Are sound holes essential additions for all CBG's?
Is sound hole scaled to box size.?
Can sound holes be placed on rear of CBG builds?
Is it critical where sound holes are located on the box?
How many can go on 1 buils?
These are my ? that relate to real ex-used cigar boxes, and not home made ones.
Any sugestions?...cheers
Replies
My theory is the sound holes don't do much to help the sound on these types of instruments. Recently I've opted for no holes and the guitars sound perfectly fine. But they often look cool. And that can be hard to beat.
OK let's be scientific..
It's a box. A hole let's you hear what's inside. It's something that looks cool.
Just half joking.
If I'm totally honest I don't really know much about it. I do know you don't need one if it's electric, you might even cut back on feedback if there's no hole. If the hole is too big it doesn't work well, similarly if it's too small.
I have a ukulele with no hole and it sounds fine without it. Clean design. I tried it again and it sounded muffled. Say what?
That's about it from me.
So, the basics are that sound holes are another of the many compromises that make this consarnit conundrums work.
A soundhole takes away from the size of the soundboard (face) that the bridge vibrates so you have less surface transmitting that vibration to the air, BUT it lets the internal vibration out. (tradeoff #1)
A round soundhole minimizes how much of the soundboard's strength & surface is compromised by the hole, but long narrow slit(s) of the same surface area actually accelerate the air motion through them increasing the volume, the same way a fan-spray nozzle on your garden hose works. (tradeoff #2). That's why violins/violas/cellos/doublebass have Fholes and bracing and a soundpost, to maximize the volume.
When you asked "How many can go on a box" I imagined the ultimate Swiss-Cheese scenario and grinned. It would look awesome but would likely need a mag-pickup, lol
Just to put things in a scientificatorial frame, a box on a cigar box guitar is a neckless helmholtz resonator. There are formulas that will tell you how big a hole will create the muchest volume from the size box you have though in general if you look at a few boxes you will see the popular sizes that look about right are close enough.
Fancy book learning can make your head hurt so a couple of small holes about an inch or so in diameter either side of the neck, or one slightly bigger one.
Fancy f holes also free up the top to vibrate more.
I will add my $.02 of experience - All of the info. in this discussion is useful, and demonstrates that varied experience vs. theory is all relevant. You try, learn, and discern what trips your trigger. I've built similar, even identical gits, and they all sound different. String selection, bridge material, nut or zero fret, sound hole size and placement (or none at all) create the sweet surprise of "how will this one sound?". I recently built four 4-string license plate gits, using old oak table leaves for bodies. All acoustic, no sound holes. One mahogany neck, one poplar neck, two red oak necks. Sound similar, but a little different. Again, tried different string sizes and tunings.....now one sounds banjo-y, one is kinda Uke-y, the others are more reso-git sounding. All very cool, and different. My fallback position on lpg's is that I can retro a sound hole through the top side of the body if I think it needs more music to escape. Works for me so far.
no, no, yes, kinda, as many as will fit, lots
Thanks...cheers