Go to your local parts house and ask them what they have, they'll work with you if they can make a sale

 

this one has a rectangular knockout on backplate that fits onto single gag mudring like the one above

 

The problem that I am running into, is the fire alarm device will only mount to a 4s box without a ring. Even a 2 gang ring would be too small. Seems like there should be some sort of goof ring or something for a 4s box without a ring.

 

 

Wiremold V5753

That ought to do it, if I follow the OP - or this

http://www.garvinindustries.com/ele...cal-junction-boxes/4-square-junction-boxes/1-1-2-deep-extension-rings/53151-sub

 

http://www.graybar.com/store/en/gb/...gn=Graybar>PLA>Category&utm_content=qWtncHm0|pcrid|49843464650|pkw||pmt||pdv|m|.. these actually work with the existing mud rings and will slide right in

 

http://www.receptxtenders.com/products.htm Maybe you can drill these corners and put the metal screw where it needs to go

At least they are UL listed that way. If somebody made you something, it would not UL listing

 

I am working on a job, where we have to take out horn strobes and install speaker strobes.

In order to do this, we need to remove the single gang 3/4" deep mud ring and replace it with a 4s extension.

Is there any options that aren't 1-1/2" deep? We are trying to find ways to get away from setting the box deeper in the already wall that is already covered in drywall/wallpaper.

Maybe a Wiremold extension or something?

I've never seen a horn-strobe that mounted to a single gang mud ring.

I've never heard of a speaker-strobe, just horn-strobes.

Is this a re-work of an ancient F/A system?

&&&&&&

Truth to tell, my first impulse is to pull out the Fein Multi-Master and zip out the old box.

Every horn-strobe I've touched is a volume consuming pig.

I have never seen one that could tolerate a midget back-box -- which is what a 1-gang implies.

Without any photos -- I just can't figure out what you're dealing with.

 

unfortunately a bunch of people seem to not realize that when you asked about 4s extensions you meant 4x4, 4square, or otherwise known as 1900 box extensions that aren't 1 1/2" deep. You didn't mention your desired depth, but I have a pretty good idea if you can't use the wiremold boxes that you will be using 2 1/8 or some other size if you are able to get the old boxes out. if you find something else that works please post it.

 

Do a special extension with another four square extension and now you have volume and no Sheetrock repair

 

Since it's LV wiring, can't you just yank the mud ring carefully and leave a gap?




And, what I got from the OP is that it had to be 3/4" deep, like the existing mud ring.


.

 

Ok, so after a lengthy session with the General Contractor and the Owner of the building, they REALLY did not want anything that wasn't flush with the wall. They gave us permission to cut open the wall and re-do anything we need to.

Thanks for everyone's time, there were some great fixes here....

 

there's no way to go with a modern horn/strobe the fits into existing box?

 

This is in a hotel, and they are requiring that they use speakers and speaker/strobes. It has something to do with not scaring the guests. They want everything to be voice evac now. This eliminates any opening smaller than 4s (no ring) and needs 2-3/4" worth of depth, required by the device manufacturer.