Bose Panaray MA12 Technical Foundation & Discussion - Page 7

Browse online or download pdf Technical Foundation & Discussion for Speakers Bose Panaray MA12. Bose Panaray MA12 36 pages. Modular line array loudspeaker
Also for Bose Panaray MA12: User Manual (2 pages), Installation Manual (16 pages), Installation Manual (8 pages), Installation Manual (7 pages), Service Manual (11 pages)

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Figure 2a. A traditional speaker producing spherical waves and

mounted at ear height in the front of the room results in a 26dB

difference in direct field level when the distance ratio of near to far is

1:20. A listener in the back would report the loudness to be four or

more times softer than the front.

Thus while localization is good because the speaker is placed close to the visual activity,

the system does poorly in creating the desired sound level in the audience area. No matter

what volume setting is used, the sound is either too loud or too soft in most of the audience

area – it is simply impossible to establish the correct level for the audience with such a big

difference from front to back.

To achieve less variation in speaker-to-listener distances, and therefore less variation in

sound level, the speaker can be hung in the air and tilted down at the audience as shown in

Figure 2b. This is what is referred to unofficially as the 'hang-and-tilt' approach. The ratio in

this example is 2:1, corresponding to a sound level variation of only 6 dB. The hang-and-tilt

approach largely solves the level variation problem, which is why it was vigorously pursued

as a way to satisfy customer requirements.

Figure 2b. When the same speaker is mounted in the air and tilted

down, the level variation is reduced significantly – in this case to only 6

dB – which corresponds to a near-to-far distance ratio of 1:2.

Bose

MA12™ Modular Array: Technical Foundation & Discussion

Page 7 of 36