thats pretty much it.
If u got, say, 8 svc 8ohm subs....paralleld...that'll give u 1 ohm. SOOO....if they were dvc, all parallel...you'd get .5 ohm. And with DVC you can do series-parallel wiring to get weird ohm loads. I had 3 dual 1 ohm subs wired to 1.5 ohm, series parallel.
but, a friend of mine bought some SVC 8 ohm subs to keep his amp at 2 ohm. His money, his choice. lol.