LONG Speaker Wire Questions...

[James Edward]

I need to supply long lengths of speaker cable for my block party. I'm talking 300 feet or so.
Forget audiophile sensibilities altogether; all I need to know is will it work and produce sound at these lengths without destroying the DJ's amplifier, and at loud enough volume(I know that is subjective). I will be using large JBL pro audio passive speakers with an efficiency of about 100 db. I don't know what amp the DJ will have, and I don't want mine used.
My no-low cost plan for the wire is to use electrical extension cords, and attach 1/4" jacks at each end. I'll test for continuity to ensure correct polarity. I'll need a number of them- will the connections further lower the signal strength? Such as: would four 16 ga. 75 ft be better than ten or twelve 14 ga. 25 ft pieces?
Any responses greatly appreciated. Thanks.

[Werd]

Too long, You are going to suffer what would sound like major thermal compression. Be pro and put the amps next to the speakers and run Xlr into the amps.

[DaveC]

I think the capacitance of a 300' long ic would be too high as well.

For speaker cable, check out a resistance calculator:

http://www.cirris.com/learning-center/calculators/133-wire-resistance-calculator-table

300' of 12g wire is about .5 ohms which isn't ideal but should work. It will reduce the damping factor of your amplifier and the reactive impedance could be an issue too.

You may want to ask this question on a forum that deals with pro sound and PA systems...

[James Edward]

200 feet? 150?
I am spending zero money on this. Nor will I bring out my good equipment to supplement the awful music that will be played through
it. There is no cleanser for that.
Thanks for the replies.

[Triode Pete]

200 feet? 150?
I am spending zero money on this. Nor will I bring out my good equipment to supplement the awful music that will be played through
it. There is no cleanser for that.
Thanks for the replies.

Mr. James,
Use the thickest (I suggest 10 AWG) & cheapest copper wire you can find, for up to ~ 200 ft... If you use 12AWG, up to 120 ft, without sonic degradation.

The JBL Pro Monitors appear to be very efficient, but more importantly, probably have an 8 ohm load, which is good. Lower impedances are worse, which is detrimental to the damping factor (controlling bass). You'll need thicker AWG then!

With longer runs of cable (> 200 ft.), you may lose some upper frequency extension, which may be a good thing, since PA / DJ systems have a tendency to be "bright" sounding.

The "rule of thumb" is not to have the resistance exceed 5% of the speaker's impedance. You can look up the resistance of any wire (with the corresponding length) as well as the average impedance of the JBL speakers.

Hope this helps,
Mr. Pete

[sleepyguy24]

Hi James

The past couple of events I saw the pro guys/DJs I've seen are using Hafler amps. Not the 9505 or the XL600 though.

One of the official Hafler warranty repair centers is here on LI. They also may help with your speaker wire question even if the DJs aren't using Hafler gear.

Davidson Electronics
117 Newtown Rd., Plainview, NY 11803

Phone:(516) 753-0197

Hours: Open today · 10:00 am – 6:00 pm

http://www.davidsonelectronics.com/

I hope this helps.