Do these impedances matter?

[max]

I have an amp that has four channels at 4 ohms each, but all my speakers are 2 ohms. Will this matter?
Correct me if I'm wrong, but won't the watts double coming from the amp, since the speakers are 2 ohms? So couldn't I solve this problem by adjusting the gain setting?

 

[MDC]

If you let us know the exact models of the subs and amp then we can give you an exact answer. Until then it is hard to say for sure if it would be plausable or practical to get this to work.

If you have to 2 ohm speakers and you want to wire them up individually to each channel on your amp you will need an amp that is stable at 2 ohms. 4-channels are not always stable at 2 ohms because 2 ohm speakers are not very common.

You could possibly get it to work if you wired the speakers in series. The only problem is that you would not have a left or right speaker but rather a front and back pair. The good thing would be that you could possibly bridge the amp to give you more power to the speakers (if they can handle it and if your amp is able to be bridged).

Although a lower impedance does increase power it does not mean you can simply turn down the gain to fix this problem. You would have to either have a 2 ohm stable amplifier or wire your speakers in series to get a 4 ohm load in order to successfully get your setup to work.

I doubt you meant this, but if instead of speakers you meant subwoofers then they are probably DVC. This means you could wire it to your amp without a problem if you wired the voice coils in series. If these are speaker then nevermind this part.

Good Luck!!!

 

[Rich]

Damn! I didn't even know there was such a thing as 2 Ohm speakers. A quick Internet search showed that you are right; they do exist.

As for power calculation, the power is related to the square of the current. P=I (squared) X R. But actually, it isn't quite that simple for a speaker because some of the "R" is actually a reactive load (i.e. inductive).

As for compensating with the volume control, forget it. The problem is that the 2 Ohm load is going to look like damned near a short circuit to the amplifier. The finals in the amplifier might just overheat and you could end up with melted silicon instead of power transistors.

Another issue is the size of the speaker cables. If you don't use some incredibly huge gauge of cable, you care going to get considerable power loss in the cables. For example, lets say the nominal impedeance of your speakers really is 2 Ohms. Now suppose you have a mere 1 Ohm in your speaker cables. Ok, let's do the math, you are losing 1/3 of your power in the darn cables!

If it were my amplifier, I'd probably go shopping for 4 Ohm speakers. Alternatively, you might want to make sure you have about a 2 Ohm resistance in your cables and just kiss off half your power.