yamaha "soft close"

[Paul McCloud]

I've installed both versions of the QRS fallboard closer.  They are a
pneumatic pouch, to which is tied a thin cable.  The other end of the
cable is tied to the rear edge of the fallboard.
 
One unit installs inside the action cavity, at the right rear bulkhead
behind the dag.  I was told that this version doesn't work as well as
the one which installs underneath the piano.  It is also more difficult
to install.  
The internal pneumatic unit has an arm attached to it, the end of which
is tied to the cable.  The arm will hit the treblemost hammers if not
adjusted properly.  The pneumatic unit (approx. 5" X 7") is hinged at
the left side,  and the front half swings in an arc outward towards the
keys.  The arm is screwed across the face of the front half, thus
sticking out towards the right side of the piano.  Two pulleys are
supplied with screws, and these pulleys guide the cable from the arm
across the inside right action cavity wall to the keybed and upwards to
the fallboard rear edge, where it connects through a screw-eye.  
The problem is that there is little room for the arm to move. Unless the
pneumatic pouch develops vacuum, it won't slow the fallboard, and this
won't happen until the pouch is at least partially opened.  I think I
pulled the action out of the piano at least 25 times before I was able
to make the thing work without hitting those hammers.  The compromise
needed was that the fallboard had to free-fall most of the way down
before it slowed.

The other unit installs under the piano.  It requires a hole in the
keyframe and keybed.  I was afraid of drilling the holes (I usually
measure once, drill twice, and start over), but it turned out to be much
easier than I thought.  It took only about 20 mins. to install
everything, and worked great.  The pneumatic unit is almost unnoticeable
under the piano (mounts behind the lyre or timber on one side).  You do
have to unhook the wire before you remove the fallboard, though.  

I would recommend the QRS system (and make some $$$'s too!)

My take,
Paul McCloud
San Diego