If you want to buy a piano, please refer to the following.
Basic appraisal of violin before purchase
When you buy a violin, the first question you face is: how to choose? What is good? Although such a question can't be answered simply, as long as you do it carefully according to the methods we teach you below, the possibility of paying a high price for defective products will be greatly reduced. Generally speaking, violin appraisal should not only have knowledge of production, be familiar with its technological process, but also have certain playing skills, and be carried out item by item from the aspects of materials, production and sound quality.
I. Materials
Panel: Use Picea ichthys. Picea ichthyoides has many characteristics compared with other wood, mainly as follows:
(1), its texture is firm and light, and the texture between annual rings (spring material) is soft, but its annual rings (textured autumn material) are hard and elastic, which can resist the pressure of strings and easily vibrate. So it has the best sound performance.
(2) Sound transmission speed is faster and more elastic than other wood. Its sound propagation speed along the wood grain reaches 565,438+066 meters per second, which is more than 65,438+04 times faster than the sound propagation speed in the air (350 meters per second), so it is very sensitive and effective to use the violin.
(3) It can damp pronunciation at a high frequency (3000-5000 cycles/second or above) (damping refers to the disappearance of vibration in wood, which is caused by friction between wood molecules). This is beyond the reach of other wood. The damping effect of the fish-scale board can increase with the increase of frequency, but it has little damping effect on low-frequency sounds, but it has a strong damping effect on high-frequency overtones that are not suitable for violin (that is, those sounds that are not in harmony with pitch), making them weaken and making the piano sound pleasant.
The texture of the advanced piano should be straight and even, and the fiber structure must be tight, soft and elastic. Scars, resin capsules and repairs are not allowed. The number of annual rings in the middle of spruce plate should be 5-8 grids per cm, and the width of annual rings at the edge should not be greater than 3 mm. Within the range of adjacent 20 mm, the change of annual ring width of the whole plate should not be greater than 65438±0.5mm, the change of annual ring width of the whole plate should not be greater than 2 mm, the autumn wood rate in each annual ring should not be greater than 30%, and the autumn wood width of the whole plate should be similar. Practice has proved that the texture distance is 2 mm, and the pronunciation is the best. The key of violin sound quality is the choice of panel. Due to the unremitting pursuit of the perfect timbre of the violin, the panels used in the advanced violin made by Lehe Bow Workshop have not only undergone strict selection and testing, but also must be high-quality ichthyosis spruce that has been naturally dried for more than 10 years, and a few good materials that have been naturally dried for 50 years. However, due to the increasing shortage of resources, it is difficult to get old materials over 50 years old.
Intermediate violins are upright in texture, uniform in density, without scars, resin capsules and repairs.
The texture of ordinary violins is generally straight and even, allowing a small number of scars, resin capsules and patches.
The board must be cut according to the diameter, using healthy, high-quality materials and wood with the edge skin and pith removed.
The allowable range of wood defects is as follows:
The twill of ordinary violin for advanced violin and intermediate violin of the project shall not exceed 1% length, 1% length and 2% length. Eddy current is not allowed, bending does not exceed two rings, and the maximum bending torsion vector does not exceed.
1% of the length of the bending part is not more than 2% and not more than 5%. Local wide rings are not allowed to change color by more than 2 places. Non-decaying natural and chemical changes are not allowed.
Color, after painting two should not be exposed.
The colors of the boards should be in harmony.
Second, the bass beam, sound column, front and rear wood blocks, horn wood and lining strips (all in the abdominal cavity of the piano) should be made of the same material as the panel and can be observed through the F hole.
Third, the backplane.
Use hard and elastic maple and maple colored wood. The characteristics of these woods are as follows:
1. It is easy to vibrate and transmit sound quickly, and has damping effect on high-frequency noise.
Fine texture, beautiful appearance, beautiful transverse pattern (tiger spot) after radial cutting.
The selection criteria should also be the same as the panel, using healthy wood. Some people like to use curly wood grains as backboards. More violin users mistakenly believe that the more flowers on the back board, the better the piano. The reason is that most piano manufacturers like to use beautiful backboards with good acoustic performance. In fact, as far as the backboard is concerned, the acoustic performance of the material with curly wood grain is not as good as that with straight wood grain. The quality of a piano is judged by its sound. Mr. Zu, the owner of Lehe Piano and Bow Workshop, had seen several famous pianos collected during his study in Japan. There is no pattern on the back plate, which is sawed casually. Even some famous pianos have several scars on the back plate, but the piano sounds very beautiful. There are different views on the function of backboard. Mr. Wang thinks it is important whether the tree is old, whether the grain width is uniform, whether the material is healthy, whether the color is uniform and whether the natural drying time is long enough. At present, the back materials used by Lehe are excellent maple trees that have been naturally dried for more than ten years, because the materials used in the future will become older and better. Although the back panel is not as important as the front panel in the whole violin, it still has a certain function, which makes the violin have a fixed air volume.
When the front panel vibrates, the back panel vibrates through the conduction of the sound column, the side panel and the air in the piano, so that the sound of the piano is enhanced, especially the pronunciation of the G and D strings is strong, and the back panel bears great force from the four strings. Experiments show that if the violin is not equipped with a backboard (that is, there is no air capacity) and the sound column is supported between the panel and the slats, the sound of the violin will be obviously weakened and the timbre will change accordingly. In addition, although the vibration of the backplane itself is weak, it will also radiate sound waves in high frequency range. The different thickness of the backboard and whether it is properly matched with the panel will affect the sound quality of the violin, which shows the importance of the backboard.
