Manual
POWER
1/2
Mono
3/4
Mono
5/6
Mono
7/8
Mono
9/10
Mono
11/12
Mono
13/14
Mono
15/16
Mono
Variable
Output
Expansion
Input
MixDreamXP
Discrete Class
A
16 in
2
summing mixer
dB
Model
2591
Output
MixDream XP
Model 2591
Analog 16:2 summing unit
Contents
Introduction ....................................................................
4
Analog vs. Digital Summing ............................................
4
Advantages And Special Features ...................................
MixDreamXP Advantages—An Overview .........................
Connection of Samplers, Keyboards etc. .........................
Mono Switches ................................................................
5
5
5
5
Before You Begin ............................................................
6
Rear Panel/Connections .................................................
Wiring .............................................................................
General advices ..............................................................
Input Channels ................................................................
Main Outputs ......................................................................
Monitor Outputs .............................................................
7
7
8
9
9
9
Control Elements ............................................................ 10
Output Control ................................................................ 10
Variable Output Switch ................................................... 10
Mono Switch ................................................................... 10
Expansion Input Switch ................................................... 10
GND-Lift Switch ............................................................... 11
Applications and Modes of Operation ............................. 11
Summing ........................................................................ 11
Summing of Subgroups ................................................... 11
MixDream XP in Mastering Applications ........................... 12
Linking Several MixDreamXP ........................................... 12
Linking Several MixDreamXP/Diagram ............................ 13
Block Diagram ................................................................. 14
Measurements ................................................................ 15
Power Supply .................................................................. 16
Specifications, Dimensions and Weight ........................... 17
Warranty ......................................................................... 18
MixDreamXP
3
Introduction
The MixDreamXP design plan provides for stereo mixdown at the
analog level. This concept offers high-grade analog summing
without panorama and fader controls, in turn allowing an engi-
neer to retain the entire scope of his computer automation. In
use, the MixDreamXP requires almost no departures from an
engineer‘s usual working mode, so that all his trusted DAW
features and familiar working routines remain available while
the MixDreamXP seamlessly expands his aural mixing palette.
One MixDreamXP can sum up to 16 audio tracks to a stereo
signal, and should the need arise for more than 16 tracks,
several MixDreamXP may be linked together. Owners of a
MixDream, model 2384, can expand this unit with the cost effec-
tive MIxDreamXP at an identical quality level and by the way,
that‘s where the suffix “XP“ comes from (=Expansion).
The MixDreamXP discrete class A technology is based on the
same 60-volt rails (+/- 30V) of the MixDream model 2384.
Newly developed circuitry, based on the most modern analog
components, guarantees an extremely high slew rate, a very
low noise level of -97dBu and a dynamic range of 125dB. Thus
the MixDreamXP easily reaches the technical level of the best
analog consoles.
Analog vs. Digital Summing
Nowadays, many are asking whether analog summing is better
than digital summing. But perhaps the real question is whether
digital summing better than analog summing? We at SPL don‘t
know of anyone who says so. We do know that summing with
the MixDreamXP creates an amazing signal depth, precise local-
ization and a wonderful stereo imaging. Moreover, the addition
of individual instruments results in soft and pleasant transi-
tions.
These are analog summing results that we appreciate from
past decades of the best analog technology. The MixDreamXP
now allows DAW users to exploit this potential with maximum
comfort and uncompromising quality, ensuring that nothing can
stand in the way of the engineer‘s having the best of both analog
and digital worlds.
4
MixDreamXP
Advantages
MixDreamXP Advantages—An Overview
• High-grade analog summing on just 1U rack space for amazing
signal depth, precise localization and a wonderful stereo
imaging
• No analog mixing console necessary
• No loss of computer automation
• Lower DAW processor utilization rates
• Latency free monitoring
• Surround capable (from up to 3 MixDreamXP units)
• Channel capacity expandable through linked units
• Cost-effective expansion for the MixDream model 2384
Special Features
Connection of Sampler, Keyboards etc.
Along with DAW audio tracks and effects machines or proces-
sors in the insert loops, samplers, keyboards and expanders
may also be connected directly to the MixDreamXP. Then the
Midi tracks need only be added in the DAW project, the outputs
(for example, from a keyboard) are then routed directly to the
MixDreamXP.
Mono Controls
To save converter channels, all channels may be switched to
Mono so that two signals can be converted by a paired D/A.
In this case such signals are characteristically chosen which
would receive a more central placement in the stereo mix (e.g.
kick, snare, lead vocal, bass). All channel pairs must otherwise
be panned hard left/right in the mix (see „mono switches“ on
page 10).
