# Whats up with all the 1 Ohmers?



## stevenbellm (Nov 5, 2021)

Hello all, so I have read a ton and heard a ton from users and I swear...it seems 95% go 1 ohms.
the rest are 2 ohms.

I read that higher resistance is better for quality of sound and defintely amp performacne...how hot they get.So I got a Skar 8" SVR 400 RMS and a Skar rp1200 that runs at 500 RMS at 4 ohms.
So that seemed perfect. Then I got an LC2i to up the clean signal going into the amp and its killer in my Mazda 3 hatchback.

So why is that? Everyone doing 1 ohms?


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## ckirocz28 (Nov 29, 2017)

stevenbellm said:


> Hello all, so I have read a ton and heard a ton from users and I swear...it seems 95% go 1 ohms.
> the rest are 2 ohms.
> 
> I read that higher resistance is better for quality of sound and defintely amp performacne...how hot they get.So I got a Skar 8" SVR 400 RMS and a Skar rp1200 that runs at 500 RMS at 4 ohms.
> ...


Those of us that like to drive the hell out of our subs usually end up at 1 ohm, because higher output amps are mostly designed that way.
Higher resistance loads don't necessarily equate to better sound quality or efficiency.


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## stevenbellm (Nov 5, 2021)

ckirocz28 said:


> Those of us that like to drive the hell out of our subs usually end up at 1 ohm, because higher output amps are mostly designed that way.
> Higher resistance loads don't necessarily equate to better sound quality or efficiency.


Yeah its one of those age old debates...the thinking is that as the amp runs hotter, the signal is also noisier. And that going from 2 ohm to 1 ohm... the difference isn't noticeable but from 4 ohms to 1 ohms some say that's enough of a difference where it can be heard., since youre driving the amp that much less at 4 ohms. BUT, most guys with systems like yours know a lot more than me so, Im just reciting theory, not real world experience. Thanks for your time bro.


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## khlae (Dec 31, 2016)

Consider that you can increase wattage of an amp+speaker combo through two ways: reduce the speaker impedance so more current flows, or raise the amplifier voltage so more current flows.

You won't see a lot of 1 ohm professional speakers for touring/live sound, because if the amp is plugged into 120vac or more, it's easy to raise voltage at the speaker terminals above 12volts in a relatively efficient manner to get that more power output. In a nominally 12 volt car, your amplifiers supply voltage is a bit too low to get big power numbers at higher impedance without having a boost converter that is going to at least double the voltage.

It's all tradeoffs and what you can buy that works. Lower impedance for the same wattage means more current, which means larger gauge wires that weigh more and cost more and are less flexible and waste more power, which is another downside.


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## skylineqrt4 (Jun 1, 2009)

Also with class d design there are output filters to filter out the carrier wave. Think crossover for the super high frequency. The impeadence of the speaker changes the value of the filter which can dampen high or low frequencies and make the amp non linear. Older class d designs suffered from these problems but allot of the newer generation class d circuits have greatly improved on this and speaker impeadence has become less of an issue.


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## ckirocz28 (Nov 29, 2017)

stevenbellm said:


> Yeah its one of those age old debates...the thinking is that as the amp runs hotter, the signal is also noisier. And that going from 2 ohm to 1 ohm... the difference isn't noticeable but from 4 ohms to 1 ohms some say that's enough of a difference where it can be heard., since youre driving the amp that much less at 4 ohms. BUT, most guys with systems like yours know a lot more than me so, Im just reciting theory, not real world experience. Thanks for your time bro.


Some amps are made to run best at a specific load, look at MMATS amplifiers, you can get practically any of their subwoofer amps built to run 0.5 ohm, 1 ohm, or 2 ohms, they are most efficient at the load they are designed for. Then there are the old cheater amps that were rated for 4 ohms but could run at 0.25 ohms while grilling steaks on the heatsink, and never lost any sq, until the magic smoke escaped.


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## stevenbellm (Nov 5, 2021)

khlae said:


> Consider that you can increase wattage of an amp+speaker combo through two ways: reduce the speaker impedance so more current flows, or raise the amplifier voltage so more current flows.
> 
> You won't see a lot of 1 ohm professional speakers for touring/live sound, because if the amp is plugged into 120vac or more, it's easy to raise voltage at the speaker terminals above 12volts in a relatively efficient manner to get that more power output. In a nominally 12 volt car, your amplifiers supply voltage is a bit too low to get big power numbers at higher impedance without having a boost converter that is going to at least double the voltage.
> 
> It's all tradeoffs and what you can buy that works. Lower impedance for the same wattage means more current, which means larger gauge wires that weigh more and cost more and are less flexible and waste more power, which is another downside.


