Valcom -24vdc intercom speakers

[Ben Lawrence]

I have run into a system where I had anticipated seeing a 25v or 70v system that has a valcom speaker install. This is the first time I have run into a setup like this. Each speaker seems to have its own little amplifier as opposed to a transformer on a 70v line. All the signal lines appear to be cat 5e. Essentially I am looking at trying to add some speakers and it looks like simply jumping on extra speakers is a no go? I also have larger room where a horn with some additional output would be handy. In a normal 70v system I could just swap out the speaker and utilize the larger tap. I will have to see what is involved with a higher output horn on the -24vdc line.
Are some of you guys installing these setups? What is the advantage over the typical 70v setups?

 

[Rob Timmerman]

Have you looked at the options from Valcom? You may indeed be able to simply add more of their speakers to the system.

The Valcom stuff is designed for paging, where zones are typically small and numerous. The primary advantage to distributing low-level signal + power is that multi-zone support is quite a bit less expensive for small zones, and the distribution wire may have less copper and thus be cheaper.

 

[Ben Lawrence]

Install is in an Elementary School. Just used to tapping on the end of the line to add additional speakers. Going to have to do some additional research to see whats involved. It appears as though the hallways are on 70v and the classrooms are on the -24vdc. Have the option of the original installer come in to give me a walkthrough of the system. Probably going to go that route.