Al Cramer

Really stupid question for Michael Darnton -- does FFT mean "fast-fourier-transform"? Thanks!

Marty & Jackson -- I really want to apologize to you guys -- I seem to be conflating the 2 of you in my mind. I have great respect for both of you, and you've both posted to this thread. One of you provided the magic formula and then one of you posted a link to a pdf that cited the magic formula (which I think is wrong) and I guess I got confused about who posted what. So sorry!

Totally agree! Always a bad idea to forget about la Serrinessima, as the Ottomans found out at Lepanto... Apologies for boring everybody with math, but if you're interested in relationships between string-density, tension, and frequency: I think there's a bug in the formula provided by Jackson. It's the same as the one given in the fascinating pdf he cites above, but I think it's wrong. I got some data on string tensions for helicore viola strings, also some d'addario light guitar strings. I used the formula to compute the string density (mass divided by length) for the guitar strings and got results that seemed off by 2 orders of magnitude. So I poked around on the net and found this: https://www.daddario.com/globalassets/pdfs/accessories/tension_chart_13934.pdf Their version of the magic formula features a mysterious constant (386.4). If you use it, the string density results seem plausible. Anyway: I was trying to find out if I could put guitar strings on an octave-viola. So I wrote a python program to generate this table: c2: (e2) 1.66 (a2) 1.90 (d3) 2.01 (g3) 2.02 (b3) 1.61 (e4) 1.61 g2: (e2) 1.61 (a2) 1.85 (d3) 1.96 (g3) 1.97 (b3) 1.57 (e4) 1.57 d3: (e2) 1.71 (a2) 1.96 (d3) 2.07 (g3) 2.08 (b3) 1.66 (e4) 1.66 a3: (e2) 1.33 (a2) 1.53 (d3) 1.61 (g3) 1.62 (b3) 1.29 (e4) 1.29 Each row describes a string of the octave-viola. Each entry in a given row corresponds to a guitar string (so first entry in c2 row corresponds to to e2 string of guitar). Each entry gives (tension using this guitar string) / (desired value) where desired value is string tension for a normal viola. So for first entry in first row, 1 would mean string tension is exactly what it ought to be. Instead it's 1.66 -- too much tension I think, not a good idea to these guitar strings on my axe. But my guitar strings are light weight steel strings -- classical guitar players use strings with much less tension (like 50%). So I'm going to get some flat-wound classical guitar strings and see if I can use them for c2 and g2 on octave-viola. (Note to Jackson: I hope you're not pissed at me re the magic formula. Please note that much of what I'm doing is based on stuff you posted - am close to solving my problem, and wouldn't have got so far without your help.)

Marty, that's really worth reading, thanks so much for posting. Am still digesting it. I think I buy the guy's idea that steel-wound strings were critical to the development of the cello in 17th century Italy (had no idea that happened in Bologna -- I thought all the action was up in Brescia and then Cremona). I found a good solution to my problem (turn a wide viola into an octave violin): use a 1/8 cello G string for the G, then use regular viola strings (C,G,D) tuned up 1 step to get (D,A,E). It works really well in general but the cello G is not as rich as I would like. Bows well but sounds dull when plucked. I'm going to mess around with the magic formula you provided and experiment with some guitar strings & see what develops (am currently waiting delivery of a digital scale that will let me measure string density). When I've got results worth reporting, I'll post them. Thanks again for sharing your knowledge!

Addendum to last posting -- About those "other possibilities". If the object is to turn a viola into an octave-viola, you could try this: 1. For C and G, use 1/8 cello strings. 2. For D and A, use standard viola C and G strings, tuned up 1 step. Jackson -- does this make sense to you? Please post if I'm wrong in what I just wrote.

Hi OctaveViola -- I'm working on it! I was using sensicore octave viola strings to turn a 16.5" Yita gamba-shaped viola into an octave violin. Strings are dead now, so my first attempt to restring was to use Helicore 1/8 cello strings (for E I used a a Helicore standard viola D tuned up 1 step, but you won't care about that if you're stringing your axe as an octave-viola). Results were good. I don't think it's that much worse than the sensicores octave-viola strings. So I suggest you try a set of 1/8 cello strings. There may be are other possibilities. In my case (again-- I'm trying to turn a viola into an octave violin) I'm going to try a 1/8 cello G string for my G and then use the first 3 strings from a normal viola string set (C-G-D) and tune them up 1 step to give me my (D-A-E). But that's not relevant to you, since you want true cello tuning). If you try using 1/8 cello strings, it would be great if you posted your experiences! I would love to hear about what you discover. One thing I pretty sure of is that you won't implode your viola because of string tension.

