Speck x.sum User manual

x.sum
16 Channel Line Mixer
Reference Manual
speck electronics

Speck Electronics products are warranted to the original owner to be free of
defects in material or workmanship.
This warranty does not apply to any product subject to accident, misuse, neglect
or failure to comply with normal maintenance procedures or if the serial number
has been defaced, altered, or removed; nor will Speck Electronics accept
responsibility for damages resulting from improper installation, alteration or
unauthorized parts or repairs. If the product is modified by the customer without
permission, the customer agrees to pay for parts and labor necessary to remove
the modification before repair. The cause of the defect is in the sole judgment of
Speck Electronics.
Should a defect develop within one year of purchase from Speck Electronics or
an authorized dealer, Speck Electronics will supply the part or parts necessary at
no charge. Labor is covered in this warranty for a period of one year. Outside
service, repairs or pickups are not covered under this warranty.
Any item returned for warranty repair should be sent, if possible, in the original
packing container, prepaid to Speck Electronics, 341 E. Alvarado Street,
Fallbrook, California, 92028. If in our opinion the packing container is
improper for return shipping, we reserve the right to supply a new container at a
minimal charge.
In the interest of improving Speck products; designs and specifications are
subject to change without notice. It should be mentioned that if a change is
necessary for any reason, we make every effort to document
that change and send an "update notice" to all customers at no charge.
Speck Electronics makes no warranty of any kind with regard to this material,
including, but not limited to, the implied warranties of merchantability and
fitness for a particular purpose. Speck Electronics shall not be liable for errors
contained herein or for incidental consequential damages in connection with the
furnishing, performance, or use of this material.
This document contains proprietary information which is protected by copyright.
All rights are reserved. No part of this document may be photocopied,
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of Speck Electronics.
The information contained in this document is subject to change without notice.
All trademarks are the property of their respective owners.
First Printing - June 2006
Speck Electronics
341 East Alvarado Street
Fallbrook, California 92028
USA
760-723-4281
www.speck.com
Warranty
Notice
Edition
ii

iii

Introduction
Chapter 1Chapter 1Chapter 1 Introduction SectionIntroduction SectionIntroduction Section 111
General Thank you for purchasing our X.Sum Mixer. The X.Sum has operational
features that are easy to understand and you should be up and running in no
time. If you are unfamiliar with audio equipment or audio signal flow, it is
recommended that you read this manual. If you have any questions regarding
the X.Sum or any Speck product, do not hesitate to contact Speck Electronics.
Speck Electronics
341 E. Alvarado Street
Fallbrook, CA 92028
Phone [phone]
email [email protected]
www.speck.com
The X.Sum is delivered in a special protective container and was carefully
inspected both mechanically and electrically before shipment. All items
should be physically free of mars and scratches and in perfect electrical order
upon receipt. To confirm this, the mixer and power supply should be
inspected for physical damage that may have occurred in transit. Any damage
should be reported to your dealer and delivery company as soon as possible.
If the product is to be shipped to Speck Electronics for service or repair, attach
a tag to the product, identifying the owner and indicating the service or repair
to be accomplished. Include the model number and serial number of the
product. Place the product in the original container if available. If the original
container in not available, a suitable one can be purchased from Speck
Electronics.
If the original container is not used, wrap the product in heavy plastic before
placing in an inner container. Use plenty of packing material around all sides
of the product and protect panel faces with cardboard strips. Mark shipping
container with "Delicate Instrument" or "Fragile", and insure the shipment for
the proper amount.
Unpacking & Inspection
Repacking

Chapter 1 Introduction Section 2
The X.Sum is shipped with the following list of accessories:
· PS-6 Power Supply
· Operations Manual
· BB-03 Breakout box
· Power cord (NA version only)
The following Mix link interface cables to interface additional X.Sum’s are
available from the factory or your Speck dealer:
· 2 unit cable - P/N MP50-Link2
· 3 unit cable - P/N MP50-Link4
Use only the PS-6 external power supply that is supplied with your X.Sum
mixer. Using any other power supply or power source will most definitely
damage the X.Sum.
To avoid personal injury, do not remove the top cover from the power supply
and never operate the external power supply without the cover properly
installed. If it becomes necessary to service any part of the mixer, always
unplug the AC power and disconnect the DC interface cable before
proceeding.
Operator Safety
Summary
Standard Accessories
Upon loss of the protective ground connection, all accessible
conductive parts, including knobs and controls that may
appear to be insulating, can render an electric shock.
Optional Accessories

