JBL GTH400 - Internal Adjustments; Speaker-Level Input Impedance; Crossover Frequency Settings

11
+ - + - + -
Buffer Buffer Buffer Buffer Buffer Buffer
1 2 3
1 2 3
1 2 3
1 2 1 2
1 2 3
1 2 3
1 2 3
1 2 3
CH. 1 L IN
CH. 1 R IN
CH. 2 L IN
CH. 2 R IN
CH. 1 L OUT
CH. 1 R OUT
CH. 2 L OUT
CH. 2 R OUT
IMAGE
ENH.
1 2 3
GROUP 3
INPUT
+
+
1 – GR 3 2 – GR 2 3 – GR 1+2
1
Speaker Crossover 1 – Flat 2 – Low Pass 3 – High Pass
Preamp Crossover 1 – Flat 2 – Low Pass 3 – High Pass
GR 3 Input Mode
∑ ∑
+
+
GR 1 GR 2 GR 3
L L L
R R
Buffer Buffer Buffer Buffer
GR 1 GR 2
L L
R R
R
LP
HP
GR 1 L
PREOUT
X-OVER
GR 1 MODE SWITCH
GR 2 MODE SWITCH
1 2 3
1 2 3
LP
HP
GR 1 R
PREOUT
X-OVER
1 3 2
1 2 3
LP
HP
GR 2 L
PREOUT
X-OVER
1 3 2
1 2 3
LP
HP
GR 2 R
PREOUT
X-OVER
1 3 2
1 2 3
LP
HP
GR 3 L
PREOUT
X-OVER
1 3 2
1 2 3
LP
HP
GR 3 R
PREOUT
GR 3 Left Speaker Out
GR 3 Right Speaker Out
X-OVER
1 3 2
1 3 2 1 3 2
1
3 2
BASS BOOST
AMP AMP
GR 2 Left Speaker Out GR 2 Right Speaker Out
BASS BOOST
AMP AMP
1 3 2 1 3 2
GR 1 Left Speaker Out GR 1 Right Speaker Out
BASS BOOST
AMP AMP
❶
❶
❶
❶
❷
❷
❷ ❷
GTH400 Block Diagram
∑
∑
∑
∑
Mode 1 – L 2 – Stereo 3 – L+R
❸
GROUP 2
INPUT
1 – GR 1 2 – GR 2
❸
❸
❸
Buffer
Buffer
Buffer
Buffer
Buffer
Buffer
Speaker-level
inputs
Preamp-level inputs
+
-
Buffer
+
+
+
+
GTH400-20107 06/03/98 15:49 Side 11