not at all it's just a different way to wire a subwoofer and creates more options for wiring. it also helps match up subs to an amp you may already have.
so say if i hav a 4 Ohms dvc sub and i hook it up to the MA Audio HK2000D amp. it wouldn't give more power than say if i had a 2 Ohms dvc sub and hooked it up to the same MA Audio HK2000D amp
ive heard..in theory..ur bass response will be "tighter" with the more ohms u have..ohms is the resistence to power..but igues if u have an amp that is 2 ohm stable or 4 ohm stable it wont make a difference..correct me if im wrong..but the more ohms u have..there might be a chance for cleaner sounding bass
the ohm load is basically whaqt is hardwired into the sub to tell the amplifier how much power to out put the amp you asked about has for instance 1000 watts rms at 4 ohms and 1500 at 2 ohms the bass wont sound cleaner or anything like that with less ohms, there will simply be less power output, and with 1000 watts rms you will need a pretty nice sub or more than one because that is a lot of power
2 ohms is less resistance than 4 ohms, so the amp can feed it more power. A 4 ohm dvc sub has 2 x 4ohm voice coils, so if you wire them together in parallel, the total impedence is 2 ohms. So yeah, they just come with different impedences so that you can configure them with your system, but with subs, you want to wire them to the lowest impedence that your amp is stable at to get the most power potential out of it. If your amp is 1500wrms @ 2ohm, and you want 1 sub, you'd either want a 2ohm svc or 4ohm dvc sub. if you wanted two subs, you'd need 2 x 4ohm svc or 2 x 2ohm dvc subs.