Car Stereos: amp and sub compatibility, dual voice coils, ohm voice coils

Question
Hey Brian,

I had a question about whether this sub and amp make a good combo.  I know that you have to match the rms power and impedance of the sub and amp, but someone told me that with dual voice coils it's a little different.  Here's the sub and amp i'm looking at, and I was wondering if these two are compatible with each other.

Subwoofer: JL 12w2v2-d2
300 watts rms
dual 2 ohm impedance

Amp: Kenwood KAC-8104D Mono
500 watts x 1 at 2 ohms
        or
300 watts x 1 at 4 ohms

They said that my sub would need an amp at the impedance of either 1 ohm or 4 ohm impedance because of the dual voice coils.  So if this is true would these match?  I'm new to all of this so i'm sorry if I sound a little confused.

Thanks,

Jeff

Answer
Hi Jeff,

When you have a sub with dual 2-ohm voice coils, then you have two wiring options:  you can wire it in a way that results in a 4-ohm load for the amplifier, or you can wire it so that it becomes a 1-ohm load.  Provided that you wire the voice coils in series, for a 4-ohm load, then the amplifier would be a good match for the sub; you'd get the 4-ohm rated output from the amplifier, which matches the sub's 300-watt RMS power rating exactly.   You don't need to worry about the 1-ohm option in this case; ie, you don't need to look for an amp that has both a 4-ohm and a 1-ohm power rating.  You'll determine the sub's final impedance when you wire it to the amp, and it won't change after that (unless you change the wiring).

Hope this helps!

Brian