly not run into the wood threads wearing out on any of my speakers, if you're careful you can usually find the thread and follow that. even my mdf threads have last dozens of driver swaps.
Screws hold well in proper plywood. I have had NDF enclosure sthat ended up with a ring of screw holes on the perimeter of the driver cutout as the drive ris rotated to find new meat to hold the screws.
You only ever have to have had the nut part of a T-Nut come loose and have to ruin the enclosure to remove the driver to swaer to neve ruse them again.
The proper way to do it is threaded inserts.
dave
You only ever have to have had the nut part of a T-Nut come loose and have to ruin the enclosure to remove the driver to swaer to neve ruse them again.
The proper way to do it is threaded inserts.
dave
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Joined 2009
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T-nuts are perfects fine if they are BEHIND the wood so that the action of inserting the bolt through from the front side pulls the t-nut into the wood from the back.
If you can’t use t-nuts from the back side, threaded inserts are the choice.
If you can’t use t-nuts from the back side, threaded inserts are the choice.
It sure can be an important choice and depends on the demands of the driver itself. There was one time that I drilled the screw hole larger for the T-nut and then when mounting, the screw/ T-nut would have some space to move. I removed the teeth on the T-nut and used epoxy to support the now Toothless nut. You have to rough up the barrel and plate of the nut to help the epoxy grip, and also the epoxy must be driven into the grain/fibers of the wood as well. Yes, a lengthy process that works. Don't forget to grease the threads of the bolt so that the epoxy doesn't get a grip where you don't want it.
They may look fugly for other reasons, the photograph maybe, but if the hole is drilled to make for a snug fit of the T-nut barrel and as long as the dimension of the flange allows unobstructed entry of the driver into the opening , and the tooth is set on the opposite side of the nut from the opening so it bites into the material , it should work fine. : )
Looking at the pic again, It looks like the flange is stepped opposite the tooth so that it can be cut (or snapped?) off where installation is close to the opening.
It won’t necessarily. And you only need the experience of one going wrong. I have had it happen more than once.
dave
Depending on my build philosophy at the time, sometimes I like to have long screws that go through the baffle and into bracing material directly behind the driver (+ attached to other cabinet walls). That's where energy transfers into the box, so I like a brace there, then no spot for an insert. Other times I decide to go for a damped brace, so I don't want a rigid structure there, and that leaves space.
Then I leave it at wood screws usually, unless I think I'm going to be in and out of the box frequently. In that case I prefer 'hurricane nuts' from parts express. They have a little semi-thread that pulls into the wood as you tighten the screw down the first time (disk goes behind the wood, neck pulls into hole from the back). The part description on PE says what size drill to use for the installation hole. They don't fall out backward after you get them seated, and I have found them to be pretty nice. You can reclaim them by partially installing a screw and tapping the nut out backward with a hammer. Occasionally I use an angle grinder to chop off part of the disk in tight spaces.
https://www.parts-express.com/search?keywords=hurricane nuts&order=relevance:desc
Then I leave it at wood screws usually, unless I think I'm going to be in and out of the box frequently. In that case I prefer 'hurricane nuts' from parts express. They have a little semi-thread that pulls into the wood as you tighten the screw down the first time (disk goes behind the wood, neck pulls into hole from the back). The part description on PE says what size drill to use for the installation hole. They don't fall out backward after you get them seated, and I have found them to be pretty nice. You can reclaim them by partially installing a screw and tapping the nut out backward with a hammer. Occasionally I use an angle grinder to chop off part of the disk in tight spaces.
https://www.parts-express.com/search?keywords=hurricane nuts&order=relevance:desc
Well, at some point it then gets difficult to say anything. Sometimes even a screw goes wrong.
Nobody has asked the fellow what he is fixing the driver to.
Like I said at the beginning , applicability depends on conditions and the OP has not specified those.
I have had a threaded insert go loose (in chipboard). It was one of eight, so I just sealed that one screw with silicone. I do not like the T nuts, unless they can be accessed from the other side. In plywood, you can cut metric threads and they will be perfectly fine unless you overtighten them.
I have used the hurricane nuts before with no issues. The biggest challenge for me is to get the holes accurately drilled. Not just spot on but also plumb if I am not able to use a drill press. Dave is right about getting one wrong, however it happens. If I am using an adhesive, then I like to have all the bolts in place when the adhesive is wet with the driver mounted. That way, whatever the best position is right for the bolt, it becomes automatic as the bolt is tightened just a bit.
Thanks to all! Especially Dave. I have tried and failed at putting in threaded inserts without the proper tool--my lesson learned. john
MDF for the "Proof of Concept." Richlite for the Client speakers. THANKS! john
You are faced with the Midz’wel. If you’re going to use a wood screw then midz’wel use a T-nut!!!
I have used T-nuts often in boats, kitchen cabinets, other furniture... based on that experience, I would never use T-nuts to install loudspeaker drivers. T-nuts work best when there is significant edge distance, at least 2xhole diameter. That is rarely possible on the narrow recessed flange we create when we cut a speaker hole.
I always screw the drivers into place with a quality wood screw and a properly sized hole... I use a thread lubricant (wax is good). I tighten until just snug. If the wood threads in the hole ever get worn out, it is very easy to apply a few drops of epoxy into the hole, and re-drill the hole.
I always screw the drivers into place with a quality wood screw and a properly sized hole... I use a thread lubricant (wax is good). I tighten until just snug. If the wood threads in the hole ever get worn out, it is very easy to apply a few drops of epoxy into the hole, and re-drill the hole.
Front panel Lumber: Richlite .75 in, or 1.0 in. (w/.25-in. inset into cabinet shell).
Driver cutout circle is 121.5mm; bolt circle is 138mm.
Data Sheet: https://ptt.purifi-audio.com/shop/ptt5-25x08-nfa-01-ptt5-25x08-nfa-01-1521
THANKS!
john