MixDreamXP
5
Before You Begin
It makes good sense to think about where you place your
MixDreamXP before connecting it. It should be positioned so
that you can easily reach it, but there are other considerations.
Try not to place it near heat sources or in direct sunlight,
and avoid exposure to excessive vibrations, dust, heat, cold
or moisture. It should also be kept away from transformers,
motors, power amplifiers and digital processors.
IMPORTANT: Adjust the voltage setting on the rear panel so
that it corresponds to your local power conditions! Before
connecting the MixDreamXP or any other equipment turn off
all power!
230 V – 50 Hz/315 mA
115 V – 60 Hz/630 mA
VOLTAGE/FUSE
• Do not open the case. You may risk electric shock and damage
to your equipment.
• Leave repairs and maintenance to a qualified service techni-
cian. Should foreign objects fall inside the case, contact your
authorized dealer or support person.
• To avoid electric shock or fire hazards, do not expose your
unit to rain or moisture.
• In case of lightning, unplug the unit.
• Always unplug the cable by pulling on the plug only; never
pull on the cable.
• Never force a switch or knob.
• Use a soft, lint-free cloth to clean the case. Avoid cleaning
agents as they may damage the unit. if necessary, use an
acid-free cleaning oil instead.
6
MixDreamXP
Rear Panel/Connections
Wiring
M a d e i n G e r m a n y
d
A M S s C A t T a n d a r
D B 2 5 c o m p l y w i t h
: 1 = i G r i N W n g D / X 2 L = R ( + ) / 3 = ( – )
MixDreamXP
7
Rear Panel/Connections
General Advice
The MixDreamXP enclosure is EMC-safe and effectively shielded
againstHFinterference.Nonetheless,youshouldcarefullyconsider
where you place the unit to avoid electrical disturbances.
The MixDreamXP and all devices to be connected should be
turned off before connections are made. Always turn volume
down or mute your speakers when disconnecting or repatching
audio cables to avoid damage to your speakers and ears.
The following graph shows the correct wiring for connecting
unbalanced signals to the balanced XLR I/O connectors:
Input
Output
balanced
unbalanced
balanced
unbalanced
2
1
2
2
2
1
1
1
3
3
3
3
1=GND
2=hot (+)
3=cold (-)
Input Channels
The MixDreamXP has 16 electronically balanced inputs that
are connected over two DB25 connectors. Readily configured
cascade cables from XLR or 1/4 inch TRS to DB25 are available
in many audio stores.
Usually the analog outputs of a D/A converter that transmit
the summing tracks from the DAW are connected here. These
connectors conform to the Tascam standard with pin layout as
pictured below:
1
2
3
4
5
6
7
8
GCHGCHGCHGCHGCHGCHGCHGCH
13
25
G= GROUND (Masse), C=COLD (-), H=HOT (+)
1
14
8
MixDreamXP
Rear Panel/Connections
Right
Left
Main Outputs
The Main Outputs provide a stereo mixdown for a recording
device through electronically balanced XLR outputs. Here as a
rule you will route the stereo mix through an A/D converter for
re-recording as a new DAW track.
Main Outputs
Right
Left
Monitor Outputs
The Monitor Outputs run parallel with the Main Outs and provide
for separate monitoring of the stereo mixdown through elec-
tronically balanced XLR outputs.
Monitor Outputs
TIP: SPL’s Monitor & Talkback Controller MTC 2381 offers all
necessary control functionality for DAW monitoring at this
stage.
IMPORTANT: Since Main and Monitor Outs function in parallel,
using a non-balanced connection in one results in both outputs
being unbalanced.
Expansion Inputs
This is another stereo input based on electronically balanced
XLR connectors. It can be activated with the Expansion Input
switch at the right set of switches on the front. Usually the
Main Outputs of another MixDreamXP are connected here to
enable summing of up to 32 channels, but of course any (stereo)
summed signal can be connected here.
Expansion Inputs
IMPORTANT:TheExpansionInputsofthesummingMixDreamXP
must be connected to the Main Output of the second
MixDreamXP—never connect both Expansion Inputs!
TIP for owners of the MixDream 2384: A MixDreamXP should
always be used for Mixdream 2384 expansion. This way you
can always make use of the processing stages of the MixDream
2384 for the final stereo mix (Stereo Expander, Limiter, Master
Insert, Output Transformers).
