Page Pac

[techguy137]

I have a client that currently has a lucent/valcom Page Pac D100. It isa talkback system with 24 zones. I have limped this system along for years but it's now time to replace it as parts are difficult to find. I am looking at a Bogen TPU100 as a replacement. The client doesn't want the talkback function anymore. There are approximately 40 speakers on this system. 70v 45 ohm speakers.
My question is is the 100 watt unit going to be big enough? The old page pac is 100 watts so I am thinking so. BTW there are a mis mash of speakers attached to this. They are mostly valcom speakers. there are some bogen 8" ones. Valcom Ptech & valcom 2x2 tile speakers.
Any insight would be helpfull
Thank you

 

[YooperKen]

I think you must have the ohms/speaker incorrect. Typical speaker ratings (25v, 70V, 100v system, etc.) are often 8 ohms although other ratings are possible (4ohms or 16 ohms). Many paging speakers allow for 'tapping' at different wattage settings (e.g. 2.5w or 5w) in order to control the local volume output of the speaker, or they may have a volume control that accomplishes the same thing. The Valcom speakers I deal with have the volume control 'pot' (potentiometer) option. Those comments aside, if the current system has been and is working adequately using a 70v, 100w rated amplifier then a similar 70v, 100w rated amplifier should also work. The key is to keep the total wattage of all speakers connected to a single amplifier below the rating of the amplifier. If that isn't possible then multiple amplifiers (the situation in my facility) must be utilized to prevent overloading a single amp.

 

[DoubleDriveLine]

You can confirm the size of the system with this document from Bogan.

https://www.bogen.com/sites/default/files/2021-02/SysDsgn.pdf

Page 67 but the document starts on page 63.

The wattage is just a simple mathematical formula but it is based on new systems.

Refer to the document if you have anything more than just Ceiling speakers (horns or wall baffles).

If you had 40 70v speakers using a maximum of 4W of power each (see chart below).



40 x 4 = 160 watts

If the speakers were only tapped at 2W then you only need an 80 watt amp.

If your speakers have volume controls then they are not tapped for volume and you will have to determine wattage by best guess.

You might be fine with 100 watts but you may want to just go with the next size TPU250.

Old speakers may draw more wattage and produce less volume and you have old cabling that could start causing an issue.





For some reason this document seems to be cut short. The amplifier selection references pages 78/79 but only goes up to 77 in the document. My guess is there is more to the formula. If you think for any reason you are at or over the 80 watt mark I would go with the 250 watt amp. That statement comes from the belief there would be a percentage over the minimum amplifier power that you should use.

 

[TouchToneTommy]

The best way to know? Get an Impedance Meter (NOT an ohmmeter) and determine the total wattage draw of the existing speakers.

2nd best way to know? Audit EVERY speaker to determine its wattage tap and add them all up, allowing a percentage for copper loss of the wiring.

 

[curlycord]

All good points above, I am glad I am not doing paging anymore but I did prefer Bogen.
We used to use 1/4 watt setting for most quite applications (office, department stores) and all single home run cables!

If I recall, Valcom uses 2 pairs per speaker, power and audio, so an Amp and a separate Power Supply.
Bogen uses 1 pair, power and audio on the same pair.

I am just curious how that would wire out with a Bogen amp?

 

[TouchToneTommy]

Both Valcom and Bogen make Self-Amplified speakers, and Centralized Amplifier systems. You can't base your understanding of what's installed simply on the brand of speakers.

Knowing that there is a D100 Amplicenter involved tells us that it is using standard 70-Volt speakers with matching transformers, thus 2-conductor wiring carrying the audio throughout.

Self-Amplified speakers use 2-pair cabling, and a power supply. One pair carries the audio, the other carries the power for the small amplifier built into each speaker assembly. The power supply can be sized to handle a bunch of speakers, but you can also have power supplies that cover a section of a building if the distances and number of speakers is large.

 

[curlycord]

As always TTT, thanks for your knowledge and splaining over many years.