ahmedalalousi - 8-25-2023 at 07:15 AM
Folks,
Need a bit of advice on two accounts with this one - tuning and string count, so here goes.
First of, I need a F-F set of strings for both floating- and fixed-bridge ouds, which I'm trying to tune a full octave lower than the norm.
In other words, instead of the customary: F AA DD gg cc ff
I need it to be: F1 A1 D GG cc ff
I need these for 60cm, 58.5cm and 57cm vibrating lengths.
As can be seen from the tuning above, the base wound strings would singles, instead of pairs, except the (no) GG, which will be retained as a
double.
I tried to do the above with my Pyramid sliding rule, but A only goes down to 392.
Any advice?
Thanks,
Ahmed.
Brian Prunka - 8-25-2023 at 02:14 PM
Not sure if this is helpful at all, but my gut feeling is that this is not really going to work.
For a floating bridge oud you will want to aim for about 35-39N tension. For fixed-bridge, 30-33N is more typical. Since some strings are not
doubled here, you can probably safely go a bit higher if you can manage it (since the total tension will be less stress on the bridge without the
doubled strings).
The pitches described are: F1 A1 D2 G2 C3 F3 instead of the customary F2 A2 D3 C4 F4.
Obviously the pitches D2-F3 can be accommodated as they are within the range of "normal" tuning. The pitches F1 and A1 are the potential problems.
You will likely run into some sound quality issues due to the size of the body, soundholes, and string length not being remotely optimized for these
pitches.
The main issues to be concerned about are
• wolf tones (unbalanced body resonances due to the inappropriate body/soundhole size to produce the low pitches)
• string inharmonicity (overtone misalignment due to the inappropriate string length/tension relative to pitch).
• This is in addition to undesirable tone due to using quite thick/dense/heavy strings.
The result is likely to be a poor tone that always sounds somewhat out of tune regardless of how you tune it.
This is already usually a slight problem on many ouds when tuning B1-D2, but generally still pretty usable within this range. So your A1 is probably
just manageable with a heavy string. I suspect that the F1 will be unsatisfying regardless of what you use but you can try.
That said, the lowest pitch available on the pyramid slide rule is E1, so F1 and A1 are within range. I'm not sure why you were having trouble with
it*.
at 60cm,
F1 - #2458 gives 37N, #2460 gives 39N
A1 - #1445 gives 37N, #1348 gives 39N, #1448 guves 40N
D2 - #1033 =37N, #1034 =38N, #1035 =40N
At 57cm you are looking at #2463, 3262 or 3263 for the F1 and #1448, 1348, 1350, or 1450 for A1.
Presumably you can calculate the rest yourself.
The lower pitch range is somewhat similar to Theorbo, but of course that has a much, much longer scale length, making low pitches easier to achieve.
If you have a 60cm oud with a larger body this might work reasonably well, but I would not expect much from a 57cm oud or from a turkish-sized body.
Maybe though! Never tried this so perhaps it will be more effective than expected.
If this is a tuning you wish to use, I would suggest getting a special oud with a larger body that is at least 62cm or longer to accommodate the
tuning.
* 1) Point the a' 440 arrow at the scale length in cm, 2) point the string tension the appropriate N value, 3) check the nearest available strings in
the pitch column (F1 and A1 are marked with a line over F and A, respectively).
Brian Prunka - 8-25-2023 at 02:17 PM
You could also contact Pyramid and ask for suggestions, they are usually pretty responsive. From my recollection they are usually on vacation for
most of August (and Christmas through New Year's) so might take a little while.
ahmedalalousi - 8-25-2023 at 03:00 PM
Much obliged Brian, for the extensive reply. The issue I was having was in my trying to set the a'=220Hz, which the slide rule can't accommodate. That
being said, let's see how things work out with doing it for a'=440, and taking it from there.
Thanks ever so much once again - I'll probably keep the thread updated with my results, in case it's of benefit.
Brian Prunka - 8-28-2023 at 09:59 AM
Yes, what you are doing is a' still =440, you are just using the pitches from F' to f instead of F to f'.
There are two forms of pitch notation, Helmholtz or Scientific.
The Pyramid calculator uses Helmholtz notation, where middle C is notated c', the octave below is notated c, the octave below that is notated C, the
octave below that is notated C' (or C,), and octaves above add additional markings (c'', c''', etc.)
Most people nowadays use scientific notation, where middle C is notated C4 and octaves above and below are adjusted (C1, C0 etc.)
a' is the A above middle C, or A5. You're not retuning this note, you are just tuning the oud to use a lower pitch range. The tuning option on the
slide rule is for so-called "historical" pitch, which ranged from 380 to 455 for A5. It's not for octave transpositions.