Oh so youre saying that 4 ohms requires higher voltage, or 1 ohms? I guess its 1 ohms since its putting out more power?


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## MythosDreamLab (Nov 28, 2020)

Hello steve (that's my name as well), In my mid-size, SUV, I'm running a little 8", (4ohm) sub, with a 500w mono amp, I could theoretically add another 8" (4ohm) sub and send 800w @ 2ohms, but I am very happy with the bass mine puts out and don't feel the need to do it, plus everyone who has heard my system agrees the bass is very well balanced with the rest of the components and I worry that adding another sub would make the overall set-up too bass-heavy, which would force me to dial-back the mono amp and I'd be right where I am now (except for spending another $800...lol).

I did meet up with a local guy (I met on here - DIY) who was running a 3-way AF GB set up, Helix powered, with two Subs and it seemed bass-heavy (too much bass) for my tastes, so I think it is a matter of people having different tastes and expectations. I'm sure there are more than a few guys here, that have their Rear View Mirrors "shake" with each thump of their sub(s)...

So, I would advise to find what makes YOU happy (sound-wise) and go with it and not fall into the trap of adding subs and 1ohm mono amps to go along with "what people say"...

Cheers!


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## khlae (Dec 31, 2016)

stevenbellm said:


> Oh so youre saying that 4 ohms requires higher voltage, or 1 ohms? I guess its 1 ohms since its putting out more power?


To get the same 1000watts RMS fed into a 4 ohm speaker requires higher voltage than 1000WRMS feeding a 1 ohm speaker.

Consider ohms law, V=IR and that P=IV. Subbing ohms law into the latter gets you P=I*I*R
1000w/4 = i^2 (4ohm nominal speaker)
1000w/1 = i^2 (1 ohm nominal speaker)
Solving for I we can then plug I and the same ohm value into v=ir
v = 15.81amps * 4ohms is 63.24 volts RMS to achieve 1000 watts RMS assuming actual impedance at a given frequency is exactly 4 ohms (it's not)
v = 31.622amps * 1ohms is 31.622 volts RMS to achieve the same wattage. 

The actual numbers and such will not quite match these because an "x ohm nominal" speaker isn't actually going to be that exact impedance at many/most audio frequencies.


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## Noah117117 (12 mo ago)

How low I wire has to do with a few variables. 

First is how stable the amp is at that resistance. Some amps are really happy at 1 ohm and stay efficient, some are rated for 1 ohm, but are much happier at 2 ohms. An amp with a 1000 watt at 2 ohm rating and 1500 watt 1-ohm rating will probably be less comfortable running at 1 ohm than a 1000 watt 2ohm, 2000 watt 1ohm amp. 

Next is the sub/enclosure pair I'm using. Some subs are nominally 1 ohm and have a dcr of .8ohms, some have dcr of 1 ohm or more. Depending on the enclosure and strength of the motor, the impedance rise could get a realistic impedance much higher than dcr. That's actually a good thing because it means you're getting more output per a given voltage without actually dissipating as much power. 

Last is the capability of the electrical system I'm using. As you drop impedance the amp will drop efficiency and if the electrical is stock then usually you are going to put excessive stress on the alternator as a result. I'd much rather get an overpowered amp and run it at a higher impedance because it really can make a pretty big difference. Imagine you have a 1200 watt amp that is 60% efficient at 1 ohm vs a 2400 watt amp that is wired to 2 ohm, again a 1200 watt amp (in a perfect world) that may be 90% efficient. You'll be drawing significantly less current, which will be easier on the alt, have less voltage drop, and run much cooler.

Honestly, there are more variables, but the point is that nothing has a definite answer and what you are doing may have a different "best choice" from the next person. In general, my advice would be to stay where your amp is efficient and what your stock electrical can tolerate. In the long run, things will last longer and be more reliable.


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## stevenbellm (Nov 5, 2021)

MythosDreamLab said:


> Hello steve (that's my name as well), In my mid-size, SUV, I'm running a little 8", (4ohm) sub, with a 500w mono amp, I could theoretically add another 8" (4ohm) sub and send 800w @ 2ohms, but I am very happy with the bass mine puts out and don't feel the need to do it, plus everyone who has heard my system agrees the bass is very well balanced with the rest of the components and I worry that adding another sub would make the overall set-up too bass-heavy, which would force me to dial-back the mono amp and I'd be right where I am now (except for spending another $800...lol).
> 
> I did meet up with a local guy (I met on here - DIY) who was running a 3-way AF GB set up, Helix powered, with two Subs and it seemed bass-heavy (too much bass) for my tastes, so I think it is a matter of people having different tastes and expectations. I'm sure there are more than a few guys here, that have their Rear View Mirrors "shake" with each thump of their sub(s)...
> 
> ...


