Cab questions!

So I own a darkglass microtube900 amp And I am running it through a hartke hydrive 4x10. I was told buy the shop that sold me the amp that this would be a fine cab to pair with the amp. There is nothing wrong with my rig but I’m starting to play bigger venues and was considering adding a hartke hydrive 1x15 to the family to add a bit more bottom end BOOM. So the issue lays in the fact that I know absolutely nothing about amp impedance and if adding a 1x15 to the rig is even possible or would it even do anything? Is there any go to formula to work out is a cab/cabs are suitable for an amp? Any help advice or suggestions are welcome thanks in advance.



I’m alittle ignorant about amps and this kind stuff and every video I look up is contradictory to the last.
 
Well, the amp will run at 4 ohms, so adding another 8 ohm cabinet is fine.

Your 410 is rated at 1000 watts. The 115 is rated at 500 watts. Running at 4 ohms will take advantage of the whole 900 watt output of your amp, but....

If the 410/ 500 watt rig didn’t cover it, my approach would be to lean on FOH more than trying to cover a larger venue from the stage. Also, I personally wouldn’t want two different cabs, nor would I want two differently rated (watts) cabs.

But maybe you have no FOH?

Just get another 410, if you can handle the awkward form factor. For me, a single, 4 ohm 212 always worked best, all things considered.
 
Hydrive cabs are 8 ohm cabs and the Darkglass can go to 2 ohms, you could run 4 hydrive cabs with that head and the cabs are already prewired to do this.....It's the exact rig I run. 2 410's, 2 115's alternated top and bottom. I have massive sound and agree with above about tweeking eq for bottom end.