Linear Acoustic UPMAX2251 Manuel utilisateur
UPMAX 2251
5.1-Channel Surround-Field Synthesizer
User Guide
UPMAX 2251
5.1-Channel Surround-Field Synthesizer
User Guide
Release Date: March, 2005
Software Version: 1.021 and Later
Linear Acoustic Inc.
Phone: 888-292-3117 (US)
FAX: 717-735-3612
email: www.LinearAcoustic.com
Warranty Information
DISCLAIMER OF WARRANTIES: Products manufactured by Linear Acoustic Inc. are war-
ranted against defects in material and workmanship for a period of two (2) years from the date
of purchase. THERE ARE NO OTHER IMPLIED OR EXPRESS WARRANTIES AND
NO WARRANTY FOR MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.
During the warranty period Linear Acoustic Inc. will repair, or at our discretion replace, com-
ponents which prove to be defective, provided the unit is returned, shipped pre-paid to us directly
with a return authorization (RA) number clearly marked on the packaging. Please note, this
RA number must be present or package will be refused and returned to sender.
All requests for repairs MUST include the unit serial number to ensure quick and accurate service.
DEFECTS CAUSED BY UNAUTHORIZED MODIFICATIONS, MISUSE OR ACCI-
DENTS, UNAUTHORIZED CUSTOMER REPAIRS, OR ANY FURTHER DAMAGE
CAUSED BY INADEQUATE PACKAGING FOR SERVICE RETURN ARE NOT COV-
ERED BY THIS WARRANTY.
PLEASE SAVE THE SHIPPING CARTON AND ALL PACKING MATERIALS. FAIL-
URE TO RETURN UNIT IN ORIGINAL SHIPPING CARTON AND PACKING
MATERIALS WILL RESULT IN A CHARGE FOR NEW SHIPPING MATERIALS.
LIMITATION OF PERIOD OF ACTION ON CONTRACT: No ac tion, regardless of form,
arising out of the transactions under this agreement may be brought by buyer, its successors,
agents and/or assigns, more than three years from date of purchase.
LIMITATION OF LIABILITY: It is understood and agreed that Linear Acoustic’s liability
whether in contract, in tort, under any warranty, in negligence or otherwise shall not exceed the
cost of repair or replacement of the defective components and under no circumstances shall
Linear Acoustic be liable for incidental, special, direct, indirect or consequential damages, or loss
of use, revenue or profit even if Linear Acoustic or its agents have been advised, orally or in
writing, of the possibility of such damages.
Linear Acoustic upMAX 2251 User Guide
v
Table of Contents
List of Figures...................................................................................................................... vi
Chapter 1: Introduction................................................................................................. 5
1.1 Principles of Operation ......................................................................... 5
1.2 Signals and Levels .................................................................................. 7
1.3 Downmix Compatibility....................................................................... 8
Chapter 2: Connections and Setup ......................................................................... 9
2.1 Unpacking and Inspection..................................................................... 9
2.2 Installation............................................................................................. 9
2.3 Rear Panel............................................................................................ 10
2.3.1 Connection Ports.................................................................. 10
2.4 Front Panel.......................................................................................... 11
2.4.1 What’s Behind Door #1?........................................................ 11
Chapter 3: Applications .............................................................................................. 13
3.1 Typical Scenarios................................................................................. 13
3.1.1 Two-Channel Commercials and Interstitial Programming... 14
3.1.2 Sporting Events ..................................................................... 16
3.1.3 Music Awards-Type Events................................................... 16
3.2 Factory Presets .................................................................................... 17
Chapter 4: Menus .......................................................................................................... 19
4.1 Main Menu .......................................................................................... 19
4.1.1 Modify Processing Menu....................................................... 19
4.1.2 Setup Menu............................................................................ 21
4.1.3 System Info............................................................................ 24
4.1.4 System Options ..................................................................... 24
4.1.5 Lock Front Panel................................................................... 25
Chapter 5: Specifications........................................................................................... 27
Linear Acoustic upMAX 2251 User Guide
vi
List of Figures
1-1 Audio Block Diagram .................................................................................................... 6
2-1 Rear Panel .................................................................................................................... 10
3-1 UPMAX 2251 in a commercial upmixing application ................................................. 14
3-2 UPMAX 2251 with Dolby DP572 Dolby E Decoder ................................................. 15
3-3 UPMAX 2251 in a live sports application ................................................................... 16
3-4 UPMAX 2251 in a music awards-type program .......................................................... 17
4-1 Main Screen showing level meters to the left and menus to the right. ........................ 19
4-2 Modify Processing menu; scroll down to access Ext L/R Mix (as shown on right menu)
20
4-3 Setup menu ................................................................................................................... 21
4-4 Save Preset menu before (left) and after (right) saving ................................................. 23
Linear Acoustic upMAX 2251 User Guide
5
Chapter 1: Introduction
The Linear Acoustic UPMAX 2251 produces a 5.1 channel audio signal that is perfect
for eventual transmission via Dolby Digital (also known as AC-3) to all consumers.
The unit accepts a 2-channel input and “upmixes” it to fill as many of the 5.1 output
channels as the user selects. Any input signal from mono to LtRt (Left Total/Right
Total) surround encoded audio can be applied to the Main Input and an output will
be produced that maintains consistency with other 5.1 channel programming.
Further, external discrete sources of audio such as announcer or stereo crowd can be
applied to the unit via its Mix Inputs and can be selectively mixed with the audio pro-
duced by the upmixing process. A subwoofer, or LFE channel can also be selectively
created from the Main Input audio or via the discrete LFE Mix Input.
The UPMAX 2251 provides the following features:
• Advanced upmixing algorithm for stable, convincing surround experience.
