Cedar BRX+ User manual
LICENCE AND LIMITED WARRANTY
1. DEFINITIONS
In this Licence and Limited Warranty the following words and phrases shall bear the following
meanings:
‘the Company’ means CEDAR Audio Limited of 9 Clifton Court, Cambridge CB1 7BN, UK;
‘the System’ means an instance of the sound-reprocessing system comprising hardware and
software held on EPROM (‘firmware’) developed by the Company;
‘this Document’ means this Licence and Limited Warranty.
2. ISSUE AND USE OF THE SYSTEM
2.1 The terms and conditions of this Document are implicitly accepted by any person or body
corporate who shall at any time use or have access to the System, and are effective from the
date of supply of the System by CEDAR Audio Limited to its immediate customer.
2.2 The Company hereby grants to the Licensee and the Licensee agrees to accept a
non-exclusive right to use the System.
3. PROPERTY AND CONFIDENTIALITY
3.1 The System contains confidential information of the Company and all copyright, trade marks,
trade names, styles and logos and other intellectual property rights in the System including
all documentation and manuals relating thereto are the exclusive property of the Company.
The Licensee acknowledges that all such rights are the property of the Company and shall
not question or dispute the ownership of any such rights nor use or adopt any trading name
or style similar to that of the Company.
3.2 The Licensee shall not attempt to reverse engineer, modify, copy, merge or transcribe the
whole or any part of the System or any information or documentation relating thereto.
3.3 The Licensee shall take all reasonable steps to protect the confidential information and
intellectual property rights of the Company.
4. LIMITED WARRANTY AND POST-PARTWARRANTY OBLIGATIONS
4.1 The Company warrants that the System will perform substantially in accordance with the
appropriate section of its accompanying product manual for a period of one year from the
date of supply to the Company’s immediate customers.
4.2 The Company will make good at its own expenses by repair or replacement any defect or
failure that develops in the System within one year of supply to the Company’s immediate
customer.
4.3 The Company shall have no liability to remedy any defect, failure, error or malfunction that
arises as a result of any improper use, operation or neglect of the System, or any attempt to
repair or modify the System by any person other than the Company or a person appointed
with the Company’s prior written consent.
4.4 In the case of any defect or failure in the System occurring more than twelve months after its
supply to the Company’s immediate customer the Company will at its option and for a
reasonable fee make good such defect or failure by repair or replacement (at the option of
the Company) subject to the faulty equipment having first been returned to the Company.
The Company will use reasonable efforts to return repaired or replacement items promptly, all
shipping, handling and insurance costs being for the account of the Licensee.
4.5 The above undertakings 4.1 to 4.4 are accepted by the Licensee in lieu of any other legal
remedy in respect of any defect or failure occurring during the said period and of any other
obligations or warranties expressed or implied including but not limited to the implied
warranties of saleability and fitness for a specific purpose.
4.6 The Licensee hereby acknowledges and accepts that nothing in this Document shall impose
upon the Company any obligation to repair or replace any item after a time when it is no
longer produced or offered for supply by the Company or which the Company certifies has
been superseded by a later version or has become obsolete.
5. FORCE MAJEURE
The Company shall not be liable for any breach of its obligations hereunder resulting from causes
beyond its reasonable control including, but not limited to, fires, strikes (of its own or other employees),
insurrection or riots, embargoes, container shortages, wrecks or delays in transportation, inability to
obtain supplies and raw materials, or requirements or regulations of any civil or military authority.
6. WAIVER
The waiver by either party of a breach of the provisions hereof by the other shall not be construed
as a waiver of any succeeding breach of the same or other provisions, nor shall any delay or
omission on the part of either party to exercise any right that it may have under this Licence
operate as a waiver of any breach or default by the other party.
7. NOTICES
Any notices or instruction to be given hereunder shall be delivered or sent by first-class post or
telecopier to the other party, and shall be deemed to have been served (if delivered) at the time of
delivery or (if sent by post) upon the expiration of seven days after posting or (if sent by telecopier)
upon the expiration of twelve hours after transmission.
8. ASSIGNMENT AND SUB-LICENSING
The Licensee may at his discretion assign the System and in doing so shall assign this Licence its
rights and obligations to the purchaser who shall without reservation agree to be bound by this
Licence. The original Licensee and any subsequent Licensees shall be bound by the obligations of
this Licence in perpetuity.
9. LIMITATION OF LIABILITY
The Company’s maximum liability under any claim including any claim in respect of infringement of
the intellectual property rights of any third party shall be, at the option of the Company either:
(a) return of a sum calculated as the price received for the System by the Company from its
immediate customer depreciated on a straight line basis over a one year write-off period; or
(b) repair or replacement of those components of the System that do not meet the warranties
contained within this Document.
