JBL Prx615m Manual

							SYSTEM SET UP - SUBWOOFER
Models: PRX618S-XLF
123
4 5
9
10 6
7
8
11
Features
1  - XOVER IN / OUT:Pressing this button engages a high-pass filter that allows a smooth tra\
nsition between the subwoofer 
and a full-range speaker connected to the output connector. 
2  - POLARITY INVERT:Allows you to set the polarity of the subwoofer to either Normal (no ch\
ange) or Reverse (inverse 
polarity). The correct polarity setting will produce the best blend between the sub\
woofer and the full-range speaker and 
the strongest perceived bass response at the listening position. This is especially useful when the subwoofer is placed at 
a different distance from the listening position than the full-range speakers\
. If the bass response seems weak, try 
inverting the polarity. 
3  - LEVEL:Sound level adjustment. The 12 o’clock position is a good starting point for most usages. Onc\
e the full-range 
system has been connected the level can be varied to match and deliver t\
he desired balance (for details see Setting the 
Gain on page 24).
6  - POWER SWITCH:Turns the power on. Power “on” status is indicated with the illumin\
ation of the grille  logo.
7  - LINE SELECT:Allows user selection of different local voltage ratings.
8  - AC LINE INPUT:Standard IEC AC line input connector.
Indicators
4  - SIGNAL:Signal indicator. The green LED illuminates when a signal is present at the input connecto\
r.
5  - LIMITER:The red LED illuminates when the system overload protection is active. I\
f the input signal is too strong or the 
“LEVEL” control set too high, the red LED will illuminate constant\
ly. Illumination of the “LIMITER” LED can be avoided by 
reducing the input level or turning down the “LEVEL” control to th\
e point at which the red LED occasionally flickers.
Connectors
9 & 11 - XLR:1/4 inch phone jack balanced input connector. (see Reference section page 29 for information).
10 & 12 - XLR:Male balanced output connector. This connector provides a full-range or high-passed signal.  Dependent o\
n 
the setting of the “XOVER” switch. In addition to connecting a ful\
l-range system to the output, it’s also possible to daisy 
chain subwoofers together.
Note 3:A single subwoofer can be used with a stereo source. The input differential circuits sum the low frequency information from the  left
and right channel to a mono signal, ready for reproduction by the subwoo\
fer.
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							1  - POLARITY SWITCH
This switch changes the polarity of the subwoofer to either 0° (no change)
or 180° (inverse polarity).  The correct polarity setting will produce the best
blend between subwoofer and the full-range speaker and deliver the
strongest perceived bass response at the listening position.  This is
especially useful when the subwoofer is placed at a different distance 
from the listening position than the full-range speakers.  If the bass
response seems weak, try using this switch to invert the polarity.
2  - HIGH PASS FILTER (HPF) SWITCH
This switch affects the signal sent to the OUTPUT A & B connectors. 
a.) THRU: The INPUT A signal is passed directly to the OUTPUT A
connector and the INPUT B signal is passed directly to the OUTPUT B
connector. b.) HPF: The INPUT A signal is first passed through a 120 Hz, 
-6 dB High Pass Filter (HPF) before being sent to the OUTPUT A
connector.  The INPUT B signal is first passed through another 120 Hz, 
-6 dB High Pass Filter (HPF) before being sent to OUTPUT B connector. 
3  - LIMIT INDICATOR
The LIMIT LED (Red) illuminates to indicate that the system is
approaching clipping.  The threshold for this is actually about 2 dB
below clipping.  An occasional flickering of this on the loudest peaks
is acceptable.  If this LED is ‘ON’ for more than the duration of brief
dynamic peaks, the system is being over driven.  Continuously 
over-driving the system will result in unpleasant and fatiguing
distortion and may lead to premature failure of your speaker system.
If the LIMIT LED illuminates excessively:
• Reduce the LEVEL control
• Reduce the output level of the mixer or other source connected to the subwoofer
4  - SIGNAL INDICATORThis LED (Green) illuminates to indicate a usable signal from
connected INPUT’s.
5  - LEVEL CONTROL
Adjusts the input sensitivity of the subwoofer amplifier.  
It does not affect OUTPUTS A & B.
