1 Ohm or 4 Ohm which is better?

 

Anonymous
 
just a basic question of opinion which to you sounds better? A 1 Ohm or 4 Ohm load, or do they sound the same. considering everything is matched up.
 

Silver Member
Username: Blainew

Post Number: 943
Registered: Nov-05
if you have one amp and you want to chose 4 or 1, i would personaly go with the 1 ohm. i dont think that the advantages you gain from running an amp at 4 ohms is worth the huge loss in power

if your dealing with the same watts for 1 ohm and for 4 ohms

the 4 ohms will sound better just a little, and there are other advantages that glasswolf told me...that is.,. if you are comparing 1000 watts @ 1 ohm to 1000 watts @ 4 ohms


so lets say you have a 1000 watt @ 1 ohm amp-run it at 1 ohm

lets say money is no object and you want 1000 watts total. get an extrememly powerful amp that will do 1000 @ 4 ohms
 

Silver Member
Username: Infinity_addict

Santa Rosa, California USA

Post Number: 238
Registered: Jul-05
resistance doesn't affect sound quality.
 

Anonymous
 
Like Blaine said, 4 ohms is better, but usually not enough to justify 4 ohm over 1 ohm for most people. There's so other factors to worry about in a system before worrying about which ohm load sounds better.
GENERALIZATION
Standard setup would be a Class AB amp powering components at 4 ohms and a Class D running at 4,2 or 1 ohm depending on subs and how much power you want.
 

Anonymous
 
well here is what i got and want. 1 Alpine type r 12' dvc 2 Ohm, in a seald box 1.75cu, alpine head unit (9855 i belive). I want deep, deep bass, i listen to a lot of hip-hop, so there is aslo some difficult bass notes. i have limited room in my car (acura integra) so less equipment is better.
 

Gold Member
Username: Mikechec9

Http://www.cardomain.c...

Post Number: 2142
Registered: May-05
"resistance doesn't affect sound quality"

Sure it does. The amplifier reproduces signals more easily and with less distortion at higher impedances. To most, the difference in sq just isn't audible that low down.
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 580
Registered: Mar-04
Quote: by Mike
----- Quote: by Infinity Addict

----- "resistance doesn't affect sound quality"

"Sure it does. The amplifier reproduces signals more easily and with less distortion at higher impedances. To most, the difference in sq just isn't audible that low down."


If it "just isn't audible down that low" how can it effect SOUND quality??
 

Gold Member
Username: Carguy

Post Number: 5316
Registered: Nov-04
What Mikechec9 post is true. However, with subs, it's just too hard to detect by ear. With test equipments, yes you can see the difference.
Since lot, if not most, listen to "boom" bass, it'll sound practically the same.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 5594
Registered: May-04
The reason is that at 1 ohm you're straining the power supply and output devices of the amplifier. The effective headroom of the amplifier is cut down by a large amount in comparison to 4 ohm, the damping factor is substantially lower, the distortion is much higher, and the amplifier will run much hotter.

If you want it to sound best AND you want the system to last longer, you want to run a sub at 4 ohm. The ONLY reason to run a 1 ohm load is when you simply can't afford an amplifier that will give necessary power at a 4 ohm load.

The difference in SQ between 1 ohm and 4 ohm isn't really noticeable on low end unless you're straining the capabilities of the amplifier, but it is easier to do so with a 1 ohm load.

 

Gold Member
Username: B101

Queen City, NC USA

Post Number: 1146
Registered: Sep-05
"
Sure it does. The amplifier reproduces signals more easily and with less distortion at higher impedances. To most, the difference in sq just isn't audible that low down"

?? QUESTION

Then isnt it the AMPLIFIER that distorts NOT the subs? Correct?
OK, so if he had a good expensive amp that WONT distort at a low impdence which its rated for.
It should be no diffrence correct? << Thought thats what he was asking.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 5596
Registered: May-04
Both distort, subs moreso than amplifiers. Amplifier "sound" has been debated for quite some time, with no proof that one can really tell a difference between a midlevel amp and a super high end one at the same power level. It's just that an amplifier will distort more with a lower impedance due to the added stress upon the power supply and output devices.
 

Silver Member
Username: Juliob

Santo DomingoDominican Re...

Post Number: 101
Registered: Dec-05
BETTER BUY 1 OHM STABLE AMP CUZ THEY CAN BE USED AT 4,2 OR 1OHM SO YOU GET THE FULL PACKAGE
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 189
Registered: Jan-06
If the class D amps are being stressed then why do they run so cool at 1ohm? Polo..
 

