Horn Mounting to Baffle 4355 / 2405 / 2311

[cvengr]

I've about to set up the baffles and hardware, when some questions arose.

I read the 4350 notes regarding how to change Rt / Left sides of drivers in the enclosure, but am not fully satisfied I understand their geometry.
Tee-Nuts on int of Baffle, don't appear to be well anchored, if laden from the interior of the enclosure.

1) Do both the 2440 /2441 and the 2405 use gaskets between the driver and the baffle?

2) Are the tee-nuts receiving 2 bolts/machine screws , one from either side, or is it simple one bolt, and is it nutted only by the tee-nut or also behind the mounting plate?

Any help is appreciated.

[robertg]

The tee nuts are on the inside of the baffle to hold down the woofer and mid range. The horn and tweeter have screws coming through the front of the baffle holding them down. There is a paper gasket between the 2440 and horn, and the horn and tweeter seals to the baffle with an o-ring.

The holes have to be pretty precise for the o-rings to seal. It wouldn't hurt to smear a bit of silicone on the horn and tweeter mounting surface.

[Riley Casey]

A couple of things I've learned about Tee nuts in speaker baffles that aren't 4355 specific. Don't hammer the Tee nuts into the holes, press them in with a C clamp and add a bit of rubber cement to the outer surfaces when installing. Tee nuts are moderately reliable in baltic birch and almost worthless in MDF particularly when the tee nut is mounting close to the driver cut out. Adding a 1/4" plywood plate behind the MDF for the teeth of the tee nut to set in is not unheard of.

[cvengr]

Thanks to both.
I'm working on a test box, closer to 24" x 36" x 48", just to ring out issues.

Meanwhile I'm working the interior bracing to comply with ASCE 7-22 for Non-Structural Building Components and bracing for Sesimic Design Class D, in So CA. Not required unless 400lbs, but being on a dolly, it's worthwhile to verify internal bracing is adequate for the transducer anchorage.

Seems like the bolted connections are fairly close to the transducer openings. Ever seen a circular flange to assist the bolt anchorage around the speaker perimeter?

[Riley Casey]

The woofer clamp mounting holes are far enough from the driver cut out to not be a problem even on MDF. Most of my experience is with baltic birch portable enclosures and on those front mounting 12" mid drivers with Tee nuts was not an issue. If you are using MDF you could always use the same style clamps to move the mounting hole out from the drive cutout.

The 'O' ring gasket on easily half the factory built enclosures I've encountered over the years were not seated correctly. Those were pretty clearly a bit of accountant engineering. I'd suggest finding cork style adhesive flat gaskets that stick to backs of the speaker frames from eBay or your speaker parts vendor du jour.

[quindecima]

IMHO the T nuts are a POS, I used threaded inserts for my speaker builds. :applaud: