# Benefits and Draw Backs of running @ 1ohm



## jonjay206 (Jan 22, 2009)

Curious to know the benefits and the draw backs of running @ 1ohm on a stock charging system.

When I upgrade my system I would like to check out amps like sundown but it seems like you don't get the most of the amps unless your running it at 1 ohm.

And if I was able to run 1 ohm off of stock charging how would I figure out the max watts I should be able to get away with?


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## DARKJUGGERNAUT (Apr 14, 2004)

depends on power the load has nothing to do w it.if ur runnin 750w amp at 1 ohm..and a 2k amp at 2 ohm.the 2k amp will draw more power.its watt u power the load doesnt matter..do at the minium a big three and a dry cell any will do to start..


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## OUTHOPU (Feb 24, 2006)

I can tell you that the stock alternator will not support 2000wrms even with the big 3 and extra batteries. The 93 Fleetwood I did using a sundown 2000d at 1 ohm would shut the car off at idle when the system was maxed out. I'll be installing a DC power unit in the spring. The same car did support 700wrms before though with no upgrades, not saying the amp was performing its best though.


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## L.Daco1 (Jun 16, 2010)

> _Originally posted by jonjay206_@Feb 8 2011, 04:13 PM~19820280
> *Curious to know the benefits and the draw backs of running @ 1ohm on a stock charging system.
> 
> When I upgrade my system I would like to check out amps like sundown but it seems like you don't get the most of the amps unless your running it at 1 ohm.
> ...


Well current(in amps) = power(in watts)/voltage. So if you want to get 2000 watts from an electrical system that is running at say 14.4 volts then your system will draw right around 138 amps. Now this doesn't take into account a couple different factors which could make current demand quite a bit higher (or even lower for that matter), but it will give you a ballpark estimate to go off. 

The big 3 and a good HO alt will be a definite must for this kind of build.


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## DARKJUGGERNAUT (Apr 14, 2004)

> _Originally posted by OUTHOPU_@Feb 8 2011, 08:51 PM~19821971
> *I can tell you that the stock alternator will not support 2000wrms even with the big 3 and extra batteries. The 93 Fleetwood I did using a sundown 2000d at 1 ohm would shut the car off at idle when the system was maxed out. I'll be installing a DC power unit in the spring. The same car did support 700wrms before though with no upgrades, not saying the amp was performing its best though.
> *


something is wrong there even at actual performance u will rarely see 2k constantly w all the music notes and box rise and so forth.i run 1500 rms clamped in my car on a 100 amp alt and 2 wets and it plays fine..


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## jonjay206 (Jan 22, 2009)

So there is no benefit? whats the purpose of amps having 1 ohm 2 ohm and 4 ohm loads then for subwoofer applications only..


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## OUTHOPU (Feb 24, 2006)

> _Originally posted by ROCKSOLID84_@Feb 9 2011, 12:33 AM~19823781
> *something is wrong there even at actual performance u will rarely see 2k constantly w all the music notes and box rise and so forth.i run 1500 rms clamped in my car on a 100 amp alt and 2 wets and it plays fine..
> *


There is nothing wrong aside from the fact that the stock alternator has nowhere near the output needed. I was playing 15-20-25hz loops with the system turned up and it completely shut the car down. All wiring has been upgraded. 2 runs of 1/0 positive and the alternator is grounded from it's case to the chassis which is where the amps and batteries are grounded. All grounds were sanded clean and free of rust or corrosion. It's an infinite baffle set up so I have no idea if "box rise" has much effect or not but I've seen the amp test out at over 2500wrms clamped so my 2000wrms is already a conservative number.


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## playboi13 (Nov 4, 2010)

benefit... higher watt output from amp

drawback... lose a little sound quality


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## Jeff Rohrer (Jul 9, 2010)

> _Originally posted by jonjay206_@Feb 9 2011, 03:19 PM~19827624
> *So there is no benefit?  whats the purpose of amps having 1 ohm 2 ohm and 4 ohm loads then for subwoofer applications only..
> *


It's not about benefit, it's about configuration. If your amp is designed to put it's rms power out at 1ohm then you can achieve it by all kinds of sub configurations. most not all class d amps can be safely run at 1ohm (note: I said not all) It just depends on what amp you go with.


