DavidA

Ok guys...I pretty much know the answer...but I need a devils advocate.

I have one Rockford Fosgate P2002 200watt amp running my back Subwoofer and it is wonderful. Shakes the rearview mirror so bad I almost can't see out of it. Very nice and clean.

I just bought another of the same model that I am going to run my front and rear door separates with at 2 ohms. Should give me about 50 watts RMS per channel running in parallel. I am not worry about being able to fade front to back doors.

My question...which I know the answer...but again...

RF recommends a 10-gauge power wire to each amp. I have one 8-gauge running back there and I hate running another, but I will if I have to. I am going to try it and use the one 8-gauge to power it. Think I will blow the fuse because of the draw? Or will I get poor performance because of the amps are starving?

Thanks in advance for the advice.

89macrunner

no you won't remember fuses really only blow if thers a massive surge or a short circuit..

run a 0 guage wire to the back and just get a distro block

94x4

FWIW, I chose to run 4ga. instead of the "0" due to it's size as I wanted to keep everything out of sight as much as possible, even invisible to passengers, and found that the "O" limited the areas in which I could run it covertly, which limited my setups' flexibility in turn..

I've run the 4ga. all the way to the "caps", and then jumped from them to the amps with some 8ga. that I chose because of the size of wire that the amps' terminals would readily accomodate without my having to cut the wire down to fit, which I did'nt want to do to avoid any possible signal degradation..., but then again, I'm running somewhat more than a 200 watt setup.

My .02 on wire gauge usage.

NisAznMonk

I wouldn't think the 2nd amp would draw much power since they are running components. The total current draw may be close at high volumes, but I don't think you have much to worry about.

If it were me, I'd run a 4 gauge wire at minimum. I would only do that if you were considering running a 2nd run of 8 awg anyways.

Bumpin' Yota

I think you will be fine with 8ga. Dont put in more than a 60amp AGU fuse though....

rider_1313

you may be just fine with the 8awg, as far as 60 amp fuse for it, no. no. no. it should be fine with 25amp-30amps max. which still means that you should be fine, just check the draw the amps have, for those two "small" amps, it should be ok. but if they do pull more then 30amps, and you have to replace it, then you can run 4awg to a block, then 8awg to the amps.

DavidA

Thanks for your advice!

You are going to love this...I got the first amp new from BestBuy, an Open box, for $119, about $60 off. I got the second off of Ebay used, but it came in the factory box and it looks new, for $50 plus shipping. Such a deal!

rider_1313

nice gotta love e-bay. I just bought a [cough] jeep [cough] off e-bay.

Bumpin' Yota

notice I said nothing bigger than a 60 amp. AGU fuses go all the way to 80amp. Ideally if you draw more than 40 youll want 4ga, and its limit is about 80amps

rider_1313

ok.....not sure what your getting at, but yes i notice you said nothing bigger then 60amp. and I said you are incorrect, you don't want anything bigger then 30amp. if i were to put a 40 amp on that line(which is nothing bigger then 60amp) it would let the amp pull more current then the wire can handle, and he could end up with one very hot wire.

Bumpin' Yota

Care to bet some money on that? They most certainly do make AGU fuses larger than 60amp. Shall I go take a picture of the 80amp AGU's we sell?

And you can pull 80 amps through 8ga without any voltage loss or rise in temperature. Dont believe me, bet me 1000 bux so I put a down payment on a GSXR...

...the amount of current a wire will support is directly proportional to the wire's length. Most runs are less than 20' and about 40% less than 15'. Given such short runs there is NOTHING wrong with 40amps passing through the wire.

Secondarily, his amp is only 200watts. Assuming that its efficiency is 50% the most it could EVER PULL is 40amps. Running well into clipping territory and running the amp ragged edge. The 8ga is NOT the weakest link at that point, but rather the amp. You and I both know that a fuses ONLY role is to protect your car in the event of a short circuit..

Incidentally you should check the online wire manufacturers specs Stinger's 8ga is rated for 75amps up to a 20' run!



And I air on the side of caution - this is why I have 4 runs of 1/0 from the front to the back battery, use 1/0 to each amp from the rear battery, and use 8ga as speaker wire...

rider_1313

i'm not really into the whole online agruments thing, it's like the special olympics, win or loose, your still just a bunch of retards.

but anyway, when did i ever say that they did not make a fuse bigger then 60awg? i'll answer that for you, never.

yes there is 8awg wire out there that is rated for higher amps in a Chassis Wiring use. but for Power Transmission, MOST standard 8awg wire is rate for no more then 30amps max. can you tell him to just do it? yes. does he run the risk of over heating the insulation on the wire and it burning up when he runs 60amps through it? yes as i said, his amps will probably not pull that much, but he should not put any bigger then a 30amp fuse on the line.