The foregoing states the entire liability of the Company to the Licensee.
10. CONSEQUENTIAL LOSS
Even if the Company has been advised of the possibility of such damages, and notwithstanding
anything else contained herein the Company shall under no event be liable to the Licensee or to any
other persons for loss of profits or contracts or damage (whether direct or consequential) arising in
connection with the System or any modification, variation or enhancement thereof and including any
documentation or data provided by the Company or for any other indirect or consequential loss.
11. ENTIRE AGREEMENT
The Company shall not be liable to the Licensee for any loss arising in connection with any
representations, agreements, statements or undertakings made prior to the date of supply of the
System to the Licensee.
12. TERMINATION
This Licence may be terminated forthwith by the Company if the Licensee commits any material
breach of any terms of this Licence. Forthwith upon such termination the Company shall have
immediate right of access to the System for the purpose of removing it.
13. SEVERABILITY
Notwithstanding that the whole or any part of any provision of this Document may prove to be
illegal or unenforceable the other provisions of this Document and the remainder of the provision in
question shall remain in full force and effect.
14. HEADINGS
The headings to the Clauses are for ease of reference only and shall not affect the interpretation or
construction of this Document.
15. LAW
This Document shall be governed by and construed in accordance with English law and all
disputes between the parties which cannot be resolved by negotiation shall be determined by
arbitration in England in accordance with the Arbitration Act 1950 and 1979.
TABLE OF CONTENTS
PART 1
Operations manual
INTRODUCTION ..................................... 2
SAFETY ............................................ 3
SETUP ............................................. 4
AUDIOCONNECTIONS............................... 5
FRONT-PANEL INDICATORS AND CONTROLS ............. 7
OPERATING THE BRX+ DEBUZZER . . . . . . . . . . . . . . . . . . . . 10
OPERATING THE AZX+ AZIMUTH CORRECTOR . . . . . . . . . . 14
SPECIFICATIONS................................... 18
EMC REGULATIONS................................. 18
PART 2
An introduction to audio restoration
BUZZ REMOVAL .................................... 20
AZIMUTHCORRECTION ............................. 24
PART 1
Operations
manual
PAGE 2
INTRODUCTION
Thank you for purchasing this CEDAR Series X+ audio restoration module.
It is one of a family of the world’s most advanced and most effective noise
removal units, and it offers outstanding processing power and performance.
The full range consists of the:
QBRX+ debuzzer
Removes a wide range of buzzes and hums from any audio material;
QAZX+ azimuth corrector
Corrects the time-alignment of stereo and double-mono audio signals.
Quality, speed and simplicity are paramount considerations in the Series X+ design,
and all the units in the family are designed for professional use. Additional
Series X+ features include the following:
Q Flexibility
Each model in the Series X+ range will handle a wide range of audio
restoration requirements.
Q Portability
Each Series X+ is a compact, lightweight unit designed to fit a standard 1U
rack space.
Q Audio interfaces
Series X+ incorporates a 24-bit digital audio interface conforming to both
AES/EBU and SPDIF standards.
Q Power
Its universal power supply means that a Series X+ will work anywhere in
the world.
Q Processor
A 40-bit floating point DSP processor delivers 60MFlops so that the
Series X+ will handle the most complex processing requirements.
PAGE 3
SAFETY INSTRUCTIONS
Read these instructions, follow them, and save them for future reference.
QWater and moisture
The unit must not be exposed to rain or moisture. Furthermore, if the unit is
brought directly from a cold environment into a warm one, moisture may
condense inside it. This, in itself, will not cause damage, but may cause
electrical shorting. This could damage the unit, and even cause danger to
life. ALWAYS allow a Series X+ to naturally reach ambient temperatures
before connecting the mains power.
QMounting and ventilation
The unit may be mounted in a 19" EIA rack, or placed on a flat, stable
surface. Do not subject it to strong sunlight, excessive dust, mechanical
vibration or periodic shocks. The Series X+ is not susceptible to heat build-
up, but should be installed away from heat sources such as radiators, and
audio devices such as amplifiers that produce large amounts of heat.
If it is used as a free-standing unit, the supplied rubber feet should be fixed to the
base of the unit.
QPower sources
The Series X+ features a universal power supply that will work safely on any
mains supply in the ranges 85V to 260V, 50Hz or 60Hz AC only. The unit
should always be grounded (or ‘earthed’), and power connectors should be
routed so that they will not be walked on or pinched.
The Series X+ is connected to the mains power as long as it is plugged in
to a mains supply, so if it is not to be used for an extended period, unplug it
from the wall. Pull the connector out by the plug, never by the cord itself.
QConnections
Turn off the power to all equipment before making any connections.
QCleaning
Clean the unit only with a dry cloth. Never use abrasive pads or liquid
cleaners such as alcohol or benzene.
