Greg Przyjemski wrote these questions:

>  Volume of box to movement ratio?

Most antiques I have seen have a box no more than 25% longer than the
actual movement, sometimes less.

>  Dimensions, height, width, & depth ratios?

Not critical.  I've seen music boxes with ratios all over the place.  As
I noted before, the _box_ itself is not really the sound chamber, it is
the space between the bottom of the box and the surface it rests upon.
You can see this by starting up a music box and then picking it up
(gently) while it plays, or placing it on a soft surface, like a bed.

You will then notice it is far quieter and "tinnier" than when it is on a
flat, hard table surface. This is why music boxes are seldom placed on
top of table cloths or doilies (except by people who don't know what they
are doing).  Most music boxes I've seen seem to shoot for about 1"
between the bottom of the box and the bottom of the feet.

Very large and powerful boxes go as high as two inches.  Disk boxes are a
little different, they use a piano-style soundboard and thus have a much
large surface area to movement size ratio, but from what you've said so
far, I don't think you need worry about that.  I would guess you could,
in theory, mount a cylinder movement vertically to a large, stiff surface
and construct a sound chamber much like a speaker enclosure, but that
will _look_ distinctly odd compared to an antique.

>  Thickness of sides, top, & bottom?

Most reasonably-sized music boxes were about 1/2 to 3/4 of an inch of
good hardwood.  I have a Reuge music box using their interchangeable
version of the 72 note movement which is made of wood just slightly less
than 1/2 inch thick.  As far as I can tell from the boxes I've seen,
sides, top, bottom all are the same thickness - probably made from the
same plank.

>  Materials and coatings?

Good hardwoods.  Early boxes favor walnut and other or fruit woods, later
ones used oak a lot.  Coatings are flexible.  I believe that lacquer is
traditional, but I suspect most anything will look nice and not affect
the sound.

>  Height the box should sit above surface?

See above.  For a 72 note Reuge, I'd shoot for a bit more than 1/2 inch,
not more than 3/4 of a inch, based on my interchangeable.

>  Should the box be sealed or ported like a violin?

I've never, ever, see a sealed and ported music box.  You could
experiment, I suppose (nothing wrong with that) but it wouldn't _look_
very traditional, methinks.

>  If it should be ported, where should the port go and what size
>  and shape?  If glass is used as a lid or secondary lid, is vibration
>  due to mounting technique a concern?

It can be with a powerful movement, but with a Reuge, I doubt it like
anything.  Older boxes I've seen seem to set the glass into a bed of putty
(rather than just using putty to hold it to the wood) but that may be
just to get a better dust seal, too.  For the size box I think you may be
talking about, regular window putty is probably fine.  My Reuge box seems
to use something like felt and clips.

>  Mounting the movement to the sound board, if mounting the "bedplate"
>  off the "sound board", how high and do you use legs or block the
>  sides or block the front and back?

As Nancy said, modern practice is to screw right to the sound board, and
that may be the best solution, for modern movements tend to be much
quieter and more intimate than antique ones.  Antiques weren't designed
for a couple of listeners sitting over the box straining to hear it, they
were meant to fill up a salon full of crashing glass and people ordering
refills, they are _not_ shy about volume.  Direct mounting will give you
better sound, in my opinion.

However, if you want a more traditional look, you can mount it to two
crosspieces that go back-to-front about half or one-third of the way up
from the bottom of the box.  That will look very traditional and
antique-y from the outside, but if you are using a Reuge 72-note
movement, the winding key on top will cause the inside to trigger severe
cognitive dissonance in antique music box aficionados.  Aside from that,
no musical or mechanical problem.  =)

>I know, too many questions.  This is what gets me in trouble.

Nah.

>This is my first attempt in the world of acoustics so
>I have a steep learning curve on this one.

Yes and no.  A music box is not much like a speaker enclosure, where
angles and ratios are important to provide the right timber of sound.
Music boxes were invented long before anyone ever thought of such a
thing, and have evolved empirically to a state where they are _much_
less sensitive to such things.

The magic is in the movement and the sound board and the placement of the
sound board in relation to the table, and in not choosing materials like
pine or plywood that would tend to absorb the sound.  The other stuff is
almost entirely esthetic, I think.  Certainly none of my box work has
been sensitive to it.

regards,
Larry Smith