CARVIN C1648 User manual

LIMITED WARRANTY
Your Carvin mixer is guaranteed against failure for 1 YEAR unless otherwise stated. Carvin will
service and supply all parts at no charge to the customer providing the unit is under warranty.
Shipping costs are the responsibility of the customer. CARVIN DOES NOT PAY FOR PARTS OR
SERVICING OTHER THAN OUR OWN. A COPY OF THE ORIGINAL INVOICE IS REQUIRED TO
VERIFY YOUR WARRANTY. Carvin assumes no responsibility for horn drivers or speakers dam-
aged by this unit. This warranty does not cover, and no liability is assumed, for damage due to:
natural disasters, accidents, abuse, loss of parts, lack of reasonable care, incorrect use, or failure
to follow instructions. This warranty is in lieu of all other warranties, expressed or implied. No
representative or person is authorized to represent or assume for Carvin any liability in connection
with the sale or servicing of Carvin products. CARVIN SHALL NOT BE LIABLE FOR INCIDENTAL
OR CONSEQUENTIAL DAMAGES.
SERVICE:
In the USA go to www.carvinservice.com
Outside the USA, contact your dealer or go to http://www.carvinworld.com for your nearest
service center. Include a written description of the problem with serial number and date of
purchase.
MAINTAINING YOUR EQUIPMENT
Avoid spilling liquids or allowing any other foreign matter inside the unit. The panel of your
unit can be wiped from time to time with a dry or slightly damp cloth in order to remove
dust and bring back the new look. As with all pro gear, avoid prolonged use in caustic
environments such as dust or salt air. When used in such an environment, be sure the
mixer is adequately protected by a cover.
SAFETY INSTRUCTIONS (EUROPEAN)
The conductors in the AC power cord are colored in accordance with the following code.
GREEN & YELLOW—Earth BLUE—Neutral BROWN—Live
U.K. MAIN PLUG WARNING: A molded main plug that has been cut off from the cord is unsafe. NEVER
UNDER ANY CIRCUMSTANCES SHOULD YOU INSERT A DAMAGED OR CUT MAIN PLUG INTO A POWER SOCKET.
C1648P REAR PANEL FEATURES:
1. SPEAKER OUTPUTS The combination SPEAKON jacks also accept 1/4” plugs.
The minimum load for each amp is 4 OHMS. Chaining together more than one speaker on an output is
fine as long as the total impedance is not below 4 ohms. If the speaker load is lower than 4 ohms, the
amp may go into one of the PROTECT modes. (Two 8 ohm speakers in parallel = 4 ohms) 12 Gauge
TWIST-LOK speaker cables are an industry standard for high power applicattions (pin 1+ is POS, pin 1- is
NEG, pins 2+ and 2- are not used). Use only 16 gauge (or heavier) 1/4” speaker cables, NOT shielded
instrument cables. Turn power off before connecting speaker cables.
2. AMP ROUTING switch will select between two internally routed configurations:
OUT postion: AMP1-LEFT, AMP2-RIGHT, AMP3-MONITOR1, AMP4-MONITOR2
IN position: 1 amp each, for Monitors 1 thru 4.
Speaker output levels are adjusted from the Left/Right faders or Monitor 1-4 controls. The front panel
GRAPHIC EQs function with the amps, depending on the front panel EQ1 and EQ2 switch settings.
3. AMP PATCH INSERT jacks offer flexibility for mixer to amp signal routing. These jacks are T-R-S
(Tip-Ring-Sleeve). Tip is the power amp input. Ring is the signal sent from the mixer determined by the
AMP ROUTING switch. The limiters are post insert. Patching a compressor or equalizer between the
mixer and the amp can be done by using a stereo insert cable (like Carvin’s AP1). Connect the RING
signal to the INPUT of the external device, and the TIP signal from the OUTPUT of the device. Plugging
in a standard 1/4” cable (mono) into the AMP PATCH INSERT jacks allows any external signal to be sent
to the internal power amps.
For example, you may want to patch the GROUP outputs (1-4) into the power amps.
