Subwoofers add low end bass to your car system. When wiring subwoofers to your system, basic electrical equations can help ensure that you wire your subwoofers properly and safely!
Before wiring your subwoofer, you must know your amplifier's acceptable range of resistance. Most amps are rated at 4 ohms. You should refer to your amplifier's User Manual for your specific rating.
Once you know your amplifier's rating, you must now find out what type of subwoofers you have. Most subwoofers are rated at 2, 4, or 8 ohms. The primary goal here is to have your subwoofers wired up so that the equivalent resistance is equal to that of the amplifer's rating.
Thus, for a 4 ohm amp, the subwoofers should be wired up so that 4 ohms are seen across the terminals (positive and negative).
Basically, subwoofers are very large resistors. We can add the subwoofer's resistance (ohms) in series or parallel. Series means we are lining up the subwoofers from end to end. When in series, we add up the resistance of each subwoofer... Thus, two 4 ohm subwoofers in series makes a total of 8 ohms.
Parallel means the subwoofers are sharing both a positive and negative terminal. When in parallel and using two identical subwoofers, the resistance of the entire system is halved. Thus, two 4 ohm resistors in parallel makes a total of 2 ohms.
Thus, many combinations can be used to attain the recommending rating of your amplifier. In our example, the amplifier was rated at 4 ohms. Thus, we can have two 2 ohm subs in series (2+2=4), or we can have two 8 ohm subs in parallel (8/2 = 4).
I hope this was helpful! Enjoy the added low end bass, and let me know if you have any questions!
