# Is 1 ohm bad for an amp?



## BlueAc (May 19, 2007)

I recently picked up a RF Power 1000 and it's b/s states that the amp will do 703 at 2 ohms / 938 at 1 ohm on the sub channel. A few audio shops that I have spoken to said that 1 ohm is very hard on a amp and the car itself. Is this true? The only reason I'm asking is b/c I picked up 2 DVC 2 ohms subs to get a 2 ohm load, but if this is false I'm gonna get some DVC 4 ohm subs and get max power out of my amp. Any help is appreciated!!!


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## WrenchGuy (Jun 10, 2007)

It just pulls the juice from the electrical but 1 ohm stable is stable hook it up and SLAP!


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## BlueAc (May 19, 2007)

WrenchGuy said:


> *It just pulls the juice from the electrical *but 1 ohm stable is stable hook it up and SLAP!


So is that where a capacitor would come into play or would I need more than that?


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## Oliver (Jun 25, 2007)

With lower resistance you send more current,[ need larger gauge wire ], go to BCAE if your curious.

Current in amperes is equivalent to GPM in water.
Voltage = pressure in psi in water.
resistance to flow would equal the size of the pipe in water.


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## MaxPowers (Oct 25, 2007)

if an amp is designed to be 1 ohm stable, then its ok. running an amp not designed to do it can/will end up bad. there are some amps that can do .5 ohm, and a very few that can do .25.


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## BlueAc (May 19, 2007)

Hic said:


> With lower resistance you send more current,[ need larger gauge wire ], go to BCAE if your curious.
> 
> Current in amperes is equivalent to GPM in water.
> Voltage = pressure in psi in water.
> resistance to flow would equal the size of the pipe in water.


I picked up a 0/1 gauge RF amp kit when I got the amp.... (it extended my warranty!!! ). So I should be ok dropping down to 1 ohm?


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## WrenchGuy (Jun 10, 2007)

Just do what the amp tells you to. And upgrade the big 3 (1/0ga) and make sure your battery is in good shape and you should be fine.


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## BlueAc (May 19, 2007)

WrenchGuy said:


> Just do what the amp tells you to. And upgrade the big 3 (1/0ga) and make sure your battery is in good shape and you should be fine.


Its a brand new battery... the car is an 07. But I have a yellow top laying around from my last car, I may just throw that in the trunk for the audio system. Thx for the help, I'm gonna look into the Big 3 as well.


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## azngotskills (Feb 24, 2006)

I wouldnt run it at 1ohm personally....the higher the impedence, the easier on the amp it is....have you noticed how efficiency rates drop the lower you go? Its going into heat instead of power


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## Hillbilly SQ (Jan 26, 2007)

azngotskills said:


> I wouldnt run it at 1ohm personally....the higher the impedence, the easier on the amp it is....have you noticed how efficiency rates drop the lower you go? Its going into heat instead of power


x2. and distortion is also something to think about. as a rule of thumb i refuse to take any amp below 2 ohms. why put extra strain on an amp when you don't have to? i HIGHLY doubt you'll notice a difference in output going from 700-900 watts. i bet you'd notice a muddier tone though.


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## WrenchGuy (Jun 10, 2007)

He just said he wanted max power hell!...lol


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## Oliver (Jun 25, 2007)

Want to know more... http://www.bcae1.com/


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## azngotskills (Feb 24, 2006)

WrenchGuy said:


> He just said he wanted max power hell!...lol


Well for max power....run it at 1ohm then since they state the amp is capable to do so, Just know its going to pull more current and get hot, but its fine


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## Oliver (Jun 25, 2007)

TEAM SHIMANO/FALCON said:


> x2. and distortion is also something to think about. as a rule of thumb i refuse to take any amp below 2 ohms. why put extra strain on an amp when you don't have to? i HIGHLY doubt you'll notice a difference in output going from 700-900 watts. i bet you'd notice a muddier tone though.


