Best equipment to integrate subwoofers with desktop speakers?

I'd like to better integrate subs with my KEF LS50 speakers. I use them nearfield on my desktop. I use the setup a lot, so I'm willing to replace all the gear.

I usually drive them off a Schiit Yggdrasil/Ragnarok stack.  I've driven them with my floor standing set-up (Mytek Manhattan/Parasound JC5) and that's an improvement in every sonic way.   I sometimes add in subwoofers via XLR crossed at 80Hz which can improve the experience too (with SVS PB13 Ultra, they have some limited built in processing ability, but nothing changes to the signal the KEFs get which still run full range).  But the integration leaves something to be improved I think. 

I suspect this because I own a set of KEF LS50W too.  I prefer the passive LS50 setup to the LS50W (the imaging and vocals are just better).  But when I add in a subwoofer that changes.  The LS50W's built in processing options that can high pass the KEFs and send a sub out win over with the subwoofer integration.

I've considered a few other upgrade routes here:
-I am tempted to try out the Benchmark stack. DAC3, HPA4 pre, AHB2 x2 amps
-update the LS50 to the new META versions (haven't heard them yet, but interested)
-get a paired of sealed subs like SVS SB3000 (they're a lot smaller too which would help fit them behind the desk in front of me)

None of those fix the integration with sub issue though.  For that, I have been looking into:
-MiniDSP SHD. Would be DAC and DIRAC on 4 channels. So I could run room correction on the KEFs and the subs. I'd be stuck with digital volume control though.
-Any other preamp/processor options that have advanced subwoofer integration?  At least with the gear I've tried, most multichannel theater AVRs don't sound as good as a dedicated stereo pre.
-Should I just give up on the passive LS50 set and equipment stack and just get the new LS50 wireless II?  Seems to do everything I am looking for.  I just assumed I could build a better passive equipment stack on my own but when it comes to the subwoofer integration it seems to take out an option like the DAC3/HPA4...

It might be overkill for a desktop system, but the JL Audio CR-1 would provide perfect integration.

It is interesting that you prefer the passive version of the LS50.  It seems that most people prefer the wireless.
Thought I'd update.  I purchased the miniDSP SHD but ended up using it on a 2 channel system instead of on this 2.2 channel system.  I purchased the KEF LS50 Wireless II speakers and use them with a pair of SVS PB13 Ultra subwoofers.  One of the original sub amplifiers went up in smoke, so I replaced both with the 4000 Series Sledge STA-1200 amps which have better DSP ability.  The KEF's built in DSP has a HPF but I'm running them full range- which they start to give up steam at 80hz.  I am crossing the subs over at 75hz and using their integrated DSP and the integration seems pretty good.  This is a major sonic upgrade from both the passive LS50 and active LS50W set-ups I had before!  Way more refined. Imaging is great.  Really no negatives other than I miss the USB input compared to the old speakers.  I am using Tidal Connect for MQA and optical from the computer for everything else.