how to wire 2 amps?

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Jay_gee
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Wed Mar 29, 2006 10:43 am

Hi Guys,

Im new to installing Amplifiers in a car, never done it before.

I want to wire up two amps in my Cab, I have a 2 channel JBL amp to run my sub and I need another amp to hook to the 4 speakers inside the car. Do i need to run two power cables from the battery, one to each amp? Or is there another more obvious way? Like hooking up amp1 to amp2 to receive power? :?

What sort of amp, power wise, would be good enough to hook onto the four speakers inside? Im running 90 watts RMS speakers inside...

I hope someone can help me :)

Jay
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chu346
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Wed Mar 29, 2006 7:28 pm

You need to put in the rear of the car near the amps a fuse block that will take a large wire and split it into two or more wires and then use some short runs to the amps.

A decent amp running 30-50wrms will do the job quite well. I recommend the genesis stereo 60's, as they usually go for £80-£120 on ebay. I'd recommend just amplifing the front speakers, and if you must have rears just run them from the head unit.
appletree
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Wed Mar 29, 2006 7:29 pm

i,am not shore if this is the "correct / best way" but this is how ive done mine. ive got one large power cable from the battery to my the amp(3000watt rms) that powers my subs (1500watt rms each) and then ran a power and remote start up lead from that amp to a a second 4 channel amp that runs the front components and the rear 6x9s and found a eath that way nearer the amp to keep it as short as possible to keep out interfirence.



as for what amp you need for the other speacker i normaly try and match the amps rms figure to the rms figure of the speeakers


if you've got 4 speaker each with 150watt peak and 100watt rms
i would use a 4channel amp thats rated at 4x100watts

the subs and amp are for sale, pm me for figures and price
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chu346
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Wed Mar 29, 2006 7:49 pm

appletree, what kind of amp is that? 3000wrms 8O

Also I wouldn't run power from one amp to another. What guage wire are you using?

The amp I recommended is well upto the job, and like I said you don't need to amp the rears.
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Jay_gee
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Thu Mar 30, 2006 10:50 am

chu346, why only run the front speakers and why not the rears as well from the amp?

Where do i get a fuse block from? is it safe?

thanks
appletree
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Sat Apr 01, 2006 3:02 pm

the amps a legacy red series LA3070D yep 3000watt rms at 1.3 ohm. winkeye

dont know what guage as i borrowd it from work but is about 12mm diameter. :D
the above set up is also for sale £450ovno
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chu346
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Sat Apr 01, 2006 7:23 pm

appletree wrote:the amps a legacy red series LA3070D yep 3000watt rms at 1.3 ohm. winkeye
These amps are rated as peak not rms. They are more like 1200wrms @ 1.3 ohms. Also they normally come with 3x 30 or 40 amp fuses.
appletree wrote:dont know what guage as i borrowd it from work but is about 12mm diameter. :D
the above set up is also for sale £450ovno
That wire is not good enough for that 3000wrms of power.

BTW how many subs do you have as 2 subs don't normally give 1.3ohms and 3 subs would mean that you need 4500wrms of power.
appletree
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Sat Apr 01, 2006 7:47 pm

in the instruction book there are 3 different power figuresdepending on how its wired. 4ohm 2ohm or 1.3ohm i thought that was a bit weird as you would think that it would have been 1ohm :mad:

either way next to the 1.3 ohm diagram it shows a power figure of 3000watt rms

iam running 2 legacy 15" subs off the one amp, when i bought this set up i was advised to choose this amp as it was designd to run the subs i had bought as they used to be sold as a package, the subs are 2400watt peak and i think 1500watt rms and then they are wired so that the + of each voice coil are together and so are the - , same on the other sub and then join the 2 +'s and -'s from each sub so you end up with just 2 wires going in to the amp?

how big do you think the wire need to be?? its what fork lift trucks use for the battery conections.
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chu346
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Sun Apr 02, 2006 11:17 am

I don't know what size in mm, but you need 0 gauge wire and I think your wire is simular to 4 gauge. This size wire is only good enough for 120 amps max (IIRC) if it's to be use from the battery in the front of the car to the rear, it wouldn't be as bad if your running it from the rear battery with a shorter cable.
Grantley
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Sun Apr 02, 2006 1:02 pm

Holy mother F*cker dude 3000 w RMS, do you really need that amount of power. I seriously doubt it, its the soundproofing and instalation that makes all the differance not Watts, if thats the amp your running I recomend a power cap thats equal to 1 farad per 1000 watts of amplification. Whatever you do good luck dude and dont go deaf !
appletree
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Sun Apr 02, 2006 10:51 pm

no i dont need that much power, when i odered all the stuff the shop in question messed me about because they didn't have the sub/amp i wanted in but took payment in the hope that they would get there new stock in the ASAP but they didn't so i rang up lots and lots and tryd to get me money which was when i spoke to the manger (who was never in before...ya ya ya) he said that it was the shops police to upgarde to the nxt one in the range that they had instock which was what i got.

its to loud to listen to at full power, it just gud when your next to a chav in his 1.4 SRI corsa with sum 6x9s blarin out thinkin hes the dogs, to whack it up on a super low swep and watch his window go up :lol:
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