Diaphragm (acoustics)


Diaphragm (acoustics)

In the field of acoustics, a diaphragm is a transducer intended to faithfully inter-convert mechanical motion and sound. It is commonly constructed of a thin membrane or sheet of various materials. The varying air pressure of the sound waves imparts vibrations onto the diaphragm which can then be captured as another form of energy. (or the reverse)

In a loudspeaker, a diaphragm (generally, but not exclusively cone shaped) is the thin, semi-rigid membrane attached to the voice coil, which moves in a magnetic gap, vibrating the diaphragm, and producing sound. Diaphragms are also found in headphones, and microphones.

Similarly, the eardrum uses this same principle, using a diaphragm to stimulate nerves to transmit a neural "image" of sound to the brain. In loudspeakers, cellulose fiber (paper) has historically been the most common material used for the diaphragms, based on its low mass, and controllable acoustic properties. Synthetic fibres and binders may be added to provide specific properties. Other materials used for diaphragms include: polypropylene (PP), polycarbonate (PC), Mylar (PET), silk, glassfibre, carbon fibre, titanium, aluminium, aluminium-magnesium alloy, nickel, and beryllium.

In a phonograph reproducer, the diaphragm is a flat disk of typically mica isinglass that converts the mechanical vibration imparted on the needle from the recorded groove into sound. In the case of acoustic recording the reproducer converts the sound into the motion of the needle that scribes the groove on the recording media.

References

  • ALMA NP-001 Diaphragm Styles & Nomenclature
  • ALMA DG-001 Dimensioning & Tolerancing Guidelines for Diaphragms
  • ALMA MG-001 Measurement Guidelines for Diaphragms
  • ALMA TM-100 Test Method for Measurement of the Lowest Resonance Frequency of Loudspeaker Cones
  • ALMA TM-104 Test Method for Measurement of Diaphragm Neck ID
  • ALMA TM-114 Test Method for Measurement of Diaphragm Body Mass
  • ALMA TM-138 Test Method for Measurement of Diaphragm Assembly Mass

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Diaphragm — Contents 1 Optics and photography 2 Acoustics 3 Other 4 …   Wikipedia

  • Acoustics — is the interdisciplinary science that deals with the study of sound, ultrasound and infrasound (all mechanical waves in gases, liquids, and solids). A scientist who works in the field of acoustics is an acoustician. The application of acoustics… …   Wikipedia

  • Loudspeaker — For other uses, see Loudspeaker (disambiguation). An inexpensive, low fidelity 3½ inch speaker, typically found in small radios …   Wikipedia

  • Электромеханический фильтр — ЭМФ советского производства, предназначенный для выделения нижней боковой полосы в аппаратуре радиосвязи с промежуточной частотой 500 кГц. Ширина полосы пропускания  3,1 кГц. Механическ …   Википедия

  • Electrostatic loudspeaker — An electrostatic loudspeaker is a loudspeaker design in which sound is generated by the force exerted on a membrane suspended in an electrostatic field.Design and functionalityThe speakers use a thin flat diaphragm usually consisting of a plastic …   Wikipedia

  • Thiele/Small — commonly refers to a set of electromechanical parameters that define the specified low frequency performance of a loudspeaker driver. These parameters are published in specification sheets by driver manufacturers so that designers have a guide in …   Wikipedia

  • Intonarumori — Infobox instrument name =Intonarumori names = image capt = Russolo with his assistant Ugo Piatti and their Intonarumori classification = String range = Varied related = musicians = Luigi Russolo builders = Luigi Russolo articles = Musica… …   Wikipedia

  • Stethoscope — Modern stethoscope. The stethoscope (from Greek στηθοσκόπιο, from στήθος, stéthos chest and σκοπή, skopé examination) is an acoustic medical device for auscultation, or listening to the internal sounds of an animal body. It is often used to… …   Wikipedia

  • Headphones — For other uses, see Headphones (disambiguation). Sennheiser HD555 headphones, used in audio production environments …   Wikipedia

  • Koenig's manometric flame apparatus — was a laboratory instrument invented in 1862 by the German physicist Rudolph Koenig, and used to visualize sound waves. It was the nearest equivalent of the modern oscilloscope in the late nineteenth and early twentieth centuries.DescriptionThe… …   Wikipedia