Amp setup - Tilting back one cab and not the other

what are those wedges?

 

more manufacturers need to design this capability into their stuff! definitely a good idea, especially with smaller boxes.

that said, you should try stacking the cabs "tallways" for a TB-approved tall&skinny stack; you'd likely need less angle on your top cab, or maybe even none at all.

 

There are times it can be unsteady, but if it holds for you and sounds good, then it's all good.

 

I tried this once on an elevated stage and came to the conclusion that, while it made it easier for me to hear myself, the upper angled speaker was beaming way over the audience's heads so all the good tone was hitting them from the lower speaker only. Am I off base here?

 

IIRC, according to Bill Fitzmaurice, for an even more "correct" setup you should crossfire the cabs, i.e. tilt the bottom cab instead.
Some cancellation would still occur in front and above you but it would only affect the peanut gallery if there.
More importantly, it would be significantly more finicky to implement, entailing the use of three of those wedges instead of one (unless you used the wall to lean the cabs against, which you'd better not to since the 121H is rear-ported) or an equivalent contraption; also, I suspect the benefits over your current solution would probably be negligible - especially on tight stages, standing in the near field of the tilted top cab should offset any, or most, comb-filtering effects induced by the ceiling-eyed vertical stack.

 

Yes and no. True the highs and upper mids will be aimed more toward your head than theirs. But they have a cab they can hear, so not like they're missing anything.

 

I too endorse the "skinny stack". Once I tried it I never went back.

 

In my hypothetical arrangement, this image is taken from stage right (since of course the bottom cab wouldn't be on its back, pointing to the ceiling and with you standing over it, imagine it and the upward fired lobe rotated a couple degrees clockwise, so that the angle formed by the baffles becomes >90°). Let's say your ears are where the small square is - well, probably a little closer to the cabs than that, on 2nd thoughts: inside the (vertical in the pic, slanted IRL) lobe anyway. The audience is reached by the other macro-lobe, but there is cancellation (varying in spatial extent and I guess frequencies according to the crossfiring angle) starting at a certain distance from the system, around the plane perpendicular to the line between the centers of the drivers and equidistant from them; since that plane is tilted upwards it should not affect the audience.
(Please note this is only parroting what I think I've learnt here. Do a search on "crossfiring" and the like, and more reliable opinions should come up.)