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

Subs generally have their own amps (built in or otherwise) and you would not be running it off of the amp in the receiver. Therefore, you don't need to worry about the impedence (ohms) on the receiver when picking a sub. From what I've heard 'round here (I haven't heard it personally) the VTF-2 is a good choice.