Mike's Oud Forums

my oud versus the laws of physics!!

dliecht - 1-23-2018 at 08:07 PM

I bought my first oud, which arrived yesterday. From all I can tell, it is a quality built instrument, but arrived in dire need of a thorough set up. I am new to the oud, but not at all new to stringed instruments, and so am undaunted about doing the set up myself. But even before starting, I have run into the strangest problem, which violates all of my understanding of the physics of strings and pitch. To wit, on the first course, when I carefully tune the two strings together (I know the tuning is accurate because I am using an electric tuner) and then begin noting the string(s) up the neck, once I get higher than the musical 4th, the pitch of the first string starts to become noticeably higher than the second string. By the time I reach the octave, it is fully a 1/2 step higher. Then immediately checking the open strings, they are again in perfect pitch with each other. None of the lower courses have this problem. I have checked and carefully measured the string lengths from nut to saddle and the variance between them is minuscule. Is this oud haunted, or is there something about oud string physics of which I am not aware?!

Greg - 1-23-2018 at 08:16 PM

Welcome to the forums dliecht.

You will be pleased to know this is not unusual and that, for some reason, it usually seems to be on the first course. There is obviously one string (or both) that has (have) an intonation problem. Sometimes, it is possible to reverse one of the strings in order to overcome this problem. You can probably identify the offending string by checking the pitch using the harmonic where the neck joins the bowl.

It is not uncommon for oud makers to supply their instruments with poor quality strings. A new set of quality strings should do the trick.

Greg

Matthias - 1-23-2018 at 11:33 PM

Quote: Originally posted by Greg  

It is not uncommon for oud makers to supply their instruments with poor quality strings. A new set of quality strings should do the trick.
Greg


Hello dliecht,

I agree to Greg, in the context of all the professional sets I ever sold, this problem never occured. So for me it seems to be clear that in spite "it is a quality built instrument" as you said the strings seems to be not of that quality. Even on a simple instrument it makes sense to apply a better or good set.

You will find many custom sets in my shop, if none is well for your instrument there contact me.

Best regards
Matthias

dliecht - 1-24-2018 at 07:40 AM

Thank you Greg and Matthias! I am relieved to know this is a common problem, and I have a new set of strings on the way. I have checked the harmonics at the octave spot and clearly the pitch problem shows up there as well as when the strings are pressed. When the new strings come, I will give the instrument a whole new set up and hopefully the problem will disappear. This thing still baffles me from a theoretical perspective, even more so since testing the harmonics because it appears that the harmonic center of the 1st string is about 5/64" higher than the harmonic center of the 2d string, even though (as far as I can measure) the strings are effectively the same length. I've never seen that happen before, or even realized that it was possible - yet there it is! Thank you both for your counsel and reassurance. I was wondering whether I should return the instrument (even though I really like it generally) but you have helped me decide to stay with it and apply set up TLC. Thanks! Dan Liechty

Jody Stecher - 1-24-2018 at 09:36 AM

Two identical strings cannot behave as you have described, and as I have experienced. The answer to the riddle is likely to be that the two strings are not identical. One has a manufacturing flaw perhaps.

Greg's remedy sometimes works. Leave on the string whose intonation aligns with the the other courses. Remove the one that doesn't and put the part that was the bridge loop through the tuning peg and tie the part that was formerly through the peg into a bridge loop.

This problem occurred nearly half the time with an older, better sounding, version of Aquila nylgut than what is now being sold. It was a fabulous sounding string on most ouds but the intonation problems were hopeless. It became too expensive to use this kind of string. I found substitutes.

SamirCanada - 1-24-2018 at 10:04 AM

The Oud isn't like most other instrument, its probably the most finicky instrument to keep tuned if you are coming from a guitar background especially it is a nightmare. Also your oud arrived yesterday, the treble strings wont be settled until at least a week or so of daily tuning and playing. I sometimes stretch the strings to accelerate the process but really you have to wait for them to be settled.

I would recommend that you tune the first string of each course by machine and the other string of the same course you tune by ear. you can use the machine to get close on the second string but really the best way is to pluck each string back and forth comparing the string that is tuned to the one where you have your finger on the peg and can adjust on the fly. In my opinion, no machine tuner is better than the ear to get perfect unison. Many times in the past I would tune the two strings by machine but when played together it was obvious that they weren't tuned properly.

couple of other things to check.

- make sure the loops under the strings at the bridge are identical length.

