Neat wiring tip

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David Robinson
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#16 Post by David Robinson »

Sydney wrote:Plain copper wire and Nickel Chrome plated connectors are find as long as they are cleaned once in a while. Skin oils are corrosive, as are atmospheric pollutants.

In Chemistry the electromotive series indicates the relative tendency to be oxidized, Aluminum is near the top of the easily oxidized elements - Gold Silver Platinum are near the bottom.
The periodic table, in it's elegance shows the elements like aluminum share placement in the Groups 1 and 2 ( with highly reactive metals like Sodium ) and the "more stable" elements are in groups in the center.
For a brief period aluminum was used in home residential wiring instead of copper. Because of it's rate of thermal expansion and contraction and it's ease of oxidation it created serious problems.
Aluminum wire in service entrances is coated with Anti-oxide paste at the terminals.
What I said, but with much more eloquence... :oops:

off to play with sharp objects...in traffic!
I'm not a musician, but I play one in a band.

DJHolmz
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#17 Post by DJHolmz »

Sydney wrote:Plain copper wire and Nickel Chrome plated connectors are find as long as they are cleaned once in a while. Skin oils are corrosive, as are atmospheric pollutants.

In Chemistry the electromotive series indicates the relative tendency to be oxidized, Aluminum is near the top of the easily oxidized elements - Gold Silver Platinum are near the bottom.
The periodic table, in it's elegance shows the elements like aluminum share placement in the Groups 1 and 2 ( with highly reactive metals like Sodium ) and the "more stable" elements are in groups in the center.
For a brief period aluminum was used in home residential wiring instead of copper. Because of it's rate of thermal expansion and contraction and it's ease of oxidation it created serious problems.
Aluminum wire in service entrances is coated with Anti-oxide paste at the terminals.
As an A&P mechanic we had dis-similar metal issues alot in airframes. The tailboom on the older model Huey is magnesium and the fuselage is aluminum so you have to put a layer of duct tape down between them to prevent dis-similar metal corrosion from occuring.

Ron K
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#18 Post by Ron K »

I agree with Bill as to twisting speaker wires in cabs. Some Manufacturers do this albeit not on purpose. The wire they buy is already twisted.

I use Horizon 13 Ga. Speaker cable inside the boxes.

http://cgi.ebay.com/Horizon-Speaker-Sna ... dZViewItem

You may be able to find it cheaper somewhere but this guy alway has it and the shipping is little. At a buck a foot for 4 conductor cable it's really nice stuff. He has nice deals on Speakons as well.

His e-bay store is:

http://stores.ebay.com/The-Republic-of- ... idZ2QQtZkm

As far as Gold Plated goes I never buy them. I use gage oil on all my connections:

http://www.grainger.com/Grainger/items/1TC00

It's even good in Faders to keep them moving freely and making good contact.Tuner cleaner/lube cant hold a candle to this stuff!
Ever since I replaced sex with food I cant even get into my own pants!

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DAVID_L_PERRY
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#19 Post by DAVID_L_PERRY »

Just re-visiting this after my Omni15 build being picked up as using twisted cable.....

Image
Bill Fitzmaurice wrote:
DAVID_L_PERRY wrote: Keep in mind that the length of runs we are talking about here for speaker builds are tiny, probably the longest run is about 12-24".....
at the levels and impedances speakers operate at noise rejection isn't a factor, while capacitance and inductance are, and those are made worse with twisted pairs....
Bill. What exactly is the effect of this raised capacitance / inductance. Does it have the effect of dropping/raising/changing the crossover freq ?

Would the short runs we are talking about likely alter more than 10% of the filter values (As the filter component values are listed with a 10% tolerance).....

Dave

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Bill Fitzmaurice
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#20 Post by Bill Fitzmaurice »

DAVID_L_PERRY wrote: Bill. What exactly is the effect of this raised capacitance / inductance.
The same as a series inductor and parallel cap: it's a low pass filter.
Would the short runs we are talking about likely alter more than 10% of the filter values (As the filter component values are listed with a 10% tolerance).....
It doesn't alter the filters per se but acts as an additional low pass section in series with the drivers. With a woofer likely no matter, but could be significant with mids and tweeters.

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DAVID_L_PERRY
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#21 Post by DAVID_L_PERRY »

Thanks Bill.

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