Weak Link in chain as I upgrade from mid-fi?

@christianb5s4 What an excellent progression!  One of my biggest “aha” moments in audio was when I upgraded from a pre pro to a dedicated stereo preamp and sounds like you experienced something similar.  It truly is the heart of a truly good audio system.  Maybe a nice Pass amp next to go with your pre?  Gotta be on your radar, no?  Although I gotta say I’d make it a point to hear the GaN amps from AGD and Atma-Sphere before making any final decisions as they seem to be pretty groundbreaking amps that people are already putting in the “end-game” category, if there even is such a thing.  Best of luck in finding THE amp that ties all your other excellent equipment together. 

Don’t run out and buy B&W 800s or Wilsons. Not only will they not pair well with your current amp, they will highly limit your amplifier choices going forward.

The flip side of this is that going with high-efficiency speakers will greatly limit options there.  Always trade offs. 

Just saw this review of the new Gustard R26 DAC and think it should be very high on your list of potential upgrade options.  I trust this reviewer’s ears as his take on my Musician Pegasus DAC very closely mirrors my own impressions, so when he says the R26 performs very near the level of the incredible and much pricier Denafrips Terminator Plus this comes across to me as a no-brainer level recommendation.  Heck, buy it on Amazon and return it if it doesn’t just blow you away, but that seems highly unlikely.  While I’m very happy with my Musician Pegasus, if I was doing it over that is absolutely what I’d do.  But, I still think as good as the R26 may be and as per my prior post, adding a couple good subs will make the most significant improvement to your system and your enjoyment of it on an absolute basis.  Once again, FWIW. 

https://soundnews.net/sources/dacs/a-new-point-of-reference-gustard-r26-discrete-r-2r-ladder-dac-review/

what is the best solution to getting some controlled but blended oomph in the lower octaves?

Good question and kinda where I was going. Possibly the most impactful and immediate improvement you could make would be to add a pair of good subs — yes, definitely a pair as it improves performance markedly and makes it easier to deal with room issues. I’d suggest a pair of SVS SB1000 Pro subs you can get for $1150, and they offer a truly risk-free, 45-day trial (including shipping both ways) so if they don’t completely rock your world — but they totally will — just return them. The SB1000 Pro is a pretty small sub so won’t dominate your room, gets you down to an honest 20Hz that basically gives you a true full-range system, come with their own integration software that makes seamlessly dialing them in much easier, and SVS provides excellent customer support if you ever need help/suggestions. What many don’t realize about subs is that they not only greatly improve bass, but you’ll find when properly set up your entire soundstage will expand in all directions, imagining will improve, and even your mids and treble will sound better. And as a bonus, as you’ve got a combined system the subs will transform watching TV/movies into a completely different and much more involving experience. Frankly, and especially since you seem to like your sound already, adding a couple subs is so impactful it might cause you to forget the itch to upgrade for a while.

When you do decide to upgrade I’d start with both the integrated and speakers together as they need to play well together, and at 90Wpc your Arcam will struggle to drive most better speakers sufficiently or get the best out of them. Anyway, hope this helps somewhat, and best of luck.