Mike's Oud Forums

Problem of oud strings

sylvainbd - 6-23-2013 at 11:19 AM

Hello,

I have a new oud and i would like to put another set strings. Do you know if flatwound strings exist for oud ?!

And i would like to try with string without wound. But how to calibrate that ?!!

Thank you for your answers :)

jdowning - 6-23-2013 at 11:47 AM

To calculate diameters and/or tension of plain strings you can use the free on-line string calculator by Arto Wickla here:

http://www.cs.helsinki.fi/u/wikla/mus/NewScalc/

This calculator only applies to uniform diameter plain strings (made from one material) - not for wound strings or roped construction strings.

You will need to know the vibrating string length of your oud, the string material and the vibrating frequency or pitch of the 'open' string you are interested in.

spyblaster - 6-23-2013 at 12:14 PM

you can also talk to Nikolas Dimitriadis, i know he has done that before. he answers email very quickly and helpfully.
http://oud.gr/Contact.htm

Brian Prunka - 6-23-2013 at 12:56 PM

Quote: Originally posted by sylud  
Hello,

I have a new oud and i would like to put another set strings. Do you know if flatwound strings exist for oud ?!

And i would like to try with string without wound. But how to calibrate that ?!!

Thank you for your answers :)


To my knowledge, there are no flatwound strings available for oud. There are some made for classical guitar, I believe, and you could potentially use some of them for oud, though you would likely wind up buying full sets and using only some of the strings.

The size of the windings varies from one manufacturer to the next. Smaller windings get you closer to what you're seeking, but still far removed from flatwound strings.

Matthias - 6-24-2013 at 12:33 AM

Quote: Originally posted by sylud  
Hello,

And i would like to try with string without wound. But how to calibrate that ?!!


Hello,

first of all, my shop shows a lot of different sets composed for the oud:
http://music-strings.de/index.php?s=3&lang=eng
you find the strings of AQUILA - Pyramid - Kürschner - Savarez

If you need something different to that you find there contact me directly through the shop contact form

Best regards

Matthias

sylvainbd - 6-24-2013 at 01:18 AM

Thank you all very much.

I tried the arto's string calculator and WOOWwww results are surprising !

I am not sure about the ideal tension ... 4 kg per string ?!

So with this information :

- tensions : 4kg per string
- material : nylon 1000kg/m3
- longer string: 585mm
- tuning :
- 1 string , DO à 65 Hz
- 2 strings , MI à 82 Hz
- 2 strings , LA à 110 Hz
- 2 strings , RE à 147 Hz
- 2 strings , SOL à 196 Hz
- 2 strings , DO à 262 Hz

I get this diameters :
- DO -> 2.92 mm !! ... very big string !!
- MI -> 2.32 mm !
- LA -> 1.74 mm !
- RE -> 1.3 mm
- SOL -> 0.97mm
- DO -> 0.7 mm

Therefore , not a good idea ! nylon plain Strings are too big. i am gonna search another material more hardy. I have to try with flatwound string for classical guitar.

jdowning - 6-24-2013 at 05:13 AM

As you have discovered sylud the Arto Wikla calculator will always provide a diameter for a given set of string parameters but the result may not be a workable string as is the case with your C string at 2.92 mm diameter - too stiff to vibrate properly.
At a string length of 585 mm (Turkish?) and Arabic tuning CEAdgc' with a tension of 4.0 Kg force (39 Newtons) you will not be able to successfully string your oud over the six courses using monofilament Nylon - only the first top three courses are likely to work. A denser monofilament plastic string such as PVF ('Carbon') in place of nylon will allow use of smaller string diameter and so might extend the range to the fourth course (particularly if a lower string tension is employed).
Gut and silk strings are also denser than Nylon and have the additional advantage of being made more flexible for a given diameter, if required, by increasing the amount of twist of the string fibres during manufacture or by making them like a rope (so increasing the workable range of a string).

The modern solution for the basses is to use wound strings - generally copper wire wound on a core of nylon filament, the relatively small diameter flexible core providing the 'strength' of a string under tension and the winding providing the additional linear mass or density required to allow the string to vibrate at a lower frequency without, at the same time, adding significantly to the string stiffness.

As you can conveniently prove to yourself by running examples on the calculator, string length, density, diameter, tension and vibrating frequency are all factors in combination that determine the viability or otherwise of an instrument string. So - all else being equal - if you increase linear mass or density, a string will vibrate at a lower frequency. Likewise reducing string tension or increasing string length will have the same effect - all within physical limitations.

This paper by pioneering 'historical' string maker Eph Segerman summarises the situation concerning string design well enough and so may be of interest.

http://www.nrinstruments.demon.co.uk/StrPrim.html

Brian Prunka - 6-24-2013 at 07:21 AM

FWIW, I would consider an ideal oud tension to be closer to 3Kg, at least for Arabic music. Some players like higher tension, particularly those from the Naseer Shamma school of floating-bridge playing.

