Last night I put together a quick build using an old "Canadian Club" gift box that my wife had been holding on to for a few years. I already had the neck built for a hubcap guitar so there wasn't much to do to finish it up.
The box is 9" square, and about 3.5" thick. I put wooden cross braces across the back of the neck inside the box to help stabilize the box.
The sound is still a bit muffled... would it help to add a sound hole or two? I have some 7/8" brass grommets I could use, but since I haven't built one of these before I'm not certain where the best place to put the hole would be.
Helpful advice would be much appreciated.
no it doesnt really help at all imho.
next time don't brace the top at all, just brace the sides, the tin will brace the top plenty. A nice tall bridge and corresponding neck angle helps a lot too. I avoid cutting or altering the lid at all
To test what Phrygian is saying, put some pressure on the strings behind the bridge and strum it. It looks like there is hardly any pressure on the bridge. You can move the bridge back to about an inch and a half from the back and play it too to test it. Your scale will be off, but it should sound better.
if youre gonna pull the neck out dont stop there, splice a body end scarf join to create some pitch and make a taller bridge..
its not as difficult a job as it sounds, as long as you can access a bandsaw and you do have a bit of neck length to spare there. Ive done this mod myself to improve a cbg, message me for more info if you like :)
Can you show me an example of this? I think I know what you are suggesting, but a pic being worth 100 words and all, well you know...
Shortening the neck wouldn't hurt anyway, as it is right now it's about 1" too long for the Martin strings I have fitted.
I like being a contrarian, so here I go...
A soundhole may help or it may not. On my lunchbox build I did some testing - opening the lid a bit and closing it, comparing the loudness. When closed the sound was a bit muffled. I added an soundhole and it was louder.
I don't know much acoustic theory but it seems a soundhole gives the sound somewhere to escape. Subwoofer enclosures have a soundhole, so do acoustic guitars and such.
Your mileage may vary, though.
Hmmm.... perhaps I might consider drilling a circular grid pattern of 3mm holes in the back, like a speaker grille on an old radio or dashboard. Giving the box an opportunity to breath a bit *might* open up some of the muffled tones I am getting. And if not, I could always cover the holes with a sticker or two...