Most alts iv put on I didnt need a smaller belt because the tensioner still made it tight . Tell dude to put the smaller pulley back on. I think its pretty messed up he did that without telling you
Should have the lpf aroung 50-80 . And subsonic a little below your box tuning . . . . Where did you get the enclosure? Can you post the specs. Like dimensions of the enclosure and port area and length?