atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging can I use one pair for volume controll ?

I prewired for M&S DMC1 intercom system and I screwed up , I needed 4 pair from the master to the volume control in the wall and one pair from there to the speaker

I did the opposite so I have 4 pair in the ceiling and one pair down the wall

Im thinking I can mount MVC 1 in the ceiling above the speaker volume full then break one of the outputs to the speaker and run them thru a wall monted volume controll on the single pair

will that work ?

I was thinking of using something like valcom unit on the wall from the pdf here it looks like it should work .

the job site is 45 min away (of course ) so it makes quick troubleshooting hard

any other suggestions .

(If I really have to , I can try fishing a new cable but it would be a PITA at best , if I can get the single pair to work it would be best )

What kind of wire did you run between the

Master and VC?

VC and Speaker?

I have

4 pair cat 5 from the master to the speaker


one pair shielded from the VC to the speaker

This is what i would try.

Brown pair from MC to + side of speaker

Out the - side of the speaker tie in to red lead to VC

From VC green lead to green pair of cat 5 to MC.


The VC is nothing more than an attenuator, Correct?

well they don't use pairs

they have brown and blue/white going to green on the VC

green and brown/white on red going to the VC then blue and violet coming out of the VC to the speaker

studying the VC the green , brown/white , go the the red on the VC which is soldered to the same terminal as the blue out to the speaker

so I'm thinking I could take green ,brown/white from the master directly to the speaker

then take the brown , blue/white though the VC and it should work

which is basically what your suggesting ,Rustynails

I'll give it a try thanks

is it a attenuator ?

not sure it has B500 (ohms)
360022

stamped on the back

I'm a little out of my element with engineering sound stuff

Skip,

I after looking at the diagram more carefully, what i suggested will not work. The VC appears to be a line matching transformer also.

Is this for music?

If so, what type of speaker is in the ceiling; what are the specs and what kind of output is the MC generating.

yes music
SPEAKER

# 8-inch recessed ceiling mount speaker
# 45-ohm impedance for intercom use
# White frame and white plastic grille

https://www.mssystems.com/product_detail.php?productId=129


MASTER

30 Watts (RMS) maximum output power

https://www.mssystems.com/product_detail.php?productId=13


how about my original suggestion , placing the VC in the ceiling above the speaker volume maxed then
running one leg through a second VC

Actually, I do think that would work as you suggested.

What i was hoping for was that the MC could take a regular 8omhs speaker, allowing for my original suggestion, though having to replace both your current VC and Ceiling speaker with somthing suited for such.

Anyhow the Valcom unit will probably work.

~r

I'm going to give it a try tomorrow , fist I'm going to make a effort at running new cable and see if its possible without cutting drywall .

Ive been thinking about it all day and have several approach s to try

then Ill try the valcom solution .

hopefully one or the other will do it .

I really appreciate your input and will update as to what happens

hey skip how did this turn out