QDamage requiring service
The Series X+ contains no user-serviceable parts and should on no
account be opened or dismantled by unauthorised personnel.
It should be returned to qualified service agents when it has been exposed
to liquids, when it fails to function correctly, when it has been dropped, or
when the case is damaged.
SETUP
Unpacking
Unpack the Series X+ carefully. Save the carton and all packing materials since
you may need them to transport the unit in the future. In addition to the Series X+
and the packaging, the carton should contain the following:
Qmains connection lead
Qthis manual
Qrack mounting hardware
Qfour self-adhesive feet.
Installation site
To maintain reliability and prolong operating life, observe the following
environmental considerations:
Qthe nominal temperature should be maintained between 5° and 35°
Celsius
Qrelative humidity should be in the range 30% to 80% non-condensing
Qstrong magnetic fields should not exist nearby.
PAGE 4
PAGE 5
AUDIO CONNECTIONS
The Series X+ offers two audio connection standards, and passes its signal to
both outputs irrespective of the input used. The standards are:
QDigital SPDIF format audio data
SPDIF is used by domestic and semi-professional digital audio devices.
You should connect the SPDIF output from your source to the SPDIF input of
the Series X+ using a single cable terminated with an RCA (or ‘phono’) plug.
The SPDIF output of the Series X+ should be connected to the SPDIF input of
a recording device or external DAC.
QDigital AES/EBU format audio data
The AES/EBU format is used by professional digital audio devices.
You should connect the AES/EBU output from your source to the AES/EBU
input of the Series X+ using a single cable terminated with an XLR plug.
The AES/EBU output of the Series X+ should be connected to the AES/EBU
input of a recording device or external DAC.
Channel status
No Series X+ processes are affected by channel status data. All units will echo
any such data directly to the outputs.
AES/EBU
SPDIF
IN OUT
AES/EBU
IN OUT
PAGE 6
CEDAR BRX+ debuzzer
1 2 3 4 10 11 12 13 14
CEDAR AZX+ azimuth corrector
1 2 5 6 7 8 9 14
PAGE 7
FRONT-PANEL INDICATORS AND
CONTROLS
1 Power switch
QWhen OFF, the Series X+ is in standby mode.
QWhen ON, the Series X+ is powered up and operational.
The unit is not powered off completely unless the power lead is removed.
2 Input selector and LEDs
QWhen OUT, the AES/EBU input is selected.
QWhen IN, the SPDIF input is selected.
If a Series X+ fails to lock to an incoming signal, the LED will flash.
3 BRX+ Output attenuator and LEDs
QWhen OUT, no attenuation is applied.
QWhen IN, the signal is attenuated by 3dB.
Use of the BRX+ processor on signals close to full-scale may result in slight
clipping. This can be avoided using the attenuator.
4 BRX+ Process ON/OFF and LEDs
QWhen OUT, the input signal is echoed at the outputs.
QWhen IN, the processed signal is directed to the outputs.
Use this control for before/after monitoring of the signal. The signal delay and
attenuation are not affected by this control.
5–13 Process controls
Refer to the section specific to each model: the section on the BRX+
starting on page 9, and on the AZX+ starting on page 13.
14 Power indicator
QUpper LED illuminated indicates that the unit is operational.
QLower LED illuminated indicates that the unit is in standby mode.
Either LED illuminated indicates that power is applied to the unit.
The BRX+ debuzzer
OPERATING THE BRX+ DEBUZZER
Introduction
CEDAR’s buzz and hum removal process uses information about the fundamental
frequency and the overall volume of the buzz or hum to identify, up to a limit of
4kHz, all the harmonics that constitute the noise. It is left to the user to determine
how much of that noise is then removed.
Fundamental frequency
Your first job will be to identify the fundamental frequency of the buzz or hum.
This is accomplished most easily by setting the PROCESS button to ON and then
rotating the BUZZ POWER and ATTENUATION knobs to their maximum values (fully
clockwise). There may be artefacts such as a ‘comb-filtering’ effect at this point.
You can safely ignore these because they are a consequence of the over-
processing being applied by these maximum settings.
Note: If the buzz is very low in level compared with the rest of the signal, you should
initially set the BUZZ POWER to ‘12 o’clock’ rather than to maximum.
If the fundamental frequency is set wrongly then the process will not be able to
identify the buzz.
The FREQUENCY knob has three modes of operation: preset value selection, fine
continuous adjustment, and coarse continuous adjustment. You may select
between them as follows:
QPreset selection
The preset frequencies represent the most commonly encountered
fundamental frequencies. You can select between these by pressing the
FREQUENCY knob and keeping it depressed while you rotate it.
In cases where the true fundamental frequency does not lie precisely on
a preset frequency, you should use the FINE adjustment mode to adjust
the value.
