How to boost signal in very long speaker wire

[Guappo]

Hi,
At the children's camp that I work for, we have a radio station. There are speakers set around camp and of course wire going to those speakers. I wish to boost the signal at some place in the speaker wire so that the speakers on the ends of the lines are louder. We are talking hundreds of feet of line from the Amp.
The question is.... Does this device exist? I imagine a small box that uses AC power and a volume control to set the amount of boost. And of course in and out speaker lines.
Thanks in advance.

 

[jamie2112]

There are many different line amplifiers out there. You could get one at your nearest Radio Shack. Or for better line amps check out Dakiom.com..

 

[jamie2112]

greatcables.com has some great options as well....best of luck

 

[jcPanny]

Speaker volume

The speakers with the long runs are probably getting less power due to the excessive resistance in the wire. You could replace the wire with a lower gauge, or get a more powerful amp and mixer so you can boost the volume level to the speakers in questions.

 

[Rickster71]

How many speakers, and how many feet from the amp?
Sounds like you need a 70 volt system.
http://www.alectrosystems.com/audio/Distribution/70volt.htm

 

[Halon451]

I'd second Rickster's suggestion. A good 70 volt mono system would work very well in this case, especially if you have outlying areas with speakers, and no need of stereo reproduction (which in most distributed sound systems would not be a good idea anyway).

Of course with a 70 volt system you would need speakers that have variable tap settings, so that you can adjust the wattage based on how many speakers you have running in parallel with the amp, also as a factor of the amp's power output. Not sure if these speakers are capable - most that I've seen are variable in certain increments and also have selections for standard 8 ohm setups.

EDIT: Nevermind, I should have followed Rick's link before posting the above - looks like a very informative web page on 70 volt systems, and also illustrates how to use an external line matching transformer to acheive the same thing as what I mentioned above.

 

[markw]

I'll third Rick's suggestion. This is exactly what 70 volt systems are made for.

 

[BMXTRIX]

I was thinking the same thing - this is a 70v setup if I've ever heard one, and then the taps at the ends can be turned up a bit if necessary.