I've been playing out for the last decade using almost strictly 10" speaker cabs. Either I've used 210's or 410's, but always 10's. I even had a 412 cab. Then about a year ago, I started using a 115 along with a 210 cab. I always did the traditional thing and put the 115 on the bottom and the 210 on top. It was fine. But in an ever-evolving attempt at getting my sound the way I want it, the last two gigs I experimented and put my 210 on the floor, and put the 115 on top and angled the 115 back so the 15" speaker was pointed up at me. I even unplugged the 210, so I only played through the 115 (no tweeter...just a 15" speaker). What a revelation it was! Everything sounded fuller, yet still clean and punchy. Even my drummer (who, unlike most drummers is very anal about our sound, both onstage and out front...we all setup the PA sound ourselves) commented on how it was the best tone he's heard from me yet. My guitarist said the same thing. I agreed. It kind of dawned on me, that after years (almost 20?) of playing through 15's, switching to 10's (probably because it's the "in" thing to do) left me with this never ending quest to find my sound again. I wasn't sure why. I kept trying different amps, different configurations to my rig, but something wasn't quite right. I think what was missing was that full, deep bass sound that only a 15" speaker gives me. Right now I'm playing through a Peavey T-Max head into a Peavey 210 cab and a 115BXBW cab. With the 210 on the bottom, I'm not hearing as much of that cab, and mostly I'm hearing the 115. Ever since I put the 15 on top, I've been thrilled with my sound again. No boutique gear, just plain old Peavey head and cabs...but it's just so perfect! I'm using a Zoom B2 pedal and I get "my" sound out of any head/amp I play through, but depending on the cabs used, the only way I like it is when I'm playing through 15" speakers. Just for the heck of it, I played through our JBL mains (15's) and yup...still there. I played through a friend's 2-15 cab and again, there it was...my sound was right there for me. I plugged my head and Zoom through a variety of cabs (10's and 12's) at a music store, and something was just missing. But as soon as I plugged into any 15 cab, my sound was back again. I guess I've just rediscovered that I love my sound through 15" speakers and 10's just don't cut it for me any more. I know how all the 10 lovers will say speaker size doesn't matter and 10's will go just as low, and sound just as good. But while theory looks good on paper, in real world gigging, the 15" speaker sounds better to me. I love a clean sound, but I also want it to sound full and warm. 10's (regardless of how many in a cab) just sound too sterile, or too much bite, and not enough of that low end "oomph" I like to go with it. I'm planning on getting rid of my other two 210 cabs and getting another 115 (4 ohm) to go with my existing 115 (4ohm)...(and yes my head goes down to 2 ohms). Anyone else rediscover that they dig the good ol' 15" speaker over other sizes?