Im pretty sure audiobahn has or had dual 3 and dual 6 ohm subs. I remember someone asking me for advice on buying subs and showed me dual 6 ohm audiobahn "DUB" subs. FWIW I told him no, he bought them and they blew 3 months later....
Yeah the JBL GTI has dual 6 OHM's and I would recomend them to anyone. They are the best speaker's I have ever heard. ( I rock one 10 in my car and my wife's car)