Remarkably better sound possible with just 1 system component change?

I could have posted this discussion to a few other categories but chose this one because discussions related to 2 of the 4 components in question belong here.

So it's been ~2.5 yrs since I purchased my current system. I did a lot of research at the time here on audiogon, but no auditioning, and put together a system that sounds very, very good to me.

While I have no complaints, the itch to upgrade has surfaced recently.

I am curious as to whether you guys think it will be possible for me to replace just 1 of my primary 4 components and obtain significantly better sound as a result. The more discernible and obvious the sound improvement, the better obviously. I am not looking for a marginal upgrade - I want dramatically better sound. And I am not looking to replace more than 1 component at this time. I am hoping to get a few ideas/candidates and then may decide to audition some of the recommendations before making a decision. Hopefully some of the upgrade paths are such no-brainers that I may even be able to take a leap of faith without auditioning. Note also that acoustic room treatments are not viable in my current listening location.
My current 4 part system:

1. Lumin D2 - 100% of my listening is streaming via Tidal
2. Mcintosh C2600 preamp
3. Mcintosh MC452 amp
4. Focal Kanta 2 speakers

Cables are Cardas Golden presence RCAs from the Lumin to C2600, Cardas Clear Cygnus XLRs from the C2600 to the MC452, and Kimber 8TC speaker cables to the Kantas.

Soundstaging, dynamics, imaging and overall clarity are all great. I have to say I love the Be tweeters. And the bass is punchy, tight, fast and certainly sufficient for my needs. Vocals and overall sound are warm, liquid smooth and analog-like, just the way I like it. (Forgive me if I've botched some of the characterizations - I'm no expert at this). The only thing I can think of that could use some improvement is the sound quality at lower volume levels, although that is not terribly important to me since most of my listening is in the 90+ Db range. Would be nice, though.

So while I do love the overall sound, surely dramatically better sound can be obtained via a 1 component swap? Budget is ~10k. Or will I need to spend more, or upgrade more than 1 component to achieve the desired result?

Thanks in advance for your time and thoughts.

I'm having trouble pulling up the room image but yours sounds rather drastic for audio but not to worry. My own room is a combination of walls of windows with Rocky Mtn views I will not ignore. Almost every other space of bare wall is covered with oil paintings (luckily not more glass). I love my space. It's for scenic beauty, music, and art and literature (separate TV area).

If you have a primary position/chair for listening (or TV) then I'm with golfmd2 in recommending room correction as the single largest bang for the buck you will ever hear. I use a DSPeaker Anti-Mode 2.0 Dual Core and I promise you that you will not hear a larger improvement in the sound of your system once you room correct for bass peaks.

That DSP is under $1000 and it seems many outside our community can't really hear much so adjust for your chair and don't worry. With the apparent liveliness of you room (somewhat like mine) you can easily dial down the treble highs due to reflections. Hearing good speakers correctly and properly equalized for a room is an absolutely stunning A/B revelation. (Trying to boost nulls is a joke. Don't.)

I'd have originally said DSP and a sub, for cheap:  an SVS SB-3000 (pretty amazing-I have one). I use an REL Britannia B1 so I think you'll be thrilled with those new S/812 subs. I'd beg you to try the DSP unit and I'm positive you will only have good things to say when you dial it in; I'll never sacrifice mine and it made good Raidho D2 speakers sound even better.  Good luck.

Keep the speakers at least 3 feet from the wall behind it. I always thought mine were until I was looking at some acoustic panels and traps (GIK acoustics told me it wasn't worth doing the limited things I can do because of my multiple listening positions and the room, and my wife).

They were only about 30" from the wall in back of them and I moved them out another 6" and it made a noticeable difference.
Another possibility is to upgrade the components in your speaker crossovers. Not change the values. Change the quality.

Few speaker manufacturers spend much on crossover components. You can make a HUGE difference in sound by upgrading capacitors (to film and foil), inductors (to air core) and resistors (best is bare nichrome wire, and dirt cheap), without spending half of your budget. I use MIT Multicap RTX series styrene caps as my go-to caps - you can spend more, but I doubt it would make any difference in your system.

Same goes for preamp and amps, but these can wait until you mod your speakers. Best of all, it's easy to DIY.

Good luck!
I don't get the concept that inprovements have to cost a dime. Back in the 80's I did sold audio and did "tunings" - my name for it -  for rich guys who owned equipment I couldn't even dream of, like Infinity IRS's, Apogees, CJ Premier 4's Quicksiler 190's., etc. I had a 40 year career in the nightclub business. When I ran the Copa in NY all my amps were Macs and now I keep my 1700 around for it's sentimental value. Its tuner and phono are OK through my Spendor s3/5s but only I know what buttons to fiddle with to get it to sound right. In this setup my Marantz  MT6225a and Shure M3D sound life like and sooo much fun. I have a lot of stuff and change it around just for fun. Next up is a Fleawatt amp I just picked coupled with  different preamps to see what happens. My 300B was made by 3Dimension Audio, the guy whose amps were used to voice the original Magicos, and it's in California for a checkup before I sell it, and maybe just keep my Art Audio Symphony ll. At my age I'm lucky I can still lift them. LOL
I know something of this subject.
What one can achieve through properly tuning a system is far more than can be done by throwing money at it. Most equipment sounds more alike than different, if it's any good. After all the goal is transparency, n'est pas?Speaker placement and AC filtering come first.  It takes time and a lot of listening, but you can focus the imaging and sonics through placement, or by ameliorating the placement required by circumstance. Room interactions are much reduced at low volume levels, so you might try lowering your usual volume so more detail comes through. Sometimes the softer instruments come through more easily because less power is being used and the power supplies can better keep up, even with Macs. Don't forget that power requirements are logarithmically related to volume, which is why listening loudly compresses dynamics. Every tech who is a true pro knows that if it sounds compressed you lower the volume.After all this time, I still enjoy this.
Peace and Love,