Biwiring non-biwired speakers

Hi,

An audiofoolish friend of mine told me that puttin' a biwired speakercable on a non-biwired speaker would be better than the single-wired version of this cable. Is this the (always) case ?

I'm moving on to Nirvana SX speakercable and was wondering wether I'd take the biwired version to connect my Symphonic Line Kraftwerk with my Kharma's ...

Thanks,

Renaat Mattheus