Speakers: yes..
I keep my sound level well below 80dB using a radio Shack SPL meter at seated position. usually down around 72 dB.(one thing if you have complaining neighbors: get a rat shack sound pressure level meter. Then you can argue exactly what you sound level is from the seared position, and REPEAT it for a manager etc to hear it. if your music is not measured, you cannot argue and the other person will always be right)
I live in a senior only over55 apts, and I NEVER want to have any complaints ever. So I keep it quiet at all times.
I have Magnepan 3.6, with Bryston 4B-SST2 and other stuff, an additional VAC standard pre.. The big thing is getting the tonal balance at low volume.
Another thing I just got is a great headphone amp. I have Senn HD800s and the 'Notorious' Singlepower (they expode, they kill!) headamp. Love it, using it right now.
Anyway, planar are THE sort of speaker, because they do not push bass through the walls the same as box speakers. (for the same apparent bass performance) I don't know why.. they just do not. I had B&W 805s and at the same volume the low notes would go through the walls. With the Maggie 3.6 i have now, the lows do not travel through the walls.
The very best would be quads, $10,K new, but the new Magnepan 1.7s at $2,000. new. or Magnepan 3.6s $5K new
Maggies take up a LOT of room. i have mine so I can use the space behind them for stuff. You may not have the room for planar speakers in a studio...
The other thing I would mention is small, or really big. The small box speakers may give you the SPL without the bass. then use a sub to CAREFULLY dial in the bass, which, with almost any self-powered sub you can easily adjust. The big thing is Rock you have to cut the bass to survive noise complaint-free, then for classical chamber, folk or Jazz you can turn up the bass in the sub for realistic lows.
Some really big speakers have the ability to run a low levels with a big sound. Klipshorn come to mind, It's IMO the medium and mid-small that cannot, because they ARE smaller, and are designed to play LOUD, they just do not have the right sort of design to play quiet.
So you need really small that are designed to play softly.. or really big, that do not have the design limitations to play softly.
This does not give you very many items to look at, but i hope it helps.
Also, for low volume use tubes.. at least in the preamp. It will give you a more natural sense when playing at lower levels.