What's the difference between 4 Ohms and 2 Ohms in subwoofers?

Question

I have recently sold my old 12" P3's and purchased the 08 model, I'm not very Savvy with car audio as i'd like to be. With the new Subs I had a choice between 2 Ohms and 4 Ohms, my older ones were 4 Ohms so that what I went with. I powered my old ones with a 550 punch amp, older model. I plan on buying another amp exactly like it to have the power of 2 amps. Also if there is a good wiring guide for wiring 2 seperate amps that would also be helpful. Thanks!

Answer 1

The lower the OHM the less resistance the current will have while traveling to the amp and then to the speakers. Try this wiring diagram, it is easy to read and understand.

http://www.edesignaudio.com/wiring.php

Answer 2

The ohm load of a voice coil comes into play when designing a system. It depends on the final ohm load you are looking for.

There is a good wiring calculator here that can explain it a little easier than I can. http://www.the12volt.com/caraudio/woofer...

Basically, your desired final ohm load and the number of subs your are going to use will help to determine which coil configuration you need.

Neither configuration is louder, better, or more reliable. It's just a measure of the resistance applied to the sub.  

Answer 3

Ohms is resistance.  The lower the number, the less resistance there is on the circuit.  A 2 ohm sub requires less power from the amp to run it than a 4 ohm sub because, at a 2 ohm load, the amp is not experiencing as much resistance.  Since the P3's are dual voice coil 4 ohm subs, that means you have some options in wiring them. You can wire them in parallel for a 2 ohm load or in series for an 8 ohm load. The amp is 2 channel, so ur gonna have to bridge the channels if your running one amp to each sub.  Unfortunately, that amp is not stable at 2 ohms in bridged operation, so if you got 2 of those amps you would have to wire it so that each sub sees 8 ohms, which would leave you way underpowering your subs. If i were you, i would first try to exchange those for the 2 ohm version because then the 2 P550's would be perfect.  If you cannot do that, then i would recommend looking at the P1000.1bd, it can run both the 4 ohm P3's with ease.