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## jonjay206 (Jan 22, 2009)

> _Originally posted by Jeff Rohrer_@Feb 9 2011, 04:16 PM~19829460
> *It's not about benefit, it's about configuration. If your amp is designed to put it's rms power out at 1ohm then you can achieve it by all kinds of sub configurations. most not all class d amps can be safely run at 1ohm (note: I said not all) It just depends on what amp you go with.
> *



So there isn't going to be any difference if I was to choose.

amp A: 1500 wrms @ 2ohms
or
amp B: 1500 wrms @ 1ohm


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## socalconcepts (May 7, 2007)

> _Originally posted by jonjay206_@Feb 9 2011, 12:19 PM~19827624
> *So there is no benefit?  whats the purpose of amps having 1 ohm 2 ohm and 4 ohm loads then for subwoofer applications only..
> *


THE OHM LOAD ITS KINDA A MATHMATIC GAME SAY AMP PUTS OUT 500 WATTS AT 4 OHMS AND AT 2 OHMS PUT OUT SAY 800 WATTS (SAME AMP) YOU CAN SEE AN INCREASE IN WATTS RIGHT WELL NOW YOU TAKE THE SUBS TO MAKE THAT OHM LOAD WHICH COULD BE 1, 2, 3, 10 SUBS BACK IN THE DAYS YOU WOULD SEE SOME GUYS RUNNING 10 SUBS AT A 1 OHM LOAD AMPS WAS RATED 25 X 2 = 50 WATTS BUT AT A 1 OHM LOAD WAS PUSHING 400 OR 500 WATTS 

DISATVANTAGE IS THE AMP WORKS HARDER AND MAY GET HOT AND SHUT DOWN AND I HAVE EVEN SEEN THEM BURN UP THIS HAS BEEN MY EXPERANCE AND 2 CENTS HOPE THIS HELPS


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## Jeff Rohrer (Jul 9, 2010)

> _Originally posted by jonjay206_@Feb 10 2011, 02:34 PM~19836323
> *So there isn't going to be any difference if I was to choose.
> 
> amp A:  1500 wrms @ 2ohms
> ...


No, if the amp is designed to use a 1ohm resistance safely, then that is as low as you want to go with resistance. There are people who run there's lower then recommended but they run the risk of damaging the amp. This is where a good quality of amp comes into play. Longevity, actual rms values achieved, and less distortion. The worse the components used in an amp, the more those things are thrown out the window so to speak.
Again you can't think of ohm loads themselves as beneficiary unless the amp is designed to run them.


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## jonjay206 (Jan 22, 2009)

> _Originally posted by Jeff Rohrer_@Feb 10 2011, 12:57 PM~19836867
> *No, if the amp is designed to use a 1ohm resistance safely, then that is as low as you want to go with resistance. There are people who run there's lower then recommended but they run the risk of damaging the amp. This is where a good quality of amp comes into play. Longevity, actual rms values achieved, and less distortion. The worse the components used in an amp, the more those things are thrown out the window so to speak.
> Again you can't think of ohm loads themselves as beneficiary unless the amp is designed to run them.
> *



Got it!!!

Part 2?

So for my DTS says my alt is 220 amps how many watts can I safely run off of it?


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## Jeff Rohrer (Jul 9, 2010)

> _Originally posted by jonjay206_@Feb 10 2011, 04:34 PM~19837062
> *Got it!!!
> 
> Part 2?
> ...


Are you sure 220? where does it say that? and if it really is that's most likely at 2000 rpm's or more not idle. There will be varied answers to your question either way. If your going to buy a Class D amp (which I recommend) you will be better off as for efficiency at least on the subs. most cars pull 60 to 1000watt amp depending on whats running i.e blower motor ac/heat, lights. I never have told anyone to run more then 800-100 watt amp on a stock electrical. Of course I have 2000rms and 1200rms watt amps running on a civic alternator both amps are class A/B and I have never had a problem. There not putting out nearly as much as they could if I had proper electrical. So people do it, but end up with light dimming, dead alternator, battery and so on. The best plan is figure out what kind of bang you want, like everyday street or db drag hair trick bass and go from there.


