MODUK DEF STAN 02-557: PART 1 PDF

This Defence Standard (DEF STAN) specifies the principles necessary in identihg the most appropriate loudspeaker assembly for each particular application and its location, whilst maximizing the probability that the resulting selection is satisfactory in practice.

Loudspeaker coverage is often less than satisfactory due to alack of correct quantity, power or type of loudspeaker, coupled with a failure to understand the need to specify the exact location of each loudspeaker and its angle of direction. This has been particularly true on weatherdecks and passageways where conflicting requirements of the clean ship technique have urged that large surfaces be kept free from projecting ancillary equipment.

Simple, step-by-step design rules are given which, if correctly followed and applied, should result in the correct selection of loudspeaker assembly for each particular application.

The selection may be made from the list of loudspeaker assemblies presented in Table 4.1. In most circumstances the loudspeaker selection procedures may indicate a loudspeaker fiom this range, but there may be cases where a ‘unique' combination of requirements will mean that the list does not contain an assembly appropriate to application. In such cases reference is to be made to Fleet Wide Systems Integrated Project Team Leader (FWS IPTL).

Once the correct loudspeaker assembly has been selected, satisfactory performance will be achieved only if the loudspeaker is sited correctly and mounted properly. This Standard presents a number of loudspeaker siting rules which, if observed, should tend to optimize the performance of the loudspeaker when installed.

The selection procedures in this Standard are based on acoustic theory, but they also take account of the design margins that need to be applied because of the practical problems encountered in audio systems and the acoustic environment. To aid the designer in his appreciation of these problems, general characteristics of the acoustical environment, physical and acoustical environment parameters and system features that affect the choice of loudspeaker have been included.