-Plug one end of each cable into the GROUP jacks on the top panel of the mixer.
-Plug the other ends of the cables into the AMP PATCH INSERT jacks.
The GROUP 1-4 faders will now control what is heard at the SPEAKER OUTPUTS.
4. AMP CLIP LEDs - The red CLIP LEDs will flash when an amp has reached it’s maximum output.
Occasional flashing caused by bass frquencies is OK. Consistent flashing caused by higher frequencies
may damage drivers due to excessive distortion. This will not damage the amp.
5. PROTECT LED - The yellow LED indicates the power amp system has gone into one of its protection
modes. There will be no output from the amps. If the amp output has been short circuited, or overloaded
by putting less than 4 ohms on the output the amp will go into protection. Check for shorted speaker
cables and speaker impedance, then reset the POWER switch (off-on). If the amp has overheated, lower
the volume and make sure the fan vents are not blocked. Wait for the fan to cool the amps. Normal
operation will return in about 1-3 minutes.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
IMPORTANT! FOR YOUR PROTECTION, PLEASE READ THE FOLLOWING:
WATER AND MOISTURE: Appliance should not be used near water (near a bathtub, washbowl, kitchen sink,
laundry tub, in a wet basement, or near a swimming pool, etc). Care should be taken so that objects do not
fall and liquids are not spilled into the enclosure through openings.
POWER SOURCES: The appliance should be connected to a power supply only of the type described in
the operating instructions or as marked on the appliance.
GROUNDING OR POLARIZATION: Precautions should be taken so that the grounding or polarization
means of an appliance is not defeated.
POWER CORD PROTECTION: Power supply cords should be routed so that they are not likely to be
walked on or pinched by items placed upon or against them, paying particular attention to cords at plugs,
convenience receptacles, and the point where they exit from the appliance.
SERVICING: The user should not attempt to service the appliance beyond that described in the operat-
ing instructions. All other servicing should be referred to qualified service personnel.NG: If your unit is
equipped with a fuse receptacle, replace only with the same type fuse. Refer to replacement text on the
unit for correct fuse type.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL!
This symbol is intended to alert the user
to the presence of uninsulated “dangerous
voltage” within the product’s enclosure that
may be of sufficient magnitude to constitute
a risk of electric shock to persons.
This symbol is intended to alert the user
to the presence of important operating
and maintenance (servicing) instruc-
tions in the literature accompanying
the appliance.
1
C1648P REAR PANEL
C1648P POWER AMP SPECIFICATIONS:
RMS Continuous Power: 4ohm: 500W/amp
8ohm: 300W/amp
Frequency Response: ±0.5dB, 20Hz-20kHz
±1.5dB, 10Hz-25kHz
THD: (50% output) 0.09%
Output Noise: < -75dBu speaker out (all levels minimum)
Protection Circuits: Soft Start, Short Circuit, No Load, SpeakerGuard,
Thermal Shut-Off, Protect and Clip Indicators,
Amp Peak Limiters.
Maximum Gain: Mic in to Speaker Out: 74dB
Power Requirements: Auto switching:120VAC or 240VAC, 50-60Hz, 1000VA
Size: 22.25”W x 16.25”D x 5.6”H
Weight: 25 lbs.
C1648P 2000w Powered Mixer
“OUT” uses LEFT/RIGHT for AMPS 1&2
254 3
C1648P BLOCK DIAGRAM

CARVIN ENGINEERING DATA C1648, C2448, C3248, C1648P 4-bus MIXER OPERATING MANuAL
76-02448a 0210
C1648 featuring 4-band EQ and 8 channel sends
CONCERT 48 SERIES The C1648(P), C2448, and C3248 feature 16 to 32 channels with true 4-bus
performance. The C1648P adds four 500 watt power amplifiers. Never before have so many features been
packed into such a rugged, compact USA made mixer. The best feature of the Concert 48 Series is the
sound. Sound that is pure and quiet enough for digital recording studios. Everything is logically laid
out making the powerful features simple to use. The knobs have been located so that adjustments can be
made quick and easy with visible pointers showing you the status of your mix at a glance.
