This link is from the Klipsch forum and was posted by ELENA from Italy, who saw a similarity with one of my front-loaded annulled designs. His design (which we will call the ELENA horn)is a front-loaded reflex-ported corner horn of short length. Here is his paper in pdf format on the subject.Since the reflex porting eliminates the possibility of annulling the driver, he has come up with a unique approach which uses tuned cavity filters along the horn pathway to reduce the reactance peaks and tuned ports along the channels to increase the response in the troughs caused by the short pathway and unannulled driver. The back chamber is also ported to the front of the cabinet. It's well worth investigating.
DM