Internal Wirng - Car Battery Power Cable

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I'm at the stage where I need to buy some cable do the internal wiring of my enclosure.

Something on the Maplin website caught my eye:
Car Battery Power Cable
"High quality OFC 4AWG copper cable made from 1050 strands of 0.16mm diameter copper"

Based on hearing of people using Cat5 for speaker cable for example, I was wondering whether this 'Car Battery Power Cable' is feasible/advantageous over (often expensive) cable branded as 'speaker cable', considering it's a lot more copper for the money (£4.98 a meter).

Worth considering? Or is there a fundamental difference between speaker cable and other cables?
 
Vikash said:
"High quality OFC 4AWG copper cable made from 1050 strands of 0.16mm diameter copper" Worth considering?
What is your crossover inductor wound with? If it's anything less than wire of truly heroic proportions, then save your money for something that will actually make a difference.

Of course, if you simply *want* to have such nifty wire, go for it! :)
 
What is your crossover inductor wound with? If it's anything less than wire of truly heroic proportions
There is no crossover yet :). It will (eventually) be on the outside of the enclosure.

Does your reasoning not apply to the wire gauge used in the voice coil too? I see a fat wire leading up to a driver and then see a thin strand that carries the signal from the driver posts to and around the former and wonder if this makes a difference when talking about cables?
 

GM

Member
Joined 2003
No matter what marketing hype or folks who just like to endlessly debate say, wire is wire and it's all about L-C-R and how it interacts with the amp, with the biggie being resistance (voltage drop), so if your wire run needs to be 4ga to keep VD vanishingly low (no audible power compression), then battery/welding cable wire is the next best thing to solid core. Otherwise, from a performance POV, it's a waste of money.

If you do need wire this big, then I recommend you bi- or tri-wire with the appropriate size solid core wire (preferably silver plated) for the mids/HF.

GM
 
I've just made a cable using Cat5e. It looks pretty cool :)

I measured the resistance at 0.2-0.3 Ohms over the ~1.2 meter cable. Does this seem high?
 

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Hi Volenti,

Yeah, I thought so too. But after downloading the wire gauge calculator spreadsheet from TNT-Audio.com, the theoretical SPL loss is only 0.06db and damping factor = ~117. A helpful little spreadsheet.

I don't know what I'm looking for in the damping factor. A higher number the better I guess?

For comparisson, the 3m 10 AWG cable has SPL loss of 0.07 and DF = ~100. Not much different.

I'm guessing anything less than ~0.1db SPL loss is acceptable for a cable over its distance?

And another pic...I can't believe there's so much cat5e lying under my nose, and it never occured to me to try it...duh.
 

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A better idea is to use copper "buzzbar" , it's a bit expensive
though. You'll need to cut some slots in the rear of your
enclosures to pass the buzzbar's through. Around 6" x 1/2"
approx. These have the advantage of zero / immeasurable resistance over a long length & high current capability.

Regards
Andrew

TFPIC:D
 
Two comments :

1. Vikash, when you measured the resistance of your CAT5 cable did you remember to subtract out the resistance of the meters leads. Hook the positive to the negative lead and measure the meter's resistance (mine is 0.4 ohms) and subtract this value from the reading when measuring the CAT5 wire. I have made a similar set of speaker cables that are about 8 ft long and got a resistance less than 0.1 ohms (below what my DMM meter could measure) so I probably should have used my LCR meter.

2. To reinforce GM's point. If you look at the voice coil wire, it is probably tiny compared to all of the other wires in the signal path from the amp to the driver. The voice coil probably has 100 ft of wire or maybe even more (enough to produce an 8 ohm DC resitance, I'll let somebody else calculate the length). So ask yourself this question. At what point does an 8 ft speaker cable, and all of the crossover wiring, become as big a factor as this long length of very small voice coil wire. I consider this analogous to water flowing in a fire hose through a 10 ft long nozzle the diameter of a drinking straw. How important is the diameter of the fire hose?

In reality the speaker cable and the interconnects are important and can make a difference in the sound. My experience has been that as long as the DC resistance is kept very small, the differences in cables occur at the high frequencies where the wire/connectors can roll off the response. At these frequencies the cable can become inductive or capacitive and alter the sound of the system. But at some point you reach the level of diminishing return, I think car battery cable may be way out there on the curve.

Try the CAT5 wire as shown in the pictures, I was surprised at how much better it was compared to my more expensive cables (now shoved under the couch). Simple, cheap, easy to make, how much more could you ask for in a cable?
 
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