SUPERB SOUND State-of-the-art low impedance, low noise preamps are featured on every channel. The
balanced common mode rejection is better than 70 dB to eliminate cable noise. All main outputs are balanced
to guard against system noise. The near theoretical limit on distortion has been achieved with THD below .01%
to guarantee the purity of your sound, ensuring it will be dynamically open and transparent.
TRUE 4-BUS DESIGN The CONCERT 48 Series offers increased mixing flexibility over standard
stereo consoles by letting you assign channels to one of the 4 sub groups or L/R. This allows you to mix
the entire drum, horn, choir, etc. into one sub group, which feeds the L/R faders. This is an easy way
to control the volume of grouped mics and inputs. If you don’t need subgrouping, you can depress the
channel L/R button and the channel goes directly into the L/R output like a standard stereo console. All
4 sub group outputs have balanced outputs.
4 COMPRESSORS Each of the 4 sub groups feature a studio-grade compressor to reduce the output
when it gets above the level you set with the COMP control. Ideal for drums or horns.
TWO EFFECT SENDS / TWO 24-BIT EFFECT PROCESSORS Two built-in 24-Bit effects, each
offering 256 stereo effects, is a first in a 4-bus mixing console. Since there are two, you no longer have to
choose between vocal reverb or that awesome guitar chorus - you can have both! Each processor offers lush
REVERBS, rich CHORUSES, thick textured FLANGING and pristineECHOES with fully adjustable parameters
for damping, decay, depth, speed, time and regeneration. Both processors can be sent back into the monitor
mix so the performers can hear exactly what the audience is hearing.
SIX MONITOR SENDS Every channel has 6 MONITOR sends with MASTER output level controls and
XLR balanced outputs.
4 BAND EQ/DUAL MID SWEEPS The superb EQ system gives extended 15 dB boost and cut tone
shaping. The LOW frequency control builds bass starting with 20 Hz through 80 Hz for a solid non-flabby
low-end. The LO MID and HI MID FREQ controls offer variable freqency settings from 45 Hz to 2kHz and
200Hz to 10kHz to enhance all instruments and vocals. The 11.5k Hz HI treble control adds sparkle to your
top-end without adding harshness. Both the LOW and HI are “shelving”, which means they are effective from
20 Hz and up to 20k Hz. The LO CUT switch eliminates stage rumble or other unwanted low frequencies
that would normally rob power from your woofers.
TWO 9 BAND EQUALIZERS Precision equalizers provide 1 octave adjustments to tune in your overall
sound and control feedback. Unlike one stereo equalizer, two independent 9 bands offers greater flexibility.
You can assign the EQs to the L/R outputs or to the monitor 1/2 outputs. Center frequencies are 63, 125,
250, 500, 1k, 2k, 4k, 8k & 16k Hz.
CHANNEL FEATURES Every channel has a full balanced XLR and LINE (1/4”) preamp with an INSERT
jack for a compressor or EQ that also serves as a DIRECT OUT when plugged half way. The PAN control
directs the channel into the L/R output or any of the 4 sub groups after depressing the appropriate ASSIGN
switches. The PFL (pre fader listen) switch allows you to hear the channel in the headphones before the
fader is turned up. A solid “on” condition of the PEAK LED indicates that the MUTE switch has been
activated which turns the channel off including all monitor and effect sends. When flashing during use,
the PEAK LED also lets you know when to adjust the channel’s GAIN control to prevent channel distor-
tion. The SIGNAL LED lets you know that a signal is coming through the channel starting at –20 dBu. A
silky smooth 60mm audio taper FADER with dust cover delivers professional fade-outs. The PHANTOM
power switches provide power through the XLR connectors for use with condenser mics like the Carvin
M90S in groups of 8 channels.
RECEIVING INSPECTION—read before getting started
INSPECT YOUR MIXER FOR DAMAGE which may have occurred during shipping. If damage is
found, please notify the shipping company and CARVIN immediately.
