Mike's Oud Forums

Is concave soundboard normal?

alexoud - 4-24-2012 at 02:46 AM

I bought a used oud. I'm new to the world of ouds, and was told by the seller that some soundboard curvature is normal over time.

When I place a straight edge on the soundboard, so that it makes contact near the bridge, and at the place where the neck meets the body, I find that the middle of the soundboard is curved 5mm away from the straight edge.

Is this really typical? If not, how can I repair it?

Any advice would be appreciated.

IMG_2228_BW_S.jpg - 19kB

Greg - 4-24-2012 at 02:51 AM

Hello Alex,

Welcome to the forums. Yes, it is normal for there to be a small distortion. 5mm would be around the maximum I would be comfortable with. But I play a Turkish sized oud and they tend to distort less than some Arabic sized ouds. An important measurement at this stage of proceedings is the height of the strings above the fingerboard, where the neck meets the body. What does that measure?

Regards,

Greg

alexoud - 4-25-2012 at 02:35 AM

Hi Greg,

The height of the strings where the neck meets the body is 3.5mm for the high string and 3.0mm for the low string.

The other thing that seems a little bit odd to me is that because of the concavity of the soundboard the part of the fingerboard that rests on the soundboard is at a slightly different angle than the fingerboard of the neck.

Let me know if a picture would help to explain what I mean.

Thanks,
Alex

bulerias1981 - 4-25-2012 at 08:34 AM

Concave soundboard is something makers do intentionally, and is also something that may happen over time. I prefer a slight "dip" in the soundboard at the center for a couple reasons. For a fixed bridge, the oud would be under less stress, and its less likely to receive buzzing on the fingerboard past the neck joint. There are a couple ways to makers to render the top convex. You'll have a problem if the opposite geometry occurs.. such as a convex top.. which it bulges UP. That is an oud under stress and a failure in construction of the face.

alexoud - 4-25-2012 at 02:14 PM

It sounds like the things that I was noticing are fairly typical. Thank you both very much!

Greg - 4-25-2012 at 05:05 PM

Quote: Originally posted by alexoud  
Hi Greg,

The height of the strings where the neck meets the body is 3.5mm for the high string and 3.0mm for the low string.
[snip]
Thanks,
Alex


That sounds fine to me Alex. Enjoy your playing.

Greg

Dr. Oud - 4-28-2012 at 01:11 AM

The face is intentionally built concave to avoid it bulging or bowing up. All Turkish ouds use this feature, but not all Arabic ouds. If the face is built perfectly flat, the torsion of the fixed bridge will twist the face between the braces. The next brace forward then becomes a pivot point, which causes the face to bow upwards between the next braces, just under the center sound hole. This distortion can interfere with the vibration amplitude of the strings causing rattling or buzzing. When the face is built with an depression or concave, this condition is avoided. The concave face can be achieved by either trimming the sides down or shaping the braces.

jdowning - 4-28-2012 at 03:59 PM

This portrait of Turkish oud player Dr Gülçin YAHYA KAÇAR illustrates the sound board profile of her oud quite well.

The lighting casts a shadow of the 6th course on the sound board which - if the sound board was perfectly flat - would appear to be a straight line. Instead - to judge by the shadow - the fingerboard slopes slightly downwards from the neck joint to the top edge of the main sound hole. Across the sound holes the sound board is more or less flat and then curves up to the bridge.


gulcin yahya sound board profile.jpg - 16kB

Ararat66 - 4-29-2012 at 12:29 AM

My Tasos Theodorakis oud based on Manol, is the same and this 'dip' is consistent with the side of the bowl so if you place a straight edge from one side to the other it is flat across the oud but curved longitudinally.

Leon