Dedicated Vinyl system next upgrade?

@paulgardner
NP thanks for the clarification. Then we know that you have reached your maximum of treatment as I said before. ;)

Then it is time to measure and identify issues and solve them with a little DSP in the signal path between preamplifier and power amp/s. With that solution you do not need to put any sound treatment anywhere.
Benefits:

• Better integration between sub/s and speakers by:
• > by be able to compensate distance/time difference between sub/s speakers.
• > by be able to use Lindquist steeper x-over filter that he also advocate for.
• Adjust the unlinear frequency response of your speakers (all speakers has that more or less) or maybe there is a dip that you like.
• Adjust for unlinear frequency response how your room interact with your speakers.
• Being able to adjust for "Equal-loudness contour" (Fletcher-Munson curves or international standard ISO 226:2003)
• Being able to adjust for your own preferred sound preference.

Probably something that i have forgot..

Regarding the integration between sub and speakers.. I am able to turn off my bookshelf speakers. And only listening to the subwoofer. I got very surprised when I could hear faint in the background when the subwoofer were playing the sound of the singer and other instruments that is higher in the frequency range..
And the cut of frequency were at the lowest setting at 40 hz!
I should not be able to hear a singer at all. I suppose the implementation of the knob on my subwoofer were using a shallow x-over slope perhaps max 6 dB/octave.
But with the DSP doing its job and I use 48 dB/octave at 53 Hz. Now the problem is solved with that the subwoofer will only amplifie and play those frequencies it should and nothing else.

I guess I am on optimize's side in this with a few caveats. Room control will correct frequency and time issues better than any other method by a long shot. But, it will not change the way a room sounds. It is not eliminating reflections or preventing echo. It's time correction is purely between drivers and subs. If you have a reasonable room and sub woofers set up correctly room control is all you need. Unfortunately, this is usually not the case. In the bass if the nodes in the room vary widely the power required to correct them will clip amps and bottom out woofers. With two subs if you put them right up against the wall or in corners symmetrically placed around the satellites you can minimize this. With one sub you can forget it. 
Most people do not understand that room control is done at very high resolution with high bit density. In my unit it is 48/192. Resolution this high is invisible, vinyl sounds just as vinyl always sounds except better.
I am working on pictures of my system including shots of the computer screen with measurements and corrections for the virtual systems page. I am having a hard time capturing the screen without haze so, if anyone more skilled in photography has any ideas they would be greatly appreciated.

Paul, if you go for a new tonearm I might suggest in order of expense the Origin Live Zephyr, Kuzma's 4 point 9 and finally Schroder's CB. Before you buy any tonearm please check the spindle to pivot distance and make sure the pivot will land squarely on your tonearm board which is not very large. Again, in terms of bang for the buck just changing the cartridge to one that is more compliant than the Hana will make the largest improvement in sound quality and eliminate some of your woofer pumping. I always assume people are using a full 2 way crossover for the subs. If not, getting a proper 2 way crossover will stop woofer pumping dead and drop distortion in your satellites by an order of magnitude. It will also allow you to raise the crossover point and make seamless integration easier. 

Back to room control, if you think the frequency response of your system is reasonably flat you are sorely mistaken. Unless you have room control This is a generalization I am more than happy to stick to. If you get a calibrated mic and impulse testing program,  https://www.parts-express.com/dayton-audio-omnimic-v2-acoustic-measurement-system--390-792 ,you will see aberrations over +- 10 dB. Your fequency response curve will look like the rocky mountains. I have ESLs and I will show you all their response curve once I get the photography down.  

Regarding tonearm.
If/when try to get one there you can get added functionality. Otherwise you get just the same and probably only little better in some regards.

One added functionality that will generate better sound quality is if you can get one with the ability to adjust the VTA (SRA) on the fly  during playback. Yes we can always do it manually back and forth with a less of a success. So do a tone arm swap that counts.

Another alternate is to get a tone arm that you could in the future could add maybe a "Easy VTA" to it at a later time.

 Anyway good luck with your upgrades. :)

Compare the sound of your system to head phones. Good headphones are pretty flat. Except for the presentation your system should have the same tonal balance as the headphones. I think (not sure) that this may be the reason many love their headphones. They sound more right than their systems even though the band is in the middle of their head. I suppose then the mark of a good system is that it sounds like the headphones except the band is in front of you where it belongs.

If you are in the mood for an experiment, then try to replace your Clearaudio TT with a vintage direct drive like Kenwood KD990 (or similar) or Technics SP 10 or 12 with a tonearm that matches the wonderful Hana SL.