SAVE THE CARTON & ALL PACKING MATERIALS. In the event you have to re-ship your unit, always
use the original carton and packing material. This will provide the best possible protection during
shipment. CARVIN and the shipping company are not liable for damage caused by improper packing.
SAVE YOUR INVOICE. It will be required for warranty service if needed in the future.
SHIPMENT SHORTAGE. If you find items missing, they may have been shipped separately. Please
allow several days for the rest of your order to arrive before inquiring.
RECORD THE SERIAL NUMBER on the enclosed warranty card or below on this manual for your
records. Keep your portion of the card and return the portion with your name and comments to
us.
USA customers register online at: www.carvin.com/registration
All other countries register online at: www.carvinworld.com/registration
For your records, you may wish to record the following:
Serial No.________________________ InvoiceDate___________
MASTER FEATURES Each of the 4 SUB GROUP faders can be switched to the L/R outputs or
used independently through their own balanced output jacks. Each of the sub group’s PFL switches
allow you to listen to the sub groups in your headphones before it is turned up. The L/R MAIN output
faders are independent for added flexibility over a single stereo fader. A MONO/SUB control sums
both the L/R outputs together (pre-graphic EQ) for a center, side fill or subwoofer output. The stereo
HEADPHONE control tracks the METER switches which allow you to look and listen from the L/R,
MONO, MONITOR 1-6 outputs, USB IN, REC OUT/USB, and channel and group PFL switches. The
master section also features 2 EFFECT SENDS, 4 RETURNS and RCA RECORD OUT jacks. All 6
MONITORS, L/R and MONO outputs are balanced XLR, while the 4 SUBGROUPS are balanced 1/4”.
SWITCHING POWER SUPPLY Our exclusive 125k Hz switching power supply eliminates
transformer noise. Like a laptop computer, go anywhere in the world and not worry about power
because you can run on any voltage from 90 to 250VAC. The C1648P will automatically switch
for 120VAC or 240VAC ranges.
ENGINEERED TO LAST Hidden deep in the heart of these USA made mixers is the SMT construction
that utilizes surface mounted components to prevent malfunctions caused by vibrations. Sealed controls
and switches guard against the outside elements while heavy-duty jacks provide a positive connection
to your cables. Fire retardant FR-4 military spec circuit cards feature double-sided copper to eliminate
radio frequency interference. Precision 1% tolerance components guarantee your settings will be
accurate every time. The Concert 48 Series is built to strict standards.
Optional Accessories:
USM16-MC,USM-BP wireless systems (Require USM-KIT)
C1648: CB1648 Heavy padded bag, RW1648 Road Warrior™case
C2448: CB2448 Heavy padded bag, RW2448 Road Warrior™case
C3248: RW3248 Road Warrior™case
C1648P: RW1648P Road Warrior™case
CONCERT 48 SPECIFICATIONS:
For C1648P power amp specifcations, see back page
Mic Input: Balanced XLR, Mic Imp. 150ohms
Line Input: Balanced 1/4” Jack Imp. 10k/20k bal.
Frequency Response: Mic or Line Inputs: 20Hz-20KHz ±0.5dB
Total Harmonic Distortion: Less than .01%
Equivalent Input Noise: 150 ohm source: -117dBu
Output Noise: less than -90dBu Master Line Out
Output Headroom: +28dB XLR bal, +20dB 1/4” unbal.
