Violin Forum/Message Board

[MANFIO]

Violins are a bit more uniform than violas and celli. Many viola and cello makers like to play a bit with original models in order to get the sound they are looking for.

I read a small, but quite good article by Frank Ravatin on the latest "Journal of The Violin Society of America" called "Cello Making, Models and Measurements", one of those rare articles with fresh and usefull information for makers. He comments the pros and cons of his 3 models and how he has been working with them to get a better sound.

I've been playing with viola models in the past, so I found these parts quite interesting:

"Though I prefer the forma B, I still work on this model and try to improve things with a few stratagems, like fitting the bass bar more parallel to the grain of the spruce (I forget the subdvision by five to get the inclination), making the back arching 4 or 5 mm lower than the top and reducing the distance between the f-holes" ...

"The distance between the f-holes will change with the model. Using the forma B, it ranges from 92 to 96 mm, and up to 106 mm using larger models. Now I use the smaller width to give more focus to the sound".

Well, violas and celli will vary a lot in width and f hole distances... We can find a 40.2 viola made by Guadagnini with 55 mm distance (upper eyes) and a viola made 4 years late with the same size but an upper eyes distance of 51.5, quite a big difference.

I'm going to cut the f holes on my current viola tomorrow, so I would like to hear about your experience with f hole distances in your personal models.
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[actonern]

Hi Manfio:

I'm guessing you have the Sacconi book, so you'll probably have read this, but here is what (english translation) he has to say on page 91...

"...In fact the worst defect of an instrument comes from spacing the ff holes at a greater distance than the instrument needs... because this defect increase the central surface area and reduce the ability of this surface to vibrate with freedom...for the more one enlarges the surface area to be vibrated, the more one reduces the ease of vibration...the sound which results from this will be weak and superficial because it is poor in harmonics...

"...The opposite error, that is placing the ff holes nearer than normal, contracts the vibrating surface on account of the excessive nearness of the feet of the bridge to the ff holes This is equally a defect even if not as serious as the preceding one. The vibration, being constricted between the closer ff holes, remains limited to the central zone instead of extending itself to the entire belly. The sound of the instrument is thin, without body, not well balanced, shrill in the upper register and poor in the lower.

I know your post was focused on violas, and Sacconi is writing about violins here, but there may be something of relevance to consider nonetheless.

[KenN]

I know Micheal said that larger violins are trickier to do, but are great when done well. I noticed the Maggini I have started has a rather normal 42mm spacing between the f holes, even though it is 115 wide at the c bouts. Maybe this helps keep the high end frequencies up, while the extra size boost the low end. It seems like you could make the plates stiffer, relatively, to help the high end, and still get a good rich g sound, mainly from the extra size instead of more flexible plates. If you made the f hole spacing wider it might just sound like a viola instead. Just thinking, I don't know.

[MANFIO]

Thank you all!
I reduced the upper eyes distance to 50 mm (in my "Nannerl" viola, pics of it can be seen in my site) and that (perhaps with other things too) produced the focused sound I was looking for, from now on I'll adopt it.

Now, on the presente viola, I'm experimenting with the parallel bar mentined in the article with the new viola I'm going to close tomorrow.
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[Jack H.]

Not a lot of experience in making new ffs for instruments, but i do know that it is a lot easier to get a good sound out of an instrument set up when the measuremnets are more standard.
I have a cello in the shop ( an Ifshin antiqued) it is a bergonzi model and the ffs are about 105 apart and I cannot get any good sound out of it. the bass bar is set up for a 92 mm bridge.

I think I will go with a very thick sound post and a very thick bridge this time.
It is getting quite annoying trying for a year ( not continuously) to get a saleable sound out of this oversized cigar box!

[MANFIO]

Hi Jack! With the 50 mm upper hole distance I'm using a 52.5 wide bridge with good results, but I know some luthiers wold do the contrary...
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