Running speaker wire a loooooong distance....

[kpippen]

Hello everyone,

I would like your opinions on the following question(s):

I need to power two JBL JXR125 at 150ft away from the power amp. Is it OK to use two or three twisted pair 12AWG speaker cables in parallel for this connection? Are parallel runs just as good as using a single 8 or 6AWG monster style zip cord? I would prefer to run parallel jacketed twisted pairs if this doesn't present some other kind of problem(s)?...

Three 150ft 12AWG twisted pairs in parallel...............to............One 6ft 14AWG
----------------------------------------------------O
----------------------------------------------------O----------------------------[JRX125]
----------------------------------------------------O

Thanks very much in advance!...

[kpippen]

Advise..opinion....anybody????

[Zilch]

12 Ga. stranded is 1.71 Ohms per 1000 Ft.

You're running 300 Ft. round trip, 0.513 Ohms for single, by my calcs.

Rule-of-thumb is <1/10 the load impedance....

[kpippen]

12 Ga. stranded is 1.71 Ohms per 1000 Ft.

You're running 300 Ft. round trip, 0.35 Ohms for single, by my calcs.

Are you saying that one twisted pair 12 Ga. will keep my insertion losses below .5 db?.. This is the goal?

[Zilch]

Note I fixed the calc.

What's your load impedance?

[kpippen]

Rule-of-thumb is <1/10 the load impedance....

Zilch,

My bad....I read right past this part.. So your saying it all depends on my load impedance 2, 4, or 8 ohms?

This is good information but,....the question stands... Does it make any difference in regards to parallel runs or a large single run?

[kpippen]

Note I fixed the calc.

What's your load impedance?

Zilch,

On one run the impedance will be 4 ohms constant, and on the other run the impedance will be 8 to 2 ohms depending on the amount of stage monitors used...

[Zilch]

Yes, it depends upon the load impedance.

If it's 8 ohms, the loss is ~0.5 dB.

@ 4 ohms, it's ~1 dB.

Doubling the wires cuts the resistance in half.

If you're driving 4 ohms, and you want to stay at 0.5 dB, you gotta run doubled wire feed....

[mikebake]

Put the amp right near the speakers and run 150 ft mic cords to the amp from the mixer/source. 150 ft speaker wire runs risk losing bass, punch, etc. In pro audio, the amps live near the speakers.

[kpippen]

Put the amp right near the speakers and run 150 ft mic cords to the amp from the mixer/source. 150 ft speaker wire runs risk losing bass, punch, etc. In pro audio, the amps live near the speakers.

Hi mikebake,

If I could I would,...but in this particular application I need to keep the amps in the sound booth along with the mixer...

[Zilch]

[Draggin' out the calculator again, then....]

Triple run cuts the resistance to 1/3,

Looks like you're at 0.7 dB loss running 2-ohm load with triple....

[kpippen]

If you're driving 4 ohms, and you want to stay at 0.5 dB, you gotta run doubled wire feed....

Zilch,

Other than cost...would it hurt to run a triple?

[kpippen]

Looks like you're at 0.7 dB loss running 2-ohm load with triple....

OK... does it hurt to run a quad?

[Zilch]

Nope, assuming your amp can handle 2-ohm load. Just make sure your connections are good. That means clean, tight, and protected.

I wouldn't worry one heck of a lot about stage monitors sounding perfect....

[kpippen]

This is good information but,....the question stands... Does it make any difference in regards to parallel runs or a large single run?

OK.... By the way the thread is moving I'm assuming the answer to my question above is NO?