Maximum Gain: Mic in to Master Line Out: 74dB
Crosstalk: Adjacent channels: -60db at 1KHz
Common Mode Rejection: -75db at 1KHz
Phantom Power: 48V (channel groups of 8)
Channel EQ.: 4 band active,LOW: 80Hz ±15dB
LO MID: 45Hz to 2kHz ±15dB
HI MID: 200Hz to 10kHz ±15dB
HI: 11.5KHz ±15dB
9 Band Graphic EQ.: ±12dB 63, 125, 250, 500, 1k, 2k, 4k, 16k
Power Requirements: Except C1648P: 90 to 250VAC 50-60Hz, 20 to 60VA
Powered C1648P: Auto switching:120 or 240VAC, 50-60Hz, 1000VA
Size/Weight: C1648: 16.25”D x 22.25”W x 3.5”H / 18.1 lbs
C2448: 16.25”D x 30.0”W x 3.5”H / 24.4 lbs
C3248: 16.25”D x 38.1”W x 3.5”H / 31 lbs
C1648P: 16.25”D x 22.25”W x 5.6”H / 25 lbs
12340 World Trade Drive, San Diego, CA 92128
www.carvin.com

C48 SERIES CONTROLS
CHANNEL FEATURES
1. 1/4” LINE INPUTS
The line connectors are for connecting balanced and unbal-
anced instruments and line level sources such as drum
machines, keyboards, ETC.
2. XLR MIC INPUTS
The balanced Mic inputs are for connecting microphones that
use XLR connections. Both the LINE and XLR MIC inputs
can be used simultaneously.
3. CHANNEL INSERT/DIRECT OUT
To insert channel effects, compressor, etc. use a 1/4” TRS (Tip
Ring Sleeve) cable (see INSERTS AND DIRECT OUT illustration
on page 5 for TRS details). To achieve a direct out from the
channel, insert a standard 1/4” cable to the first “click” (1/2
insert).
4. GAIN
The GAIN controls the input level for the channel. If the GAIN
is set too high, the PEAK LED will flash and distortion may
occur. Decrease the amount of GAIN until the PEAK LED
does not flash. It is important that the gain control should be
kept next to the PEAK LED flash point to maintain the lowest
noise of the channel. You can use the channel PFL switch to
monitor the channel input level and use the meters to adjust
the GAIN control to 0dB. This will give a good reference where
the GAIN control should be set.
5. LOW CUT SWITCH
A 75 Hz LOW CUT filter helps eliminate unwanted low frequen-
cies. Great for reducing “boom” noise from mic stands or
from acoustic/electric guitars. Turning up the LOW EQ when
using this filter can help create a punchier bass response.
6. ACTIVE 4 BAND EQ WITH DUAL MID
SWEEPS
The C48 SERIES mixers provide studio EQ. The ±15 dB boost
or cut gives an overall 30 dB range for powerful EQ control.
The active circuits deliver deep bass from the 20-80 Hz LOW
control. The MID controls work at 45Hz to 10kHz, depend-
ing on the MID FREQ controls. The HI control functions at
11-20k for crisp highs.
Start out with all tone controls at their center “zero” position.
Determine which position your MID FREQ sounds best, then
cut or boost your HI, HI MID, LO MID,and LOW frequencies as
needed. If you are trying to mic instruments such as acoustic
guitar or drums, try various mics and mic placement before
adjusting your tone controls. A typical setting may be: HI -3,
HI MID+5 (MID FREQ set at 4kHz), LO MID -4 (MID FREQ set
at 700Hz), and LOW +3. Don’t be afraid to adjust the HI and
LOW controls to get good presence and depth while reducing
the LO MIDs to clean up your sound. This is one of the keys
to great sound.
7. HI & LO MID SWEEPS
These controls allow you to select which frequency (from
200Hz-10kHz or 45Hz-2kHz) that the MID controls will boost
or cut. By adjusting the MID FREQs, you can select the exact
frequency that will best complement various inputs. 700Hz
and 4kHz are recommended settings for the MID FREQ
control for guitar and vocals.
8. MONITOR 1 THRU 6 SEND CONTROLS
The channel MONITOR controls allow you to create six
independent monitor mixes. The MONITOR signals (pre-EQ,
pre fader) are routed to the master MON 1, 2, 3, 4, 5 and 6
controls (#22) respectively before going to the XLR output
connectors (#40).
9. EFF 1 & EFF 2 SEND CONTROLS
The EFF 1 or EFF 2 control sends signal (post EQ, post fader)
from the channel to the master EFFECTS 1 or EFFECTS 2
levels to the internal processors (#18) and to the EFF 1 or
EFF 2 output (#38).
