Response In The House - JBL 4671 Instruction Manual

Another consequence of using loudspeakers with
flat power response is that little system equalization will
be required. Figure 15 illustrates this. At A, we see the
boundary absorption in a typical well-designed theater.
Note that it is quite flat over the frequency range. High-
frequency losses due to air absorption are shown at B,
FIGURE 15. RESPONSE IN THE HOUSE
20
ROOM BOUNDARY LOSSES
EXPRESSED IN dB
(TYPICAL)
AIR LOSSES AT 15 METERS,
50% RELATIVE HUMIDITY
ON-AXIS
SCREEN LOSSES
(15 MIL THICK VINYL, 8% OPENING)
SUM OF CURVES
A, B, AND C
and typical high-frequency screen losses are shown at
C. When we add all of these losses, we get the response
shown at D, and this is exactly the acoustical response
we would observe in the room if we were using a loud-
speaker that had flat power response.