I have noticed a disturbing obsession around here, with efficiency of cabinets. Now am I the only one who buys cabs for the way they sound rather than any figures on "efficiency"? I have tried very efficient cabs that just sounded awful - boxy, indistinct etc. And I have tried cabs that were very inefficient but sounded great! So who really cares? My view is that if you are only interested in total volume, to the exclusion of anything else - like high-quality sound - that you would be better off buying a road drill, or a small amount of explosive, rather than a cab!