Thanks man, I appreciate it. I think Im more like you than the neighborhood thumpers.


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## Patriot83 (May 10, 2017)

Seems to me the main or only reason to run a 1ohm sub system is to maximize wattage. I talked to an amp manufacturer recently who said he sells a lot more 1ohm amps than 2ohm amps. In fact, he recommended buying 1ohm over 2ohm amps simply because of the versatility factor. I said I'll never really need to run 1ohm. He said "but what if you want to run 2 subs in the future? You won't need to change amps." He also said it did not cost more to build 1ohm capable amps. Just have to change 2 or 3 parts. I personally will never run 2 subs again (pretty sure) or run over 1000 watts so I stuck with the 2ohm amp but, everything he said def made sense.


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## ckirocz28 (Nov 29, 2017)

Patriot83 said:


> Seems to me the main or only reason to run a 1ohm sub system is to maximize wattage. I talked to an amp manufacturer recently who said he sells a lot more 1ohm amps than 2ohm amps. In fact, he recommended buying 1ohm over 2ohm amps simply because of the versatility factor. I said I'll never really need to run 1ohm. He said "but what if you want to run 2 subs in the future? You won't need to change amps." He also said it did not cost more to build 1ohm capable amps. Just have to change 2 or 3 parts. I personally will never run 2 subs again (pretty sure) or run over 1000 watts so I stuck with the 2ohm amp but, everything he said def made sense.


Yeah, a 2 ohm stable amp won't run safely at 1 ohm, but a 1 ohm stable amp will definitely run safely at 2 ohms.


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## 96jimmyslt (Jan 31, 2011)

You're running 500w, you're not really diving into the hobby yet. You go ahead and buy a $1,000 amp that does 5k at 1 ohm and run it at 4 ohms for 1500w if ya want I guess.


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## nyquistrate (Apr 17, 2011)

96jimmyslt said:


> You're running 500w, you're not really diving into the hobby yet.


? What does the sub amp wattage have to do with discerning someone's participation in the hobby?


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## FAUEE (Jul 22, 2010)

If you're running skar equipment you don't need to worry about impedance hurting your sq, lol.


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## SQ_Bronco (Jul 31, 2005)

Assuming amps are operating within limits, the biggest issue with 1 ohm loads is that wire impedance becomes a larger factor. You’ll lose something like 300W if you try to push 2000W through a 12GA wire at 1 ohm, while a 4 ohm load rise would be lower impact, like 50W.

Those are ballpark numbers of course. I posted exact numbers a little while back and can’t find the thread now, and don’t feel like redoing it.


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## stevenbellm (Nov 5, 2021)

96jimmyslt said:


> You're running 500w, you're not really diving into the hobby yet. You go ahead and buy a $1,000 amp that does 5k at 1 ohm and run it at 4 ohms for 1500w if ya want I guess.


Yeah that all made no sense to me and never can lol. I dont need to do all that crap bro, my Skar SVR 8" 400 RMS wired at 4 ohms is a great match with my rp 1200 amp. The Audio Controls LC2i adds a lot of clean boost before the amp so I have amp gain at around 40%.
So the HHR is still running strong huh?


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## spudicus (Sep 15, 2015)

stevenbellm said:


> Hello all, so I have read a ton and heard a ton from users and I swear...it seems 95% go 1 ohms.
> the rest are 2 ohms.
> 
> I read that higher resistance is better for quality of sound and defintely amp performacne...how hot they get.So I got a Skar 8" SVR 400 RMS and a Skar rp1200 that runs at 500 RMS at 4 ohms.
> ...


The largest thing that has an effect on quality, given all other things are equal (quality of electrical components etc), is how hard you are pushing the amplifier to it's limits. When you get near, go over the designed operating range for an amplifier you start to get distortion/clipping. Pushing or running the amplifier to its limits also cause it to run hotter.

What I like to do is to go oversized on the amplifier, and then dial it back on the amount of power it outputs to match what the speaker/driver is rated for. That way the amplifier is not so taxed, basically it's like the amp is jogging, vs running at a sprint.

