Nortel Networks Paging amp and speakers

Howdy,

I am wondering about speakers connected to a paging amp.  How do I go about
figuring out how many speakers can be connected to a paging amp?  Basic math
and common sense tells me that a 35 watt amp will be able to drive 5 seven
watt speakers.
Is this correct?
Is this one of those circumstances where they say the Amp is 35 watts, but
really it is only 20 watts.
Then again, I know that sometimes the speakers wattage is measured in RMS or
something and what seems like a maximum of 5 speakers is really 10.

So, how do I figure out how many speakers I can connect to my Bogen TPU35B?

Thanks in advance,

John

John wrote:

That has a 70 volt output.  That type of output exists so you can feed
speakers very far away - 1000+ feet.  Also so you can feed many - maybe
60 to 80 or more if you were just playing quiet soothing background
music without paging.  In a warehouse, you might feed 10 to 15 horns
that would be loud enough for paging

The speakers must have a "70volt transformer" - 70v amp would fry the
speaker or at least load the thing down real far.  That transformer
will have 3 to 5 "taps" or wires, each one being louder and a greater
load.  The taps will be identified as "quarter watt, half watt, up to 2
watts probably.  Those WATT numbers cannot exceed 35 when added.

Of course, there is a normal speaker output - 16 ohms is what I see on
the spec I found online.  In that case, I think you just wire in series
parallel as to not end up lower than 8 ohms (my guess the amp is quite
durable) and if you can hear, that's good.

Go 70 volts...that is the standard.

Yes and no.  You don't want to be the one closest to a trumpet tapped
at 7 watts.   In general practice, 3-5 amps feeds a trumpet and 1-2
amps feed ceiling speakers very well.


Three methods, Math, trial and error, and an Impedance bridge or a
combination of the 3.  I hear the new impedance bridges are digital
and pretty slick and TPU 60's aren't very expensive either.
.  

Carl Navarro

That tells me what I needed to know.  I found out that the speck I was
looking at for the speaker was adding all of the possible taps on the
speaker tranformer to arrive at the 7 watts they were reporting.  I would
not have figured that out if you hadn't pointed me in the right direction.

Thanks for the information.  I don't know what I'd do without you guys
helping me out.

John