Originally Posted by basscooker
just put the gb on top, and be mindful of the possibility of it reaching its limits way earlier than the avatar. and pay attention to what it tells you.
Yup...no way to predict it other than to try it.
If you stack them on end to make a tall, skinny stack, that will put the crispness and clarity of the Genz in your ear, allowing you to hear yourself better, and thus not having to turn up so much and risk any damage.
Another benefit of that is it will spread more of your sound widely (the uppermids and highs) across the audience so you have a more even sound for more listeners.
One disadvantage maybe a bit less coupling in the lows, but that is usually outweighed by the increased dispersion.
One thing that can cause whackiness in the lows is if one cab is ported and one sealed, or both ported but tuned at fairly different frequencies from each other, like one 40hz and one 50hz.
Sometimes the mid whackiness can be bettered by simply placing the top cab a bit forward or rearward of the bottom one to correct some phase issues. These experiments will usually result in sound that's either more clear/coherent or more smeared/weird.
In the end, you don't know what's up without just olaying and hearing them for yourself.