What's the difference between a hexagonal barrel and an octagonal barrel?

Specifically, it is the difference on the barrel, which is not necessarily related to the timbre. The sound of erhu mainly depends on the material (including wood and snakeskin), so if we insist on the difference, we can only say that it is the difference in appearance.

The following is an expert's explanation of the difference between hexagon and octagon.

The traditional erhu piano barrel is a hexagonal piano barrel, which is made of six wooden boards stacked and glued. The total length of the Qin barrel is 129- 13 1mm, the diameter of the front outer opening is 87-89mm, and the upper diameter of the rear outer product is 79-81mm.

However, in the development of modern music art, the timbre and volume of erhu are still not suitable, so in the mainstream hexagonal erhu, various improved erhu appear constantly, mainly to solve the musical inadaptability of erhu.

After many years of erhu reform practice, erhu's reform on the piano barrel includes octagonal and round piano barrels in addition to hexagonal ones. At present, the more reformed erhu sold in the market is the square tube erhu, which is a new erhu variety successfully developed by 1975. This musical instrument reform achievement won the second prize of scientific and technological achievements of the Ministry of Culture. Fiona Fang erhu has an octagonal front opening and a circular back opening. The barrel length 133mm, the longitudinal diameter of the front opening is 86mm, the transverse diameter is 92mm, and the inner diameter of the rear opening is 84mm. A small bamboo tube is installed in the center of the piano tube to enhance the volume in the high-pitched area, but in recent years there is a trend to cancel the bamboo tube.