• Fully compatible with all surround formats including Dolby Digital
•Upmixed surround field is infinitely adjustable in width and depth.
•External inputs allow mixing of discrete audio signals with internal upmix.
• Relay bypassed digital inputs for “mission critical” broadcast applications.
• Built-in adjustable delays to compensate for video path processing.
• Simple front panel user interface and display.
1.1 Principles of Operation
The UPMAX 2251contains two paths for audio signals. The first path contains an up-
mixer, a bass extension filter to create the LFE (Low Frequency Effects) or subwoof-
er channel, and a simple but powerful set of mix controls to vary each element of the
surroundfield. The second path provides discrete inputs for the Center, LFE, Ls (Left
Surround), Rs (Right Surround), Lf (Left Front) and Rf (Right Front) channels. The
upmixed and discrete outputs are selectively combined to allow for the addition of
specific audio elements to the upmix-derived elements.
Please refer to Figure 1-1. It should be noted that this diagram is a general represen-
tation of signal flow. Please consult the appropriate section of this manual for an ac-
curate description of actual functionality.
Linear Acoustic upMAX 2251 User Guide Introduction
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Main In
Lt/Rt
Left
Center
Right
UPMIXER
Surround
+
+
+
+
Mix In
Center
Ext Center
Level
Center
Width
Ext LFE
Level
80 Hz
+
Mix In
LFE
Surround
Width
+
+
Ext Ls
Level
Ext Rs
Level
Mix In
Ls
Mix In
Rs
Surround
Depth
Ext Lf
Level
Ext Rf
Level
Mix In
Lf
Mix In
Rf
Main
Out Rs
Main
Out Ls
Main
Out LFE
Main
Out C
Main
Out Rf
Main
Out Lf
Figure 1-1 Audio Block Diagram
Linear Acoustic upMAX 2251 User Guide Introduction
7
Two-channel audio is applied via the Lt/Rt Main Input. The audio is upmixed to pro-
duce Left, Right, Center, and Surround signals. The Left and Right outputs of the
upmixer are passed unmodified to the Left and Right Main Output.
The Center channel output of the upmixer is passed through the Center Width con-
trol which varies the amount of center channel audio present at the Center Main
Output versus how much is summed back into the Left and Right Main Output. A
setting of 100% indicates that all of the upmixed Center audio is being fed to the Cen-
ter Main Output, while 0% indicates that all of the upmixed Center audio is being
fed back into the Left and Right Main Output. The 0% setting is the same as “Phan-
tom Center” mode common on some decoders.
The Left, Right, and Center outputs of the upmixer are combined then 80Hz low
pass filtered and when selected via the LCR Sum To LFE switch are passed via the
LCR Sum Level control to the LFE Main Output.
The Surround output of the upmixer is passed through the Surround Depth control
which varies the amount of surround information present at the Ls/Rs Main Output
versus how much is summed back into the Left and Right Main Output. A setting of
100% indicates that all of the upmixed Surround audio is being fed to the Ls/Rs Main
Output, while 0% indicates that all of the upmixed Surround audio is being mixed
back into the Left and Right Main Output.
All outputs of the upmixer can also be selectively combined with signals applies to
the Mix Inputs. The Mix Inputs are available for all channels and have Mix Level
controls that vary from off to +6dB. Note that the +6dB range is provided for con-
venience, but a full-scale signal applied to these inputs can be increased to clipping,
so settings above 0dB should be used carefully and sparingly.
1.2 Signals and Levels
The Linear Acoustic UPMAX 2251 is calibrated for -20dBFS environments, but will
work fine with other reference levels with the minor caveat that the analog LtRt util-
ity output (on the LtRt/Aux DB-25 connector) is fixed at -20dBFS=+4dBu.
The sample rate of the UPMAX 2251 is nominally 48kHz, but the unit will run at oth-
er sample rates as determined by the signal applied to the AES REF input. Please note
that currently this causes the test tones to change slightly in frequency, but has no
effect on the program audio.
Below is a list of the inputs and outputs of the UPMAX 2251:
• Lt/Rt Main Input - Main input to upmixer
•Mix Inputs (C/LFE, Ls/Rs, Lf/Rf) - Direct mix inputs to the main output channels
Linear Acoustic upMAX 2251 User Guide Introduction
8
•Main Outputs (Lf/Rf, C/LFE, Ls/Rs) - Main audio outputs in SMPTE 320M format
• LtRt Main Output - A utility two-channel downmix of the 5.1 channel program (this
output is also available as an analog signal on the LtRt/Aux connector)
1.3 Downmix Compatibility
Downmixing is the process where the individual channels of a Dolby Digital signal
are combined in order to be reproduced from a given number of channels. For exam-
ple, a 5.1 channel program must be downmixed to be reproduced from a stereo speak-
er system and so the left and right channels are combined with the left and right
surround signals and an attenuated version of the center channel before being output
as a stereo signal. This type of signal is called LoRo (for Left only/Right only).
Downmixing may also produce an LtRt compatible signal by performing a pseudo-
surround encode. A 90-degree phase shift is applied to the surround signals in the
Dolby Digital encoder prior to the actual encoding stage so that after downmixing
from 5.1 to 2-channels in the consumer decoder the signal can be heard in surround
by the many consumers that only have a matrix surround decoder.
An extremely important design goal of the Linear Acoustic UPMAX 2251 was that
the output be downmix compatible. Not only stereo and surround, but also mono-
and it had to sound good in 5.1! A tall order that has been satisfied.
One important thing to remember is that to ensure widest compatibility, the Dolby
Digital encoder must be set to apply a 90-degree phase shift. Luckily, this is the de-
fault position for most of the presets, however please consult the encoders user man-
ual to find the menu location where this setting can be checked.
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Table des matières
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