Home demo. ProAc D48R and Spendor D9

I did listen to Harbeth 30.2, but it was with an amplifier I believe was not up to the task, a Sugden A21SE that seemed underpowered to me and an accompanying friend. I want something more dynamic and with much better low frequency extension. I liked the Spendor SP2/3R2 much more (but with a much stronger and expensive Densen amplifier, to be fair).
Would the big bass of the bigger speakers also muddy the midrange at moderate to low volume levels?

ThaNks again for your assistance!

Would the big bass of the bigger speakers also muddy the midrange at moderate to low volume levels?

In a small room there is a potential that bass would muddy the midrange at moderate volume.The thing is, the ProAc D48R is very easy to drive. I posted my experience from this weekend where I brought the $89/pair Pioneer SP-BS22-LR speakers into my main listening room to see how they fair with good ancillaries. While they punched too much above their price range, on similar CDs, I had to raise the volume to 11'o clock position for them, compared to somewhere between 9-10 o'clock position for the ProAcs. I believe, the D9s are also similarly sensitive.But if your room has an "open" layout, the bigger speakers might be alright. This means, you don't have a closed room, but your audio room opens to a kitchen or living room or some other room. We have one gentleman on this site who owns a D40R and has been very happy with them as he has an open layout.

I’m afraid it’s a closed room. Not sure what is the significance in this context of the fact that the D48R is easy to drive.

Isn’t it a matter of too much bass extension, exciting some room modes (say, below 30 Hz) that other less extended speakers wouldn’t touch? Because if this is all the problem and, let’s say, D30RS extends to 30 Hz and D48R extends to 20 Hz, then the problem would only be apparent with recordings with significant content between 20 and 30 Hz - and there’s not a lot of it in the music I’m listening except for the symphonic (occasionally) and organ music. I have a feeling that I’m on thin ice here...

Also, can this "too big a speaker for the room" problem be addressed with some room treatment? All this guesswork is worrying me as this is not the kind of expense I’m likely to be able to repeat in the foreseeable future. Some people recommend mini monitors like Dynaudio Special 40 for a space like mine, others are cramming Harbeth 40.2 and the like and declare themselves very satisfied...

Finally, to return to my original question, between D30RS and D7 what would you choose for piano reproduction and why? I care a lot about timbre and especially that tactile, percussive quality of the upper range of the piano I tried to described above.

I currently own the D30RS and all I can say that they exceed my expectations by far first they sounded a little bit blur,weak dynamics and laid back after a very long break-in they are now wonderful their ribbon twitters give very natural life like highs,the mid is superb detailed and the bass is powerful , punchy and accurate on of the best I ever heard .the soundstage is huge and the sound is very natural . I think the D30RS will work very well in your size space without overhang bass that the D48 might do. Didn't hear the D7  however one of my friends who considered to buy them heard them at high end show and was very disappointed.

The Harbeth 40.2 are wonderful speakers but need very large space to fulfill their huge potential IMO your space will not work for them.