Chapter 1 Introduction Section 3
The X.Sum is a 32 x 4 line mixer that can be used for external DAW summing
or as a line mixer for synths, samplers, and effect returns. Any of the 16 stereo
channels can be assigned to either the main stereo Mix output or the stereo
Mix-B output.
Connect the X.Sum to virtually any line level source: balanced, unbalanced,
transformer, or transformer-less. The X.Sum has high headroom that will
handle balanced signals up to +28dBu. All audio inputs and outputs are fully
balanced and available on TRS connectors.
The X.Sum includes the Model BB-03 external breakout box that adds
connections for the Mix-B outputs and Mix-A "pre-fader"outputs. The left and
right Mix-A pre-fader outputs bypass the X.Sum's master section and master
level control so you can use your own external preamps to add character and
color to your mix.
16 Stereo Line Inputs-
· Stereo level control.
· Pan/balance control.
· Mix assign switch that routes input channel to the main stereo mix or
Mix-B stereo mix.
· Mono Switch.
· Left and right balanced TRS inputs.
Master Section-
· Master level control.
· Stereo/mono switch
· Monitor/Phone level provides adjustment to headphone jack and Mix-B
output.
· Balanced TRS stereo mix output.
Multi-purpose I/O connector.
Expandable to 128 inputs.
Breakout Box & Expander cables.
X.Sum General
Description
X.Sum Features

Chapter 1 Introduction Section 4
Line input impedance
Balanced
Unbalanced
Maximum input level
Output Impedance
All Active-balanced outputs
Maximum output level (2k load)
All Active-balanced outputs
Frequency Response (12 dB gain)
(Any line input to mix output)
THD+n
(+12dBu any line input, Gain 12, +24dBu mix out)
Crosstalk (1kHz)
Channel to channel
Input to Mix out, channel mix deselected
Input to Mix out, channel level off
Noise (22Hz-22kHz)
Residual Mix-A and Mix-B output noise
Mix-A output - 16 channels routed, faders off
DC Power Requirements (Mixer)
AC Power Requirements (External supply)
Dimensions (Mixer)
Dimensions (External supply)
Weight (Mixer)
Weight (External supply)
Total shipping weight
30K ohms
15K ohms
+28dBu
60 ohms
+28dBu (Balanced)
3Hz-54kHz (+0/-.5dB)
.0024%
-100dBu
-95dBu
-89dBu
-102dBu
-87dBu
+/- 16.5 VDC @ .8A
100-120 VAC 50/60Hz 1 amp
220-240 VAC 50/60Hz .50 Amp
WxDxH=1.75" x 19" x 10.75"
(44mm x 483mm x 2734mm)
WxDxH=4.6" x 2.75" x 7.3"
(117mm x 70mm x 185mm)
11 Lbs (5kg)
3 Lbs (1.4kg)
15 Lbs (6.8kg)
Specifications

Chapter 1 Introduction Section 5
Figure 1. X.Sum signal Flow
INPUT
LINE
SUMMING INPUT
MIX-A (PRE-FADER) MIX-B OUTPUT
HEADPHONE
LEVEL
MONITOR
R L R L R L
OUTPUT
LEVEL
MASTER
MULTI-PURPOSE
I/O
RIGHT LEFT
MIX
S
Typical of 16
MIX-B MAIN MIX
MIX ASSIGN
S S S
MONO
MONO
MIX-B MAIN MIX
MONITOR
LEVEL
PAN
MAIN MIX BUS
MIX-B BUS
INPUT CHANNEL MASTER SECTION
RIGHT
LEFT
To Multi-Purpose
I/O Jack
To Additional
X.Sum Mixer
LINK CABLE
(Option)
(MONO)
RIGHT LEFT
COMBO
BREAKOUT BOX
To Multi-Purpose
I/O Jack
MIX-B
OUTPUT
RIGHT LEFT MIX-A
OUTPUT
(Pre Fader)

