Steve Gadd uses 12 and 13 racks ! Traditional size and suspended 14 and 16.I guess we're not getting any 12/13 love here. I blame Steve Gadd for getting everyone on this kick that you must have a two inch interval between drums for them to sound different. Fact is, if you know how to tune, you can make it happen. We've been doing it long before Yamaha marketed the 10/12/14 interval to us. And everyone seems to forget that in the beginning, Steve's floor toms were only one-inch apart - he originally used a 10x14 and a 12x15 tom hanging from one stand.
If you're really stuck on the idea that you need the big separation, why not go 10/13/16? Then you have a three-inch difference! Of course, if you wanted an extra tom, you'd need a 19" floor tom, and a 7" rack tom.
At one show I played in college, I used an 8/12/16 set-up. FOUR inches between! Comical!
We may thank Gadd for the suspended floor toms idea, but the 10/12 up are more a Weckl thing.
I guess I'll be repeating myself here, but the volume is important. 10x7 is really small, too short note to my taste : I play 10 & 12 racks in power size and it's OK (10x9, 12x10). The 10x9 can go low enough and sustain long enough. That being said, unmicked, like Larry, I favour the 12 and 13 racks : Ok they sound close when you play in a row, but this isn't what I do the most, the important thing is to have a good sounding tom right in front of me.