10. PAN CONTROL
Each channel’s PAN control allows stereo imaging by pan-
ning Left or Right during recordings or live performances.
The PAN control also works for the sub-mix groups. A center
position will send a channel’s signal to a pair of sub-group
faders (1-2, 3-4 when assigned). By panning hard left, the
signal is routed to only sub-group fader 1 or 3 when assigned.
Panning hard right routes the signal to sub-mix fader 2 or 4.
Dual element pan controls provide 15dB greater separation
than standard pan controls
11. CHANNEL SIGNAL GREEN LED
The SIGNAL LED is pre-fader and post EQ. This LED helps
the operator verify that the channel is receiving a signal
from the mic or instrument inputs even when the channel
fader is off.
12. CHANNEL RED PEAK LED
This peak indicator is pre-fader and post EQ. If the PEAKLED
flashes, the channel needs a reduction with the GAIN control
(#4) to prevent distortion. A “solid” lit PEAK LED indicates
that the channel has been MUTED.
13. CHANNEL MUTE SWITCH
The MUTE switch will interrupt the channel signal. This
feature saves having to reset your faders and monitor sends.
The PEAK LED will light solid ON with no SIG LED.
14. CHANNEL PFL SWITCH
This switch allows the operator to listen to a channel (pre
fader listen) in the headphone mix to set tone and gain levels
as well as see the channel at the LED meter output (#33).
15. CHANNEL ASSIGNMENT SWITCHES
These switches assign the channels’ signal to the Master
L/R faders, or to the SUB-GROUP faders 1& 2, 3& 4for
sub-mixing in stereo pairs. For mono, PAN fully to the left
and assign a channel to Sub-Group fader 1 or 3 only. PAN
fully to the right and assign a channel to Sub-Group fader 2
or 4. Likewise assigning the L/R switches sends the channel
directly to the main L or R faders.
16. CHANNEL FADER
The CHANNEL FADER adjusts the output level of the chan-
nel. The signal will go to one or more of the Master Faders,
depending on both the Channel Assignment switches and the
PAN control. Calibrated 60mm FADERS with audio tapers are
featured for smooth fade-outs. Slide all faders down when
connecting your inputs.
17. MIC PHANTOM POWER SWITCH / RED
LED
This switch provides +48v power for condenser mics such
as Carvin’s CM90E in groups of 8 channels. This leaves the
remaining MIC inputs for sources that don’t require phantom
power. The LINE inputs are unaffected.
MASTER SECTION
18. DUAL STEREO 24-BIT EFFECTS
PROCESSOR
The internal 24-BIT stereo processors receive signals from
the channel EFF1 and EFF2 controls and the master EFF1 and
EFF2 controls. If the adjacent PK (peak) LED flashes, reduce
the level from the channel or master EFF1 or EFF2 send
controls. A “solid” PK LED will show EFFECTS 1 or 2have
been muted by the MUTE switches. The RETURN control will
adjust the volume level of the selected effects. Remember each
channel has its own two EFFECT sends that will send the signal
to the effects processors. The red PK LED will indicate when the
effects signal from the channel is distorting. Reduce the level of
the channel EFFECT control until the PK LED stops flashing.
EFFECT AND PARAMETERS
a.)ECHO: When the SELECT control is at the “seven O-clock”
position, it is selected to the first ECHO setting where you
get a single repeat echo (minimal regeneration). Turning
the PARAMETER control to 1 will provide the shortest delay
time between the original signal and the echo. Increasing the
PARAMETER control to the right will increase the time delay
between the original signal and the echo. To increase the
number of echo repeats, turn the SELECT control clockwise
to “9 O-clock” (maximum regeneration).
b.)REVERB: When the SELECT control is at the “ten O-clock”
position, it is selected to the first REVERB setting. Turning the
SELECT control clockwise will increase the amount of high
frequencies in the reverb. Turning the PARAMETER control to
1 will provide minimal decay time of the reverb. Increasing to
the right will increase the reverb decay time.