True Dat, for a 3 dB increase you need to double the amps power.

For 10 dB increase add a zero on the end of the amps power rating, ie.. 100 watts-1,000 watts


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## Oliver (Jun 25, 2007)

You could add some cooling fans


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## BlueAc (May 19, 2007)

TEAM SHIMANO/FALCON said:


> x2. and distortion is also something to think about. as a rule of thumb i refuse to take any amp below 2 ohms. why put extra strain on an amp when you don't have to? i HIGHLY doubt you'll notice a difference in output going from 700-900 watts. i bet you'd notice a muddier tone though.


That's why I ask these questions... I've never taken any amp below 2 ohms either, but I figured since there was a power gain then why not. But you guys all made valid points. I' just gonna keep my IDQ's and run the amp at 2 ohms.

Thx guys...


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## Exalted512 (Jul 23, 2006)

Ive ran my T40001 at .5 ohm in competitions before 
-Cody


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## Oliver (Jun 25, 2007)

Exalted512 said:


> Ive ran my T40001 at .5 ohm in competitions before
> -Cody


Nice amplifier

T40001bd 
4000 Watt Class-bd Mono Amplifier 
Get ready to wake the neighbors with Rockford Fosgate's flagship Power amplifier - the T40001bd. This magnificent amplifier is rated at a whopping 4000 watts RMS and will capably drive multiple subwoofers. Just make sure your subwoofers can take it! A high-output alternator and large capacitor are recommended. 

MSRP $2,799.99 


Sweet!!
Power T40001bd - 4000 watt 1-channel amplifer
2000x1 @ 4 ohms, 3000x1 @ 2 ohms, 4000x1 @ 1 ohms.


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## bigabe (May 1, 2007)

Really, it depends on the amplifier. There are many amplifiers out there that are designed to run at 1ohm or lower... My subwoofer amplifier, an Earthquake 40UHC-Gold is a high current design that is basically useless until you're down around 1ohm. Same goes for many of the USAmps high current models (USA-100HC, USA-50HC...), and even some of the old Soundstream Class A rigs.


So I don't think it's fair to have a "rule of thumb" referring to never running any amp below 2ohm.


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## Oliver (Jun 25, 2007)

Good point BigAbe!!

Haven't seen any of those US amps around, they were stable to .25 ohm if memory serves me right

If you upgrade your vehicle right, anything is possible!!


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## envisionelec (Dec 14, 2005)

bigabe said:


> Really, it depends on the amplifier. There are many amplifiers out there that are designed to run at 1ohm or lower... My subwoofer amplifier, an Earthquake 40UHC-Gold is a high current design that is basically useless until you're down around 1ohm. Same goes for many of the USAmps high current models (USA-100HC, USA-50HC...), and even some of the old Soundstream Class A rigs.
> 
> 
> So I don't think it's fair to have a "rule of thumb" referring to never running any amp below 2ohm.


I'll be running an old Soundstream REF 500 at 1 ohm bridged, but the amplifier is specifically designed to do so. I do tend to lean on the volume knob a bit and enjoy the occasional car shaking bass, but I don't expect any major problems.


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## Oliver (Jun 25, 2007)

EZAudio, Am I right about the US 50HC, do you know what the stability of those amps were?


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## bigabe (May 1, 2007)

Hic said:


> Good point BigAbe!!
> 
> Haven't seen any of those US amps around, they were stable to .25 ohm if memory serves me right
> 
> If you upgrade your vehicle right, anything is possible!!



The OG 100HC was .5 ohm stereo and 1ohm mono stable. Same goes for the 50HC and the 25HC. However, plenty of people would run them down to .25ohm stereo or .5ohm mono with no problems at all as long as they put a couple fans on the things.

For some new amps... Digital Designs makes amplifiers that are capable of .5ohm mono operation at up to 19V!!!! We're talking about 10,000+ watts of true, clean power (for burpage only though... of course).