Chapter 1 Introduction Section 6
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Chapter 2 Installation & Setup 7
The following information should give you the basics on how to install the
X.Sum mixer and power supply. The proper installation of the X.Sum
requires a clear understanding of audio wiring, AC distribution, grounding,
and shielding techniques.
If the X.Sum is being installed into a larger studio or as a expander to a host
console, it may be necessary to retain the services of someone experienced in
these matters.
One of the primary reasons that the power supply of the X.Sum is external is
to insure that the power transformer enclosed within the power supply chassis
maintains a safe distance from the active electronics of the X.Sum. For that
matter, any device that has a strong magnetic power field should be kept at a
reasonable distance from the X.Sum and its audio cables.
Because the power supply does not use a cooling fan, it is silent and can be
located in the same room as the mixer. It is important that the ventilation
holes are not obstructed and that the unit is operated in free air to prevent
overheating. Allow a minimum of 4”(100mm) of clearance from all
ventilation holes.
The X.Sum's power supply can operate with two mains settings of 115 VAC or
230 VAC 50/60hz. Before switching “on” the power, you should verify that
the voltage setting on your power supply is configured to match the AC mains
requirements of your country. If the AC mains voltage needs to be changed,
this procedure should be performed and checked by a qualified technician.
Before connecting the DC power supply cable to the X.Sum, make certain the
power switch is set to the “off” position.
To connect the power supply to the mixer, fit the circular connector from the
power supply to the chassis mount receptacle on the rear of the X.Sum. The
respective connectors are keyed so the plug and the receptacle can fit in only
one direction.
General
Power Supply
Installation
Installation
& Setup
Always turn the power supply “off” and disconnect the
DC power cable before servicing the X.Sum mixer.
!

Chapter 2 Installation & Setup 8
In the unlikely event that a fuse blows, it is EXTREMELY important that a
fuse of the same type and current rating be replaced. The chart below in
Figure 2 lists the fuse current ratings to be used for your countries mains
voltage. All fuses are 20mm x 5mm slow blow type.
The X.Sum will operate satisfactorily over a wide range of ambient
temperatures, and the external power supply will operate from -10º C to
+30 ºC. If the power supply is installed in an equipment rack that also
contains heat producing equipment, adequate ventilation should be provided.
This will prolong component life and maximize operational stability.
While the internal circuitry of the X.Sum is fully shielded by the chassis,
installation should nevertheless be planned to avoid locating the X.Sum
immediately adjacent to power amplifiers, power supplies, or any source of
Electromagnetic emissions.
Any device that emits a high EMI (Electro Magnetic Interference) or RFI
(Radio Frequency Interference) energy field should be treated with suspicion.
EMI is considered any unwanted signal which adversely affects the operation
of the mixer or the mixing system. This subject is discussed in Chapter 4.
Electronic equipment such as power amplifiers, power supplies (especially
wall mount type), video monitors, computers, certain synths and samplers
must be located away from the X.Sum and its associated cables. It may be
necessary to alter the positions of certain equipment that you feel would cause
buzzes or hums in the mixer system.
A quality installation is essential when wiring any audio system. When the
time comes to actually interconnect your equipment, proceed slowly.
Interfacing the many pieces of electronic equipment to your mixer and audio
system should be a logical, methodical process.
Start by connecting only the monitor power amp (or active monitors) to the
mixer, and then add one line signal to the mixer at a time; carefully listening
and monitoring your progress. If a problem arises, such as a buzz, hum,
intermittent signal, or nonexistent signal, stop at that point and solve the
problem before proceeding.
Environmental
Considerations
Physical Placement of
Adjacent Equipment
Hooking up the Mixer
Fuse Chart for PS-6 Power Supply
100 VAC 120 VAC 220 VAC 230 VAC 240 VAC
1.0 Amp .5 Amp1.0 Amp .5 Amp .5 Amp
Figure 2.

