Need help with dating Dunlavy SC4's

@jijoh123  great advice. Do you think if I mated my sc4's with a pair of sc4a's that they would produce a little Athena?

@viridian   this isn't a debate about sealed or ported enclosures. It's about finding out about a manufacturing date of the above mentioned speakers. 

If you have any advice on their age, please share. Would welcome your input.Thanks.

Don't know the age but he worked making stuff for the military.amir did a great interview with him you should search for that. He tweaked every speaker in his sound lab in Colorado prior to shipping them. I have the sc 5,sc6 and 2002. They are big heavy and sound great to this day. There are some forums that have heavily modified his speakers. He did first order crossovers and had patterns on the felt around the speakers   long live the legacy of that engineer.enjoy the music.

@viridian  I completely apologize! In my sleepy state I failed to immediately associate your name to the previous and very helpful post. Also sorry I misinterpreted your humor. These threads can easily turn heated with differences of opinion. I was only trying to avoid that. In the future, please continue to add your input to my posts. I've read many of your replies and you always add important info. Although it can be sometimes hard to interpret humor with just the written word, but I will try and lighten up. My apologies, and thanks again for your info.

@judsauce, A little more history since there seems to be some interest.

John Dunlavy studied engineering and developed new theory for and helped design antennas for the military prior to building speakers.  He opened Duntech Audio in Texas with a stand/wall mounted model which may have been reviewed in Audio magazine by Bert Whyte.  Soon after (sorry I don't have dates) John moved to Australia and began building large floor standing models. TOTL was the Sovereign,  followed by the Princess, my model.  Mine were 5-driver, 3-way, in a WMTMW vertical array.  They were 6' tall and weighed 180 pounds each.  John was a proponent for time and phase alignment so designed all his speakers with that.  

I had the Princess for 19 years so learned a bit about them  They were rated at 90 dB efficiency but that was optimistic.  I tried many amps over the years and the best were Parasound mono JC-1s, rated at 800 watts into 4 ohms.  After several years I noted a scraping sound which was resolved by rotating all 4 woofers 180 degrees.  Eventually I had three friends who also owned Princess so I learned they required a large room to sound their best, with some distance from front and side walls.  I sold them only because of a pending move but I still miss them.

I had the good fortune of speaking with John a couple different times at the CES in Vegas.  That was after he opened DAL.  Most of that model line up was similar to the Duntech line.  My Princess were siblings to the SC-IV and IVa.

@viridian, You might lighten up a bit here.  I had the same initial impression as judsauce with your vented comment.  You have a history of knowledgable and helpful posts so that one surprised me.  Obviously I too missed your humor.