Mackie THUMP212XT Owner's Manual page 11

ThumpXT Series Loudspeakers: Rear Panel Features continued...
4. 1/8" Input Jack [Ch. 2]
This input channel may accept an 1/8" line-level
signal from a phone, tablet, MP3 player, or other signal
source.
NEVER connect the output of an amplifier
directly to a ThumpXT input jack. This could
damage the input circuitry.
The 1/8" line-level connection may be used
simultaneously with channel 2's combo
jack – XLR or 1/4" – and/or Bluetooth
connection. In other words, if there is a physical
connection to the 1/8" line input, another physical
connection to the combo jack AND a device is
connected via Bluetooth, none of those inputs
will be interrupted. An easy way to look at it is...
there are extra inputs! The 1/8" line-level connection
and XLR (or 1/4") connection sum together
and do not override each other.
5. Mic / Line Switch [Ch. 1]
Because an XLR connector may be connected
to a mic or an instrument, this switch adjusts
the channel's input sensitivity to optimize channel 1
for mic or line-level signals. If a mic is connected,
this switch should be engaged and the gain knob –
more below – set to mic. If an instrument is connected
to channel 1 (via XLR), this switch should be
disengaged and the gain knob set to line.
6. Gain Knobs [Ch. 1 and 2]
If you haven't already, please read the "Quick Start"
section on page 4. Setting the gain correctly will ensure
that the preamplifier's gain is not too high, where
distortion could occur, and not too low, where
the quieter, exquisitely-delicate passages might
be lost in background noise.
The gain knobs allow signals from the outside world
to be adjusted to run through each channel at optimal
internal operating levels.
If connecting mixer outputs to ThumpXT inputs,
set the gain knobs to 9:00 ["LINE"] for optimal
sound and performance.
Keep in mind that these "MIC" and "LINE"
markings are for reference only and may
need to be raised or lower.
7. Thru Jack
This is a male XLR-type connector that produces
the mix from the input jacks. Use it to daisy-chain
several ThumpXT loudspeakers together off the same
signal source(s).
They are wired as follows, according to standards
specified by the AES (Audio Engineering Society):
Balanced XLR Output Connector
Pin 1 – Shield (ground)
Pin 2 – Positive (+ or hot)
Pin 3 – Negative (– or cold)
See page 8 to learn more about daisy-chaining
ThumpXT loudspeakers.
CH2
CH1
6
5
8. Main Volume Knob
The volume knob adjusts the overall signal level
at the input to the built-in power amplifiers.
It ranges from Off (– ) to MAX (maximum gain).
• Thump loudspeakers are designed to operate
with a +10 dBu signal when all knobs are at
the center position.
• Thump loudspeakers may accept up to a +20 dBu
signal by turning down the channel gain in line mode.
• Turning the main knob past center position will
provide enough gain to connect a microphone directly.
Most microphones will want the knob somewhere
around the 9:00 position. For safety, if you're plugging
in a mic, start with the volume off and gradually
rotate it clockwise until you achieve the desired
volume... and be on the lookout for the dreaded
shriek of the feedback monster.
SHIELD
3
COLD
2
HOT
SHIELD
3 COLD
2
HOT
MAIN
VOLUME
8
4
THRU
7
Owner's Manual
11