I run two 1,500 watt subs wired down to 1ohm off of an 8,000 watt 1ohm amp. As long as you set gains properly, you will not blow your subs, will have a clean signal, and the amp runs cooler. I've also beat the hell out of those subs, and they never over heated, the dust cap only ever got slightly warm (like barely noticeable above ambient).


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## WestonWW (Feb 26, 2015)

From a SQ stand point I've read that the damping factor of an amp is cut in half with each impedance step (8,4,2,1). If an amp has a damping factor listed (better SQ amps) it's usually at the 4 or 8 ohm load. Damping factor is related to how much "control" the amp has over the driver movement. Damping over 100 is considered good.


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## SQ_Bronco (Jul 31, 2005)

pretty much every amp manufactured since 1995 has had an acceptable damping factor, though. It was a big deal in the days of tube amps but not really something to worry about today since it’s trivial to add negative feedback to a solid state amp.


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## rob feature (Nov 15, 2015)

stevenbellm said:


> ...The Audio Controls LC2i adds a lot of clean boost before the amp so I have amp gain at around 40%.
> ...


Boosting isn't doing you any favors.


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## khlae (Dec 31, 2016)

SQ_Bronco said:


> pretty much every amp manufactured since 1995 has had an acceptable damping factor, though. It was a big deal in the days of tube amps but not really something to worry about today since it’s trivial to add negative feedback to a solid state amp.


Yet, some people don't like negative feedback.....


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## stevenbellm (Nov 5, 2021)

rob feature said:


> Boosting isn't doing you any favors.


Brainfried now. I thought we wanted to send the hottest clean signal to the amp from the LC2i? Which requires use of bass boost. Im wrong?


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## daloudin (Nov 2, 2020)

stevenbellm said:


> Hello all, so I have read a ton and heard a ton from users and I swear...it seems 95% go 1 ohms.
> the rest are 2 ohms.
> 
> I read that higher resistance is better for quality of sound and defintely amp performacne...how hot they get.So I got a Skar 8" SVR 400 RMS and a Skar rp1200 that runs at 500 RMS at 4 ohms.
> ...


If you REALLY want to know why then you need to understand amplifier theory. Nearly all amplifiers for car audio are current driven in which case you get maximum output at minimum impedance. 

Your approach to running at higher impedance is admirable and back when watts were more expensive and subs were all about efficiency this was common practice. Large scale PA systems still use this practice as the limiting factor is usually the service where the concert is held. By using higher impedance and maximizing efficiency they reduce the necessary supply kVa and keep from tripping breakers.

Now that Watts are cheap and high excursion, high Q subs with tight tolerances and heavy duty suspension are common it's easier to push impedance lower and simply use more power. 

Here's some light reading: 





The serious flaws of voltage drive | Current-Drive - The Natural Way of Loudspeaker Operation


The serious distortion and interference effects of voltage drive and how they are avoided by current-drive



www.current-drive.info





Sent from my SM-G965U using Tapatalk


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## stevenbellm (Nov 5, 2021)

daloudin said:


> If you REALLY want to know why then you need to understand amplifier theory. Nearly all amplifiers for car audio are current driven in which case you get maximum output at minimum impedance.
> 
> Your approach to running at higher impedance is admirable and back when watts were more expensive and subs were all about efficiency this was common practice. Large scale PA systems still use this practice as the limiting factor is usually the service where the concert is held. By using higher impedance and maximizing efficiency they reduce the necessary supply kVa and keep from tripping breakers.
> 
> ...


Thanks a lot man


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## Infektid (7 mo ago)

spudicus said:


> The largest thing that has an effect on quality, given all other things are equal (quality of electrical components etc), is how hard you are pushing the amplifier to it's limits. When you get near, go over the designed operating range for an amplifier you start to get distortion/clipping. Pushing or running the amplifier to its limits also cause it to run hotter.
> 
> What I like to do is to go oversized on the amplifier, and then dial it back on the amount of power it outputs to match what the speaker/driver is rated for. That way the amplifier is not so taxed, basically it's like the amp is jogging, vs running at a sprint.
> 
> I run two 1,500 watt subs wired down to 1ohm off of an 8,000 watt 1ohm amp. As long as you set gains properly, you will not blow your subs, will have a clean signal, and the amp runs cooler. I've also beat the hell out of those subs, and they never over heated, the dust cap only ever got slightly warm (like barely noticeable above ambient).


You also get a lot more dynamic headroom .