The backboard, like the panel, often adopts the double-frame method, and the backing material of the veneer is also very common, because of the huge tree body, this piece of material can be cut from the veneer when selecting materials. It must be pointed out that the use of double frame or single board has little influence on the sound of the piano, and the head and side plates of the piano should be made of the same material as the back plate. The allowable range of wood defects in the back panel is the same as that in the front panel. The side plate, the piano head and the bridge are all made of the same material as the back plate.
Fourth, the difference between the two piano types: the two best piano types recognized in the world today:
The characteristics of the piano are: the upper part of the piano is narrow, the lower part is wide and the middle part is slightly deep, which not only conforms to the outline, but also has beautiful lines. The piano board is wide and flat, with a slight curvature, thick in the middle, gradually expanding and thinning around, and the edge near the side board is the thinnest. Because the panel is moderately thick, it is easy to vibrate. Qin Si has strong pronunciation, loud voice, beautiful timbre and excellent transmission effect. People often use words such as roundness, implication, richness and purity to describe its timbre.
Melon piano is characterized by small radian, relatively flat piano board, slightly different thickness between the middle and the periphery of the panel, wide piano in the middle and upper part of the piano body, and round but not deep waist. The horn of the piano is not as prominent as that of the Sioux people. The lower part of the piano body is narrow, the sound hole is long and the style is unique, and the piano head is large and the style is magnificent. Because Guaqin only pays attention to the pronunciation effect of the piano, the appearance of the piano is slightly inferior to that of Su, but the vibration of the piano board is strong, the pronunciation is deep and loud, and the transmission effect is good. Lehe only makes violins according to the size of loofah.
Verb (abbreviation of verb) technology
The process of violin making is very demanding. Mechanical processing can only produce the cheapest ordinary piano, and good pianos are all made by hand. Pay attention to the following points when choosing:
1. Whether the overall lines are smooth and even, and whether the edges and corners are smooth and moderate.
2. Whether the rubber edges of the side plates, surfaces and backboards are neat and uniform in width,
3. Whether the piano head and fingerboard are upright.
4. Whether the height of the fingerboard is correct (after tuning, the seam between the outer arc of the lower section of the fingerboard and the panel is 2 1mm 1).
5. Whether the backplane pattern is symmetrical. (for advanced pianos)
[6] Whether the radian of the board surface and the position of the sound hole are symmetrical.
(7) Whether the middle seam of the piano board is tightly adhered and whether there are black lines.
⒏ Whether the inlaid lines are neat, whether the paint color is elegant and even, whether the surface is smooth and bright, whether the luster is transparent and whether the wood grain is exposed.
The easiest way to stick the piano body firmly is to hold the neck firmly with one hand and use the knuckles with the other.
Tap the side of the piano body panel and listen to its sound. If the sound is drums, it means good adhesion. If the sound is an empty shell, it proves that there is degumming.
Oil-soluble natural resin varnish should be used for advanced violins, and alcohol-soluble natural resin varnish and synthetic resin varnish can be used for intermediate and general violins.
6. Strings As far as violin strings are concerned, it should be said that this is still a weak link in China. On the one hand, the pitch of a handle is not very accurate, and then there are problems with the timbre, which needs to be studied and solved by everyone.
At present, the violins produced by Lehe Bow Workshop all adopt DOMINANT and PIRASTRO, two internationally renowned brands, to ensure the sound quality of the products.
Seven, string horse
The string horse is a very delicate accessory on the violin, and its material directly affects the sound quality of the violin, so choose a string horse with good material. Of course, it is also important to cooperate with the violin in production. At present, all the mid-range violins produced by Lehe Bow Workshop adopt French luxury string horses.
Eight, sound quality
Sound quality is the most fundamental identification of violin, but only those who have certain playing skills and are familiar with the correct sound quality of violin can be sure.
Volume: the sound is loud and clear, of course, it is obtained through the correct playing method. You can try to play the piano according to the high position, especially the G and D strings. If the sound played in a high position can be soft and loud, it shows that the pronunciation of the piano is ideal. On the other hand, if there is a harsh squeak, it means that there is something wrong with the placement of accessories, and even ordinary violins can't have obvious noise.
These four strings are pronounced evenly. In the range of violin, the intensity of various frequencies should be uniform or relatively uniform, and one tone should not be particularly strong and the other tones should be particularly weak. In particular, the low-frequency sounds on the G and D strings are louder. The minimum requirement should also be that there is no obvious difference between the four strings. Any piano with a loud and even pronunciation sounds very pleasant. Otherwise, if the pronunciation is too weak or the strength is very different, it will sound unpleasant or harsh.
1. timbre: The timbre of violins varies greatly due to different materials, production methods, sizes, strings, pigments and assembly. Advanced violins must have pure and soft high notes, full and powerful low notes, and implicit and concentrated pronunciation. Specific to each string, E string is required to be clear and bright, A string is as soft as a song, D string is elegant, and G string is rich and deep. In this way, the piano sounds mellow and beautiful without any noise.
13. Harmony: The fifth tone in each position of the violin must be harmonious and not different, and it cannot be obviously different from the ordinary violin. In addition, the four strings of the violin are required to be sensitive in pronunciation, fast in vibration transmission and not dull. And the vibration lasts for a long time and decays slowly. If you are not familiar with the above identification methods, you can also choose the most convenient comparison method.