Standard stereo wiring
- Thread starter bogan bob
- Start date
Outlanded
Leaving Skid Marks
Hey Guys,
anyone know what the power that goes to the standard decks is like? Ive got an Alpine Multimedia Centre to go in (Screen, Brainbox&Amp, DVD Stacker, CD Stacker & Tv Tuner..... Think i might run a new power cable from the firewall for the power (always on)? Or are they pretty good stock?
Cheers,
Brent
anyone know what the power that goes to the standard decks is like? Ive got an Alpine Multimedia Centre to go in (Screen, Brainbox&Amp, DVD Stacker, CD Stacker & Tv Tuner..... Think i might run a new power cable from the firewall for the power (always on)? Or are they pretty good stock?
Cheers,
Brent
I really don't think there is any issues with the stock wiring Brent. Running a new 12v feed will only give you more junk to deal with, let alone an new penetration through the fire wall is a bitch to do, Unless its all going to be mounted in the boot.
In vehicle systems are fairly robust and can handle a fair bit when it comes to electrical issues, I would be more worried about securing all that gear so it doesn't rattle around!
In vehicle systems are fairly robust and can handle a fair bit when it comes to electrical issues, I would be more worried about securing all that gear so it doesn't rattle around!
SiliconAngel
1 AYC Bar
Brent what kind of amp are you talking about? If its a 50W built-in jobbie, then using the standard constant will be fine. But if its a REAL amp, then you'll need hi current power to it.
People often wonder why car audio uses such massive (4, 2 and even 0 gauge) cabling. The reason is because cars (generally) run off 12V, which causes the current draw (amps) to be very high for applications requiring any reasonably large amount of power. When working out what size cabling you need, its important to understand the relationship between Voltage (V), current (Amps, I), resistence (ohms (Ω), r) and power (Watts, P).
Voltage times Amps gives you Watts:
P=VI
So if you have 1000W RMS amp, at full load you'll be drawing 84amps down that cable! That's where resistence (ohms, r) comes in - if your cable has too much resistence, not only will you be unable to pull down enough power (causing your speakers, most likely your sub, to lose volume and sound pretty terrible), you'll be doing your level best to melt the cable while you're at it! (think extremely dangerous fire hazard...)
Current (in Amps ,I) equals Voltage divided by resistence (in ohms)
So I=V/r, or to get resistence, r=V/I
In the previous example, you'd need a cable with a resistence of 0.1428Ω to handle 12V at 84Amps. But to make life easier, here's a table that can simplify your cable selection:
__________________Length of run (in feet)__________________
Current......0-4....4-7...7-10..10-13..13-16..16-19..19-22..22-28
0-20A.........14.....12.....12.....10......10.......8 ........8.........8
20-35A.......12.....10......8.......8.......6........6 ........6.........4
35-50A.......10......8.......8.......6.......6........4 ........4.........4
50-65A.......8.......8.......6.......4.......4........4 ........4.........2
65-85A.......6.......6.......4.......4.......2........2 ........2.........0
85-105A......6.......6.......4.......2.......2........2 .......2.........0
105-125A....4.......4.......4.......2.......2........0 ........0.........0
125-150A....2.......2.......2.......2.......0........0 ........0........00
So continuing our example, for a car audio application we'd be talking a cable run of 13 to 16 feet to get to the rear of the vehicle typically, so for that we'd need at least 2 gauge (American Wire Gauge or AWG) cable for something capable of handling 1000W draw. Personally I'd err on the side of caution and just run 0 gauge, but be aware that such cable is very thick and takes up a LOT of room...
Eventually cars will move to 42 volt, making all this massive cable completely obsolete overkill... But until then, be prepared to weigh your ride down with LOTS of copper!
People often wonder why car audio uses such massive (4, 2 and even 0 gauge) cabling. The reason is because cars (generally) run off 12V, which causes the current draw (amps) to be very high for applications requiring any reasonably large amount of power. When working out what size cabling you need, its important to understand the relationship between Voltage (V), current (Amps, I), resistence (ohms (Ω), r) and power (Watts, P).
Voltage times Amps gives you Watts:
P=VI
So if you have 1000W RMS amp, at full load you'll be drawing 84amps down that cable! That's where resistence (ohms, r) comes in - if your cable has too much resistence, not only will you be unable to pull down enough power (causing your speakers, most likely your sub, to lose volume and sound pretty terrible), you'll be doing your level best to melt the cable while you're at it! (think extremely dangerous fire hazard...)
Current (in Amps ,I) equals Voltage divided by resistence (in ohms)
So I=V/r, or to get resistence, r=V/I
In the previous example, you'd need a cable with a resistence of 0.1428Ω to handle 12V at 84Amps. But to make life easier, here's a table that can simplify your cable selection:
__________________Length of run (in feet)__________________
Current......0-4....4-7...7-10..10-13..13-16..16-19..19-22..22-28
0-20A.........14.....12.....12.....10......10.......8 ........8.........8
20-35A.......12.....10......8.......8.......6........6 ........6.........4
35-50A.......10......8.......8.......6.......6........4 ........4.........4
50-65A.......8.......8.......6.......4.......4........4 ........4.........2
65-85A.......6.......6.......4.......4.......2........2 ........2.........0
85-105A......6.......6.......4.......2.......2........2 .......2.........0
105-125A....4.......4.......4.......2.......2........0 ........0.........0
125-150A....2.......2.......2.......2.......0........0 ........0........00
So continuing our example, for a car audio application we'd be talking a cable run of 13 to 16 feet to get to the rear of the vehicle typically, so for that we'd need at least 2 gauge (American Wire Gauge or AWG) cable for something capable of handling 1000W draw. Personally I'd err on the side of caution and just run 0 gauge, but be aware that such cable is very thick and takes up a LOT of room...
