Subwoofer Suggestion

Hi guys I need your suggestion regarding subwoofers. My system is composed of Focal Kanta 3, Kanta center, 706BK it would be used 50/50 for music and HT. My room size would be 13m by 4m by 3(Length,width,height). Would it be better to go for dual pb1000/sb1000 or single sb3000 or single pb2000 or single PSA S1500?
I bought 2 SVS sb2000 subs on sale for $650 each (price reduced when they brought out the sb2000 pro model).  They compliment my Martin Logan 60XT towers.  I set the crossover at 80HZ and let the subs handle frequencies below that.  Room placement is not optimized and I seldom play music real loud.   I’m not sure I have them dialed in correctly — read somewhere that mains show be set at 20 HZ and let the subs handle below that (?).  Don’t know if that advice works or not.
@bob540 may I know the size of your room?
What are you trying to achieve?  Is it to seamlessly fill in/extending the lower bass resisters while maintaining a cohesive fidelity or do you want the movie theater chest thumping experience?  These are 2 very different goals as the AudioKinesis Swarm seems to lean towards the former.  
What are you trying to achieve?

My 1st priority is to seamlessly integrate a subwoofer into the system that would be able to dig deep while pressuring the room a bit. The 2nd priority is the HT. Idk if this is feasible due to my budget 😂
I suspect you know the truth. You’re very fortunate to have great sounding highly resolving speakers. Imagine swapping out one of the Focals mid/bass drivers for a lower quality one- you probably wouldn’t have liked the lack of cohesion/sound and wouldn’t have purchased in the first place.Another analogy is if you heard a larger Focal speaker with bigger bass drivers but these bass drivers were also sub par, you’d likely reject them also.

On the cheap, you may get away with extending linearly your bass registers such as the AudioKinesis Swarm (which I believe is an great price/performance product) while maintaining cohesion and detail, but if you want both excellent performance on par with your Focals AND increased bass power, you’re going to have to spend more $ to the level of Rel or JR Audio for instance for the larger units. Otherwise, you’ll have to compromise.

Single subwoofers can be very problematic due to room modes, and multiple subwoofers can damage your pocketbook.

If I were in your shoes, though not ideal, I’d seriously consider the Swarm. It would definitely elevate your system significantly towards both goals, level out room modes, and hopefully may be satisfying enough.

Another option is to use cheaper less fidelity subwoofers used exclusively for HT.

Also, you may consider the used market to save $ and/or upgrade.  However, I haven’t researched whether or not the wear and tear of used subwoofers should be a concern/issue.