- make sure the nut is filled correctly. I have seen it where basically one of the file cut in the same course was deeper as such one string was getting stopped at the fingerboard and the other a bit higher on the nut. I use a 4 cm piece of string leftover from 1st course "c'' that I shim under the strings up to the nut, it makes all the strings stop at the same distance since they rest on that string right before the nut.


Brian Prunka - 1-24-2018 at 01:29 PM

Quote: Originally posted by SamirCanada  


I would recommend that you tune the first string of each course by machine and the other string of the same course you tune by ear.
you can use the machine to get close on the second string but really the best way is to pluck each string back and forth comparing the string that is tuned to the one where you have your finger on the peg and can adjust on the fly. In my opinion, no machine tuner is better than the ear to get perfect unison. Many times in the past I would tune the two strings by machine but when played together it was obvious that they weren't tuned properly.




Yes, this.
And this:
Quote:

- make sure the loops under the strings at the bridge are identical length.


It is impossible for the harmonics of the string to be anywhere other than exactly 1/2, 1/3, 1/4, 1/5 etc. the length of the strings
If the harmonic is in a different place, then the string is a different length, somehow. Some bridges allow the string loops to reside in rather different positions.

As you go up the neck, the discrepancy is magnified.
For example:
a 0.3mm difference between the strings on a 60cm oud is a 0.5% discrepancy. By the time you are at the neck joint it is now a 0.75% discrepancy. At the octave, it is a 1% discrepancy. This isn't close to a half step, but it is significant enough to be severely out of tune.


Some strings have issues and are inconsistent. But if this were the case, the harmonics would be in tune and only the fingered pitches would be out of tune. Of course things aren't mutually exclusive and there could be multiple problems.

Your tuner is not precise enough to say that the strings are in tune in unison. The margin of error on tuners varies (this is on purpose, partly, because extremely precise tuners quickly become very difficult to use). As Samir said, tune one string and then try to match the second string to the first by ear. You will hear when there are no beats between the two; this is more precise than using a tuner for the second string.

The nut could be an issue but it isn't as common as the other things.

Somewhat of an aside, but the tempered tuning on a tuner deviates from pure tuning by the following amounts, using the second highest string (usually g in Arabic, a in Turkish standard tunings) as reference:
1 c': tuner is 1.8 cents too high
2 g: reference
3 d: tuner is 1.8 cents too low
4 A: tuner is 3.6 cents too low
5 F: tuner is 3.6 cents too high
6 C: tuner is 1.8 cents too high

if 5 is G then it is fine, if 6 is D it is 1.8 cents too low.

For Turkish, 1-4 are the same, but
5: F# tuner is 5.4 cents too low
6: C# tuner is 7.2 cents too low
or
6 B: tuner is 3.6 cents too low

or
5: A tuner is correct
6: E tuner is 1.8 cents too low

While you won't be able to tune with this degree of precision, it's helpful to know which direction the tuner is off for each string so you know that it's safer for the 1st string to be a little low than a little high, etc.



dliecht - 1-24-2018 at 01:51 PM

Thank you Jody, SamirCanada and Brian for your input! You have all given me a lot of ideas to work with. I can see that oud is not just an instrument but something more like a lifestyle description! I am happy to be getting into it, even at my old age. BTW Jody, that old LP of yours, Going Up On the Mountain, remains one of my very favorite for many decades now. It is the only recorded version of "Turtle Dove" of which I am aware. Thanks! Dan Liechty

Jody Stecher - 1-24-2018 at 03:26 PM

Quote: Originally posted by dliecht  
Thank you Jody, ....that old LP of yours, Going Up On the Mountain, remains one of my very favorite for many decades now. It is the only recorded version of "Turtle Dove" of which I am aware. Thanks! Dan Liechty


Thanks!

I learned it from a recording myself, back in the mid 60s. It was Bessie Jones, from Georgia. Here's a link:

https://www.youtube.com/watch?v=eG20GMXQcmc

There have been subsequent recordings by others since my 1976 release. All the ones I heard were bizarre.

Speaking of bizarre: that's a good description of the "tuning" one gets from using electronic tuning devices for anything but a basic reference. (for gg for instance). Not only do different brands of tuner disagree, even specimens of the same model of the same brand give varied results. This has been discussed on this forum a while back. If I remember correctly member Oudistcamp posted a photo of an oud peghead with 3 or 4 electronic tuners attached. A string had been sounded. Each "tuner" had a different opinion.

dliecht - 1-24-2018 at 06:57 PM

Thanks for that link Jody!