Me thinks he's got an Audio Concepts SV-10 and is confusing it with SVS. ACi used to sell to the DIY market eons ago.
Who knows what the subwoofer guide is? Maybe a copy of the Loudspeaker Design Cookbook or possibly some other book that ACi offered at the time.
Found a a link with pictures to an
SV10 project...look familiar? Found T/S parms
here.
-Brent