atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging 25V speaker on a 45 ohm line

Hello, I have a system running with 45 ohm speakers. How can I put a 25V speaker on the 45 ohm line and get satisfactory volume? Is there some kind of transformer?

I think something that might be along the lines that I could use is the Valcom VS25V, but I cannot find any information online about it--or any other similar product.

I'm assuming the 45 ohm speakers are self-amplified (power pair & audio pair). The only way to get output from a 25V speaker is to drive it from a 25V output on an amplifier. The smallest amplifier we offer is a 15W model: SWM-15. I'm sure others may be able to recommend other models that would more adequately suite your needs.

If the existing speakers are self-amplified, the audio signal feeding them would also connect into the 25V amplifier. I would recommend running a cable from the 25V amplifier to the new 25V speaker.

I hope this helps!

Hi Valcom, thanks for your help so far. I don't know if the speakers are self-amplified or not yet. I do know the system they are connected to is a Simplex 50100 series PA system.

Who is the manufacturer of a Simplex 50100 series PA system? 45 ohm speakers used to be on intercom systems.

As Valcom said, a 25 Volt speaker is designed to work on a Constant-Voltage PA system (like a 70.7 volt system, but with a lower voltage so as not to require class 1 wiring).

Why do you want to use that 25 volt speaker?

Sam

Called Valcom, and got it squared away. Solution is to use a V-LPT one way paging adapter and go with self amplified speakers.

Nice. Glad we could help!

Hi Valcom, out of curiosity, could I connect this V-LPT paging adapter to the input of this: https://www.crownaudio.com/ca_htm/ca-a.htm

According to ohms law P=E²/R the 25 volt speaker would match the 45 ohm system if it had a 13.888 watt transformer. A lower wattage transformer will still work but give you a lower volume.

Hi metel, was that an answer to my previous question (re: the crown amp)?

No Tim that was for the 45 ohm speaker question. You would need a 14 watt/25 volt transformer to equal the same power as a 45 ohm speaker. You could also use something like this