KEF lineup is good, though, bit pricy.
I found KEF Q500 Musical, but bass shy. I paired it with Marantz PM6004
BTW, Recently, I bought, Marantz PM6004. Despite, not-so-good reviews, I bought POLK TSx330T from ProFX Kolkata, In my opinion, it is very much musical, bass-line is tight and highs are tamed, though mid is not that open, I thing that's the attribute of my PM6004, but bit tweaking on my HTPC's control gives me good mids too. Initially, it sounded boomy but proper speaker placement, room acoustic and interconnect have shown gradual improvement. I am a newbie in this hi-fi world but I have noticed that simply removing/placing speaker grills can improve/degrade the sound quality of any hi-fi system!
Are you sure, that you are using right interconnect? I was using 3.5mm to RCA stereo cable that came with ASUS Xonar sound card, and for that system sounded boomy but when I changed it with quality cable from
Ghent Audio --- B01 3.5(1/8") TRS(M) to RCA(M + M) Canare L-4E6S Cable , I perceived huge improvement.
From your, previous threads , I know, that you tried many tricks but till now, haven't got the desired result! So, I would request you, change the interconnect. If you have any audiophile friend, you can borrow it from that friend for testing purpose.
Another thing, I want to tell you that please don't use PC fans on the top of your amp. probably, you are thinking putting more air into the amp will make your amp run cool!!! but in that course will also pump zillions of dust particles inside amp, and dust is one of the main enemies of any electronic gadget