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Old 7th April 2010, 13:02   #121
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Quote:
Originally Posted by santosh.s View Post
No, I didn't mean it was done at gun point! I wanted to get things installed by any of the well known installers. Talked to 4-5 of them, but all of them ridiculed me when I told them to use Finolex/L&T for power cables. Then I offered to provide it myself, but then I came to know that none of them "work that way"! Did not have enough experience/patience/tools to DIY. You get the point, I suppose.
OFC is just something that sales orientated types get excited over. To us techos it is just a load of cows excreta, we just go home to our wives to get our orgasms. The finer wire is an advantage only for flexibility, nice to have but more expensive.
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Old 29th May 2010, 16:35   #122
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I am building up a Carpc which has a 360W DC-DC PSU. Need confirmation for making sure my power wiring calculations are safe.

I already have a 1.5sq mm wire (the one used for domestic wiring inside the walls). Can I use three wires of this in parallel to connect my 360W PSU to the Distribution box, 10ft away.

My calculation is as below:
1.5sq mm = 16 AWG = 15 Amp current carrying capacity.
3 cores would share 360W into 120W per core, i.e. 10Amp per core.
3 cores = 15x3 = 45Amp capacity, so this should be safe.

1. Please confirm if my calculations and assumptions are correct. The usual consumption of carpc would be 150-180W, but would want to cover 360W capacity to be safe and have enough future upgrade potential.

2. Also I am planning to power the PSU from my already existing distribution box setup for my ICE (2 amps totaling to about 1200W RMS). There is a 0 gauge wire from Battery to Distribution box. I hope it will be fine to wire PSU from DB and there is no need to draw wire directly from Battery.
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Old 30th May 2010, 21:35   #123
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Yes it will be safe !!!!
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Old 30th May 2010, 22:08   #124
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Yes, it will be safe and cheaper as well.
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Old 31st May 2010, 22:09   #125
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Quote:
Originally Posted by kURETI View Post
A modern 12V amplifier is a current hungry beast. Resistance only makes it mad. Feed it with oversized power cables and you will be rewarded with sonic purity.
Quote:
Originally Posted by Sam Kapasi View Post
You are welcome. I would trust L&T's specifications over Boss specifications anyday.

Leaving aside the flexibility and quality of insulation, i find no difference in the POWER cabling of a good ISI brand of multi strand wire (Indian) versus any power kit made anywhere in the world. Provided the cross sectional area is the same.

I DO find a difference, both in the line level RCA cables and in the speaker cables.
Quote:
Originally Posted by Sam Kapasi View Post
Simple. Take the power rating of each amplifier. Say you have 2 amplifiers of 200W each. Total 400W
Now P=voltageXcurrent.

400 = 12 X ?
? = 400/12 = 33.33 A

Add a little to that for good measure and you can use a 50A fuse normally OR a 40A fuse if you want to be extra safe.

I hope that was simple.
Quote:
Originally Posted by low_bass_makker View Post
Sam Bhai one more simple method. Add the total sum of the fuses on the amps.

For eg if the one amp is having 25+25 amps fuses and the second amp is having 25 amp fuse then put a 75 amps fuse.
Quote:
Originally Posted by kURETI View Post
Speaker wire is also important in terms of size and strands for the same reasons but the jacket is not as important because it will not see the same chemicals as the power wire. When shopping for speaker wire, look for oxygen free copper (OFC) wiring. The size of your speaker wiring depends on the amount of power going to your speakers and the length of wire from the amplifier to the speakers. Most systems will need to use 16 gauge to 12 gauge wire.
Some posts in this thread I found very valuable.
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Old 1st June 2010, 12:37   #126
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I see most people are particular about OFC when speaker wires are concerned, as opposed to power cables. What is the reasoning? (orgasms apart)
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Old 1st June 2010, 16:46   #127
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Thats because the speaker load is in the range of 1,2,4 ohms in those setups. cheap speaker cable pull up the resistance due corrosion in the wire connections.

you can do this with power cables also.
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Old 1st June 2010, 17:51   #128
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Gigy, does having OFC wire help prevent corrosion even when copper is exposed?
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Old 1st June 2010, 18:49   #129
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if stripped clean it doesnt but with time the joint is left exposed to elements and then resistance builds up.
i am not a audiophile and have used different wires till date but the last one is ofc type but not a branded one.it still shines after a year and looks good.

Last edited by gigy : 1st June 2010 at 18:56.
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Old 1st June 2010, 19:17   #130
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No, OFC has nothing to do with corrosion / joint failure in screw connectors like in an XO or speaker terminal. OFC supposedly has better conductivity, but according to standards the difference is only 1%.

The failure occurs due to minute amounts of sulphuric, hydrochloric and such acids, or substances that leach metals like zinc, etc. affecting the (nickel, chrome or cadmium) plated brass pressure plate or screw in the connector first. Gradually, if left unattended, the ionic action in such environments tend to affect the copper too. The chemical residues increase the resistance at the joint. That is also the reason for using gold-plated connectors where failure is not an option.

The best cure / preventive is very simple - white petroleum jelly (vaseline) which provides a protective cover that inhibits ionic action from happening. Just as the battery guys recommend.
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Old 15th August 2011, 11:51   #131
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Default Re: So.... why do we need those thick wires??

The finer strands in wires make them a better bet . electricity travels on the edges of the conductor rather than on the inner path . The more no. of strands the better the wires are .

Caps do have a value addition .

For example if an amp needs 50 amps of current and the cable can provide 50 amps in a typical setup then why does one have to go in for a cable which can deliver higher amps ? For the "occasional extra" during music playback wouldn't a cap fill in the void ?
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Old 3rd June 2014, 11:24   #132
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Default Re: So.... why do we need those thick wires??

Folks, continuing this discussion on OFC, I could never understand Oxygen Free as the copper wiring is anyway 99.9% purity. I have till date not found anyway in which speaker cable is different from power cable.

The differences could be:
1. Thinner stranding in speaker wire less resistance - not done in power wires as it is expensive
2. The dielectric or the insulator is rated for lower voltage in speaker wires to reduce capacitance
3. Snake oil

I used to work in a professional Sound & Lighting rental firm (one of the best in India) and my guys used to swear by Finolex for power wires. I would not hesitate to pit it against any international brand for power wires, the only advantage could be that the imported wires will be more flexible, a great advantage in the field but not of much use during a one time install.
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Old 14th November 2016, 23:43   #133
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Default Re: So.... why do we need those thick wires??

How are Polycab cables compared to Finolex and Havells?
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Old 19th October 2017, 17:47   #134
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Default Re: So.... why do we need those thick wires??

Was laying fresh wires in the Safari Storme, to be used instead of the stock wires. While the stock wires are quite thin, one learning today was - not to use any of the cheap wiring kits. I have used 14 ga speaker wire that I got from Amazon, but fell short on the last feet ( from cross-over to Woofer). I tried to use the wire that came with one wiring kit, but found that these wires are actually thick on insulation but thin on conductor. I will now get some more 14 ga speaker wire locally and complete the wiring.
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Old 29th November 2017, 16:13   #135
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Default Re: So.... why do we need those thick wires??

Quote:
Originally Posted by condor View Post
While the stock wires are quite thin.
For the subwoofer, you would always take 3 sets of thin wire and plait them like Kimber Kable has done in the photo below. You will get 3x the area and hence 1/3rd the DCR.
Attached Thumbnails
So.... why do we need those thick wires??-kable4prspeakercable5ft.jpg  

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