Wow! Thanks for posting. I had no idea this was such a problem. Am 100% in support of the elephants, but confiscating old violin bows isn't going to help them much. I hope US customs has got its act together. I guess I have to give them credit for trying. Would you happen to know what responsible bow-makers are using now for the plate at the top? I studied my one good pernanbucco bow (contemporary, purchased in late 90's) and it looks like ivory. My other bows (ipe wood, carbon fiber) look to be some kind of hi-density delron-ish plastic.

Was just curious -- have there been any actual cases where people traveling with their instrument were hastled at customs because of CITES? I ask because the issue crops up here periodically, and am wondering if we're worrying about something that never happens (of course, no one wants to the first).

Excuse a stupid question from the peanut gallery, but isn't the neck really short on that instrument, which would be why the OP thought it baroque? (Maybe I'm just misreading the photo...)

This is great! I'm going to try 1/8 cello Helicore strings for my G,D,A; and get a normal Helicore viola D string & tune it 1 step to get my E (again: I'm trying to turn this unusually wide 16.5 viola into an octave-violin). Marty, it was super kind of you to include that formula. Even a small cello is way bigger than a viola, and I was afraid that the viola couldn't handle the string tension. But I think your formula says T is proportional to L^2. On my viola vibrating string length is 14.25. 1/8 cello Helicore specs say they're for a vibrating strength length of 18.5. So that means -- when I put them on the viola -- I will only have to bring them to .6 the tension required for the small cello. Am pretty sure the Yita viola can handle that as it seems like a pretty solid build. I will try this and report back in a couple of weeks. Thanks to everyone who gave advice.

Just wanted to thank deans for his additional posting, and also Jackson for suggesting a useful strategy. The octave-strings thing is a weird world. If anyone's interested, I got into it because of this youtube video: She wanted to turn a viola into a cello. I wanted an octave violin, so I got a viola & set of sensicore octave viola strings. I tossed the the low C and bought an "E octave-viola-string" that sensicore offered (I guess for 5-string violas?). Result was a very nice instrument for recording. The voice was small compared to a cello but still bigger than that of my fiddle. It's a pity nobody's making octave-viola strings anymore! Thanks again for the suggestions, I will soldier on and see where they lead me.

This is exactly the kind of advice I was hoping for. Re string length: the instrument is a pretty normal 16.5" viola, except unusually wide. I use it as an octave violin (not an octave viola). So if I understand correctly: Dominant vd'amore A and D should work; also their A(7th), which I can tune down a step to get my low G. For the top E: could I just get a standard Dominant viola D string and tune it up a step? Many thanks for your suggestions! This stuff seems like it ought to be simple but it makes my head spin a bit.

They make octave violin strings. As I understand it, they acquired Sensicore a couple of years ago (who made both), but seem to have discontinued the octave viola strings. Derek, it would be lovely to play cello, but my wife has threatened to leave me if I clutter up the place with more (big) instruments. I was kind of hoping somebody who has experience with the viola d' family of instruments (braccio, amore) might have some suggestions. Thanks!

I have an abnormally wide 16.5" viola (Yitamusic) that I set up as an octave violin (G-D-A-E). It's not going to fill any concert halls but works great for recording. When I bought it a couple years ago, I strung it with Sensicore octave viola strings. The strings are kind of dead now and I want to re-string, but the Senscores are no longer available. I could buy octave violin strings, but this baby is a lot bigger than a violin & I doubt they'd work. When the A string broke I replaced it with a Helicore 1/8 cello string, and the result was ok but kind of dull. Does anyone have any ideas? Thanks!

If for some reason you want to learn how to play, the instrument might have some value to you. Go to some site like fiddlershop and get a low-end carbon fibre bow. Also some strings like Corelli or Dominants, then put them on so the strings lie in the grooves on the bridge. (And don't forget to get some rosin!) Then check out some of the approx. 1 million videos posted on youtube for beginning violin & see what happens!