Gold Member
Username: James1115

Ct

Post Number: 5058
Registered: Dec-04
class 'A' amplifiers were VERY inefficient. Class 'AB' amplifiers are also inefficient but are more more efficient than class 'A' amplifiers. Class 'AB' mobile amplifiers are generally 60% efficient when driving a 4 ohm load at maximum power (just before clipping). The reason that these amplifier configurations are inefficient is because there is a difference of potential (voltage) across the output transistors and current flowing through the output transistors. When you have voltage across the device and current flow through the device, there will be power dissipation in the form of heat. The power needed to produce this heat is wasted power. When there is (virtually) no voltage drop across a device (such as a large piece of wire or a transistor), there can be a significant amount of CURRENT flow through the device with (virtually) no power dissipation. This means that there is virtually no heat given off (highly efficient). The inverse is also true. If you have a significant amount of VOLTAGE across the device (transistor, wire...) but no current flow through the device, again, there will be no wasted power.
OK, now to the point. A class 'D' amplifier, which may also be known as a switching amplifier or a digital amplifier, utilizes output transistors which are either completely turned on or completely turned off (they're operating in switch mode). This means that when the transistors are conducting (switched on) there is virtually no voltage across the transistor and when there is a significant voltage across the transistor (switched off), there is no current flowing through the transistor. This is very similar to the operation of a switching power supply which is very efficient.

bcae1
 

Silver Member
Username: Ucfsaxman

Oviedo/orlando, Fl

Post Number: 613
Registered: May-05
bc/ they were designed to run at low impedences. thats why they're class D.
 

Silver Member
Username: Blainew

Post Number: 944
Registered: Nov-05
overall...in my opinion there is really not point to run your subwoofer setup at 4 ohms to get maximum power out of your subs, if you can just run them at 1 ohm. its a big save of money too
 

Gold Member
Username: James1115

Ct

Post Number: 5059
Registered: Dec-04
a waste of money? maybe if you know that the set-up you are planning on running is going ot be what you want for a long time to come. Say you have a class d amp that does 400@ 4 ohms 800@ 2 ohms and 1600 @ 1ohm. ok now you have a amp that does 100 @ 4 ohms and 200 @ 2 ohms and 400 @ 1 ohm. I would rather spend the money on the bigger amp and run 1 sub at 4 ohms for the time being and know that if I wanted to add another sub I could drop it to a 2 ohm load and be ready to go without having to buy a new amp, sell my old one, and buy a new sub. It's a convience thing in my book. If you are just getting into car audio chances are you will not be happy your first tinme around and will be rebuilding atleast once in the future why not be prepared?
 

Silver Member
Username: Juliob

Santo DomingoDominican Re...

Post Number: 103
Registered: Dec-05
james what you said is exagerated cuz is the same thing with an amp that throws 500wrms4ohm 1000rms 2ohms and 1200wrms 1ohm and you can buy one that throws 600rms 4 ohm and 900rms 2ohm which one you will buy cuz i'd buy the 1 ohm stable. If you don't then you have a problem dog!
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 194
Registered: Jan-06
Other than a convenience issue, a class D should not fall under the 4 ohm rule as for they run more efficient at lower impedence? So it is safe to say get a larger amp and run it at a lower higher impedence (more efficient, less heat) for mids and highs, then use a class D at lower impedence because that is where it is most efficient? Polo..
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 195
Registered: Jan-06
I mean run the mids and highs amp at higher impededence. :-O
 

Silver Member
Username: Blainew

Post Number: 945
Registered: Nov-05
as james said ..kinda..

if your buying stuff to keep....use it at one ohm

theres really not theat big of a difference in sound quality
 

Anonymous
 
thanks for all the post, i have decided that i will just get a jl 500.1 amp, and run my sub at 4 Ohm and if i decide to get another sub i will be able to run them at 2 Ohm. i found a great deal from a friend to get the amp for 100 american
 

Gold Member
Username: James1115

Ct

Post Number: 5061
Registered: Dec-04
wow that really is a deal:-) I just bought one for $470 but that was retail so I got hosed but atleast I got a warranty:-)
 

Gold Member
Username: James1115

Ct

Post Number: 5063
Registered: Dec-04
"james what you said is exagerated cuz is the same thing with an amp that throws 500wrms4ohm 1000rms 2ohms and 1200wrms 1ohm and you can buy one that throws 600rms 4 ohm and 900rms 2ohm which one you will buy cuz i'd buy the 1 ohm stable. If you don't then you have a problem dog!"