Chapter 2 Installation & Setup 9
Due to the high performance of the X.Sum, it is recommended that you use
only the highest quality audio cable. A high quality cable by definition is a
cable that provides good mechanical strength, high microphonic noise
immunity, high frequency response, low crosstalk, and 100% shielding ability.
All audio cable used with the X.Sum should be a 3 conductor foil shield type
(2 inner conductors and a shield drain conductor). It is not recommended that
the 2 conductor "off the shelf cables" be used.
All wire and cable interfaced to the X.Sum should be terminated with high
quality connectors. A ¼" plug or XL connector should make a positive
connection to its respective mating jack and provide adequate strain relief to
its cable. All connectors should also have a metal shell to provide 100%
shield for exposed conductors.
To clean the front panel, wipe the surface gently using a soft lint-free cloth to
avoid scratching the panel or markings. Paper towels are not recommended.
Commercially available window cleaner solutions may be used; however, the
solution should be applied to the cloth and not the panel to avoid the seepage
of liquid to the inside of the enclosure.
Do not use brushes or feather dusters to remove dust. This may cause dust to
fall into the openings around the pushbutton switches.
Cleaning

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Chapter 2 Installation & Setup 10

Chapter 3 Operation Section 11
In this section we hope to give you basic information on the operation of the
X.Sum and adequately describe its controls, switches, and connectors.
The information in this section of the manual is intended to help with the
technical process when using your X.Sum. Words alone could not adequately
describe how to adjust the controls for every situation you might encounter
with the X.Sum. You should experiment with settings and routing techniques
to achieve the best results for any particular situation. Your ears should be
your best gauge of how to adjust the settings on the X.Sum to make the sound
fit your requirements.
Before any attempt is made to operate the mixer, it would be a good idea to set
all the mixers controls to their neutral positions. This gives you a reference
point to work from when adjusting controls and switches.
All volume controls should be set to their full counter-clockwise setting. All
pan controls should be set centered. All pushbutton switches on the input
channels and master module should be set to the out position.
Overview
Default Control
Settings
Mixer Operation

When any future reference is made to the controls or switches of the X.Sum, it
will be assumed that they have been set to their neutral positions.
Use this channel signal flow diagram shown below in Figure 3 as a reference
when reading the descriptions of the controls, switches, and connectors [1]
through [16] in this chapter.
Signal Flow Diagram
Chapter 3 Operation Section 12
Figure 3. X.Sum signal flow and reference designations.
INPUT
LINE
HEADPHONE
LEVEL
MONITOR
OUTPUT
LEVEL
MASTER
MULTI-PURPOSE
I/O
RIGHT
LEFT
MIX
S
MIX-B
MAIN
MIX ASSIGN
S
S
S
MONO
MONO
MIX-B
MAIN
MONITOR
LEVEL
PAN
MAIN MIX BUS
MIX-B BUS
RIGHT
LEFT
(MONO)
RIGHT
LEFT
COMBO
BREAKOUT BOX
To Multi-Purpose
I/O Jack
MIX-B
OUTPUT
RIGHT
LEFT MIX-A
OUTPUT
(Pre Fader)
12
13
9
7
5
6
8
3
10
11
4
1
2
14
15
16

Chapter 3 Operation Section 13
Input Channel
1
3
42
The smaller (inner) knob of the black capped concentric is a dual rotary
potentiometer that simultaneously and equally adjusts both the left and right
channel levels.
The 0dB mark is the "unity gain" setting for the input channel. There is 12 dB
more gain available past the “0db” mark.
It is recommended that the input channel be set to this "0dB" mark when the
X.Sum is being used exclusively as a summing box.
The larger (outer) knob of the black capped concentric pot used in conjunction
with the input level control [1] and Mix Assign Switch [3] allows an input
channel to be panned to either the Mix-A or Mix-B outputs.
When an input channel is operated in the stereo mode, this control acts as an
odd/even (left/right) balance for the selected subgroup pair. If the channel is
operated in the mono mode or has a mono source connected to the Left/Mono
input jack, then this control acts as a traditional pan.
The Mix Assign Switch allows an input channel to be assign to the Mix-A or
Mix-B left/right outputs. A red L.E.D. indicates that the channel has been
assigned to the Mix-A outputs.
When the mix switch on any channel is in the "out" position, the channel's
stereo signal is routed to the Mix-B stereo outs. When the mix switch is
depressed on any channel, its stereo signal is routed to the main Mix-A
outputs. This function is on a per-channel basis so you can have some of the
input channel's assigned to the main stereo Mix-A and others to Mix-B.
When depressed, this switch sums the left and right signal together. The
summed left/right signal can be panned using the pan pot. A yellow L.E.D.
indicates the operation of the Mono switch.
1. Input Level Control
3. Mix Assign Switch
2. Input Pan/Balance
Control
4. Mono Select Switch