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## dumdum (Feb 27, 2007)

stevenbellm said:


> Brainfried now. I thought we wanted to send the hottest clean signal to the amp from the LC2i? Which requires use of bass boost. Im wrong?


Bass boost takes away from sq, set gains correctly… noise won’t be an issue with a sub amp 👍🏼


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## SQ_Bronco (Jul 31, 2005)

stevenbellm said:


> Brainfried now. I thought we wanted to send the hottest clean signal to the amp from the LC2i? Which requires use of bass boost. Im wrong?


You might, but don’t confuse “gain” with “boost”. A “gain” increases voltage level across the entire range of frequencies inside the pass band. A “boost” distorts the signal by adding equalization at a small range of frequencies around a center point, like 40 hz. Adding boost will result in very peaky bass and can very quickly cause your amp to clip, adding significant distortion. Every 3 dB of boost requires twice as much power from the amplifier.

The lc2i does not add “boost”. It does two other things to try to improve your sq. First, it attempts to restore the low frequency information that the stock system removes. It then outputs a fixed high level output gain and an adjustable bass gain that allows you to increase or decrease gain (not boost) at low levels.

A “hot” signal is just part of your gain structure. A high voltage output from the lc2i allows your amp to make full power with a low gain on the amp, helping to prevent hiss. Be careful though, because if you exceed the amplifier’s upper input limit, it will also clip.


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## stevenbellm (Nov 5, 2021)

SQ_Bronco said:


> You might, but don’t confuse “gain” with “boost”. A “gain” increases voltage level across the entire range of frequencies inside the pass band. A “boost” distorts the signal by adding equalization at a small range of frequencies around a center point, like 40 hz. Adding boost will result in very peaky bass and can very quickly cause your amp to clip, adding significant distortion. Every 3 dB of boost requires twice as much power from the amplifier.
> 
> The lc2i does not add “boost”. It does two other things to try to improve your sq. First, it attempts to restore the low frequency information that the stock system removes. It then outputs a fixed high level output gain and an adjustable bass gain that allows you to increase or decrease gain (not boost) at low levels.
> 
> A “hot” signal is just part of your gain structure. A high voltage output from the lc2i allows your amp to make full power with a low gain on the amp, helping to prevent hiss. Be careful though, because if you exceed the amplifier’s upper input limit, it will also clip.


Dude thanks so much. So if I understand you I want to turn up the LC2i Bass knob and Accubass knob as high as possible without clipping. Oh and the Accubass that compensates for rolloff? Since I dont have roll off I can just use the Accubass as another bass knob...but Ill be darned if I know which I should favor? Grr. You know? Should I rely more on the Bass knob or the3 Accubass to raise the voltage?


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## stevenbellm (Nov 5, 2021)

daloudin said:


> If you REALLY want to know why then you need to understand amplifier theory. Nearly all amplifiers for car audio are current driven in which case you get maximum output at minimum impedance.
> 
> Your approach to running at higher impedance is admirable and back when watts were more expensive and subs were all about efficiency this was common practice. Large scale PA systems still use this practice as the limiting factor is usually the service where the concert is held. By using higher impedance and maximizing efficiency they reduce the necessary supply kVa and keep from tripping breakers.
> 
> ...


A belated thank you. yeah I did it this way with the 1200 watt amp working with the one sub at 4 ohms..besides it running cooler in the TX heat and (supposedly) sounding better than the 1 ohm setups, cos theres hella headroom for me to upgrade subs and keep amp.


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## stevenbellm (Nov 5, 2021)

rob feature said:


> Boosting isn't doing you any favors.


Hello, I said that wrong...duh my bad. Not boosting...turning up voltage i should say? I think? lol


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## SQ_Bronco (Jul 31, 2005)

stevenbellm said:


> Dude thanks so much. So if I understand you I want to turn up the LC2i Bass knob and Accubass knob as high as possible without clipping. Oh and the Accubass that compensates for rolloff? Since I dont have roll off I can just use the Accubass as another bass knob...but Ill be darned if I know which I should favor? Grr. You know? Should I rely more on the Bass knob or the3 Accubass to raise the voltage?


imho the best use of a bass knob is to have a convenient way to turn the bass down when you want to, but ymmv.

Here’s what Audio Control says in the manual:

“OK, what if your bass doesn’t roll off, but you still want more?
No problem! Turn the AccuBASS® Level control fully down, rotate the threshold control fully clockwise to lock in the bass equalization. Now you can turn up the AccuBASS® Level control for the amount of bass you want.”

Play around with it and see what sounds best and report back  just be careful not to overdo it.


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