I don't even know how to respond to that! was that english? DOG!
 

Anonymous
 
ya was lucky to find it so cheap, but i was wondering i was told that it is only 65% effecent is that really a bad thing?
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 199
Registered: Jan-06
If it is a class D amplifier which I think it is the efficiency should be upwards of 80%. Polo.
 

Gold Member
Username: James1115

Ct

Post Number: 5071
Registered: Dec-04
yeah its higher the 65%
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11154
Registered: Dec-03
"Then isnt it the AMPLIFIER that distorts NOT the subs? Correct?
OK, so if he had a good expensive amp that WONT distort at a low impdence which its rated for."

speakers will always produce at least 10% distortion.. that's just the nature of how they work. Just like speakers are only about 5% mechanically efficient.. meaning for every 100 watts of power you pump into a speaker, you get about 5 watts of work in return.

now, that being said the amplifier still produces several types of distortion, the two biggest being intermodular and harmonic distortion. THD is what we're talking about in nthis thread though, and as impedance drops, THD goes up, just like the SNR and Damping factor go down along with efficiency (meaning the amp can't control the sub as well, you have more noise floor in ratio to the actual signal you're trying to produce, and the amp returns less work per amount of power it takes to produce that work.)
As John said, 4 ohms is better for SQ than 1 ohm. This holds especially true for class AB amplifiers for full range operations. You can get away with poorer amp performance with subs because they tend to mask distortion more easily. That does not mean the distortion isn't still there.
The issue you hit with 1 ohm loads on sub amps is that you have the power supply pushed to near it's limit even at nominal performance levels, so when you do crank it and blast the subs, the power supply and it's electrical components (capacitors, FET rails in the output stage, transformers, etc) are strained so badly that your amp will begin clipping almost guaranteed, in addition to producing more heat which equals more distortion, and when the amp reaches this point, it will affect SQ because it will begin to sound more "flat" or lifeless, lacking dynamic range.

note when we talk about distortion in amplifiers we're mostly discussing even ordered harmonic distortion, which is harsh and unpleasant to the human ear. Other types of distortion can be far less noticeable, or even desireable to some like with tube amps.

"If the class D amps are being stressed then why do they run so cool at 1ohm?"

Polo, because a class D amplifier works in a completely different manner to a class AB amp, and class D has a higher efficiency, meaning they produce more work per amount of power input.
a class D amp samples the input signal at a high rate, then uses the output stage to digitally reconstruct the sampled signal at a higher amplitude.

The issue here though is that it's the output stage and power supply that are stressed, and those two portions of any amplifier are essentially the same.

"bc/ they were designed to run at low impedences. thats why they're class D."

no, sir. they were designed to run at low frequencies, due to the enormous amounts of distortion they produce, class D amps aren't fit or suitable to run at higher frequencies. They'd sound so bad, nobody would use them for full range operation. The problem lays in how fast the transistors can switch, which directly relates to how high of a frequency they can produce cleanly.

Juliob, you really have a lot to learn about amplifiers, and I humbly suggest tha you study how they work a bit more before diving into discussions of this depth. There are more things to consider than just how much power the amp puts out and at what load. Amplifier class, power supply type and design, etc.

"Other than a convenience issue, a class D should not fall under the 4 ohm rule as for they run more efficient at lower impedence?"

nope. no matter what class the amp is, you're still limited by the amp's power supply capabilities which is what affects most of what we're discussing here.

" i have decided that i will just get a jl 500.1 amp, and run my sub at 4 Ohm and if i decide to get another sub"

here you're talking about a class D amp with both regulated power supply and regulated output stage. You will get 500 watts from that amp no matter how you run it between 1.5 and 4 ohms.

http://www.glasswolf.net/caraudio/amplifiers.html
 

Anonymous
 
hey cool thanks glasswolf for the indepth info and the link, you got anymore links you can give me so that i can learn more about car audio, anything to do with car audio would be great, Thanks.
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11158
Registered: Dec-03
www.bcae1.com
www.the12volt.com
www.betteraudio.com/geolemon/
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 211
Registered: Jan-06
Well I am sure glad my amps come with dual power supplies! :-O Polo..
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