Speaker Design Method
Introduction
Step 1:
Room
Characteristics
The steps below summarize the speaker system design method. Use these steps in conjunction with the Tyco Safety Products iTool (described later in this chapter).
Determine if the room requires advanced design methods. Some characteristics of a difficult location/space include:
•High Background Noise Levels (Greater than 80 dB).
•Large Spaces with High Ceilings (Greater than
•Unique Room Shapes (Rooms with many different angles, spherical shapes, etc.).
•High Reverberation Times (T60 > 1.5).
Step 2: | Use the steps below to calculate the number of speakers: | |
Calculate the | 1. Determine the | |
Number of Speakers | ||
|
Step 3:
Audio Power and
Individual Speaker
Wattage Tap
Step 4:
Model Design to Predict Intelligibility
Step 5:
Verify Final
Installation
2.Using D2 and the speaker's polar response, calculate the speaker's coverage area.
3.Select a layout pattern and calculate the number of speakers required for the area.
Use these steps below to determine the required audio power:
1.Using the speaker's sensitivity and
2.Determine the SPL requirements by adding the required
3.From Step 1, select the wattage tap that satisfies the SPL requirements determined in Step 2.
4.Multiply the wattage tap selection by the number of speakers in the room to determine the total audio power required.
This optional step is recommended for areas of high reverberation or of complex geometry. Modern modeling tools such as EASE® from
As part of system commissioning the audibility for every area must be verified. This can be accomplished with a simple SPL meter set to read decibels with the “A” weighted filters applied. The audibility of the primary evacuation signal is measured, typically a temporal coded horn or slow whoop horn is used. The audibility of emergency voice/alarm communications messages is typically not recorded due to the varying nature of speech.
