nadir
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Soundholes
I have always wondered on the sizes of soundholes on the oud. The soundhole on my Arabic oud obviously is a lot bigger than my Turkish oud but WOAH
it's a big difference...
How large do you think soundholes should be?? Does it really make that big of a difference in the sound? (Like one soundhole instruments opposed to
three soundhole instruments).
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sydney
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Hi Nadir
Funny that I came across 6 ouds in my life and they were all with a 110 mm dia. sound hole . maybe it is a standards for arabic ouds.
I personally don't think it matters if it was 10 mm plus or minus but I do believe that it is decided by the locations of the inside pracings
near the hole. Did I make sense then?
regards,
Emad
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Zulkarnain
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Hi Sydney
I dont think it matter too...I just play!
Salam
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Elie Riachi
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Size matters here
The size of the hole determines the projection of the sound "dispersion angle", just like the diameter of a speaker. Each tone will have a
certain dispersion angle which is determined by the frequency of the tone and the diameter of the hole or holes. The smaller holes will serve to
project the higher frequencies.
Peace
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david
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 So do you think that ouds should have three sound holes or just one
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chuckerbutty
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A lot of old pictures show ouds with no soundhole at all - would this perhaps indicate a mixed skin/wood face?
Purely in aesthetic terms, my preference is for a single soundhole unless the face is heavily decorated, in which case three looks nice as well.
I'm not hugely into the elliptical soundholes seen on Bashir ouds, I get the impression that they clash with the shape of the instrument.
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Elie Riachi
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| Quote: | Originally posted by david
So do you think that ouds should have three sound holes or just one |
Hi David,
My oud has 3 holes and it is the only one I have heard live. I would say each will have it's own sound mix and whatever sound blend the
musician prefers.
We need the people who have access to a variety of ouds (1 hole, 3 holes) to comment on the sound difference.
Peace
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Dr. Oud
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| Quote: | Originally posted by Elie Riachi
The size of the hole determines the projection of the sound "dispersion angle", just like the diameter of a speaker. Each tone will have a
certain dispersion angle which is determined by the frequency of the tone and the diameter of the hole or holes. The smaller holes will serve to
project the higher frequencies.
Peace |
Some interesting acoustic theories here. Here's my $.02:
The hole or holes in the face are traditional esthetic affectations and have little to no affect on the sound. The reflection of the lower frequencies
from the volume of the body requires only a very small hole to be released to the listener. Take a look at your headphones or ear canal pretty small
holes, what? The physics of wave propagation are such that the higher frequencies are dispersed or broken up when they hit any object, but low
frequencies are reflected. Speaker size is a factor of the materials used in the speaker construction rather than soundwave characteristics (look at
Bose speaker systems).
The sound of any stringed instrument is 80% produced by the string alone (re: harp). The soundboard adds overtones determined by it's structural
characeristics and bass resonance is added by any cavity or relective suface (oud or guitar body, grand piano top).
So my opinion is that the holes are not a factor in sound production. The longer and bigger the string, the lower the pitch capability. The higher the
tension, the stronger the soundwave or volume. The bracing placement, size and shape determine the overtones or tone color of the sound. The size or
volume of the body provides more or less bass resonance.
An interresting approach to string instrument design was developed by Dr. Michael Kasha
http://www.cybozone.com/fg/kasha.html
and first constructed by Richard Scjnieder.
http://www.cybozone.com/fg/schneider.html
This design is the result of a mathmatical analysis of acoustic properties rather than purely structural elements in traditional designs.
http://www.jthbass.com/kasha.html
How about a Kasha oud? hmmmm?
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Zulkarnain
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Hi
Thanks Dr Oud for clearing up! 
Salam
**as I said...I just play the Oud!!
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Elie Riachi
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Clearification
I agree with what Dr. Oud is saying. However, the dispersion that I am talking about is associated with the "diffraction" or bending of the
soundwaves rather than the dispersion by means of reflection. One can examine the opening in front of the tweeter component in certain speaker
systems. The reason it is there is because high frequencies tend to be directional and will propegate in a straight line, by making them travel
through a hole or even a rectangular slit they will tend to bend or spread out sideways away from the center as they exit the opening. The angle of
this spread is determined by the ratio of the wavelength of the particular frequency to the diameter (in case of circular) or width (in case of a
slit) of the opening. There are slightly different formulae for calculating these angles for the different shape holes.
Could it be that part of the sound produced by the string, travels inside the oud through the hole, gets disperssed as it passes through the hole so
now the wavefront is conical, then reflects after hiting the concave bowel of the oud, passes through the hole again, getting dispersed again and then
combining with the sound waves being prduced by the string, producing an interference pattern at the listeners location (all of this occurs at the
speed of sound ~343 m/s). This and other variables combine with the acoustics of the sarroundings giving a certain sound atmosphere experience to the
listener?
Peace
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Elie Riachi
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Thanks for the link
Thanks for the link Dr. Oud, very interesting.
I often wondered why make oud necks out of lighter woods such as mahogony?
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Dr. Oud
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| Quote: | Originally posted by Elie Riachi
Thanks for the link Dr. Oud, very interesting.
I often wondered why make oud necks out of lighter woods such as mahogony? |
TO keep the oud in balance. The body and face are very light such that the neck and peg box outweigh them and make holding the oud more difficult.
Mahogany is a relatively stiff wood and is used for necks in many stringed instruments. Reinforcing the neck can eliminate any tendance for it to warp
under string tension. Guitar necks often have truss rods installed to adjust the resistance to the string tension. Ouds normally don't have
access to the inside of the neck block to make the adjustment, although I've have seen one on an oud by Sukar.
Now about those sound wave shapes, whew! I think we need an acoustical engineer to moderate this subject.
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Elie Riachi
Oud Junkie
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Correction
In my previous post, I meant to say diffraction instead of refraction.
Also, it makes you wonder about the effect a rosette or "shamsiah" has in the hole, if any at all?
My appologies, I do not mean to complicate the subject.
I guess what it boils down to for the player and listener is if they like the sound the particular oud makes.
Peace.
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Elie Riachi
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| Quote: | Originally posted by Dr. Oud
Now about those sound wave shapes, whew! I think we need an acoustical engineer to moderate this subject. |
I am thinking the sound waves form conic sections of a sphere, kind of like an ice-cream cone with ice-cream on top but without the pointy bottom.
The other shapes I'm refering to are of the holes.
I am definetly not an expert on the subject. I base my posts on my understanding of the principles physics and I try to apply it to the oud.
I do lack the real world long time experience that Dr. Oud has with the oud and other musical instruments. So I am greatfull to have such an
experienced luthier comment on these posts.
An acoustical engineer would be a great person to have join the forum in my oppinion.
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