powering two pairs of Dahlquist DQ10s

On the wall!!!! Blasphemy. DQ10s are not moose heads or flat-screen TVs. Forget the second pair until you get the first pair positioned correctly.

YUK....get them off the wall

The wall is the right place, DQ10s should be seen and not heard! LOL You can power them both with the same amp IF it will handle low impedance loads. Running them in parallel will halve the impedance the amp sees, not all amps will be happy with this. Why do you want to use 2 pairs, more volume? A sub for one pair may be more practical. Electrostatics and planar are doubled to increase volume and bass, cone speakers are more problematic as they will usually play loud enough and the multiple drivers will interfere with each other to a greater degree.

I agree with the other posters who recommend getting them off the wall. They generally will like being in or near the cardas recommended locations - see cardas' web site.

I had two pair, twice. The best sounding happened to be side by side on stands that raised them about 18-20 inches off the floor. Each pair was driven by an Audio Research D76A, which were driven by an Audio Research SP3A1. The system was one of the best I've ever heard - open, airy, played deep and tight and loud with excellent transient response, detailed but pleasing highs. Rock and roll was close to perfect. If I could get that sound back I'd never want to make another tweak.

I later had a 2nd double pair that I mounted in custom steel frames so that they were vertically stacked rather than horizontally side by side. This configuration was visually more impressive but sonically not as good, but it could have been different/lesser electronics and/or less desirable room acoustics.

In any event, DQ-10s are classics and worth every penny if you find good ones on the used market. 2 pair has the potential to be a knockout.

I have 6 pairs of DQ10s set up. I used some industrial strength metal racking obtained from Lowe's and modified them to accommodate all the Dqs. They are essentially stacked upon each other in three sets of rows. I am unable to post a picture here. If you send me an email to jenguillo7@cox-internet.com, I'll send you a picture and schematic of how they are hooked up. Essentially l amp is pushing 2 sets of DQ10s. Your amp must be able to handle the split load. Good luck.