I have a marantz pm7000 integrated amp and am wanting to add a sub. My question is that for one speaker set up, the marantz say 8ohm minimum and for a two speaker set up 16ohm minimum? Does this mean I can't add an 8ohm sub to my system. In addition does it also mean that I can't add a 4 ohm sub (like aperion?). I am considering the Hsu vtf-2, but am open to suggestions. My two channel sytem is strictly for music at this point. Thanks for any help