Jeremy, by delay tops I assume you mean mid/hi cabinets that are delayed to be time aligned with the subs. Yorkville has a processor that, depending on which of their top boxes you use, generally sets the delay at either 10ms or 5ms. I use Turbosound TQ440s with my LS1208s and a DBX260 processor, and based upon a SmaartLive time alignment, with the tops stacked directly on top of the subs, at the front edge of the subs, got delay time for the 12" flush mounted speaker in the TQ440, within the 10ms range, so that is what I use if I ground stack the TQ440s on top of the LS1208's. Depending on what speaker you use, it could vary from this of course, but if they are in phase with the LS1208's and front mounted I would guess they would also be in the 10ms range for time alignment. Hope this helps.