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## Oliver (Jun 25, 2007)

Thanx, Bigabe !!

I looked at amp guts and found this for a 50 HC 

2 x 25W @ 4 Ohms
2 x 33W @ 3 Ohms
2 x 50W @ 2 Ohms
2 x 100W @ 1 Ohm
2 x 185W @ ½ Ohm
1 x 100W @ 4 Ohms bridged
1 x 132W @ 3 Ohms bridged
1 x 200W @ 2 Ohms bridged
1 x 375W @ 1 Ohm bridged
Fuse: 75A


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## Oliver (Jun 25, 2007)

Yeah these Z2's will keep your subs bumping 
http://ampguts.realmofexcursion.com/DD_Z2/


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## bigabe (May 1, 2007)

You should see the numbers people are getting out the of new Z1a and Z3...  

People on the Sounpressure forums are claiming up to 14,000RMS!!!


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## squeak9798 (Apr 20, 2005)

TEAM SHIMANO/FALCON said:


> and distortion is also something to think about.......i bet you'd notice a muddier tone though.


I would disagree.

A competently designed amplifier, intended to operate at a 1ohm load (or whatever it's lowest rated stable impedance is) should still be capable of operating at distortion levels below audible thresholds at that impedance.


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## jearhart (Jul 28, 2006)

the power increase isnt worth it. espetially if you already have the subs to run at 2ohms.


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## bigabe (May 1, 2007)

squeak9798 said:


> I would disagree.
> 
> A competently designed amplifier, intended to operate at a 1ohm load (or whatever it's lowest rated stable impedance is) should still be capable of operating at distortion levels below audible thresholds at that impedance.


Orion made a a special edition amp that they claimed had "unmeasureable" THD levels at some of the most ridiculously low impedances I've ever seen... here's the amp I'm talking about:

http://ampguts.realmofexcursion.com/Orion_Concept_97.3/



> Output Power at 12V:
> Stereo
> 2 x 0.5W @ 4 ohms
> 2 x 1W @ 2 ohms
> ...


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## envisionelec (Dec 14, 2005)

bigabe said:


> Orion made a a special edition amp that they claimed had "unmeasureable" THD levels at some of the most ridiculously low impedances I've ever seen... here's the amp I'm talking about:
> 
> http://ampguts.realmofexcursion.com/Orion_Concept_97.3/


S/N Ratio 150dB??? I find that VERY hard to believe. Instrumentation amps have trouble reaching that level of noise, let alone a car amp.
There is more resistance in the emitter resistors and speaker wiring that their test load!! In order to produce just 0.5W per channel at 4 ohms, you'd have to have a rail supply of a whole +/-3.414V. Subtract typical losses in an amp of 1-2V for Bipolar outputs, and you've lost almost all your audio output to heat.

I call a huge truckload of BS on those specs. Please, prove me wrong.

EDIT: I found some pics of the board - they're using 63V rail filter caps. Someone is playing spec games. It certainly grabs attention - and if I were to guess, the numbers are simply made-up.


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## bigabe (May 1, 2007)

I'm just the messenger.... that's why I said the manufacturer "claimed" those numbers.

I'd love for them to be accurate. That'd be really cool.


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## envisionelec (Dec 14, 2005)

bigabe said:


> I'm just the messenger.... that's why I said the manufacturer "claimed" those numbers.
> 
> I'd love for them to be accurate. That'd be really cool.



Ah...personally taken.  Well, I'm just responding the the printed specs, not your point. I'm not a hard-ass like that.


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## monkeyboy (Jun 12, 2007)

IIRC that was when people would strive to run 4-6 amps in the 1-150 watt class. It was Orion's way of saying "enough is enough". You can claim any spec, but what the amp would really put out was never published.


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## Oliver (Jun 25, 2007)

Guess who owned one of the hundred...Tristan, of course


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