Speaker CABLE size???

[CME-LFT]

Hi guys, i was thinking of putting the front two speakers in my sportivo to run off an amp.

I took the door trim off and the factory wiring looks small that goes to the speakers, so my thoughts where that i was going to run the speaker cable from the amp in the boot to behind the head unit and join the cable into the originals going to the speakers (not bringing the cable all the way to each door.)

My question is, what size cable should i buy seeing as the factory wiring is pretty slim already. Jaycar happen to be selling a 30m roll of (so called heavy duty) speaker cable which is 18AWG 24/0.20mm, they state that its suited for systems above 150watts. (to what its limit is, is unknown)

Im running 6.5/6 inch sony in the front 200wat peak, 75wat rms and the amp in the back is a 2 channel 300 wat rms amp i think. (obviously i wont put it over the top and end up blowing my speakers.lol)

Will this size cable suffice? or should i go bigger. My thoughts where also that it should be neater to join into behind the head unit seeing as the 18awg is not such a thick cable.

What size cable have most of you guys run for you front splits to the amp and any suggestions on install would be helpful

Thanks guys :)

P.s i tried searching already.

[CME-LFT]

Anyone?? Any ideas at all??

[supertownace]

generally speaking with amp to speaker wiring you aren't looking for what the cable will handle wattage-wise...more so what sort of signal loss will there be.

most mobile audio systems have around 20 to 30 volts running through their speaker cabling...the main difference is the wattage.

for most "rear amp/front speaker" setups i have used 2mm twin core cable....this provides plenty of capability to upgrade the system later on if you so desire. i generally use the 2mm twin cable for front/rear speakers and 6mm twin core for subs. subwoofers need the larger cable to cope with the "instant" power needed for that deep down thump that shakes front windscreens and the like....keeping this cable as short as possible will help too. this is why you see a lot of sub enclosures with the amp tacked onto the back.

when retro fitting a new system into a car with an exisiting system i generally only use the original head unit harness for things like main/switched power and also things like remote antenna and backlighting. for everything else i run separate/new cabling.

if you install your amp/s into the boot area of your car be sure to run ALL your power cabling down one side and ALL signal/speaker cabling down the other side. this isolates your signal cabling from any interferrence that may come from power cabling....and yes it DOES happen.

also....run a separate earth lead from the negative terminal of your battery to your amp/s...make sure your head unit/signal processing is also earthed to this cable. it prevents noise from "ground loops" entering the system and creating problems.

hope this helps

cheers

[supertownace]

one other thing.......

the earth cable from your battery to your audio system.......make it the same size as your positive cable......if not the next size BIGGER.. the reason for this is so that there is no restriction or "resistance" for any current returning to your battery.

cheers

[CME-LFT]

Hey thanks for that, but im still a lil confused.

From you explanation are you saying that if you were to install an amp rear/front splits that you would run speaker wire all the way to the doors instead of going to the head unit and using the factory harness wiring that runs to the doors already? (it must be a pain to do neatly)

Also, u say 2mm, how can i work that out, everything i look at is like 24/0.2mm,......or 2x79/0.2mm

Now i know that 24(no, of strands) 0.2 (thickness of each strand) but if i multiply them i get 4.8? it that nearly 5 mill? (my maths isnt the best atm.lol)

Also, you reckon you could use house cable? cause i got a ton of 2.5 mm2 twin lying around.lol

[supertownace]

Hey thanks for that, but im still a lil confused.

From you explanation are you saying that if you were to install an amp rear/front splits that you would run speaker wire all the way to the doors instead of going to the head unit and using the factory harness wiring that runs to the doors already? (it must be a pain to do neatly)

Also, u say 2mm, how can i work that out, everything i look at is like 24/0.2mm,......or 2x79/0.2mm

Now i know that 24(no, of strands) 0.2 (thickness of each strand) but if i multiply them i get 4.8? it that nearly 5 mill? (my maths isnt the best atm.lol)

Also, you reckon you could use house cable? cause i got a ton of 2.5 mm2 twin lying around.lol

the size reference i have given is the diameter of the conductor inside the cable. and no house cable isn't a good idea as it's too stiff and is intended for house use only.

from your original question you asked if the speaker wiring already fitted to the vehicle was suitable for what seems to be a high powered audio system. the answer i gave is "not really".

yes you will need to run new cabling to your new speakers from your rear mounted amp.....(how else does the signal get to them??) forget about using the original speaker cabling already there. no it's not that hard to install new cabling. i did it for 2.5 years and in all sorts of vehicles..all you need to remember is to use common sense and use cable ties to make it neat.

cheers