powering two pairs of Dahlquist DQ10s

You could always use a Speltz Autoformer to bring the impedance of two pairs operating off of one amp back up to double or even triple the impedance of a single pair.

Years ago, I heard 2 sets stacked, the top set was upside down. The guy made a bracket that molded around the top edges of the bottom set and the top set slid into the bracket, then had screws or bolts go through the side of the brackets into the speakers that stablized them fairly well. in this case, 2 sets were an improvement over 1 in almost all area's.

Find a pair of Audio Research D-76A's. I have a customer who had modified DQ-10's. I refurbished his amp and it sings!!!!It sounds better than when it was new because the new caps are much better than the stock ones.

Timlub or anyone remember who suggested the stacked DQ10s?? Someone marketed the metal brackets you are talking about and the reviews were very favorable. I can't find it on the internet. I remember when Mark Levinson sold his stacked DQ10s on ebay, that is when I researched it and pondered the idea. Hifigeek, how did your customer modify his DQ10s? I have added 12 inch Infinity polypropylene "car" woofer :)..fits perfectly in hole...little close in depth.... and Heil midrange driver and infinity tweeter to replace piezo.... love them. My friends think I am crazy...but $500 total in speakers and I am having fun. FYI, I compared Double Dyna to D76A on these speakers and it was amazing how similar the midrange was on two completely different designes....Just like Harry Pearson said. Also, I just read a Jim Bongiorno interview where he stated he "HATED" tubes...love it. I had to turn the bias up (Enid Lumley told me what blue pot) ;) on the Dynaco to make it sound more like the 76A....The Dynaco ran HOT!! Well, back to trying to bias the ARC Classic 60...having fun again.
Oh, DQ10s on the wall... I have several comments, but I shouldn't.....but thanks to the post anyway.

I had a nice pair of DQ-10s in the early-to-late 1980s and really liked them. About 1983, I installed the Randall Research modified crossover and drivers with nice results. With today's crossover components, wire and drivers, I would imagine that you could assemble a really nice pair.

Properly powering all four speakers with a single amp would be a tall order, to be sure. Get them away from all walls! not behind or on sides. Properly set up, they will image like crazy, with light, airy highs. I can only imagine how nice four would sound.....