Mix and match subs?


I have a Paradigm x10 sub and am planning on adding a second sub. 
Would integration be difficult if I a) got a 10 inch sub from another brand (thinking SF Gravis III to pair with my SF speakers); or b) the x12 from Paradigm (for getting even deeper).

Or c) should I just keep all the same and get another x10?
w123ale
It is better that the subs match for proper integration with music due to tonal and sound pressure variations due to driver and cabinet size which effect the sound greatly.
Strangely I've done both. My second sub was the same as my first and they are placed at the front. After reading about the benefits of four, I purchased a pair for my rears that might be considered inferior. To be honest, the improvement is terrific even though there is a mismatch.


Just got back in. Using Paradigim on the surround sound setup for my footboard based second bedroom system. Center channel and bookshelves in all white. Using a Boston sub and HSU 15” sub for that setup. Really love it. That HSU sub also serves my emerging 2 channel  wall and the long theater wall with  3 other subs. Only two of those match each other but they are all 3 the same band. The two matching are sealed and go to 18HZ. The other of the same brand goes to 23 while the Boston stops at 38 (who woulda thunk it the way if satisfies in HT duty. The HSU goes to 16 at I believe 16 HZ. It’s a hybrid with EQ and 2 ports that came with plugs for tighter 22HZ musical notes. This is somewhat happen stance, or what happens despite planning. Good deals came and away my money went and with the new products coming well before the more than month away promised shipping dates. The $1 hold charge for my preorders lasted 2/12 days before a month magically went away and a phone call confirmed my products were shipping that day and seeing the full charge on my card was indeed a legitimate transaction. I wanted at least two matching subs in this system since the 90s. Getting back in the hobby with my then 14-year-old son this most recent May, and redoing his gaming rig with the best curved 65” monitor 2021 could get us,  was the impetus to at least start adding subs and pulling 3 old receivers out of mothballs to examine exactly how much the dust of antiquity had done to their sex appeal but most importantly, examine them for real use by mixing with old Krell, Thiel and whatever else that was now dirt cheap but offered excellent 2 channel use, but not much else. Well, the sex appeal of the 90s gear is the warm and fuzzy factory for me and helped to rekindle my 2 channel love ask my Infinity Modulus 90 system look as good as it ever did with no wear and tear or marks, nicks, scratches, paint swirl or deteriorated grills or stand. Still have the spikes in sealed bags. But that beautiful and timeless Darth Vader looking face is a face I love as much as Day 1. They have delivered on everything promised and now I am returning the favor to finally get them some new dance partners.even though the matching is few, the dancers are the right crew if you want to eliviate all your bass problems. All these subs have a myriad of controls and moves, if you will. They could be set and forget (yes, I know -forgotten- but paying respects to Ron Popiel) , but I’m in the middle of painting the large room and redoing everything and anything  to give me two HTs and a separate 2 channel wall with its own seating. It’going to be cramped at 24” x 22” with a step down entryway lasting 15’x 3’ wide  that leads to an entry nook and a separate 3’x5’ notch in the corner that adds to the space (dual walk-in closets too on the back wall opposite the longwall where everything except rear speakers will live . And back there, I will try to hide two good small subs but nothing anemic like something with micro in the name or something that uses the word but in the ad copy. Paradigm will make a good choice as they will scheme up with the old mini high line 55” 4K TV that  but sits at the foot of my bed on the red and black norstone 48” 3 tier rack. With the new subs, it will make a great little compact Lo -Fi HT but now, with all 5 subs, it sounds like a giant killer, most notably, I no longer covet the B&W speakers I once really wanted and thought for sure I’d own.      It’s possible they could be something beyond the parts of all matching subs, very possible.    But what I’ve happen upon is: a clean little modern bass loving band of brutish, smooth and mostly mesmerizingly beautiful members in this rag tag happenstance assemblage of formerly single bass boxers l making their way in the world just fine without me. But I like to to think the sum of these parts is far more satisfying than a bunch of synchronized clones each born with a silver spoon in its mouth waiting for Johnny and the gang to bring the meters, beer, pizza and a  few of the entertainer friends Johnny knows from his day job as the DJ for Molly Brown’s 3xs a week on the busy nights. 
Hello,
I have blended two totally different subs together with great success. This was talked about not to long ago. In fact you may want a sub that can reach down a little further. I am now running to JL Audio F110s with the JL Audio CR1 crossover and two REL T9s. MC and several others have a lot of good advice on setup. By going to 4 subs it made a huge difference in the bloom but also the sound blends across the whole room. The entire frequency, not just the bass. 
So 2 subs is definitely my max. Seems like there are differing opinions on to pair or mix and match. Seems to me a Paradigm x10 and x12 might work pretty well together. I would think in the frequencies where they overlap that they would blend well and the the x12 would take me down to 20hz. 
Or in the shared frequencies, would they not blend too well because they are different drivers?

Has anyone mixed subs with two driver sizes and had a bad result?