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remote sans mic

Hi: I'm outa ideas. I want to add a wireless extension to a facility PA system to avoid wiring through an area unfriendly to said wire. I don't have far to go (30+/- ft.) from an existing circuit. Existing is indoor, as will be speaker of extension. Outside is very noisy. I can't find anything commercially that will do or that won't be an expensive total system tapping into the existing one at the source, quite a distance away I'm thinking that I can tap into the speaker wire of the existing, match the signal to the input of a cheap wireless intercom and amplify from a recieving unit to a horn (or whatever) in the target building. The hitch(s): Though I understand enough electricity/electronics to build the circuits that I want, I know nothing of Audio (tone deaf) and can't find ANYTHING on PA systems to build my working knowledge base. If this is enough information for someone to go on, then any help would be much appreciated.

Reply to
fatnlazy
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a few questions are needed.

make and model of existing PA amp? is it a 70 volt system? 100 volt system? or 8 or 4 ohm?

do you have line of sight from the proposed transmitter to receiver?

how much power in watts are you looking for? or how large an area?

do you need vocal or music quality?

is this for a church? (to get an idea of the budget)

tapping the speaker line is possible, however you might find that the system is objectionably noisy. this would be achieved by using a product similar to a DOD stagehand

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would provide and attenuated and isolated signal to the wireless transmitter. its much better to utilize a "line" output rather then a speaker level output is at all possible.

if you are thinking of using home type products please reconsider. in general these products dont hold up well in envirnments where pro equipment is needed.

heres are some places to look for wireless products

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Reply to
TimPerry

Thank You Tim: This is, or was, to be my attempt to save time on a directed project of dubious value, while there are many things needing done. I should have found you a little earlier, as it seems I'll be running conduit now. You may not be interested in this now, but I included it just in case, in appreciation.

To answer your questions with some brevity: I shouldn't have said "cheap" though cost was an issue and the locations of the erstwhile transmitter and receiver are clean, climate controlled, and protected. The area between, the opposite. There is "supposedly" some literature on the PA system, though...???? and during my shift the equipment isn't accessible. Though I may go in today just to satisfy my curiosity. It's accessed by the company's phone system and the wiring was installed apparently in several stages with no concern about where wire might have previously been run. Couldn't map it with a whole crew. Also, till now when a new speaker was wanted, and there is a wire pair close, it's cut and new wire tapped in. You said; "70 or 100 volts". I assume (correctly?) that there is a DC voltage to power the horns and a signal impressed on that. I came to this notion because with all the cobbled patches, splices, and taps it still works. You also mentioned 4 or 8 ohms. Not that type of system? You were trying to determine what is is? Thanks again. les

Reply to
fatnlazy

Les, apparently you have a paging amplifier interfaces with a phone system that runs in one big zone throughout a building.

the usual method for this is referred as a 70 volt system (sometimes 25 volt or 100 volt). it works quit a bit like the high voltage power grid because the power is distributed as a high voltage and low current. each load (speaker)therefore is required to have a transformer. usually these are multi-tapped primary and secondary. the primary is set for the amount of power you want to output (usually several taps up to 5 watts). the secondary matches the speaker impedance (usually taps are 4,8,and 16 ohms) it is important not to overload the system. you should know how many speakers are on each amplifier zone and what power each is set for. add up all the powers to determine if additional speakers can be added without risk of loading down the system and perhaps causing amplifier failure. placing a 8 or 4 ohm speaker directly across this type of line will inhibit the proper operation of the entire zone.

a longer and better explanation can be found here

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pictures
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(valcom is a popular source for contractors parts)

there are other newer and arguably better systems where each speaker has its own amplifier attached. this requires a DC voltage source to operate and shielded signal wires to prevent hum and noise pickup.

i would recommend you consult with a local sound instillation company in this matter.

Reply to
TimPerry

I just bought a wireless "outdoor" speaker system. The transmitter end plugs into the earphone or phono jack of a radio/amp/tv/whatever. The remote end can run off of D cells or a supplied wall wart. It sounds good and has a lot of volume - it might be perfect for you. I bought it at Home Depot - regularly $100 - on clearance for $25.

The "outdoor" part is a lie on the part of the manufacturer. It says, in small print, "not for use in damp locations". But if your remote location is not damp, it should work for you. You would have to figure out how to feed the signal to it. That might be as simple as feeding from the existing speakers through say a 4.7 uf electrolytic to the input of the transmitter. Get down to Home Depot and see if they still have them at the $25.00 price. If not, you can have mine for what I paid, plus shipping. I was going to put the thing in the garden until I read the fine print.

Reply to
ehsjr

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