MixDreamXP
9
Control Elements
Output Control
The Output control regulates the MixDreamXP output level (at
the Main Outs). Its range extends from -14dB to +7dB. With
this Output Control final levels can be ajdusted to accommo-
date subsequent A/D converters. Because the Main Outputs
and Monitor Outputs run in parallel, both outputs are regulated
globally via this control.
dB
Output
Variable Output Switch
Variable
Output
The Output Control is activated by the Variable Output switch
situated among the front-left group of switches. When this
Variable Output switch is deactivated, the Input Level remains
unaltered (Unity Gain).
Mono Switches
1/2
Mono
3/4
Mono
All MixDreamXP channel pairs (1/2 through 15/16) are by default
panned hard left/right. This configuration is the only sensible
way in which each signal contributing to the stereo sound
canvas can retain its placement and automated characteristics.
However, for mono signals (such as kick, snares, lead vocals
or bass that should appear in the middle of a mix), it would
be a waste to use (in hard L/R panned channels) what would
amount to two required converters for a mono result. In such
cases, each channel pair can be switched to mono mode (red
status LED), so that, for example, there might be a (mono) kick
on channel 1, snare on channel 2 and bass on channel 3, etc.
IMPORTANT: Panning for such instruments in the sequencing
program should place the kick hard left, the snare hard on the
right, and so on.
Expansion
Expansion
Input
The Expansion Inputs provide an additional XLR stereo input
(see page 9 for details) and can be activated by the Expansion
Inputs Switch in the front-right group of switches. Typically this
stereo input would provide for linking with another MixDreamXP
unit.
10
MixDreamXP
Control Elements
GND Lift Switch (Rear Panel)
The GND Lift switch separates internal ground from chassis
ground. The switch can be activated to eliminate ground loop
humming which may occur if the MixDreamXP is connected
to units with a different ground potential. The switch should
normally be in the GND position to maintain the shielding effect
of the metal housing.
GND LIFT
Applications and Modes of Operation
Summing
Tracks destined for analog summing are routed from the DAW
to the MixDreamXP via A/D converters. Identical converters are
ideal to exclude level and sound differences.
Although you may often wish to sum more than 16 tracks, a
general recommendation to reduce track numbers is to route
those tracks to a common output bus of the sequencing program
which are not played back simultaneously in your arrangement.
This way you avoid digital summing and your production bene-
fits from the full potential of 100% analog summing.
With mono signals one should switch these to mono mode
to confine them to single D/A converter, thereby avoiding the
waste of having to use a D/A pair for one mono track (see „Mono
Switches“ on page 10). IMPORTANT: In the DAW such signals
must be panned hard left or right.
Summing of Subgroups
To reduce track numbers, there are two other options besides
the above mentioned „Summing“ tip:
Well, you could buy additional MixDreamXP (which we confess
would make us happy—and we‘re sure would not disappoint
you) or sum your grouped tracks with the MixDreamXP itself.
For example, if you‘ve done a chorus backup in 16 solo tracks,
you can adjust your panning in the DAW and the MixDreamXP
sums a stereo mix which is recorded again—the sound benefits
of analog summing are larger than the disadvantage of a further
A/D-D/A conversion.
MixDreamXP
11
Applications and Modes of Operation
MixDream XP in Mastering Applications
Your MixDreamXP is predestined for mastering applications, as
we‘ve planned its superior sound quality for just such occa-
sions.
Two applications areespeciallyinteresting:1)discreteMastering,
and 2) upsampling to SACD/DVD-A formats.
1) Normally a studio mastering engineer requires that a stereo
file be made available for his or her work. But in such a mixdown,
any problems (for example, significant variations in volume
among instrumental subgroups) will mean equally significant
limitations to your final mastering options. Instead, however, if
one masters from a discrete mix with single tracks or subgroups,
each of these can be adjusted just as easily and quickly in the
mastering process—to the extent that even individual groups
can be tweaked with different processing. Your final result is
clearly better and the time needed, minimal—especially since it
is less likely that a new mix will be called for.
2) Multichannel sessions can be summed in the infinite reso-
lution of analog signal processing equipment, something that
may also be of special importance when an engineer wishes to
upsample to SACD or DVD-A.
Linking Several MixDreamXP
An expansion connector provides for a second MixDreamXP
input should 16 channels not suffice. IMPORTANT: The Main
Outputs of the second MixDreamXP must be connected to
the Expansion Inputs of the first unit; do not connect both
Expansion Inputs.
If more than two MixDreamXP are to be summed, we recom-
mend to employ a further MixDreamXP as master—otherwise
the signals from the first MixDreamXP (to cite a “worst case
scenario“) would unnecessarily be summed in each following
unit.
