Speaker diaphragm

Murakami, M., Nakamura, K., Nishiki, N., Tajima, I., Okazaki, M. and Yoshimura, S., High-quality graphite for speaker diaphragms. In Proceedings of International Symposium on Carbon, Tsukuba, Japan, November 4-8, 1990, pp. 978 981. 

Acoustical coatings Speaker diaphragms high sound propagation speed high stiffness low weight... 

After World War I ended, work at the Edgewood medical research laboratories continued. New gas masks were developed, such as those with high-eyepoint lenses for use with binoculars, and masks with speaker diaphragms. As those who have worn mission-oriented protective posture (MOPP) gear know, one cannot really be heard through a mask. Initially, scientists at Edgewood worked on oilcloth-... 

Cellulose G luconacetobacter Agrobacterium Aerobacter Achromobacter Azotobacter Rhizobium Diet foods, speaker diaphragms, medical pads, artificial skin... 

Bacterial cellulose has been also explored in a series of technical applications. For instance, SONY Corporation and Ajinomoto developed an audio speaker diaphragm membrane using a compressed low thickness ( 20 pm) BC membrane, that is currently utilized in audio headphones (Figure 2.10) [4, 58]. 

The acoustic velocity of SiC has been measured using both ultrasonic resonance [1] and ultrasonic pulse echo techniques. The latter has resulted in the appearance of CVD-SiC diaphragms in commercially available speakers [2]. 

Speakers create sound by moving a diaphragm in and out to displace air. Most diaphragms are in the shape of a cone, traditionally made of paper. Paper cones are inexpensive, lightweight, rigid, and nonresonant. 

I started my scientific career in Sony as a researcher on zinc-air hatteries. After 8 years of R D on electrochemistry, my research field was shifted against my will to electroacoustic materials, specifically materials for diaphragms of electroacoustic transducers including loud speakers, headphones, and microphones. 

Direct radiators are the most widely employed form of loudspeaker design. These are speakers in which a diaphragm is directly coupled to the air mass and radiates directly into the hstening area. Although... 

FIGURE 3.60 Electrovoice dynamic speaker unit with a whizzer attached to diaphragm to increase the midrange and high-frequency response. Source Tremaine, H.M. 1973. Audio Cyclopedia, 2nd ed., p. 1090. Howard Sams.)... 

Generally, a material having high sonic velocity that has a low internal loss is preferred. Thus, bacterial cellulose is a material well suited for these diaphragms, and it has been commercialized in various types of speaker units and headsets. 

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