Not all of them did,as I have a pair of AX3's from the late 1980's that were not ASW designed. The AX5 had a rear firing built in sub, and the AX3 had a front firing model

I am sure that Axiom must have pics of the older models. I recently found a marketing piece and my factory tour pictures from the 1990 time period. I am working on getting them scanned and posted