QFine adjustment
Pressing and releasing the FREQUENCY knob toggles between the COARSE
and FINE (0.01Hz below 100Hz, 0.1Hz above 100Hz) adjustment modes.
The COARSE and FINE indicators in the FREQUENCY display will tell you
which mode you have selected.
PAGE 10
PAGE 11
Q Coarse adjustment
If you do not know the fundamental frequency, you will need to ‘hunt’ for it.
Alternatively, you may know the frequency, but it does not lie close to one of
the presets.
In both these cases you will wish to adjust the FREQUENCY control in coarse
steps. Pressing and releasing the FREQUENCY knob toggles between
COARSE and FINE (0.01Hz below 100Hz, 0.1Hz above 100Hz) adjustment
modes. The COARSE and FINE indicators in the FREQUENCY display will tell
you which mode you have selected.
If you are hunting for the fundamental frequency, best results are usually
obtained by starting at the maximum frequency (130Hz) and scrolling
slowly down through the range until you hear the buzz or hum become
significantly attenuated.
Note: You must be careful to find the true fundamental frequency. If the buzz has a
50Hz fundamental frequency, a frequency setting of 100Hz might possibly be of
some audible benefit: it would attenuate the even harmonics, but it would not
attenuate the fundamental itself or any of the odd harmonics. Similarly, a setting
of 25Hz might have some beneficial effect, but it might damage the true signal at
25Hz, 75Hz, 125Hz, and so on. In both cases the processing would be more
effective if 50Hz was correctly selected.
Tracking indicators
The BRX+ searches for a buzz fundamental in a small window centred on the
displayed fundamental frequency. The width of this window is approximately 1Hz
at a setting of 50Hz, and increases with increasing frequency. If a consistent buzz
is detected within this window, one or more of the tracking indicators will light.
The top tracking indicator LED is a red, downward-pointing arrow which lights if
the displayed fundamental frequency is higher than the detected buzz frequency.
The bottom indicator LED is an upward-pointing arrow which lights if the displayed
fundamental frequency is lower than the detected frequency.
If either of these LEDs is lit, you should use the FINE adjustment mode to tune the
fundamental frequency until the central green LED lights to indicate that the
algorithm is optimally set.
The tracking system takes approximately two seconds to settle, and will thereafter
automatically track slow fluctuations of the buzz, provided that it remains within
the window. If no consistent buzz is detected in the window, any or all of the LEDs
will flicker as the algorithm continues to ‘hunt’. Loud musical components that fall
within the window can upset the operation of the tracking system; this effect is
minimised by correct setting of the BUZZ POWER control.
Buzz power
Once you have correctly identified the fundamental frequency, the buzz or hum
should be inaudible or, at the very least, greatly reduced. However, the BUZZ
POWER and ATTENUATION controls have not yet been adjusted so it is likely that
the material is being over-processed.
Your next step, therefore, is to reduce the BUZZ POWER control to a level just
above that at which the buzz becomes audible again.
Attenuation
If both the FREQUENCY and BUZZ POWER controls are set correctly, you will have
given the BRX+ all the information it needs to correctly identify the buzz or hum,
both in terms of its frequency spectrum and its amplitude. It now remains only to
determine how much of the noise is removed from the signal.
Your final step, therefore, is to reduce the ATTENUATIONcontrol (turn it anti-
clockwise) to a level just above that at which the buzz becomes audible. In
doing so, you will minimise the possibility of any signal being removed along
with the buzz or hum.
Note: There are occasions where a signal suffers from two or more buzzes or hums and
in these cases it will be impossible to remove the problem in a single pass of the
audio. If you encounter a signal damaged in this way, you should perform
multiplepassesusingthe
BRX+,orasinglereal-timepassonaCEDARf o r Windows
system.
PAGE 12
The AZX+ azimuth corrector
OPERATING THE AZX+ AZIMUTH CORRECTOR
Introduction
CEDAR’s Phase/Time correction process uses information common to the left
and right channels of a stereo signal to determine the offset between the
channels. It then recreates the signal with sub-sample accuracy so that the
channels are correctly aligned.
The process has two primary stages:
QYou or the AZX+ determines the timing error
QThe AZX+ corrects the timing error.
To aid rapid setup and accurate processing you can monitor the output:
Qbefore or after processing
Qin stereo
Qwith the left and right channels summed (mono sum)
Qwith the right channel subtracted from the left (mono difference).
The display indicates the time shift being applied to the signal. A positive number
indicates that the right channel is being delayed with respect to the left; a negative
number indicates that the right channel is being advanced relative to the left.
The principal control on the AZX+ is the ADJUST knob, located to the right of the
TIME SHIFT display.
PAGE 14
This manual suits for next models
1
Table of contents
