View Full Version : The alien

Graham McDonald
Mar-04-2008, 1:39am
Here are a couple of pics of an experimental mandolin with semi-side mounted soundholes/ports and the soundboard carved to around .110" all over the the centre section braced with a 3x3 carbonfiber/cedar lattice (of which there is a pic in the 'in progress' thread from a couple of weeks ago. The idea behind the soundholes is to allow more of the soundboard to work and the lattice is an attempt to reduce the mass of the soundboard while retaining the stiffness. In the end the soundboard is maybe a little too stiff and the sound is a bit bright, though certainly well balanced from string to string. A loud mandolin though, but lacking a little warmth in the bottom end.

It does look like one of those aliens that they found in Roswell in 1947 (well maybe!)

Graham McDonald
Mar-04-2008, 1:42am
A side shot of the soundholes. The soundboard is Sitka, the rest of Tasmanian blackwood. The back is carved normally

Graham McDonald
Mar-04-2008, 1:47am
Mike Compton was in town the day it got strung up, so I asked him to give it a workout. He politely said it worked fine, but didn't think it was really a bluegrass mandolin. (which it isn't) Still, the idea works. The soundboard didn't collapse and it certainly sounds like a mandolin. I will do some A-B listening with some other mandolins as V.2 takes shape

jim simpson
Mar-04-2008, 8:35am
I think it's cool to experiment with stringed instruments. I wonder if anyone has constructed a mandolin without soundhole(s)? I suppose one could leave the soundhole till last to see.

Bertram Henze
Mar-04-2008, 9:05am
I think some bindings around the soundholes would make it look more like an intentional design - would also add much to the cool "alien" look; maybe white mother-of-pearl to match the tuners?

As it is, it looks somehow - well, vulnerable or naked; somebody might come along and ask if there was not enough material for the soundboard (ducking and running) http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif


Mark Walker
Mar-04-2008, 10:38am
If nothing else, it'll be easier to get a pick accidentally dropped into it out! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

Seriously though, it's an interesting concept and instrument. Gotta think outside of the box on occasion!

Mar-04-2008, 12:14pm
I think this is an elegant design that merely needs tweaking to be right on.

Bill Snyder
Mar-04-2008, 12:34pm
Graham, although very different the sound holes makes me think of Jacob Reuven's instrument.

Mar-04-2008, 1:03pm
Did you end up making the "easy acess" back? Do you plan to mess with the braces or leave it alone? Looks great!

Graham McDonald
Mar-04-2008, 4:32pm
This one was a 'proof of concept'experiment, both practical and aesthetic. The soundboard and soundholes idea have worked pretty well. The bolt-on back didn't. There was still enough flex in the sides under string tension to move the neck up, even with the carbonfiber co-ordinator rods. I eventually just glued the back on which stabalized the structure. The adjustable neck idea, using the co-ordinator rods, didn't work and I was pretty sure the neck would have just removed itself under string tension and I eventually just bolted it in place. I have another idea for an adjustable neck which will see light in the next one. The soundboard could come off fairly easily, as it is lightly glued into place with hide glue with newspaper as a spacer, and I might remove it, lower the height of the lattice a bit and give it another try. But is almost as quick to just build another and work on some of the details, like trying to work out how to run binding around the soundholes as the edges are quite thin. With luck I should have V.2 ready by the time I come over for the GAL Convention in June.

Thank you all for your comments



Mar-05-2008, 2:55am
Have you considered cutting the same curvature into the ribs as you have on the soundboard. I think that might be an interesting look.


Graham McDonald
Mar-05-2008, 6:11am
Carving the sides away to make a bigger soundhole/port is one idea I have thought about. I suspect you could carve a chunk out of the sides and not touch the soundboard at all, but the whole thing might look even stranger.

The trend towards soundports in the sides, and the discovery that adding all that extra soundhole/port area doesn't affect the sound much has me thinking about how radical a change in the size of an F-hole or equivalent can we make before there is much effect on the sound. I can remember Dave Cohen throwing some physics about Helmholtz resonances into a discussion in changing f-hole size a year or so ago and his contributions are always very solidly based in observable science rather than folklore or received 'knowledge'.

There are some interesting ideas out there. A guitar builder named Roger Thurman has patented a soundhole/port idea which effectively takes a big bite out of the upper bout soundboard and sides, which he claims lets the soundwaves trapped in the upper bout of the guitar out! There is a description of his ideas in American Lutherie no 91.

The work of Jimmy D'Aquisto on his experimental jazz guitars 20 or more years ago and the more recent work of Doug Martin building balsa and carbonfiber violins has pretty effectively exploded all the old ideas about violin style f holes on carved instruments. James Condino is making mandolins with three round holes on the treble side of the soundboard and three more on of the bass side rib. The 'Loar is God' brigade won't pay much attention to these experiments, but curiosity is a wondrous thing and it is fun playing round with ideas. This whole idea came about with a serious toothache and the consumption of much codeine based painkillers. It might be thought of as a Samuel Taylor Coleridge moment of inspiration #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

The idea of a balsa and carbonfiber mandolin body is very tempting...



Jim Rowland
Mar-05-2008, 10:14am
Arthur Overholtzer,a prize-winning classical guitar maker,was contemplating the construction of a classic model with the narrowed end of the corpus at the tail and the wider end at the neck to sort of extrude the sound out of the sound hole. Don't know if he got around to it in his lifetime or not.

Adam Tracksler
Apr-18-2008, 6:09am
I was watching a documentary called "Djangomania" on the sundance channel, there was one guy with a guitar with the upper bouts sawed off and open, it looked weird, but sounded good in the 5 seconds they edited it into... may be worth looking at and trying out.

Jim Garber
Apr-18-2008, 7:29am
Demeglio built mandolins with sound ports as far back as the 1890s. That have a very loud effect to the player and a slight reverb.

Apr-18-2008, 7:34am
I owned a Charlston Guitar a few years ago that had this fanned group of soundports on the back. It actually made it sound pretty good as long as the person listening was playing it. When you got out front it didn't sound too good.

steve V. johnson
Apr-20-2008, 12:28pm

I really like the ideas I see in your Alien mandolin!

Why is it that it's not a "bluegrass mandolin"? Certainly it doesn't -look- right for BG orthodoxies, but is it that it doesn't have
that 'bark' chop sound? I also infer from the context that you weren't particularly intending ti for a "bluegrass mandolin", right?

I'm ambivalent about the binding notions, but then, I favor plainer visual styles... Perhaps a wood binding...

I hope you've learned enough from this one to continue developing this design!



Graham McDonald
Apr-20-2008, 10:35pm
The 'not a bluegrass mandolin' comment was Mike Compton's. It was an observation, not trying to be disparaging or anything. I was most gratified he took the time to play it for a few minutes and give me some feedback.

It doesn't respond the same way as an F5, mostly I think because I over-engineered the carbonfiber lattice and it is just too stiff. The next one might well be an F style body and I have another idea for an adjustable neck which should work better. I'll probably try another soundboard on this one first and build it a bit lighter and see what happens.