6  - INPUT A & INPUT B CONNECTORS
These electronically balanced, XLR connectors accept input signal from l\
ine-level sources. a.) INPUT A and INPUT B are combined be fore
being routed to the PRX618S internal Low Pass Filter (LPF) and interna\
l amplifier. b.) INPUT A and INPUT B are also routed to the  OUTPUT
A and OUTPUT B connectors (see HIGH PASS FILTER switch).
7  - OUTPUT A & OUTPUT B CONNECTORS
These provide either a loop-thru or a high-passed line level output of t\
he signal from the INPUT A and INPUT B connectors respecti vely.  
These connectors work with the HIGH PASS FILTER (HPF) switch.
8  - SPEAKER LEVEL INPUT CONNECTORThis 1/4" TS phone jack allows connecting of the speaker level output of an amplif\
ier or powered mixer to the PRX618S internal  amplifier.
9  - AC INPUT CONNECTOR
For attachment of the included power cable.
10  - POWER SWITCH
Turns the AC power to the unit on and off.  The power ‘ON’ LED illuminates to indicate that the unit is on. 
11  - POWER INDICATOR
Indicates AC power status of the unit, on and off.  The LED (Blue) illuminates to indicate that the unit is on. 
22
SYSTEM SET UP - SUBWOOFER
PRX618S
12
3 4
5
7
9
9 10116 8
Models: PRX618S
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							PRX600 series systems have been designed to allow the connection of a va\
riety of sources. This provides a
great deal of versatility, especially with the PRX612M and PRX615M, as a microphone or instrument\
 can be
connected directly to the input. Low level outputs from consumer product\
s like MP3 and CD players can also 
be accommodated. 
There are two user selectable gain or input sensitivity ranges: Mic and \
Line. For the majority of applications, 
the system will be receiving a signal from a mixer, equalizer of other professional grade product. In this case
“Line” should be selected and the “LEVEL” adjusted to the 12\
 o’clock position indicated by the +4 dB region. 
The “LEVEL” control can then be trimmed to optimize the performanc\
e of the system (see Setting The Gain). 
When a microphone, instrument or other consumer product is connected to \
the system, first ensure that the
“LEVEL” control is at its minimum, counter-clockwise, OFF position\
. Then select the “Mic” input sensitivity and 
slowly increase the level. If the “LIMITER” LED illuminates you sh\
ould back the level down again. If the
“LIMITER” LED illuminates and the “LEVEL” control is at its \
minimum setting then you should try selecting 
the “LINE” input sensitivity range. 
WARNING: SELECTING THE “MIC” POSITION WITH THE LEVEL CONTROL IN ANY POSITION OTHER
THAN THE “OFF” POSITION MAY RESULT IN EXTREMELY HIGH SOUND PRESSURE LEVELS. 
SETTING THE INPUT SENSITIVITY
LINE
MIC
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							SETTING THE GAIN
Only a properly set up system will guarantee maximum performance with a \
minimum of distortion and feedback.
(This is as true for self powered systems as it is for passive systems)\
. An easy rule to follow is: “Everything
should clip at once.” 
Following these simple steps will ensure you are getting the optimum per\
formance out of your complete system. 
1. Once the source has been connected to the input of your mixer, adjust the input sensitivity (or trim) so that the highest input levels are set to just before clip (or when the \
input LED just starts to flicker). 
2. Position the channel fader for that input to 0 dB. 
3. Position the Master output fader to 0 dB. 
4. With the “Mic/Line” button set to “Line” (because the syste\
m is receiving a line level signal, or commonly called a +4 dB signal), set the “Level” control to the 12 o’cl\
ock position, and adjust until you have 
attained an appropriate volume for the room or until the “LIMITER”\
 LED just begins to flicker. 
For in-depth articles related to gain structure please refer to the webs\
ite where you can find the JBL Sound
System Design Reference Manual: http://www.jblpro.com/pub/technote/ssdm_99.pdf 
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							APPLICATION EXAMPLES
PRX615M
Basic Sound Reinforcement System 
This is a very basic sound system. PRX600 series speakers allow the dire\
ct connection of sound sources,
without the need for extra mixer or pre-amplifier. The XLR or 1/4 inch input jack provides versatility and cabling
options and the mic/line input sensitivity selector switch optimizes the\
 speaker gain for the input source.
