2 ohm vs 4 ohm?

[VoTran24 10+ year member]

hey guys i was wondering what are the pro's and cons of running a amp at 2 ohm or 4 ohm. I thought that running it 4 ohm was the standard and the normal thing to do, but I see almost everyone on this forum talking about running theirs at 2 ohm's? I also heard that it's unsafe to run at 2 ohms or lower. please give me some input. thanks

I just read somewhere that RE doesnt make the xxx in 4ohm's. I heard that the pg 1200.1 doesnt give out a lot of extra power at 2 ohms so I wanted to just run it at 4 ohm's since its "safer" and not much difference in power. So do you guys have any suggestions? Or can i run it at 2 ohms and not have to worry about it? thanks for any input

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[Norcalracer283 10+ year member]

Well, by the sounds of this post, your a noob. As long as your amp is 2 ohm stable, your fine. And to my knowledge, an Re sub can be wired in for just about any load depending on how you wire it, and depending on your coil setup..... check the wiring forums for wiring diagrams to help you out

 

[Norcalracer283 10+ year member]

Also, i am pretty sure the XXX is a dual 4 ohm sub or dual 2, and custom can be a dual 1 ohm....so it can be wired in many many ways....

 

[VoTran24 10+ year member]

yea i am a newb. I tried to use the search button but i couldnt find an answer. I remember reading somewhere that running the amp at 2 ohms make it hotter or somethin.

whats the difference between a regular 4 ohm sub and a dual 4 ohm sub? If i wanted to run the dual 4 ohm sub at 4 ohms would it be the same as wiring it as a regular 4 ohm sub?

thanks for helpin me out

 

[jellyfish420 10+ year member]

you cant run a dual 4ohm @4 ohm only 2 or 8 ohm. get a dual 2, youcan run that at 4 or 1 ohm. igot mine at 1ohm to squeeze every last watt outta my amp.

 

[JimJ 5,000+ posts]

by the way, the PG 1200.1 does full power from 2-4 ohms. Doesn't matter.

The new Xenons actually do full power from 1-4 ohms. Cool.

 

[maylar 10+ year member]

2 ohms makes the amp put out more current and power, so yes it'll make the amp run hotter and stress the output transistors more. But if the amp wasn't designed for that they wouldn't rate them at 2 ohms.

 

[csf]

The resistance (ohms) and the power is based in simple electrical engineering theory.

Basically, as you decrease the impedance/resistance (going from 4ohms to 2 ohms), you *theoretically* double the power (think of going from a regular garden hose to one twice as big). Your amp puts out twice the power, provided it can handle it (and the electrical system of the car and install in general).

The problems arise when your amp can't handle it or when you lose damping/control/sound quality by asking the amp to do too much.

Having dual voice coils just give you flexibility in your install. Say you have two 4 ohms coils - now you can run the speak at 2 ohms, 4 ohms (one coil) or 8 ohms, depending on your amps. Get a new amp? You can adjust pieces and parts around to fit instead of being left w/ a big, new amp that won't work well w/ your old subs.

 

[sickmint79 10+ year member]

as long as the amp is rated stable at the ohmage you are fine. the real consideration (ignoring budget) is whether you want to be running 2 channels, a mono amp, or a 2 channel amp bridged to mono mode. sound quality is best out of a mono amp, then a 2 channel amp... a 2 channel bridged to mono will lose some sound quality.

 

[bigcarbigsound 10+ year member]

Amps run cooler and control speakers better at higher impedence (ohms) but you sacrifice power. Thats is why moast home audio amps and speakers run at 8 ohms because you have an almoast unlimited power source. So if you want power and you amp is decent quality shouldent have any problems running at 2 ohms. Now if you have a cheep amp (Not PG there good) it might run at a 2 or 1 ohm load but it will sound sloppy.

 

[squeak9798 5,000+ posts]

sound quality is best out of a mono amp, then a 2 channel amp... a 2 channel bridged to mono will lose some sound quality.

That may be your personal preference, but not a fact.

 

[tRiGgEr 5,000+ posts]

you cant run a dual 4ohm @4 ohm only 2 or 8 ohm. get a dual 2, youcan run that at 4 or 1 ohm. igot mine at 1ohm to squeeze every last watt outta my amp.

Hey Jellyfish who is that in your pic. Just some random chick pic???

 

[mud 10+ year member]

Thats is why moast home audio amps and speakers run at 8 ohms because you have an almoast unlimited power source. So if you want power and you amp is decent quality shouldent have any problems running at 2 ohms. Now if you have a cheep amp (Not PG there good) it might run at a 2 or 1 ohm load but it will sound sloppy.

Actually, most home amplifiers run at high impedance because they already have a switch mode power supply operating at 60 (or 50) Hz, aka wall power (and, as you said, almost unlimited power). Car amplifiers run off of DC, so they have to have their own SMPS, which engineers usually make operate at a very high frequency (~50,000 Hz) so that they can use small, efficient transformers.

And as for an amp "sounding sloppy" at 2 or 1 ohms, I don't suppose you have any actual information to back that up?

 

[jellyfish420 10+ year member]

Having dual voice coils just give you flexibility in your install. Say you have two 4 ohms coils - now you can run the speak at 2 ohms, 4 ohms (one coil) or 8 ohms, depending on your amps.

i always heard only running one coil would ruin a sub. is this not correct?

yup, just some b!tch i found with a f*ckin' sweet ***!!!

 

[squeak9798 5,000+ posts]

i always heard only running one coil would ruin a sub. is this not correct?

No, it won't ruin the sub. But it will completely change the subs parameters, which means the recommended box size won't work and you would need to re-measure the subs T/S parameters, the motor strength is reduced, power handling is decreased, etc etc etc. So, while it won't ruin the sub, it's not a good idea for the average joe to try it.