4. VOLUME ADJUSTMENT (BS-678T and BS-678BT)
Adjust the sound volume by rotating rotary switch on the speaker’s side panel.
Switch position
3
2
1
OFF
Sound volume
0 dB
– 6 dB – 12 dB
off
Note:
Switch position is factory-preset to “ 3.”
O
FF
3
1
2
VOLUME CONTROL
8 Ω
13 kΩ
6.7 kΩ
3.3 kΩ
1.7 kΩ
0
COM (white)
Bridge
[ 2-wire system ]
HOT (black)
Matching
transformer
COM
Attenuator
HOT
(+)
R
(R)
(–)
SP
N
(N)
(C)
I
nput
connector
(R–C SHORT)
8 Ω
13 kΩ
6.7 kΩ
3.3 kΩ
1.7 kΩ
0
COM (white)
Bridge
COM
(COM)
(–)
HOT (black)
HOT
(HOT)
(+)
Matching
transformer
I
nput connector
COM
5. WIRING DIAGRAMS
5.1. BS-678 and BS-678B
5.2. BS-678T and BS-678BT
8 Ω
13 kΩ
6.7 kΩ
3.3 kΩ
1.7 kΩ
0
COM (white)
Bridge
[ 3-wire system ]
HOT (black)
Matching
transformer
COM
Attenuator
Normal
R
Common
Emergency
SP
N
(N)
(R)
(C)
I
nput connector
