This calculator is intended to help you determine the impedance of a speaker or subwoofer wiring configuration. There are many ways you can connect multiple speakers together. The most common and best way is to connect them in parallel. You do this by connecting the positive speaker wire from the amp to the positive terminal on the first subwoofer. In the picture below, one channel is shown.
The formula above is for multiple subwoofers with the same impedance.Example: You have three eight ohm woofers. Inserting the variables in the formula gives you the ratio 8/3. Eight divided by 3 gives you approximately 2.66 ohms. If your subwoofers were four ohm versions, you would get an answer of 4/3 or 1.33 ohms. This would cause a problem for most amplifiers. There are some high current competition amplifiers that can handle these lower impedances, but in general most amps won't run with this load. If you are not sure, contact the manufacturer of your amplifier. This also the same way you wire an amplifier in mono except in a mono wiring schematic you usually use the positive of one channel and the negative of the other channel. When you use a mono configuration, the impedance load at the amp is half as much.