MIMF

So, this project was born out of writings by the eminent Australian Acoustician and Researcher John McLennan. John's research can be viewed at this link http://www.phys.unsw.edu.au/music/people/mclennan.html One essay in particular, http://www.phys.unsw.edu.au/music/publi ... fholes.pdf ,got my creative juices flowing and the result is below.

Although my subsequent communication with John suggests more can be done, the result from this experiment is an instrument that has a greater power than any I've previously made, and although the E string fades quickly, sound post adjustments should remedy this problem. I intend to post a sound sample on youtube as soon as possible.

The instrument is made from Douglas fir (top), Tasmanian Blackwood (back,sides and neck) Ebony (f/board,nut,saddle,tailpiece), and is tuned with Gotoh stealth mini tuners with a ratio of 18:1. The bridge is maple and the blocks, linings, bass bar, top bracing and soundpost is King William Pine.

The slits you see that are replacing the F holes are not meant for sound production, but to provide an increased free plate vibrating area at the bridge position.

Close up of the free plate area at the bridge

Full view of front

Scroll area for want of a better word

I dig. Any shots under the hood?

No shots under the hood Jason, but there is really no need. It has a standard bass bar and sound post with two lateral braces emanating from the bass bar across the top and bottom bouts.... just to stiffen those areas. The back is carved and arched in the usual way of a traditional violin.

Barry,

Enjoyed seeing your design. Interesting that you used douglas fir for the top. I had already decided to try that for my next. From some left over 4x4 posts from another project. Your post has inspired me to get started on it. Thanks

John

I don't think you'll be sorry with a douglas fir top on your violin. It's a good tonewood.

Jason, I have another flat top fiddle on the bench and decided to post you a pic of the bracing system I use.

Barry, just a question for you- what is the grain direction in that long brace? It looks the opposite of what I would use in a guitar.

That's some super-funky bracing, Barry. Like branches. Very interesting, indeed!

I think Mark is asking about flat vs. quartersawn for the braces, yes?

So, those "sound holes" are just slots to give the top the same type of belly movement as a standard violin instrument? Why did you decide to use a "guitar" soundhole? (Is this where the McLennan reading comes in?) It seems to me that this is creating another open/broken edge in the plate that takes it farther away from standard violin geometry and mechanics. I can picture this instrument with side ports or some of those top/side edge ports.

However you cut it, this is very cool!

EDIT: I'd be interested in Al Carruth's observations.

Yes Mark, they are slab cut very much on purpose. There is a school of thought out there that flat sawn is actually as strong as quarter sawn while being more flexible for the application such as a bass bar in a violin. That combination appeals to me because, while the sound post is the "island" in a violin, the bass bar is the boogie master. More reading here http://liutaiomottol...quartersawn.htm By the way, Stradivari made a number of violins with flat sawn bass bars during his golden period.

Jason, correct. The "slits" are there to free up more of the vibrating area of the belly around the bridge. That's why they are so close to the "C " bouts. Good question on the sound hole. John McLennan suggested to me that he envisaged the sound hole under the finger board, but when I pointed out that the sound post would then be a nightmare to fit, he agreed. However, he then suggested that the sound hole be elliptical and the slits vertical. An elliptical sound hole better accommodates the traditional position of the bass bar and curiously, in the scheme of a two litre violin (usual average capacity), to achieve 280 Hz, the area calculation of the sound hole is 1375 square millimetres.

In the elliptical shape, this works exactly for the bass bar to sit right along side the sound hole as you can see in the last pic. The bass bar in the first experiment with a round hole misses the bass foot of the bridge by nearly 5 mm. Not ideal.

I would also be interested in Al Carruth's observations.

I like! Different and quirky, but for a reason, instead of the usual different and quirky for the sake of being different and quirky....

My best violin also sports a fir top, BTW. Good stuff, that.

That link didn't work, hope this one does http://www.liutaiomottola.com/myth/quartersawn.htm

Mario,
Thanks so much. Coming from you, those comments inspire me to keep going. And yes, I wouldn't do this stuff unless I had a reason, and if I can add to John McLennan's fine research on the subject, then it's mission accomplished.