How to decrease the volume of a grand piano

[pytheamateur]

I am hoping to play in a small recital to a small circle of friends some time in June.  I desperately need some extra hours of practice in these couple of months.  I can find extra time but the main issue is neighbours.  At the moment I stop practising after 9pm, but am hoping to extend to 10.30pm without the neighbours complaining.  Does anyone have any practical tips on how to minimise the sound of a 6 ft grand piano travelling to neighbours' house?

I already play with curtains and door closed.  I have the lid closed with the piano cover as well as a double-bed mattress on top.

Would it be a good idea to use the una corda pedal to further decrease the volume (that is, to use it like the middle practice pedal in upright pianos)?  I hardly use it at the moment in my normal playing, but  I am worried that if I use it as a practice pedal now, this would decrease its effect when I learn to use it in the future, because the grooves in the hammers will become too deep from too much use that it will no longer sound much different to when the pedal is not pressed.

[hfmadopter]

There is a big difference between a neighbors house and an adjoining apartment ! If it is indeed a house you might try having someone play a bunch of note on your piano as you have it set up now, go outside and listen before assuming they are hearing a whole lot of what you are playing after going through another set of walls. If it's an apartment then you probably have a problem.

I own a grand about your sized grand. For silent practice I use a digital with headphones though. There is nothing I dislike more than trapping sound inside of my grand, I usually have the top up. I don't have close neighbors but we have a tenant in an adjoining apartment, with lots of room separation. He sleeps like a log, but 3:30 am when I feel inspired would even tick me off if it wasn't me playing ! We like our tenant, I don't want to tick him off.

[pytheamateur]

There is a big difference between a neighbors house and an adjoining apartment ! If it is indeed a house you might try having someone play a bunch of note on your piano as you have it set up now, go outside and listen before assuming they are hearing a whole lot of what you are playing after going through another set of walls. If it's an apartment then you probably have a problem.

I own a grand about your sized grand. For silent practice I use a digital with headphones though. There is nothing I dislike more than trapping sound inside of my grand, I usually have the top up. I don't have close neighbors but we have a tenant in an adjoining apartment, with lots of room separation. He sleeps like a log, but 3:30 am when I feel inspired would even tick me off if it wasn't me playing ! We like our tenant, I don't want to tick him off.

I live in a town house and therefore have neighbours next to both walls.  There's no-one living on top or below the piano room, but apparently, the next door neighbours could hear me play (they say I play beautifully, haha).  So I need to stop sound from travelling sideways.

I was hoping to get a good quality digital piano for practice at night.  I was looking at the Yamaha Avant Grand series, but it's too expensive for me at the moment (they are asking for more than £5,000 for an N1).

[hfmadopter]

I was hoping to get a good quality digital piano for practice at night.  I was looking at the Yamaha Avant Grand series, but it's too expensive for me at the moment (they are asking for more than £5,000 for an N1).

For late night practice I was thinking keyboard and headphones. Avant is in a class where it could replace your grand all together perhaps, especially the N3 ! But a lot of keyboards have acoustic like action in them these days and headphones cuts out the speaker system, you don't even need a keyboard with speakers for what you want to do..

[indianajo]

The churches have quilted covers for their grands which drape halfway to the floor all around and keeps the piano at a semi-stable temperature.  Something similar could be devised that uncovers the keyboard to give you access to it.  Much of the sound of a grand comes from the sides and the bottom, thus covering these up with quilting should help some.  
These custom wraps are likely quite expensive. If you want to try to sew together something similar, out of fabric and insulation bats,  I recently found an industrial supply that sells polyester batting in rolls at an attractive price. This material is not scratchy like the fiberglass insulation available at the lumberyard.  The supplier in the USA is mcmaster.com, the product I bought was 1/2" thick, 20" wide, 15' long for $12. Part number 2122k316.  They have thicker and wider rolls, which I recommend for this purpose, but I don't have access to their catalog on this computer to look it up. (my javascript is inoperative on this computer, the one I order mcmaster parts from suffers a core error every 2 minutes).  
I find plastic keyboards don't feel anything like a grand piano, nor does my console piano. The only thing that comes close is a modern Steinway studio piano, which has a quite heavy touch.  I didn't buy one, for that reason, it was too heavy for my light bones and joints.  
Being a bit shy, and not liking to meet my neighbors on the wrong terms, I bought a house with 15' separation from the neighbors, before I bought a piano.  I'm up to 30' separation from the neighbors now, in an unfashionable neighborhood, one mile from the county courthouse and 8 blocks from city hall.   Not a bit like the typical American exurb with huge houses crammed together on pie shaped lots.  

[marao]

I went through a similar problem to yours.
I researched several alternatives and decided that was the best use of carpet on the floor and duvet covering the piano, which must be completely closed. On days that I needed to play until very late at night I wore a blanket or another duvet inside the piano, without pressing the string.

Having done this, follow the recommendation of ashadopter  ... go outside and hear from as sound is being produced. You will be amazed!.

[pytheamateur]

Thanks for your suggestions. I don't think wrapping the piano around with quilt or putting a duvet inside the case is going to muffle the sound to a sufficient degree. I'm now thinking of placing a piece of velvet between the hammers and the strings, similar to what happens with the practice pedal in upright pianos. Has anyone here ever tried that?

[quantum]

You may wish to consider soundproofing drywall.  It's not technically soundproof, but is specifically made for sound damping applications such as noisy neighbors or movie theaters. 

Sound energy is also transferred through the physical contact between the piano and the floor.  So you may need to consider adding some isolation there as well. 

[stanleyy]

You might want to try to insert insulation wool at the bottom of the piano (where the soundboard is) it will reduce the sound greatly. And also a thick woolen cover on top of the piano. 100% wool fabric would be ideal as it doesn't trap moisture which can damage the wood. Hope this help.

[clifw]

I have had a similar problem with volume of my Yamaha C6 in a living room with a dome ceiling. The solution I used that worked very well was to build a 3 footed coffee table the shape of the soundboard. It was trial and error to get the right size. I had to compensate for the pedal rods. I then placed 3 layers of beach towels on top of this table and 1 layer of acoustic foam. I them covered the whole thing with very thin black material and stapled it to the underside of the table. I then placed it under the piano. It worked perfectly without changing the color of the sound. The finished table top is about 1 inch from the bottom of the Dampp-Chasser water tank. The beach towels did the trick. They are the most absorbent material and clearly the cheapest. It all looks fine and does not detract from the aesthetics. I do leave the lid open to the first support. I also made a 100% wool felt piano-string cover to help maintain tuning but it made no noticeable difference in sound volume. 
Hope this helps,
Clif

[g_s_223]

Purely for practice, a Kawai VPC-1 + PianoTeq software + PC + headphones is pretty good option.