Sometimes, well, all the time, the simpliest things make the biggest difference. If your amp is too loud, but you have to turn it up - this thing does the trick. It isn't cheap, and you could make do with a do-it-yourself solution; but this thing is really well constructed, heavy duty and looks totally professional. The thing folds down flat as a pancake; you can run cables easily in the "channel" between the panels and it weighs about 14lbs. Nice. I actually ran my Germino Club 40 and then Lead 55(!) full bore in my 12 x 18 office today; and didn't die. It was still LOUD, but I am still here typing this now. Impressed! You can use this in combination with the THD Hot Plate to tame most anything and still get your tone. I like the Hot Plate at -4db and -8db; I can suffer it at -12db; now with this I bet I can bring the amp level up to where the speakers start adding their magic and the tone becomes much more "present" and "full" and still not take anyone's head off. And, it looks cool. I have a rehearsal on Monday then a big show on Tuesday; this thing will be going with me. Thumbs up to Clearsonic. The A2-4 is as simple as can be and works great.