Advantages and disadvantages between Ohms

[cstac 10+ year member]

Ok, I'm unclear on something about ohms. What are the main differences of run 2 Ohm compared to 1 Ohm? Also, looking into running 2 10" Subs off either 250 total watts Rms @ 2 Ohm or 500 total Rms @ 1 Ohm, Subs are 250 Rms each, just curious which will sound better/louder, and the reason why? THanks for the input.

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[Johnny Law.Lulz 5,000+ posts]

OHms is resistance, its all in the VC of your subs, obviously 500 will be louder because tis more watts.

Now the right question would be asking the difference between 500 @ 1 ohm and 500 @ 2 ohm.

 

[cstac 10+ year member]

ok, i see, but really my ? should be stated 500 @ 1 ohm or 250 @ 2 ohm which is better for sound quality with a little bump in the trunk? I think thats how i should have stated it. But any suggestions on this ? Thanks again

 

[cstac 10+ year member]

But also would like to know the difference between 500 @ 1 ohm and 500 @ 2 ohm, so any suggestions about this ? feel free to comment. Just trying to get a little more intelligent about systems.

 

[taintedplay 10+ year member]

between 500x1ohm and 250x2ohm def go with 500x1ohm. about 500x2o and 500x1o i dunno

 

[Johnny Law.Lulz 5,000+ posts]

It all depends on your subs, you can just pick one. If you have 2 DVC 4 ohm subs you cant run both on 2 ohm. Theres a lot of varibles your not thinking about.

 

[HighTQCummins 10+ year member]

From the info I've gathred so far lower ohm rating pulls more power out of the amps but makes them work harder. Not necessarily bad if the amp can take it. Now if you were to run at 250w @ 2ohm, this is a much more conservative rating and will lower the likelyhood of equipment failure. However in most cases (pretty much all) this will not be as loud.

 

[I Like Waffle]

Less resistance almost always = more power from the amp. But at a higher ohm load the amp is more efficient (less heat generated, etc). So 500 x 2 ohms and 500 x 1 ohm would just be more/less stress on your electrical.

 

[Fiercetimbo17 10+ year member]

Less resistance almost always = more power from the amp. But at a higher ohm load the amp is more efficient (less heat generated, etc). So 500 x 2 ohms and 500 x 1 ohm would just be more/less stress on your electrical.

Not completely correct. Many class D's now a days are designed to be most efficient at full output/lower ohm load. For all other class amps that is generally correct.

However almost all amps (with some exceptions like Zapco DC) increase THD the less resistance, some doubling as impedance drops. However in subwoofers THD is not a big deal and in a car environment many claim not to be able to hear anything below 5% THD.

 

[nauc 10+ year member]

most amps put out more power the lower the impedance so you could get more watts for your buck running at a lower impedance

example...

125 watts at 4 ohms

250 watts at 2 ohms

500 watts at 1 ohm

 

[smoka 10+ year member]

An example would be comparing the resistance of your subs to an inverse of rpm's of an engine.

If you half the resistance (2 ohm to 1 ohm) it would be like doubling the RPM's of an engine. Sure the engine will go much faster (more power), but unless its a high quality motor (amp), then it wll break down sooner with the added abuse.

If you want to run at 1ohm, then buy a high quality amp.

Less resistance almost always = more power from the amp. But at a higher ohm load the amp is more efficient (less heat generated, etc). So 500 x 2 ohms and 500 x 1 ohm would just be more/less stress on your electrical.

Efficiency = Pout / Pin * 100

Not more efficient, just running at half the power.

The difference between 500 @ 2 ohms and 500 @ 1 is that one of the amps will be twice the size of the other....

 

[I Like Waffle]

Not completely correct. Many class D's now a days are designed to be most efficient at full output/lower ohm load. For all other class amps that is generally correct.However almost all amps (with some exceptions like Zapco DC) increase THD the less resistance, some doubling as impedance drops. However in subwoofers THD is not a big deal and in a car environment many claim not to be able to hear anything below 5% THD.

Good info timbo. I had always heard they were more efficient at a higher load due to less heat generated and etc, but i guess theyve came a long way with the class D designs. But about the THD, I hear from people that infinity coax speakers sound like junk because theyre 2 ohm vc (mostly installers that think they know everything, shop owners, etc.) Now i know where they get that from, lol.

 

[cstac 10+ year member]

Ok, thanks for the input. Just to let you guys know the amp is stable at 1 ohm and its made by memphis so I would say it will do just fine at 1 ohm, besides has a 2 year warranty.

 

[Plutoman 10+ year member]

Good info timbo. I had always heard they were more efficient at a higher load due to less heat generated and etc, but i guess theyve came a long way with the class D designs. But about the THD, I hear from people that infinity coax speakers sound like junk because theyre 2 ohm vc (mostly installers that think they know everything, shop owners, etc.) Now i know where they get that from, lol.

I'd have to say that for anything running off an HU, the infinity coax's sound better, due to the extra power they gain reducing the amount of clipping and THD.

Just to throw that in there. I don't think there's much of a noticeable difference between 2 and 4 ohms, except possibly with higher quality systems, fully deadened with good speakers, that you could notice.