a forest of pipes: presenting the 37’s sheng from the inside

Wu Wei – Alexis Baskind
Sheng! Project – TPMC, Sorbonne Université, IRCAM

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this web seminar has been given and broadcasted live on december 9, 2020, within a series of seminars about the chinese instrument “sheng”, with the world-class sheng master wu wei.

abstract

in the vast majority of existing studio and live productions, the sheng is represented as an external sound object, i.e. a sound source (typically positioned forward) with a given distance and width, placed in a real or virtual space, as it is usually done for other instruments in music production.

the research presented here consists in proposing a perspective reversal, i.e. to develop methods to set the listener metaphorically inside the sheng, surrounded by the pipes, similarly to the image of the “forest of pipes” sometimes used for the church organ. This idea, which for the organ may be technically easier (though still complex) to implement, poses significant difficulties for the Sheng because of the size of the instrument and the radiation of the pipes (mostly directed outwards). Alternative methods for the design of the microphone system must therefore be sought to overcome this obstacle.

this presentation is part of the “sheng!” research project coordinated by liao lin-ni of the tpmc, implying many participants and institutional partners (sorbonne université, ircam, université de montréal, mcgill university…)

contents

goals of the project

  • set the listener metaphorically inside the sheng, surrounded by the pipes (perspective reversal)
  • tradition and existing experience as starting point
  • compromises between the aesthetical goal (forest of pipes surrounding the listener), the design of the sheng (pipes close to each other, mostly radiating outwards), and feasibility

design of traditional shengs and of the 37’s sheng

  • traditional asian mouth organs
  • wu wei’s instrument: 37’s sheng
  • 3 types of pipes
  • note range in the traditional and the 37’s sheng
  • sound sources in the 37‘s sheng

usual microphone systems for the sheng

  • one or two overheads on the top front
  • one close microphone on the top
  • wu wei’s usual 5-microphone system (supported by overheads)

design of the new microphone system

  • starting point: 4 large-diaphragm cardioids (akg c414) on stands
  • second step: 4 miniature hypercardioid microphones (dpa 4099) attached to the instrument + omni (akg c417) on the top
  • method for optimisation of the microphones
  • possible adjustements for a single microphone

further research

  • support this empirical research with scientific studies about the sound radiation
  • proceed to further tests with amplification, various concert halls, with other musicians
  • start a reflection about spatial post-processing, i.e. methods to project those 5 signals around the listener
  • continue research and experimentation on beats and difference tones
  • capture low-frequency information, (even) more dynamics on attacks
  • electroacoustic processing of the captured sound