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This topic comprises 2 pages: 1 2
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Author
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Topic: Terminating heavy-gauge speaker runs
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John Hawkinson
Film God
Posts: 2273
From: Cambridge, MA, USA
Registered: Feb 2002
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posted 08-18-2006 06:59 PM
Hi, all.
We're getting ready to clean up some heavy-gauge speaker runs that were run in a hurry a while back, and I'm curious what people use to terminate such runs.
At the moment, we have 8AWG coming off of dual banana connectors into amps, and running straight into the speaker. This has proven a bad idea, because 8 AWG is really hard to work with. There is a lot of strain and weight on the amp-side connectors. And, of course, on the speaker end, getting 8AWG under screw terminals is painful (this was no surprise).
We'll switch out the speaker end to a Neutrik Speakon NL8. Ideally we'd like to terminate the wire run in a wall plate near the speaker -- how should we connectorize that? One thought is to use a Speakon there as well, but they're a tad pricey and (more importantly) don't accomodate 8AWG. We could butt-splice the 8AWG down to 12AWG and run the 12AWG into an NL8 receptacle, and then use a short 12AWG jumper NL8FC cable between the speaker and receptacle.
Historically, we've used NEMA twistlock connectors for those receptacles (who knows why? They don't seem to be cheaper than Speakons, and they top out at 5 conductors anyhow, which doesn't work for triamped speakers). An NL8 mated pair is ~$15, versus about ~$50 for a mated NEMA L23-20 pair.
On the amp side, we have a mix of QSC amps (EX and PLX series),
both with 5-way binding posts and NL4 Speakons. It seems clear we want to use the 5-way posts with dual banana plugs, since that lets us swap amps and channels much more easily than the Speakon would (because we use some amps in bridged mono configurations and some in 2-channel mode, and switching between requires rewiring the Speakon, whereas the we can just rotate a dual banana plug 90 degrees).
A couple of previous topics touch-on these issues, but not too deeply:
Questions:Anyhow, at the speaker end, how should we get from 8AWG into an NL8 male (or other) panelmount? A few of inches of 12AWG seems the right answer, but should we buttsplice, wirenut (seems dodgy), barrier strip (excessive?), or something else?
Similarly, on the amp side, it seems clear we need something less weighty feeding into the dual banana, what's a good choice for stepping it down?
Thanks for your thoughts.
--jhawk
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Monte L Fullmer
Film God
Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004
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posted 08-20-2006 04:15 AM
quote:
not the twisting of speaker cables thing again!
..which brings the intesting question on this - I have some old 6 plexes that had two mono houses that were converted to stereo, and the left/right and surrounds were run with 14g twisted pair - and the twisted pair was done on site by taking two rolls of 14g put these rolls on a broom handle, with a person holding the broomhandle to keep the two rolls taught, with the person handling the drill, playing tug-of-war with the holder by operating the drill and to make the twisted pair runs.
What I couldn't get over, with all of this twisting, tuggin and fishing all of this through rather small conduit, why not use the simple 14/2 braided wire by itself since I've seen other installs using this much simpler version instead of all of this twisting?
I know that of the twist is to keep the flux lines from each wire at a minimum, but with the other, it seems that there is no difference no harm in the sound reproduction .....
...have to ask .... - thx_monte
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John Hawkinson
Film God
Posts: 2273
From: Cambridge, MA, USA
Registered: Feb 2002
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posted 08-20-2006 11:43 PM
Oh, Steve. The problem with the MIT thing is that we spend a little too much time overanalyzing ![[Smile]](smile.gif) . Nobody's really comfortable with the wire nut approach, and butt-splicing #8 without solder is of questionable reliability, as is putting on ring terminals, so we look for a fancy terminal block solution with clamping terminals...
You say, "Don't forget on the 8-pole speakons that you double up on the LF section for a 3-way speaker system..."
err...I just went and checked the speaker in question with a multimeter (screw terminals, not the speakon, because it was easier). 4- and 4+ are not paralleled with anything else inside the speaker. (This is a JBL PD5322/64 with a 339335-001 "input plate, NL8" and a 352565-001 "PD, NL8, input cup overlay").
Unless the screw terminals 4+/4- are not in paralled to the Speakon, they are unused, not doubled up for LF.
As for the cue markers--oh jesus. I AM SUCH A SLACKER.
"I'll do it Real Soon Now(tm)."
Maybe you guys could take the twisting crap back to the twisting crap thread?
--jhawk
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Steve Guttag
We forgot the crackers Gromit!!!
Posts: 12814
From: Annapolis, MD
Registered: Dec 1999
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posted 08-22-2006 09:45 AM
quote: John Hawkinson
err...I just went and checked the speaker in question with a multimeter (screw terminals, not the speakon, because it was easier). 4- and 4+ are not paralleled with anything else inside the speaker. (This is a JBL PD5322/64 with a 339335-001 "input plate, NL8" and a 352565-001 "PD, NL8, input cup overlay").
Unless the screw terminals 4+/4- are not in paralled to the Speakon, they are unused, not doubled up for LF.
Trying to make me look bad, eh? Yes you are correct that JBL did not double up on the terminals. They are considered "loop through" terminals.
But, bright guy...you can place jumpers on the screw terminals to double up the +/-1 with the +/-4 terminals so that the smaller gauge snake cable wires are not an issue for the LF section. Don't forget to match + for + and - for - ![[Wink]](wink.gif)
Steve
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