I have compiled a collection of diagrams most commonly used with equations to figure final load. For each equation, Z is the final load and R# is the impedance of each coil. Just be aware that an amplifier can only handle so low of an impedance before problems begin. Check the owners manual for this information.

Terms:**SVC** = Single Voice Coil**DVC** = Dual Voice Coil

**SVC Series **-

Not often used but for lower impedance drivers. Two 2 ohm would be 4 ohm.

Equation: Z = R1 +R2

**SVC Parallel **-

Equation: Z = 1 / (1/R1 + 1/R2)

Equation: Z = 1 / (1/R1 + 1/R2 + 1/R3)

Equation: Z = 1 / (1/R1 + 1/R2 + 1/R3 + 1/R4)

**SVC Series-Parallel **-

Equation: Z = (1 / (1/R1 + 1/R2) + (1 / (1/R3 + 1/R4))

**DVC Series **-

Again, not often used but for lower impedance drivers. A dual 2 ohm would be 4 ohm.

Equation: Z = R1 +R2

**DVC Parallel **-

Equation: Z = 1 / (1/R1 + 1/R2)

**DVC Parallel-Parallel **-

Equation: Z = 1 / (1/R1 + 1/R2 + 1/R3 + 1/R4)

**DVC Series-Parallel **-

Equation: Z = (1 / (1/R1 + 1/R2)) + (1 / (1/R3 + 1/R4))

**Quad DVC Parallel-Series **-

Equation: Z = ((1 / (1/R1 + 1/R2)) + (1 / (1/R3 + 1/R4))) / ((1 / (1/R5 + 1/R6)) + (1 / (1/R7 + 1/R8)))

If you need a custom drawing, just ask. You can email or IM me @ sparky3489@yahoo.com

Happy thumping!