c.)CHORUS: When the SELECT control is at the “one O-clock”
position it is selected to the first CHORUS setting. Turning the
SELECT control clockwise will increase the amount reverb in
the chorus. Turning the PARAMETER control to 1 will provide
a minimal chorus depth setting. Increasing to the right will
increase the chorus depth.
d.)FLANGE: When the SELECT control is at the “four O-clock”
position it is selected to the first FLANGE setting. Turning the
SELECTcontrolclockwise will increasetheflanger’sspeed.Turning
the PARAMETER control to 1 will provide minimal flanging depth.
Increasing to the right will increase the flanger’s depth.
To send effects to the monitors, use the “TO MONITORS”
controls, MON 1/MON 2 & MON 1/MON 3. The center posi-
tion on both controls is OFF.
19. SEND 1 & 2
Sends signals from the channel EFF 1 and EFF2 controls to the
internal processors and to the EFF1 and EFF2 output jacks.
20. RETURN 3 L-R
Receives stereo or 2 mono effect signals from the RETURN 3 L
/R jacks. These signals will also be present at MON 1 (#40).
21. RETURN 4 L-R/ USB IN
ReceivesasignalfromtheRTN4L/R1/4”jacks(#39)and fromthe
rear USB port. These signals will also be present at MON 1.
22. MONITOR 1-6 CONTROLS
These are the master outputs for the six monitor sends. These
correspond to the MON 1-6 XLR output jacks (#40) .
23. GROUP/SUB-MIX FADERS 1-4
Once a channel has been assigned to one of these faders,
the mixing process is simplified to using these four faders. If
these faders are not assigned to the Master L-R faders (#28),
then each fader is bused to the corresponding 4 GROUP 1/4”
outputs (#41). By assigning the 4 faders to the Master L-R
faders, the operator can use the faders to sub-mix groups.
QUICK START UP
If you’re like most new owners, you’re probably in a hurry to
plug your mixer in and use it. Here are some brief instructions
to get you going quickly. With the mixer unplugged and the
unit turned off, complete the following procedures:
1. CONNECTING AC POWER TO YOUR MIXER
• The mixer can be used with 120 or 240VAC (it automati-
cally switches internally)
• Use only a grounded (3 prong) power outlet to prevent
a shock hazard. This gives the quietest grounding for your
mixer.
2. CONNECTING INPUTS TO YOUR MIXER
• For low level balanced devices such as microphones, plug
into the balanced MIC inputs using a shielded microphone
cable with XLR connectors.
• For high level balanced or unbalanced devices such as
instruments & keyboards, plug into the LINE input jacks
using a shielded cable with 1/4” phone plugs. Adjust the
GAIN knob for the mic or line input being used.
3. TURNING YOUR MIXER ON
• Adjust all channel FADERS and master LEVEL controls to
their OFF positions
• Adjust all channel’s HI, MID, and BASS controls and the
two master 9 Band GRAPHICS to their center positions.
• Adjust the Channel “PAN” controls to their center posi-
tions.
• Turn the mixer on by the rear panel POWER SWITCH
and watch for the POWER LED. Your mixer is now ready
to operate.
C1648, C2448, C3248 & C1648P 4-BUS MIXERS
2

24. GROUP PFL SWITCHES
These PFL switches allow the operator to monitor the entire
GROUP mix. If
distortion is heard or if the PFL level is near
PEAK on the Master L/R METERS, lower the channel faders
assigned to that group. Also check the channel PEAK LEDs.
25. GROUP ASSIGNMENT SWITCHES
These switches send the sub-group mix to the main L/R faders.
For mono mixing, assign to both L/R.
26. COMP 1-4 GROUP COMPRESSORS
/ LEDs
Each of the 4 sub groups features a compressor, which will
reduce the output when it gets above the level you set with
the COMP control. Set at “0” there is no effect.
As you turn UP the COMP knob, the lower the
maximum level. The compressor circuit is
pre-fader, so you can set the COMP once and
still adjust the group fader as needed. The LED
will indicate when the compressor is working.
