Sound stage

I've forgotten how to figure out the impedence for the old Dynaquad adaptor. I'm using Ohm Walsh 2 speakers (4ohms) in front and old Spendor 8ohms in the back. Talk about soundstaging, but I've wondered what kind of load this is putting on my B&K ST1400 amp. It seems to be working without any problems.

Thanks, Fotopres, and you would be right about the Ohm Walsh speakers and ambience, but they sit in a large and pretty dead room. I don't think that two speakers are enough in such a sound swallowing place. Digital processing didn't somehow feel right, but old Dynaquad usually does the job, and it's my favorite word, cheap. The Spendors work fine for ambience, though their sound is not as effortlessly "soundstagy" as the Ohm Walsh or the Spicas that I have.