car audio - power cable selection

[jstiles]

I have always known the myth of super-sized speaker cables, but wonder if there is a difference in the power cables for a car audio amp. I was at an electronics store and the salesman was recommending a 4 gauge power cable because I was running it 20 ft to a 500watt amp. Before I plunk down $80 on a power line I wanted to be sure I was not being fed a myth. Hell, if you need 4ga to go 20ft how the hell am I getting power to my house over those dinky little wires the utilities company uses??

Is there really a legit need for this beefy cable or will a 10 Ga be sufficient to get power from my mustang battery to the trunk where the amp and subwoofer will be installed?

Isn't the fuse the more important aspect of this line? I have noticed that most kits I find are higher wattage rated, wouldn't this be a bad thing for me (in other words the fuse on that 1000watt kit won't protect my poor little 500watt amp from a surge of 700watt juice)?

Thanks in advance for your help!

 

[Grador]

Power in your house is 120 volt, power in your car is 12 volt. For each Watt you're drawing 10 times the amperage across the cable in the car. 4 gauge is a good idea but I'd shop around a little.

The inline fuse isn't to protect your amp from issues, that's what the amps internal fuse is for. The inline fuse is to protect your cars power system from a short.

 

[vecc76]

I can only give you my thoughts on a larger wire for a car than home. I would have to say it has to do with the direct current that is used by a car as opposed to alternating current in a home. Direct current is primarily a lower voltage (12v car battery)and also flows one direction as where alternating current (120/240 in a home) flows in a cycle, that said, direct current carries more of a steady flow of power, but only over short distances. As far as a 4 gauge wire from your battery to your amp? I'd say yes. if you can put a amperage meter on your car battery crank it over and have another person read the amps it draws when started, you'll be surprised its quite a bit. So 4 gauge can handle somewhere in the 60/70 amp range, not to say a smaller gauge will not do the job you could risk damage to the wire and your amp. I'm sure you've seen car systems hitting so hard that headlights dim. All that power from your amp flows back and forth through that feed wire. Now your fuse is very important, only get the size fuse that your amp specifies, any larger or smaller is not good, to small it could blow all the time, to large and it may not blow at all, shorting everything that wire feeds. Again just some insight

 

[hizzaah]

Lots of good info on this site:
Basic Car Audio Electronics

I just put a 4 channel amp in my girlfriend's Jeep. It has an internal fuse of 30A so my online fuse is 30A and my power/ground wires are 8 gauge. I plan on adding a sub woofer and another amp that uses 2x 30amp internal fuses. When I do that I will upgrade the power/ground to 2 gauge for the main one, then use a distribution block and use 4 gauge to both of the amps. The main in line fuse will be 90A and the two at the block will be 30A and 60A..

I would shop around. Look on amazon, you can buy nice wire by the foot for cheaper than the kit will cost you at best buy or wherever you went. Knukonceptz is what I'll I'll be buying when I do mine.

We won't get into the OFC vs CCA debate here

 

[mtrycrafts]

We won't get into the OFC vs CCA debate here

Good thing. We would not want anyone to start crying or blood being drawn.

 

[hizzaah]

Good thing. We would not want anyone to start crying or blood being drawn.

Yeah, i found myself in the middle of this debate a while back and I would've thought I had smacked a hornets nest

 

[mtrycrafts]

...and I would've thought I had smacked a hornets nest

Well, that is what it would have been, round two.