These 5 cabs are tuned at 40hz. I am using 2241h drivers driven off a seperate aux feed from the mixer into a rane 2-way crossover and only using the low ouput with the xover dialed in at 80hz. So, 80hz and down on a sperate gain knob on the desk. This way I can add or subtract the four double subs and balance with the fullrange mains.

I found 37hz a little low for my liking.
scotty.