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## Jeff Rohrer (Jul 9, 2010)

Go to a couple of car shows and see if some people will let you sit in the car, find one who's bass you really like and ask them what amps there running and how much power. Then come here and let us know what kind of amps and power your thinking about running. That'll be a little easier to tell you then.


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## DARKJUGGERNAUT (Apr 14, 2004)

> _Originally posted by OUTHOPU_@Feb 9 2011, 03:39 PM~19828742
> *There is nothing wrong aside from the fact that the stock alternator has nowhere near the output needed. I was playing 15-20-25hz loops with the system turned up and it completely shut the car down.  All wiring has been upgraded. 2 runs of 1/0 positive and the alternator is grounded from it's case to the chassis which is where the amps and batteries are grounded. All grounds were sanded clean and free of rust or corrosion. It's an infinite baffle set up so I have no idea if "box rise" has much effect or not but I've seen the amp test out at over 2500wrms clamped so my 2000wrms is already a conservative number.
> *


 from ur post i can see y the car shut down was ur amp hot???...how are ur grounds connected to frame..??


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## Jeff Rohrer (Jul 9, 2010)

> _Originally posted by ROCKSOLID84_@Feb 11 2011, 01:54 AM~19841767
> *from ur post i can see y the car shut down was ur amp hot???...how are ur grounds connected to frame..??
> *


Obviously you can't, he said it was an infinite baffle setup. Apparently you have no clue what that means


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## JOE(CAPRICE)68 (Jul 5, 2008)

> _Originally posted by jonjay206_@Feb 10 2011, 11:34 AM~19836323
> *So there isn't going to be any difference if I was to choose.
> 
> amp A:  1500 wrms @ 2ohms
> ...


no


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## jonjay206 (Jan 22, 2009)

> _Originally posted by Jeff Rohrer_@Feb 10 2011, 02:05 PM~19837289
> *Are you sure 220? where does it say that? and if it really is that's most likely at 2000 rpm's or more not idle. There will be varied answers to your question either way. If your going to buy a Class D amp (which I recommend) you will be better off as for efficiency at least on the subs. most cars pull 60 to 1000watt amp depending on whats running i.e blower motor ac/heat, lights. I never have told anyone to run more then 800-100 watt amp on a stock electrical. Of course I have 2000rms and 1200rms watt amps running on a civic alternator both amps are class A/B and I have never had a problem. There not putting out nearly as much as they could if I had proper electrical. So people do it, but end up with light dimming, dead alternator, battery and so on. The best plan is figure out what kind of bang you want, like everyday street or db drag hair trick bass and go from there.
> *



Right now I have 2 12L5's off a zx1000.1 and and my components off of a zx350.4 on the stock charging system. No issue's at all. the volt reader is 14.4, but after a few minutes in the car of driving it drops down to 13.4 or so.

I got the 220amp from searching acdelco site for stock replacement. So I'm assuming that is exactly whats in the car.

I'm lookin at a Sundown SAZ1500 and 2 12's FI BL's

Reason I ask about stock electrical is because I don't know how I could do the big 3 (over my knowledge base).. Bat is under the back seat and jumper box under hood, just don't know how all the wires would run.


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## Jeff Rohrer (Jul 9, 2010)

> _Originally posted by jonjay206_@Feb 11 2011, 01:45 PM~19844502
> *Right now I have 2 12L5's off a zx1000.1 and and my components off of a zx350.4 on the stock charging system.  No issue's at all.  the volt reader is 14.4, but after a few minutes in the car of driving it drops down to 13.4 or so.
> 
> I got the 220amp from searching acdelco site for stock replacement.  So I'm assuming that is exactly whats in the car.
> ...


Before spending any money, I would put the new stuff in and then run dmm on your battery and see what its doing while playing something low at 75% volume. you may not need to do anything.


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