Eventually cars will move to 42 volt, making all this massive cable completely obsolete overkill... But until then, be prepared to weigh your ride down with LOTS of copper!
Outlanded
Leaving Skid Marks
the brainbox for the alpine unith as a 4X50w amp which i know is ok with stock wiring, but the 2 stackers, tv tuner, screen, all draw power from the same source and i found in the other car i had them in, I got a drop on the main wire on full load and the screen wasnt as clear as it should be.... but i coulded be stuffed running a wire through the firewall of my focus.. it had a double firewall setup= pain in the bum....\
What do you think?
What do you think?
SiliconAngel
1 AYC Bar
Personally I'd run it, but then I'm used to stripping a car apart to install stereos...
What I DO try to do when I'm running a power line, though, is make sure I run one big enough so that I'll never need to run another - so run 0 or 00 gauge through the firewall and then use a connector box to split whatever other cables I need off it, one to power the deck, two more to power amps etc. You'll only need about four foot of cable to get from your battery positive through the firewall anyway, so four feet of 0, 2 or 4 gauge cable won't be that expensive... its just making sure you can find a grommet big enough to take the cable that's the problem!
Oh a tip for running cable through firewalls - I usually just use a straightened coat hanger (with the curly bit cut off one end). I wrap the cable through the twist at the other end and then attach it with electrical tape, then stick the coat hanger wire through the grommet. Go around to the other side of the firewall and just pull it through. Trying to force fat cables through small holes can be EXTREMELY difficult, especially when you'd otherwise need to pull the dash out to get access to some places.
What I DO try to do when I'm running a power line, though, is make sure I run one big enough so that I'll never need to run another - so run 0 or 00 gauge through the firewall and then use a connector box to split whatever other cables I need off it, one to power the deck, two more to power amps etc. You'll only need about four foot of cable to get from your battery positive through the firewall anyway, so four feet of 0, 2 or 4 gauge cable won't be that expensive... its just making sure you can find a grommet big enough to take the cable that's the problem!
Oh a tip for running cable through firewalls - I usually just use a straightened coat hanger (with the curly bit cut off one end). I wrap the cable through the twist at the other end and then attach it with electrical tape, then stick the coat hanger wire through the grommet. Go around to the other side of the firewall and just pull it through. Trying to force fat cables through small holes can be EXTREMELY difficult, especially when you'd otherwise need to pull the dash out to get access to some places.
Outlanded
Leaving Skid Marks
Yeah, I have some 2 or 4 gauge kicking round from a previous car, so ill use that. You know a good location to get that power cable through the firewall? Putting all my gear in will be the first task for the legnum.... just waiting to get it... hehe
SiliconAngel
1 AYC Bar
Both Steve and Carsten have some useful info (including pics) for how to get power cable through the firewall in this thread 
Ground wire anyone?
G
Guest
Unregistered
chassis ground,
dont use the factory one, its shit!
dont use the factory one, its shit!
SiliconAngel
1 AYC Bar
Yes you should always ground straight to the chassis, making sure to use the same wire gauge for earth as you had for power in.
G
Guest
Unregistered
possibly power, some jap cars, moreso ones with in-window antenna's need power to boost them, thus alot of people complaining about poor radio signal in jap cars.
Outlanded
Leaving Skid Marks
Hey Sydo,
that adaptor you have, does that just change the factory loom to straight wires so it can be wired into any deck adaptor?
My car has a tap deck/radio in it, will it be suitable for that?
Cheers
Brent
that adaptor you have, does that just change the factory loom to straight wires so it can be wired into any deck adaptor?
My car has a tap deck/radio in it, will it be suitable for that?
Cheers
Brent
Yes, that's it. You still have to solder some wires, but you can do that in the comfort of the toilet (if you like) rather than hunched down inside your centre consol.
Solder this adaptor to your new head-unit, and it will then plug straight into the factory mitsubishi wiring loom.
np - I have installed a 'cheap' kenwood unit. My reasoning behind choosing a kenwood was so I could still utilise the 10disc changer in the rear.. Unfortunately this logic seems to have backfired and, although the plug is correct and all wiring finished, the changer is not working.
- Thread starter
- #38
Finally connected my deck up today, good to have some beats to cruise to
The one thing we worked out was that the white/blue wire with an unknown function is quite possibly an earth wire? it seemed to work in that function but we still earthed to the chassis just in case.
The one thing we worked out was that the white/blue wire with an unknown function is quite possibly an earth wire? it seemed to work in that function
but we still earthed to the chassis just in case.
SiliconAngel
1 AYC Bar
Andy that looks like the cable to the secondary antenna. Kieran's posted some more details including links here.So what's this then?
Sure, the larger one is the antenna, but what's the smaller one on the right?
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