Ο ΤΖΟΥΡΑΣ ΠΟΥ ΦΤΙΑΧΝΩ ΤΩΡΑ ΘΑ ΕΧΕΙ ΣΤΡΟΓΓΥΛΗ ΚΙ ΟΧΙ ΟΒΑΛ ΣΑΝ ΤΟΝ ΠΡΟΗΓΟΥΜΕΝΟ. ΣΚΑΦΟΣ ΜΑΝΙΚΟ ΟΛΟΙΔΙΟ
ΟΤΑΝ ΦΤΑΣΕΙ ΝΑ ΚΟΥΡΤΙΣΤΕΙ, ΤΟΤΕ ΘΑ ΣΟΥ ΠΩ ΜΕ ΣΙΓΟΥΡΙΑ. ΑΛΛΑ ΚΑΙ ΠΑΛΙ ΕΧΟΥΝ ΑΛΛΑΞΕΙ ΔΙΑΦΟΡΟΙ ΑΛΛΟΙ ΠΑΡΑΓΟΝΤΕΣ.ΛΙΓΟ ΤΟ ΚΑΠΑΚΙ, ΛΙΓΟ ΤΟ ΚΑΜΑΡΩΜΑ, ΛΙΓΟ ΤΟ ΕΝΑ ΛΙΓΟ ΤΟ ΑΛΛΟ, ΠΙΑΣΕ Τ ΑΥΓΟ ΚΑΙ ΚΟΥΡΕΥΤΟ ΔΗΛΑΔΗ................
ΑΚΡΗ ΔΕΝ ΒΓΑΖΕΙΣ ΠΟΤΕ, ΑΛΛΑ ΚΙ ΑΥΤΟ ΕΙΝΑΙ ΟΛΗ Η ΟΜΟΡΦΙΑ ΕΤΣΙ ΔΕΝ ΕΙΝΑΙ?
Ναι όλη η ομορφιά όπως το είπες!!!!ανυπομονώ να ακούσω τον τζουρά σου!!Εγω σκέφτομαι να βάλω σεένα μπαγλαμαδάκι που φτιάχνω τέτοια κυκλική ροζέτα (αυτή με το σχέδιο μέσα στην τρύπα νομιζω έτσι λέγεται) περισσ΄τοερο γιατι μου αρέσει η ιδέα να την φτιάξω αλλα δεν θα ήθελα να χάσει σε ήχο ....
βρήκα σε ένα άλλο forum που ένα παιδί έκανε πείραμα σε ίδιο όργανο με και χωρίς ροζέτα If you go to the topic 'Old Oud - New Project' (on page 5 of the Oud Projects forum) I report on a series of trials undertaken to try to measure the acoustic effect of soundhole diameter as well as the effect with or without a rosette (page 10 of the topic).
Due to the large number of variables in the construction of an oud - no two instruments can be identical acoustically even if they appear to be alike - these tests were carried out on a test instrument with modified sound hole to simulate different diameters etc.
It is well known that sound hole diameter relative to the volume of the instrument body cavity can be used to tune/enhance the loudness in the lower registers (the, so called, Helmholtz effect) and so increase bass response. This was confirmed by the tests.
The tests also indicated that there is little or no difference in loudness between an open sound hole and one fitted with a rosette that is - as far as the Helmholtz effect is concerned - the rosette diameter is equivalent to an open sound hole of the same diameter.
Interestingly, the presence of a rosette appeared to increase sustain compared to that obtained with open sound hole and also seemed to result in a smoother attenuation (decay) of the sound vibrations so had some (small?) effect on the quality of sound.
An oud or any other musical instrument is a less than perfect Helmholtz resonator so attempts at precise analytical analysis in order to establish a convenient formula to calculate design of an instrument with optimum acoustic response may likely always be in vain.
Nevertheless, the more successful luthiers throughout history seem to have, intuitively, 'got it right' one way or another (judging from the variations in instrument size and geometry). One good reason, perhaps, for modern makers to follow the old established luthier traditions and instrument designs?
