I had a friend (who shall remain nameless) who did quite well in the "high-end" cable and interconnect business. While there are certainly differences to be heard between materials, I have found that I can make my own cables (and interconnects, for that matter) for a fraction of the cost of the brand-name stuff, and it's fun to "DIY" a cable. As a matter of fact, http://www.diyaudio.com/ and http://www.tnt-audio.com/ are really interesting sites. I intend to build a pair of these cables in time: http://www.tnt-audio.com/clinica/triple_t_e.html

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1992 300D 2.5T
1980 Euro 300D (sadly, sold)
1998 Jetta TDI, 132K "Rudy"
1974 Triumph TR6
1999 Saab 9-5 wagon (wife's)

The program speakers in the auditorium here at work are quad amped with a total of about +2000W a side. The amps specify a minimum of 16ga wire and we're using 12ga for a max of about 200'. You'll need to know the load capacity (impedence) of the amplifier and the rating in Ohms of your speakers to wire them correctly and properly load the amp.

14 ga for your application is probably OK. 70V will allow smaller gauge wire but create more expense with the transformers needed. Post the amp brand, model, specs if possible along with the speakers.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

I will check that out this evening. I don't think the amp is anything special.

Yamaha's website says that the speakers are rated at 6 ohms. I have no idea how that matches up with the amp.

Wiring speakers in parallel yields lower impedence. In your case, 6+6 will equal a 3 Ohm load. Wiring them in series will add the load giving 12 Ohms. Your amp will probably be rated at some wattage at 8 Ohms and some greater wattage at 4 Ohm per channel if it's stereo. Some amps can also be bridged which changes things again... That's why I was looking for specs on the amp too.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

If your amp has four outputs you should be fine. But if it doesn't, running the speakers in series is much easier on the amp.

First connect the plus terminal from one speaker to the minus terminal of another speaker. Connect the other two terminals like you would a normal speaker, ie., plus terminal on the speaker to the plus terminal on the amp, minus to minus. Do the same with the other two speakers.

Now you've effectively made a stereo system with two twelve ohm speakers. Much easier to drive.

__________________
You don't need a weatherman to know which way the wind blows - Robert A. Zimmerman

In long runs like this it is best to avoid low impedances. By connecting all the speakers in series (at the amp) you would have a 24 ohm load. Resistive loses in the wire would be nil at that impedance.
To make up for lost current (P=I*E) bridge the power amp. By bridging the amp the peak voltage (E) doubles. Doubling the voltage=quad power.

Buy one 500 foot spool of 14ga single conductor wire. Run this from the amp location to the first spkr(#1) positive, from there connect #1 negative and run it to #2's positive. #2's neg to #3s pos. #3's neg to #4's pos. #4's negative will return to the amp completing the circuit. Use a 9 volt battery to "click" these two wires confirming the circuit is complete. When you touch the wires to the battery you should here a click. Same when disconnecting them. It may not be real loud so listen to each spkr carefully while someone is connecting the battery.

Place the amp in bridge mode and connect one wires to the amps positive termanals. Nothing is connected to the negative termanals of the bridged amp.

Thiis will be the cheapest solution and the amp will be very happy with this load.

I've done many large iinstalls and engineer sound for touring bands so, feel free to PM if you need help with this.

Remember, P=I^2*R. 14ga wire can easily handle 15a even over a fairly long length. At 24 ohms, that gives a power of 5400 watts.

In this case the current carrying capacity of the wire is unimportant. It's the resistance that is of concern. I believe 14ga to be somewhere around 0.5 ohms per hundred feet. Not much in a 24ohm circuit.

I'd be more worried about the acoustics of the arena. Reverberant fields wreak havoc on the intelligibility.

Kuan and Whiskey Dan have my head spinning now. I don't get electricity.

I looked at my amp. It is a Sony STR-DE197 stereo receiver. On the back it says it has 190 watts. It has 4 sets of speaker terminals - an "A" set of left and right, and a "B" set of left and right (total of 8 wire connectors on the back of the amp). Below the speaker connections it says "Impedence - Use 8-16 [ohms]", except it used the symbol for "ohm" instead of the word.

I have never heard of bridging an amp, so I did some googling on it. How do I know whether this amp is bridgeable?

What does that mean?

OK, Your Sony is not bridgable. Some pro PA amps combine the A&B channels (left and right) to make one big power amp.

Since the amp will only handle a minimum impedance of 8 ohms you will have to wire two speakers in series and hook them to the left channel "A" . Then the two remaining and connect them to the right channel "A".

The Sony you have is rated at 100 watts per channel into 8 ohms. I doubt that will be anywhere near enough power for this application.

How big is the arena? How loud is the ambient noise?

Most audio power amps have two channels labeled either A and B or left and right.
Audio signals (the voltage on the spkr wires) consist a of complex alternating current. One wire goes positive relative to the other wire, then it goes negative. (AC)
This is what makes the spkr cone move in and out. More voltage, they move further making more sound. Faster movement means a higher tone, higher AC frequency.
Some pro amps and car stereo amps allow you to "bridge' those two cahnnels to make one big amp instead of two smaller ones.
In bridged mode one channel (either the left or right) is fed a signal 180 degrees out of phase such that its output goes negative when the other (non inverted) channel goes positive during the alternating cycle. This creates twice the voltage if you connect to the two positive terminals. Twice the voltage equals four times as much power (provided the amp can supply the current).
Any amp can be bridged with a simple inverting circuit. However, very few amps can accually provide reliable power this way.

In your case its a moot point. Lets hope for the best.

1ea. RadioShack 2054, PA Amp. (~$90.00). Use the 70V output and:
4ea. RadioShack 70VTR Transformers (~$60.00ttl) Run 14/2 lamp cord from Home Depot to: 4ea. RadioShack 1445 Outdoor Powerhorns (~$140.00ttl) I’m thinking the wire was somewhere around $160.00. Get 2ea. RadioShack Dynamic Microphones (~$30.00ttl) So your son (and his cousin) can yell at your daughter “You’re gone!!” when she knocks over a barrel running mid/high teens at age10. (a little brag there…sorry)
You'll also need about $30.00 in zip-ties.

You’ll need a $6.00 1/8”-to- RCA adapter cable so the kids can just bring out their iPod or portable CD player and plug them in and leave the nice stereo gear with the $50.00 per foot monster cable in the house where it should be.

The amp has 100Hz, 1kHz and 8kHz tone controls to add some lows and cut back the highs you’ll have with the horns.

No – It’s not stereo. But it’s a riding arena for God’s sake. Not a concert hall.

But that’s just me.
You guys with the high-powered calculators and more hi-tech audio system brains than I’ll ever have can probably come up with something really cool to put into a filthy dirty high humidity bug infested occasionally rodent visited (indoor, or not) environment, I’m sure.

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1980 300D - Veggie Burner !

You will need bigger than 10 gauge wire for 250' if your speakers are 8 ohm impedence. See table in the article:

http://www.roger-russell.com/wire/wire.htm

One cheap alternative is Romex. Great stuff if you are wiring a house for sound. A tad hard to bend but not impossible.

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MB-less

You can bridge it. On your amplifier you have two left channel outputs, output one and output two, each with one positive and negative terminal.

On the left side, get a wire and connect the plus from output one to the minus from output two.

+
-
\ <--- wire
/
+
-

__________________
You don't need a weatherman to know which way the wind blows - Robert A. Zimmerman