Chapter 3 Operation Section 14
6
7
8
9
This pot acts as the master volume to the Mix-A output. The operation of this
control does not affect the operation of the Monitor level [7].
When depressed, this switch sums the left and right signal together, creating a
mono composite for the Mix-A. The operation of the Mono switch does not
affect the Mix-B stereo mix. A yellow L.E.D. indicates the operation of the
Mono switch.
The Mono switch allows the user to check for any out-of-phase signals or
simply monitoring your mix in monaural.
This adjusts the overall level to the headphone jack on the front panel and the
Mix-B outputs on the external breakout box (Model BB-03). This control
operates independent of the Master Level Control [5]. The source select for
this control is the Mix-B Select Switch [8].
This switch simultaneously changes two monitoring functions of the Monitor
Level Control [7].
The first is that it selects the source for the headphone jack. In the "Out"
position the source for the headphone jack is the Mix-A stereo bus and when
depressed the source is the Mix-B stereo bus.
The second function of this switch is that it changes the Mix-B output signal
to the breakout box. In the "Out" position the source for the Mix-B jacks is the
Mix-B stereo bus set at a fixed level (pre the monitor level). When this switch
is depressed, the source for the Mix-B jacks is the Mix-B stereo bus under the
control of the Monitor Level Control [7].
This standard 1/4" stereo phone jack will accommodate most popular stereo
headphones. The tip of the stereo jack is the left headphone signal and the ring
of the jack is the right headphone signal.
Master Section
5. Master Level Control
6. Master Mono Switch
7. Monitor Level Control
8. Mix-B Select Switch
9. Headphone Jack
5

Chapter 3 Operation Section 15
10
11
Typically, this input is used to connect one side of a stereo or dual channel
source. The "mono" designation on the left jack indicates that this jack should
be used when you have only a monoural source.
Typically, this input is utilized to connect the alternate side of a stereo or dual
voice source. An input channel cannot function in stereo unless the right input
is connected.
The 16 stereo input channels of the X.Sum will work with either balanced tip-
ring-sleeve (TRS) ¼" plugs as or unbalanced tip-sleeve (TS) ¼" plugs.
The configuration for the ¼" TRS Input Jacks are as follows:
Tip = High (+)
Ring = Low (-)
Sleeve = Ground
Input Channel
Connectors
10. Left/Mono Input Jacks
11. Right Input Jack

PIN 2PIN 2
PIN 3PIN 3
PIN 4PIN 4
PIN 5PIN 5
PIN 6PIN 6
PIN 6PIN 6
PIN 8PIN 8
Mix Out-A - LeftMix Out-A - Left
Mix Out-A - RightMix Out-A - Right
CommonCommon
Sum In- LeftSum In- Left
Sum In - RightSum In - Right
CommonCommon
PIN 1PIN 1
For Breakout BoxFor Breakout Box For Link CablesFor Link Cables
Mix Out-B - LeftMix Out-B - Left
Mix Out-B - RightMix Out-B - Right
Link Out - LeftLink Out - Left
Link Out - RightLink Out - Right
CommonCommon
Link In- LeftLink In- Left
Link In - RightLink In - Right
CommonCommon
Chapter 3 Operation Section 16
Output
Connectors 12
13
17
15 16
14
Figure 5. Pin-outs for Multi-purpose I/O connector
12. Mix Output Jacks
13. Multi-purpose
I/O Connector
These balanced 1/4" TRS phone type connectors are the left and right outputs
for the stereo mix bus. The signal present at these jacks is adjusted by the Mix
Master Control [5] on the front panel.
The configuration for the ¼" TRS Mix Output Jacks are as follows:
Tip = High (+)
Ring = Low (-)
Sleeve = Ground
Figure 4. BB-03 combo breakout box
1
8
The multi-function I/O connector is used to connect the BB-03 Breakout Box
or link up to two additional X.Sum's.
The pin-outs for the multi-pupose I/O connector are shown below in Figure 5.
Note - All active-balanced output circuits of the X.Sum were designed for
balanced lines and should only be connected to balanced inputs. If
that is not possible and it is necessary to connect to an unbalanced
input, care must be taken not to connect the low (-) terminal to
ground. If the low (-) terminal of these outputs is connected to
ground, the result will be a high level of audio distortion.