You can't blame a speaker for it's sound when you put it into a position that is acoustically forcing it to have a catastrophic response. If you insist on using the speakers like that, only a seriously wrong tuned speaker may sound better or what you expect to be "right".
Where did I say this has no effect? It has effect on all my speakers. But speakers that already have a small issue in this region will have an even bigger one compared to speakers who have no issues like that in an anechoic situation.
Both will sound wrong, but one will clearly sound more wrong than the other. And the one that sounds less wrong will later on be easier to correct then the other.
You noise problem is nothing normal, but points to some serious fault in your gear. First on my list would be the power supply of the PC. Simply use another PC in the same position and see what changes. Noise gone= PC defective. If you can, dig deeper, if not remove it. Don't continue and try to fix an unfixable problem with more, different hardware.
Could be. But the problem did not exist before I had the sub in use. The wires got much longer and the quality of the wires is very basic. I'm not planning on replacing them by different RCA cable since I have just received everything I need to build a nice quality set of XLR cables. That was already the plan, even from before I had the new PC.
I can try with a different PC. I still have the one that got replaced by this new PC sitting in the attic.
Don't mix your specific hardware problem with any characteristic of a speaker, hiss or anything else you have "heard of".
There are so many people out there using stereo stuff wrong, that even the best products have problems sometimes. Folks always blame anything else for their problems but the main cause: Their own inability to install a fault free system. The internet is full of such stuborn people talking good products down.
Like you blaming the supply in my new PC?

I have not blamed any product for my digital noise issues, except the shoddy wires I'm using to connect the new sub to the DAC. Those are the only ones I have that are long enough and I'm only using them because I already had the plan on replacing them with XLR cables. I just had to order a few parts before I could start with building them.
None of the products on your list have any design flaws. They just can be used wrong quite easy and are more complicated than passive speaker. More options means more to do wrong.
As I don't know all of them, my favorite would be the ADAM TV5 which has a great price/ performance ratio (the best?) and does nothing wrong. For your hearing position + sub a smaller cone is better than a large one. Just a physical fact. So considering ADAM, smaller one is better.
That why I have mainly put speakers with 5" woofers in my list. Except for the Adam T7V and Kali LP-6. And there is a reason they were at the bottom of the list. The Kali climbed a bit, just because of the general quality of the speaker.
Size is indeed a factor I take into account when choosing.
My solution to your problem would be an active speaker, sub and a dedicated music PC (or laptop, but your own!) and some room correction. Which depends on your personal preference and budget. REW is great and free.
A good start would be a low priced, calibrated microphone like the Sonarworks SoundID Reference Measurement Microphone. Stay away from USB microphones, as they can not measure time dependent correctly. Which makes an interface with powered XLR a must have. Focusrite rule in price/ quality if you get one of the earlier generations.
Only buy an USB mike if you are 100% sure the room correction you use has no problem or limitation with it.
I already have UMIK-1 laying around for years.
I will use it but I will consider a better solution. I'll ask IK Multimedia what they think about it.
A last point. People build dedicated rooms to listen in with very special planing. They know it is impossible to turn any broom closet into a concert hall.
So accept your rooms and listening positions limitation or change them. Maybe it is time for a redesign of the interior?
I'm not expecting perfection. Not by far. Only better than what I have now.
I'm not even unhappy with what I have now. (except for the digital noise) But I know that with small investments I can improve on the sound.
I'm even considering small amounts of room treatments.

Step by step.
First the balanced cables. Then some active monitors. Then ARC. And in the meantime figuring out if the PC (supply) is faulty.