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70 volt auxilliary zone has low volume

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Frank DeWitt:
At audio frequencies bigger wire is always better.  There is a point where making it bigger doesn't improve things enough to be worth more money, it but it never hurts.  

A 70 volt system doesn't need very big wire because the voltage is high and therefor the current is low but big wire won't hurt it.

Ray Rayburn who has a extensive resume including designing audio systems for the US congress has published a couple of spread sheets to help select the best wire for speakers.

for low impedance systems.
http://www.soundfirst.com/LZ_DF_calculator.zip

And for constant voltage systems.
http://www.soundfirst.com/CV_DF_calculator.zip

His web site is here
http://www.soundfirst.com/technical.html

Frank

Matthias Heitzer:
If there really is a short somewhere in the line, bigger wire could make things worse, but that's the only situation i can think about.

If we are talking about AC, the electrons aren't acutally travelling through the wire, they just move back and forth.
That's a good thing, because they are as slow as 0,3 mm/s.

Let's take Sidney Pillen's straw and fill it with water.
Now we fill our mouth with orange juice and pump the juice through the water-filled straw. What will come out of the straw? It's water, and if we beginn to draw back the liquid fast enough, the juice won't drip out of the straw. (if we exclude that water and juices blends in real life)

Gary Creely:
Matthias Heitzer wrote on Mon, 10 January 2011 10:39
If there really is a short somewhere in the line, bigger wire could make things worse, but that's the only situation i can think about.

If we are talking about AC, the electrons aren't acutally travelling through the wire, they just move back and forth.
That's a good thing, because they are as slow as 0,3 mm/s.

Let's take Sidney Pillen's straw and fill it with water.
Now we fill our mouth with orange juice and pump the juice through the water-filled straw. What will come out of the straw? It's water, and if we beginn to draw back the liquid fast enough, the juice won't drip out of the straw. (if we exclude that water and juices blends in real life)


Ok, I need to just say all this back and forth nonsense about cable size is just very unlikely to have anything to do with the problem at hand. If it was 18ga or 10ga it should not be causing a dramatic loss of volume.

Matt Carr:
Well, it has been interesting and informative reading all the replies. Thank you.
I discovered Saturday when I disconnected the speaker run at mid point I was able to identify a problem with the first section. I discovered one speaker connected to the 25V side of the transformer in an old office that's not currently being used. The church didn't even know it was in there. Once it was connected to 70V everything worked great, even on the 22awg wire.
Thanks for all the feedback.

Brad Weber:
Glad you found the problem and took care of it!

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