Additional speakers may be connected (daisy chained together) in mono \
mode. 25
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							1
22
PRX618S
Right Main Output
PRX612M
Music Playback Reinforcement with Subwoofer (PRX612M Pole Mounted on a PRX618S)
This is a very powerful but flexible combination. The subwoofer provides the extra low frequency extension and
also serves as the base for the pole mount. The compact 12 inch satellite system, PRX612M is a perfect match
to the subwoofer. 
From the master outputs of your mixer route the wires to the subwoofer f\
irst and select the x-over in (high-pass)
option. Route the cable from the subwoofer output connector to the top. \
Reduce the volume of subwoofers.
Adjust the volume for the top to desired levels and match the subwoofer \
volume to achieve desired results. This
will provide a well balanced LF performance for the system. 
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							Right Main Output
PRX635
PRX612M
Monitor Output
Live Performance Or Music Playback Reinforcement System With Stage Monitors 
(PRX635 and PRX612M or PRX615M) 
This is an ideal system when wide coverage and good directivity is requi\
red, specifically in highly reverberant
rooms. The horn loaded PRX635 3-way system will control the propagation of the \
sound much better than a
conventional 2-way system. The more directional or controlled the sound is the more independent the\
 system
becomes from the room acoustics present, resulting in a much clearer sou\
nd. The PRX635’s full low end is an
additional advantage when no subs are used. The PRX612Ms are set to the “monitor” EQ setting. 
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							PRX625PRX618S-XLF
PRX612M
Right Main Output
Monitor Output
Large Live Performance Or Music Playback Reinforcement System With Stage Monitor 
(4 x PRX618S-XLF, 4 x PRX625 and 2 x PRX612M) 
For larger crowds in and outdoors, a flexible system like this will deli\
ver excellent results. The dual 15 inch
PRX625 delivers mighty bottom end and crisp highs. The combination of extra PRX618S-XLF subwoofers gives
it an even more thunderous low end. The PRX625s can be arrayed as pair of two on each side for a wider
coverage and some extra SPL (extremely useful in outdoor applications). 
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							REFERENCE
Balanced vs. Unbalanced Lines 
Your PRX600 series can accept either type of input. There are two basic types of audio system interconnections
for audio signals: Balanced and Unbalanced. 
Balanced Lines
In audio, a balanced line is a three-conductor system in which the two s\
ignal wires carry an equal, but opposite
voltage with respect to the ground wire. The ground wire acts only as a shield and does not carry any audio
signal current. Outside interference (such as RFI - Radio Frequency Int\
erference) is either shielded from the
internal signal conductor, or if it gets into the cable is cancelled out by the opposite signals \
at the receiving end.
Balanced connections are preferred for long cable runs.
Unbalanced Lines
Unbalanced cable is a two-wire system where the shield (ground wire) a\
cts as one of the current carrying signal
conductors. The center conductor enclosed by the shield is commonly known as the “\
hot” conductor. Unbalanced
audio cables do not reject noise as well as balanced lines. Unbalanced l\
ines are typical in home hi-fi type
systems and on the outputs of electronic musical instruments. These work well if the distance between the
components is short, the signal level is relatively high and all of the \
electronics used in the system are plugged
into the same AC outlet. 29
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							CABLES AND CONNECTORS
XLR/F to XLR/M Microphone CableThe standard cable for interconnection of microphone and line level signal in professional audio systems.
• Microphone to mixer  
• Microphone to PRX600 direct input
• Professional audio mixer to PRX600 
• Daisy chaining PRX600 speakers
TRS (balanced) 1/4 inch phone jack 
to XLR/MFor connecting balanced devices with 1/4 inch phone and maybe 
used interchangeably.
TRS (unbalanced)  1/4 inchphone jack to XLR/MFor connections of instruments with unbalanced outputs to balanced 
XLR inputs.
TS (unbalanced) 1/4 inch phone jack  to XLR/MThis cable is electrically identical to TRS (unbalanced) 1/4 inch phone and maybe used interchangeably.
XLR/M to RCA (phono) cableConnects consumer audio products and some DJ mixer outputs to 
professional audio equipment inputs.
TRS 1/4 inch phone jack to dual 1/4  
inch phone jackSplits a stereo output into separate left/right signals.
TRS 1/4 inch phone jack to dual 1/4   inch phone jackChange to a TRS mini-phone jack to connect to the output of a portable.
MP3/CD – player and computer sound cards to a mixer or two PRX600
speakers for stereo performance.
XLR/F to XLR/M audio ground liftUse only with balanced in and outputs
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