White Papers

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Bose White Papers


Summary: Amplified guitars are the source of some truly remarkable musical instrument sounds. At the same time, we found they are the source of acoustical problems that often prevent musicians and members of the audience from hearing the guitar as intended...


Note: The following documents discuss the Bose® Panaray MA12 Modular Array. The information is of interest as it applies to line arrays and is applicable in that context. Please be aware that the L1 is a portable line array. It is twice the height of the MA12 and has different characteristics than a single MA12. See also L1® and the Panaray® MA12

One uses polar plots to describe the behavior of conventional speakers such as constant directivity horns or small arrays built up using smaller transducers. Line arrays produce cylindrical waves in the near field and therefore, the vertical polar plots change as a function of distance. To describe the vertical radiation of a line array an industry accepted method is to use validated modeling programs and paint a picture of the radiation as a function of distance. This paper addresses the radiation characteristics of the MA12 and in addition shows measured polar plots, on-axis frequency response, controller curves, and impedance curves.

Summary: THE Bose MA12™ modular array takes advantage of the properties of cylindrical waves to meet customer requirements that until now could only be met with loudspeakers flown and aimed in more elaborate and expensive designs. With only two dimensions of dispersion rather than the three of the more common spherical waves, the sound from cylindrical waves diminishes much more gradually with distance from the source. As a consequence, listeners experience relatively little change in sound level from far away from the MA12 to literally right next to it. The same gradual change in sound with distance makes the MA12 less susceptible to feedback from microphones in close proximity. The radiation pattern of the MA12 is wedge-shaped: wide from side-to-side but sharply confined to the top and bottom of the array. The vertical radiation virtually shuts off above and below the speaker. As a result, much less reverberation is generated because almost no sound is radiated upwards to distant surfaces in the upper part of the room. The result is noticeably better clarity and intelligibility. The ultra-thin shape of the MA12 means it is easy to hide; it may be the most unobtrusive speaker yet developed given its exceptionally high output and full, balanced frequency response. The fact that the MA12 is placed at ear level (so that listeners are confined within its wedge-shaped radiation pattern) means that it can usually be installed for a fraction of the cost of more elaborate ‘flown’ loudspeakers and loudspeaker clusters. Finally, it can be matched to a low frequency enclosure (Bose Panaray MB4) when extended bass performance is needed. Taken together, these features and advantages result in a product that represents an important new tool for satisfying the most basic and important customer requirements in a wide range of common applications.