POWER AMPLIFIER OWNER’S MANUAL
6
7
1. Gain Controls –
These controls are used to match the input sensitivity of the amplifier to the particu-
lar source unit that you are using. The controls are factory set to 1Vrms.
2. RCA Input Jacks –
These RCA input jacks are for use with source units that have RCA or Line Level
Outputs. A source unit with a minimum level of 200mV is required for proper operation. The use of high qual-
ity twisted pair cables is recommended to decrease the possibility of radiated noise entering the system.
3. Speaker Level Inputs –
This input, found on the Thunder342 will allow the amplifier to operate from
source units with speaker-level outputs. Output speaker leads from the source unit should be tied directly
to the wire harness provided with the amplifier.
Wire harness color codes:
Grey / Black = Source units right negative (-)
White / Black = Source units left negative (-)
Solid Grey = Source units right positive (+)
Solid White = Source units left positive (+)
With the Smart-Engage™ auto-turn circuit, a remote turn-on wire is not necessary when connecting the
speaker-level input wire harness to a high powered source unit. The amplifier will automatically turn on
when music is received.
4. Frequency Control –
This control is continuously adjustable from 40Hz through 200Hz. Factory setting
is at 40Hz.
5. Crossover Select –
This switch determines what type of signal comes out of the amp. If you select high
pass, the crossover slope is 12dB/stereo. If you select low pass, your crossover slope will be 24dB/mono.
Available crossover frequencies are 40-200Hz.
6. Thunder EQ –
This equalization circuit is used to enhance the low frequency response of the vehi-
cle’s interior. With up to 18 dB of boost and centered at 40Hz, the Bass EQ can be adjusted to meet your
own personal taste.
7. Compression Circuit –
This new circuit, found on the Thunder942 and Thunder502, prevents the ampli-
fier from going into clipping, even at high SPL levels. The compression circuit allows the listener to play the
amplifier at high volume levels, yet protects the speakers against the potential damage that can occur dur-
ing dynamic musical passages. The circuit is switchable on/off, for those SPL competitors who run their
amplifiers into clipping on purpose. Warning: Damage to speakers may occur when the compression circuit
is in the off position.
8. EBC 2 –
The EBC, or Electronic Bass Control, allows a remote bass control to be adjusted from the dri-
ver’s seat. If the optional EBC is installed, the bass level will be able to be adjusted to overcome noise and
other interference. With EBC 2 multiple amplifiers can be controlled. (Thunder942 and Thunder502)
9. RCA Output Jacks and Switch –
These RCA outputs allow for a signal to be sent to other ampli-
fiers in a daisy-chain configuration. You can select whether the signal should be high pass , low pass or
full range. In low pass mode, the RCA outputs allow for multiple bass amplifiers to be level controlled using
one EBC.
Input Panel Layout
❶ ❻
❹
❺
❷ ❾
❾
❸
❶ ❻
❹
❺
❷ ❾
❾
❽
❼
❶ ❻
❹
❺
❷ ❾
❾
❽
❼
