Background music / public announcement systems which might include emergency messages would cover volt-line speakers and/or low impedance speakers concatenated in public address zones. Main criteria are the speech intelligibility and coverage of the different project areas. In the engineering report topics that included are:
- Analytical prediction measurements of all significant acoustic and electro-acoustic parameters, but mainly STi (Speech intelligibility index) or conversions to Alcons or RASTi.
- Loudspeaker Tables with operation characteristics and xyz position in the room and zones of public address messages
- Suggested list of supporting electronics and operational details of each one regarding specs.
- Sound System block diagram
- Cable diagram and cable trace routing on ACAD format
- Racking diagram