Thread: Music box design

I have never made a music box but the general arrangement with resonating type instruments is they are built as light as possible. Mass just deadens the sound. They also have a sound hole or holes to let the sound out. Real wood makes the best sound boards on guitars and the like. MDF would likely deaden the sound. Most music boxes I have seen also play with the lid open but I am not sure if those boxes were actually adding anything to the sound. Are you following a plan or looking to design something. I googled a couple of builds using clockwork plinkety plink gismos but none looked like the box was adding anything to the sound. I think what you have in mind may be nearer to a hurdy gurdy which is a musical instrument.
Regards
John

Thanks for this contribution, John. Considering these music boxes have been around for 100’s of years, there is very little available on the best designs. But I was able to find some advice on the Mechanical Music Digest from 1997.(online)

I have started mine, using 10mm northern silky oak for the box carcase and 4mm NSO for the soundboard (base). Box OD is 160 x 110x 75, and I am thinking that might be a bit too small. And the 10mm carcase a bit too thick. Will go for 8mm next time. But the sound amplification is quite good with this box, but I am going for maximum sound

Since the sound traditionally is supposed to come from under the music box, I have positioned the soundboard 25mm above the bottom of the box sides, and will use external legs to raise the box 25mm off the ground. This should give a nice sound chamber. WiP photos attached below. I have brushed several coat of shellac on the inside surface, with the 1/4 sawn grain of the NSO looking quite nice. The legs will be glued to the outside, so will coat that when the box is completed.

Building a Music Box By Larry Smith 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 (Message sent Fri 11 Apr 1997, 15:01:47 GMT, from time zone GMT-0400.) Key Words in Subject: Box, Building, Music

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Well I learned something from that as I had never explored how they worked before. Who knows, I may have to get into box making.
Regards
John

Hi Dengue,

I am also considering building a music box, and am in the early stages of thinking about it.

The question I have is, where is the best place to source a decent mechanism from? Online appears to be the cheapest (China) but I am looking for something a bit better if possible. Any suggestions gratefully received.

George

The Clock Shop at Montville in Qld has a good range. You need to ask for the Japanese made Sankyo movement. I have also got a really good one from from Rob Wood in Amsterdam. Much cheaper, same brand and manufacturer, prompt shipping via NL Post and Aust Post. Check out Rob Wood Music boxes web site.

Originally intended for three granddaughters for Christmas (2021), events overtook the household and they were not completed in time.

The boxes are made of quarter sawn Northern Silky Oak and the lid is a drop in panel of Red Oak. The finish is several coats of #2lb cut of shellac, followed up with UBeaut EEE-Ultra-Shine wax applied with applied with Liberon 0000 steel wool. The finish turned out very silky smooth to the touch.

My first go at using shellac, thanks for the encouragement of the beloved dictator Neil and further advice from Homey. Certainly is a black art My next project is a music box for my wife with a 30 note movement, so I am keen to give shellac another go.

The box is based on a design I have admired for years made by Alex Springall who advised on how to do the legs. (see here)

Another first for me using the little 5mm x 18mm hidden bullet hinges, requiring a lot of precision on the drill press. Strap hinges, piano hinges and butt hinges were not really suited to this small box.

The box measures 160 x 110 x 75H, and the box is 25mm off the ground with the legs. Traditional music boxes are designed for the sound to come out from underneath the box, and this box has a good loud sound. The soundboard to which the 18 note movement is attached is also 25mm above the bottom edge of the box, so basically there is a 50mm sound cavity under the movement.

The ON/Off switch is my design, after several different attempts, with the brass knob turned by a friend and with an M3 hole drilled down the centre. Works well. In the OFF position, it prevents the governor flywheel from spinning.

Love the boxes, Joe! The shellac makes a fitting finish to these heirloom pieces so I’m glad it worked out. The pictures suggest you rubbed the finish back to a satin lustre, is that correct?

Three very lucky grand-daughters!

Best regards,

Brian

Congratulations, Joe. They've worked out well. Shellac is one of my favourite finishes. Glad to have been of assistance.

hi homey, I cut it back with Ubeaut cutting compound and 0000 steel to eliminate any surface roughness, and to take some of the gloss off. Shellac ended up very glossy.
Granddaughters very happy, esp those in Covid isolation at the moment, home schooling.