I'm not sure, but if you've heard people having problems driving SV Subs with a receiver I suspect that I know why. Most SV Subwoofers are unpowered (they require a separate amp, unlike many subs that come with a built-in amp). Those are pretty hefty subs, and I'm sure that most receivers would not have enough power in their amp sections to drive one. Being a pre/pro, the 950 has no amp section, so you would need to get separate amplification for an SVS (which is what a sub like that should have anyway).
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Gonk