Power wire size

[vonivo]

Ok from looking at this site i need 0 gauge power wire and 10 gauge speaker wire to maintain proper levels as in less than .5 voltage loss.

I have 2 10in alpine type r subs and i am powering them with a JBL bp1200.1 running at 1 ohm and i have approx. 18 feet of power wire going to the amp ( i cant shorten it ) of 4 gauge oxygen free copper and approx 1.5 4 gauge grounding wire. the site also says i should be using 10 gauge speaker wire from the amp to the speakers and does the thickness of the rca cable from the line level converter matter? and what size fuse should i be using or using if i change gauges?

the amp http://www.jbl.com/car/product...uct=Y

owners manual in adobe http://www.jbl.com/car/product...uct=Y

the subs http://www.alpine-usa.com/US-e...tab=F

the fuse http://cgi.ebay.com/ws/eBayISA...20272

and the box (i know its a little small in the cubic foot size) )http://cgi.ebay.com/ebaymotors...item=

whats your thoughts? am i fine with the 4 gauge wire or should i be dropping it to 2 or 0? the new power wire isn't that expensive but it just sux tearing out the new 4 gauge if i have to switch.

any imput is appreciated thank you

P.S. what do you think about getting a capacitor also? and what size?


Modified by vonivo at 6:19 AM 3/13/2009

[AppleBonker]

What site are you looking at? Check out amp guts and they show max current draw for that amp at 114A, which is below the max listed here (though I use that site as a reference only). You'll be ok with 4 AWG for now, but if you upgrade anything later, you may require more. Also, your voltage shouldn't drop much if your alt can keep up (which it probably can't - it would be able to if the amp was the ONLY thing drawing power, but it obviously isn't) and you've upgraded the big three.

As far as speaker cables go, you'd be fine with 12 AWG (it's a bit easier to find than 10). You're not really pushing enough power to require much more than that.

Thickness of the RCA cables doesn't matter much (realistically at all) because the signal is at such a low voltage and current.

For fuses, you want to fuse for the wire's rating (not the equipment). The amp has its own fuses. You should fuse something like this:

0 AWG - 300 amp2 AWG - 200 amp4 AWG - 150 amp8 AWG - 75 amp

(anything smaller than this is a terrible idea to run for mobile A/V)

Finally, don't get a cap. Pretty much worthless. All it will do is increase draw on your system and kill your battery and alternator a bit quicker. I would recommend an upgraded battery, but that's about it. Before a cap I would always take an extra battery (but for your current setup this would be total overkill).

[kuhan]

Interesting that you don't recommend capacitors. A few people told me that I should get at least 1F cap for my total 1000W RMS system. So upgrade the battery would be enough?

[AppleBonker]

Yeah, capacitors are pretty much worthless. They're ok for show, but don't do much from a power/electrical standpoint. My last car was running three Alpine amps (1.1000, 4.150 and 2.150 - all PDX line) and I had a 20 farad cap. My headlights still dimmed fairly significantly when the stereo was cranked.

Now, I'm running about 3,000 watts (though I've got an extra battery and a better alternator) and there is absolutely no dimming (I wouldn't expect the Xenons to dim, but the other lights in the car remain constant). I would probably save the money from a cap and invest in better stereo components or an upgraded battery under hood. I personally don't see any benefit to running a cap.