Quick AMP wire Q?

Post Fri Oct 06, 2006 8:29 pm

Just mounting my amp and sub to MDF ready to fit over the weekend.
What i need to know is;

Should i have the inline fuse holder nearest to the amp or the battery,does it matter?
Is it ok to earth the amp direct to the battery or bodywork the best option?

Post Fri Oct 06, 2006 9:41 pm

near battery m8,then your wires wont set on fire when shorted....body ok to use as earth too.....how you doin?ok

Post Fri Oct 06, 2006 9:43 pm

You can earth to the chassis, just make sure that the connection is to clean metal. Bad earths are one of the main things that cause noise in a system

Earth to the battery is fine too, I've done that in mine. Just mean you have to run more cable. As gcorky said the fuse on the positive should be as close to the battery as possible as its main job is to protect against shorts along the wire

Post Sat Oct 07, 2006 12:58 am

fuse close to the batt as poss, normally within 8 inches, and if you can, fuse near the amp as well.

you are not only protecting from shorts, but also high current, too much current draw on a wire thats not thick enough can burn through insulation and cause fire, thats what the fuse ratings are for ;)

though mind you, i dont think your running much power are you? so might be fine with just the one near the battery for shorts.

grounding can be done at the battery, as long as the battery is suffciently grounded. so for example, im assuming your using 8 awg wiring for the ground, and 8 awg power, id upgrade the battery to ground wire to 4 or 0 awg, (id go for 0 awg cos it has more beinifts, and possible future expansions) then youll be fine to connect the earth wire through the batt

hope that helps bud

Post Sat Oct 07, 2006 1:08 am

Thanks fellas!

Dont know what awg the wiring is,but it is pretty phat!
Inline fuse is 50 amp!
I know the wiring kit when i got it was rated at 600watt,my amp is 400 watt.

Post Sat Oct 07, 2006 1:17 am

about a 1cm diamter? will be 4awg, that will be good enough

also keep the grounding point as short as possible!

mind you 4 awg normally has a higher power rating, normally about 1200watts RMS which leads me to think yours is 8 awg,, but your saying its phat? 8 awg is what i use for my sub speak cable!

but then again i am running 3000 watts RMS per sub, and thus need 300 amp fuse!

also whats the RMS of your amp at the impedance you are running at?
should say on/behind or on the box of the amp. and match it to the impedence of your sub.

but tbh for that wattage, 8 awg will be fine anyway so no worries if its not 4 awg. just make sure you clear as much metal as possible so the earths a good clean contact!

Post Sat Oct 07, 2006 1:22 am

Amp is MAC audio MX2000,400watt,2 ohm?
Sub is JBL GT3 12 inch(Unboxed mounted on 18mm MDF to ski hatch

Battery is now in boot,thats why i said about earthing direct to it!

Post Sat Oct 07, 2006 1:30 am

as long as the cable is as short as possible then i dont see why not, if you get any problems, then you know what to trace it back to, though i would prob upgrade it for the hell of it.

also bear in mind that sub i dont think , i might be wrong, is designed to work in free air, so watch you dont push it to its limits as its limits will be easier reached without any pressure.

summary:
keep earth as short as possible and you should be alright,
is your sub a single 4 or dual 4? ( does it have 2 terminals on the sub or just 1? (could be a dual 2 or single 2 but i doubt it.) if its got one terminal, then you are only running it at 4 ohm whcih im guessing will be about 200 watts from that amp.

whcih is even more reason to say youll be fine lol

Post Sat Oct 07, 2006 1:43 am

it has 2 sets of pre outs?

I thought it was the wrong type sub,but to be honest,dont thump the sound out,only have it loud when the kids arent in there!

Post Sat Oct 07, 2006 1:47 am

the sub has two sets of terminals yeah?

then its probably dual 4, and if your hookinh up + to + and - to - then its showing a 2 ohm load and your maximising your amps useage. whihc is cool

should be fine anyway matey

nite nite!

Post Sat Oct 07, 2006 10:51 am

hi the sub is dual 2 it is prewired out of the box as 4 ohm just use the two end terminals(one on either end), you have 4 terminals in a row, right??

also that sub is not really recomended free air, they really run best in a sealed box. best thing as go down to your local stereo shop and buy one they are only about Ãƒ”šÃ‚£30......well thats how much i sell them for....

the amp just bridge it to get the best out of it, and knock the ski hatch through to get more bass through, which i think you prob have done anyway

Kam

Post Sat Oct 07, 2006 10:05 pm

any amp installation really needs fusing at each end of the power cable - the fuse at the battery end protects your car in the event of a high current draw situation (e.g. short) and the other protects your amp(s). fit fuses as close to each end of your power wire as possible.

as for rating - a fairly good guide is to add up the fuse ratings fitted to all your amps, deduct 10amps and fit this fuse at the battery end. fitting a 5 or 10 amp smaller fuse than each amp's fuse(s) at the amp end is usually sufficient there and this offers very good protection.

for the sake of a few quid it's well worth getting this right.

paul