27. COMP LINK SWITCHES
These switches link the COMP controls for
stereo pairs of equal setting. The COMP1 or
COMP3 control becomes the master for the
pair. Link 1-2 or 3-4.
28. MASTER L/R FADERS
These faders adjust the level of the main stereo
output created by all channels and groups
assigned to L/R faders. Output appears at the
L/R balanced XLR connectors (#44) .
29. MONO/SUB CONTROL
A mono output is created from the L/R master
faders (post) for center, subwoofers, or side
fill speakers. The output is at the MONO/SUB
XLR connector (#45).
30. REC OUT/USB CONTROL
This control sets the level sent to REC OUT
L-R RCA jacks and to the rear USB port. The
signal source is the main L-R mix (pre-fader).
31. HEADPHONE AND METER
SOURCE
The stereo PHONES control sets the level
of the PHONES jack (#42). The PFL, L/R,
MONO, MON 1-MON 6, USB IN, and REC OUT
USB switches allow for monitoring of these
sources through the headphones and the L/R
LED METERS (#33).
32. PFL RED LED
Indicates that the headphone & meters are
monitoring only the channels or groups
where the PFL is switched on.
33. L/R LED VU METERS
This group of 10 LED’s offer 6 dB increment
resolution that give the operator a visual indica-
tion of the mixer’s output levels, selectable by
the METER SOURCE or PFL switches (#31).
34. DUAL PRECISION 9 BAND GRAPHIC EQs
are one octave filters at 60,125, 250, 500, 1k, 2k, 4k, 8k &
16k Hz centers that offer ±12dB adjustment to help eliminate
feedback & enhance tone for the main or monitor mix.
35. EQ SWITCH 1 & 2
These switches swap the 9 band EQ’s from the standard L/R
main outputs “OUT” to the MON 1 & MON 2 outputs “IN”
respectively.
36. USB POWER PORTS
Use these ports to supply +5V USB power to run accessories
like LED lighting or to charge MP3 players. Connect audio
outputs to RETURNS 3 or 4, or to channel inputs.
37. POWER BLUE LED Verifies the mixer is on.
38. EFFECTS 1 & 2 OUTPUT JACKS
1/4” outputs drive external effects. Connect your effects
processor’s inputs to these jacks.
39. RETURNS 3 & 4 L-R INPUT JACKS
Returns a stereo signal from an external effect. Connect
your effects processors’ stereo outputs to these jacks. If only
one jack is used, the mono signal will go to both L/R .
40. MONITOR 1-6 XLR OUTPUT
CONNECTORS
The C48 SERIES provides balanced XLR outputs. Connect your
monitor power amps to these connectors.
41. GROUP 1-4 OUTPUT JACKS
The C48 SERIES provides 4 balanced 1/4” outputs. Connect
your 4-track recorder or side fill power amps to these jacks.
42. HEADPHONE JACK
1/4” stereo jack for headphone or control room output.
43. REC OUT L-R RCA JACKS
RCA jacks for connecting to a recorder input.
44. LEFT & RIGHT XLR OUTPUT CONNECTORS
This set of balanced XLR connectors are for connecting the
main L/R output to power amps or recording gear.
45. MONO/SUB XLR OUTPUT CONNECTOR
A balanced XLR output is featured for side fills or subwoof-
ers.
46. REAR USB CONNECTOR
This rear USB connector will transmit audio to and from a
computer for recording with compatible software and driv-
ers. Output signal is the pre-fader L-R stereo mix sent via the
REC OUT USB LEVEL. Input from a computer comes into the
RETURN 4 bus, controlled at the RTN4/USB control.
3
CONCERT 48 SERIES BLOCK DIAGRAM
1
17 40 41
2
3
4
5
7
8
9
10
11
12
13
14
16
6
43
42
45
36
25 28
39 46
38
6
15
44
35
37
33
22
30
31
32
34
29
26
27
24
23
18
20 2119
19, 20, 21