In such a chain One MixDreamXP is connected to the Expansion
Inputs while all other units are connected to the usual (DB25)
Input Channels (see graphic on the next page).
12
MixDreamXP
Linking Several MixDreamXP
M a d e i n G e r m a n y
d
A M S s C A t T a n d a r
D B 2 5 c o m p l y w i t h
: 1 = i G r i N W n g D / X 2 L = R ( + ) / 3 = ( – )
13
Block Diagram
14
Measurements
Frequency Response,FFT Spectrum Analysis
Audio Precision
Frequency Response
2591 MixDream XP
05/09/05 14:48:13
ExpansionInput,FixOutput
+10
+9
+8
+7
+6
+5
+4
+3
+2
Well, we think this is „linear
frequency response“ in the
word‘sbestpossiblesense:
even at 200kHz the fall-off
is below -1dB.
+1
d
B
-0
-1
-2
-3
-4
-5
-6
-7
-8
-9
r
And mind you, typical
frequencyresponsemeasu-
rements are related to a
-3dB fall-off.
A
-10
20
50
100
200
500
1k
2k
Hz
5k
10k
20k
50k
100k
200k
A-A FREQ RESP 20Hz-200kHz.at2c
Audio Precision
FFT Spectrum Analysis
2591 MixDream XP
05/09/05 14:41:38
ExpansionInput Noise Spectrum
+20
+10
+0
The FFT Spectrum Analysis
above shows the spectrum
of noise components. We
have a very low overall level
here, in particular without
ugly „spikes“.
-10
-20
-30
-40
-50
-60
d
B
u
-70
-80
-90
-100
-110
-120
-130
-140
The analysis below shows
distortion components at
an input level of +10dBu.
There is no distortion
-150
20
50
100
200
500
1k
2k
5k
10k
20k
Hz
A-A FFT Noise .at2c
present
above
the
MixDreamXP‘s
outstan-
Audio Precision
FFT Spectrum Analysis
2591 MixDream XP
05/09/05 14:46:52
ding, low (THD+N = -103dB)
noise level.
Expansion Input, Fix Output Input Level:+10dBu
+20
+10
+0
-10
-20
-30
-40
-50
-60
d
B
u
-70
-80
-90
-100
-110
-120
-130
-140
-150
2k
4k
6k
8k
10k
Hz
12k
14k
16k
18k
20k
A-A FFT .at2c
MixDreamXP
15
Power Supply
No effort or expense was spared here. We don’t know of anyone
who makes good coffee with great beans and bad water, and we
don’t know of anyone who makes great sounding audio equip-
ment with mediocre power supplies. The best parts cannot give
you a sound without dependable power.
The MixDreamXP is equipped with an internal power supply.
Two +/-15VA transformers are capable of providing adequate
current regardless of any demands you can put on it, even when
running the MixDreamXP pedal to the metal.
The MixDreamXP power transformer is also heavily shielded to
minimize hum. The +/-30V (=60V rail) power is derived from
high quality linear regulators whose noise level borders on
the immeasurable. Extremely fast rectifier diodes and 14.000
microFarrad capacitors insure that there is enough available
current at all times and for every imaginable peak. Additional
100nF/250V MKP stabilizing condensers are present to insure
further that any conceivable peak loads will not affect your mix.
Power connection must be provided by the included standard
IEC three-pole (computer) cable. The power chain (cable connec-
tions and transformer) conforms to appropriate VDE, UL and
CSA standards. Fuses are rated at 315mA for 230V and 630 mA
at 115V operation.
16
MixDreamXP
Specifications
Frequency range:
‹1Hz-200kHz (-1 dB)
-103dBu
THD+N:
20-22kHz, Input Level +10dBu
Noise Level:
-97dBu
20-22kHz, A-weighted
Max. Input Level:
+28dBu
+28dBu
Max. Output Level:
@ 1kHz, THD+N -95dB
Dynamic range:
20-22kHz, A-weighted
125dB
-90dB
‹70dB
Crosstalk L-R:
@ 1kHz, Input Level +10dBu
CMRR:
@ 1kHz, Input Level +10dBu
Input Impedance:
Output Impedance:
Power Consumption:
10kOhm
65Ohm
36W
Dimensions and Weight
Standard EIA 19 inch Housing, 1U
Dimensions (W x H x D):
482 x 44 x 237mm
ca. 19 x 1.76 x 9.5 inch
Weight:
3,55kg/7.81 lb
MixDreamXP
17
Guarantee
SPL products are guaranteed for a period of one year against
faults in materials or workmanship. Refer to your local supplier
for full sales and guarantee terms.
18
MixDreamXP
|