Not to stir things up even farther (is that possible?) but you don't even have to look far to see hat I'm talking about in this thread. Right near the top of the intake/exhaust section is this thread. In it the OP is asking for a catback that has NO drone. He even emphasizes that he "hates drone with a passion".
CBE w/no or least drone?
The *very first poster to reply* proceeds to tell him that FI catbacks (in all their combinations) have "no drone" and are a perfect choice for him.