I've conducted a few comparo's myself, and to be honest, the whole single-blind, double-blind stuff is totally unnecessary. When a test is set up properly, you'll find that speakers differ SO MUCH that you'll laugh at the notion of DBT's. Sure, you'll pat yourself on the back for going thru the monumental extra effort to do a DBT, but the results likely won't change. Sure, once in a while you find yourself comparing two very similar sounding speakers, but in my experience, most sound drastically different thruout the midrange. Oh...one more thing. I use an 80hz high pass filter thruout the tests because newbies are so easily swayed by louder and fake bass.
My method:
1) Most important: Buy an inexpensive A/V switcher with remote from Ebay. The only cost $25 or so, and let you sit back in the listening chair and instantly switch back and forth. Instantly! None of that disconnecting, setting up, taking down of speaker BS. Your auditory memory isn't that good.
2) Radio shack meter for sound level matching. Yes, it's good enough.
3) Two pair of speaker stands if you're testing bookshelves.
4) Set them up right next to each other AB.....AB style.
5) Two amps with adjustable gain so that you can level match the two.
6) Single source...preferable CD player.
Go to town and be amazed how quickly and easily you can tell differences.
Also fun to do is to run the response thru a laptop + microphone analyser program. Then you'll see the typical monster dip in the midrange that I hate.
Ever since I did a few of these comparo's, I decided that I vastly preferred the sound of flat response pro studio monitors...and active ones at that. Different strokes, eh? Also, I don't think it's unreasonable to pit expensive monitors against cheap ones. You'll often find that their respective values don't relate to their price tags as far as sonics is concerned.
Well, that's MY 2¢
Take it with a truckload of salt.