Please, I only studied this topic for two years straight, and i only have two degrees, one in live sound production, and one in audio engineering. so go easy on me with all this talk of "bet me a 1000 bucks" i'm not sure if i can handle it.

Bumpin' Yota

roflmao - quit taking this so serious man, I forgot to toss in the smileys, its just a little debate...

I too have a degree, though not related to the autosound industry, bs in microbiology and cell science, so Im not an attawad either, and I have successfully competed at World Finals and held an idbl world record... If you want me to say you are more qualified, then sure you are more qualified than me academically and professionally.

However the maximum ac current flow for 8ga, or any wire, is inversely proportional to the length. And I'm sure you know that, most others won't. That also is what my bet pertained to. 2 inches of 8ga wont drop much voltage...hehehe...it's kind of like 'boiling' an egg by lowering the atmospheric pressure around it - its not cooked or even warm but the water is boiling!

I did some further checking around....kicker rates their wire at 35amps for a 20' run, stinger at 60 amps.

But I seccede, put a 30amp AGU only in, otherwise upgrade to 4ga.

FilthyRich

I think that is ignorant and rude.

rider_1313

sorry, it's just a joke, and uses the shock factor to make a point. but your right it is rude. sorry.

Cebby

Not to throw gas on the fire, but Street Wires disagrees with ya Bumpin'

http://www.streetwires.com/products/wireGauge.cfm

The max you would need is 4 ga.. 2 ga or 1/0 is way overkill.

Check out http://www.knukonceptz.com/ for some inexpensive wiring...

94x4

What this all boils down to DavidA, is that you said that you needed a "devil's advocate" and, judging by the posts in contention here, you got it and then some!

All in all, with the size amps that you're using and the wattage that they'll be drawing, you'll be perfectly o'kay with the 8ga. wire powering them.

You can even tie into the first 8ga. wire that you've already run inside of the car somewhere with a "T" block or "distribution block" and run your second course of 8ga. wire from it to your 2nd. amp to save having to run a whole other lead from the battery back into the car.

The only thing other than what has been mentioned here that I would advise is the use of a "cap", perhaps two .5 or 1/2 farad caps (one for each amp) to save your battery and suffering dimming lights.

Hope this helps and, man, did you step in it or what by asking that question?!?

Bumpin' Yota

No offense, but before you attempt to toss gas on a fire, particularly as a moderator, you should read things in MUCH more detail than you did here.

It does not disagree with me, because I NEVER recommended that he go to 1/0 nor 2ga! Look at my last post in regards to what I recommend.



Perhaps there was confusion because I USE 1/0 (in multiple runs) becasue I have four 2.2kW rms zapco 9.0s sitting in my truck.

Reread what i wrote and you shall see.



ps - and there is no such thing as overkill when it comes to car audio.

rider_1313

yeah, I wasn't really sure where you were going with that, but if you re-read it, me and bumpin came to an agreement kinda. so your gas only made the fire all wet and un-happy just messing with ya man. but I do think david has enough to go on, unless you want more, i'm sure we can go on for a little longer, but then you will be spending 20k on a sound system of our choice. best you take the info now and run with it.

Cebby

Let's agree that it's a misunderstanding on both parts - like the crack about "particularly as a moderator" which in your context I take offense to - regardless of the "No offense" preface..

I posted a link from a recognized industry leader in car audio wiring that recommends 4 ga. Your early posts (several of them) stated 8 ga was fine. I had missed where you said "30amp max in 8ga or then upgrade to 4ga." - my apologies. According to Streetwires, 4 ga is good for 500 watts up to 25 feet. (8 ga good for 200 watts) I'm sure for them to put a calculator on their site like that, it is on the conservative side - probably a good thing.

You did not recommend 1/0 or 2 ga for this application - I agree (nor did I specifically say you did) - another contributor at the beginning of the thread (post #2) said to use 0 ga. Just noting that if DavidA is buying open box specials that he probably doesn't want more money in his power wire than his amp. My contention is that 4 ga is probably a good (and safe) compromise.

I'm well aware that you run big power and multiple batteries, etc. Overkill is the name of the game in what you are doing (I mean that in a good way) Quite frankly I was a little shocked to hear you recommending/defending the use of 8 ga. in the first place considering the source.