Still, the two lowest courses are not likely to work with any plain string material I know of. A mix of nylon, PVF and nylgut might get you to the fourth string. It looks like to get a plain nylgut string for A, you would need about 1.3mm in order to get 3Kg. Pretty thick, not sure if Aquila makes that, I'd have to check. Who knows how it would sound.

Matthias - 6-24-2013 at 08:05 AM

[rquote=95825&tid=14076&author=sylud
I get this diameters :
- DO -> 2.92 mm !! ... very big string !!
- MI -> 2.32 mm !
- LA -> 1.74 mm !
- RE -> 1.3 mm
- SOL -> 0.97mm
- DO -> 0.7 mm
[/ rquote]

with Savarez Alliance strings ( Carbon like ) you will get:
- MI -> KF 203 mm
- LA -> KF 150 mm
- RE -> KF 116 mm

even that is too thick for LA and MI

May be gut, especially the Luxline from Kürschner can be an option.

Matthias

sylvainbd - 6-24-2013 at 11:42 AM

Thank you all again for your help.

I tried with a big monofilament nylon cable for rotofil (garden machine) !... diameter 1.3 and 1.6 mm on LA and RE. Strings didn't break but sound and touch are bad ! ...

... So now i am thinking about my bridge. I don't want to use very special or expensive strings .... I have to reduce the friction of the string and thereby use usual oud strings.

On the other side I am waiting an answer of Savarez ...

jdowning - 6-25-2013 at 04:45 AM

It might be worth mentioning here that in the late '70's some lute players (including at least one professional player) improved the performance of their plain nylon strings by twisting them to improve flexibility - resulting in better sustain and a lowering of the pitch limits for a given string length and diameter.

I have not tried this technique on an instrument but did run some tests - reported on this forum last year - to verify that twisting a monofilament nylon string does (surprisingly) indeed produce the results claimed by others.
The downside is that a twisted monofilament string becomes more sensitive to temperature change (so requires more frequent tuning) and increasing the twist reduces the tensile strength of a string (so it will break at a lower tension - however, not usually a problem for the larger diameter strings)

http://www.mikeouds.com/messageboard/viewthread.php?tid=13379#pid91...

I have not had time yet to continue phase 2 of the trials or to test the results of twisting other more dense string monofilaments such as PVF ('carbon') or 'Nylgut' to see how far the lower frequency range of these strings might be extended by the straightforward, low cost expedient of simply twisting a string.
If an oud was tuned in the old way i.e. with the top string tensioned to as high a pitch as it will stand without breaking, then it might be possible to string a five or even six course oud entirely in twisted plastic monofilament strings? Only one way to find out!

Note that 'historical' gut and silk strings made with high twist or roped or 'weighted' construction can perform over six courses especially if the top string is tuned to maximum pitch and string tension is reduced from treble to bass.
So, for example, (according to Eph Segerman of NRI) for a 61 cm string length oud strung in 'historical' gut (i.e. no wound strings) the maximum tonal range would be from f' (at A440 standard) down to F for high twist gut and down further to C for roped gut.
So - according to this information - an Arabic oud of 61 cm string length might be strung entirely in plain gut at so called 'high' pitch tuning of say F A d g c' f' (or lower if a lower pitch standard is chosen - as would often appear to be the case for practicing oudists of the 'old schools').

sylvainbd - 6-25-2013 at 07:03 AM

Thank you for this note jdowning

I call this morning savarez and they explain that often steel break nylon when friction is high. So my problem wasn't quality or model of string ...

After i did a test to decrease friction between strings and body and normal strings resist without problem :applause:

So now i have to make and add a small wood piece and the problem would disappear. Every problem have solution :)

Soon i will do a topic to show my instrument ...

Thank you all

sylvainbd - 6-25-2013 at 08:57 AM

Thank you for this note jdowning

I call this morning savarez and they explain that often steel break nylon when friction is high. So my problem wasn't quality or model of string ...

After i did a test to decrease friction between strings and body and normal strings resist without problem :applause:

So now i have to make and add a small wood piece and the problem would disappear. Every problem have solution :)

Soon i will do a topic to show my instrument ...

Thank you all

jdowning - 6-26-2013 at 05:54 AM

Glad that you have found a satisfactory solution sylud

Just a further observation for those who might want to experiment with twisted monofilament strings.

Larger diameter monofilament strings (i.e. greater than 1.0 mm diameter) can be purchased from various suppliers as harp strings (4th Octave range) up to about 1.6 mm in diameter for plain Nylon. Fluorocarbon (PVF) harp strings are available from 'Savarez' up to 2.1 mm diameter but are quite expensive, up to 40 Euros for the largest diameter.

I have located a potential supplier of low cost source of monofilament Nylon harp strings in the US so plan to purchase some their strings for Phase 2 of my experiments in twisting the strings to determine just how far their tonal range might be increased. The results will be reported on the forum here

http://www.mikeouds.com/messageboard/viewthread.php?tid=13379#pid91...

Sadly - due to the high cost - larger diameter PVF strings will not be tested but some indication of the potential might be obtained from testing some worn discarded, smaller diameter PVF lute strings that I have to hand.