Ideas on how to mute a piano

[rachmaninoff_forever]

Hey so I have a steinway L in my brothers apartment and I’m about to take it (the apartment) in June.  I was practicing for a few hours today and got my first noise complaint. 

Blanket in the strings seems like an idea but idk I don’t wanna sacrifice the quality of the sound like that.  Styrofoam in the soundboard?  Idk

[lelle]

We had the same issue with my grand.

We bought sound proofing cups for the wheels, such as these: https://www.piattinocastercups.com/

I also practise with the lid completely closed, so the sheet music stand is on top of the lid.

I have also put a blanket over the closed piano, but I stopped since the neighbors stopped complaining.

[quantum]

Look into vibration isolation pads.  They are often used to reduce vibration transmitted from machines and other industrial equipment.   You could also look into combining these with the caster cups mentioned above. 

I'd look into sound proof the room first before trying to mute the piano.  You want to maintain the quality of sound for yourself, at the same time reduce the sound for your neighbours.  Have a look at how recording studios make their spaces sound proof, might get ideas there.