BW Broadcast DSPXmini-HD Quick start guide

DSPXmini-HD
Digital Audio Broadcast Processor
Operational Manual
Version 1.10
www.bwbroadcast.com

Table Of Contents
2
Table Of Contents
Warranty 3
Safety 4
Forward 6
Introduction to the DSPXmini-HD 7
DSPXmini-HD connections 8
DSPXmini-HD metering and status LEDs 9
Meters and status LEDs 9
Quickstart 10
An introduction to audio processing 11
Source material quality, lowpass filtering and output levels 12
The DSPXmini-HD and its processing structure 13
The DSPXmini-HD processing block diagram 14
The menu system 15
The menu structure 16
Processing parameters 17
Setting up the processing on the DSPXmini-HD 20
Getting the sound that you want 24
Managing Presets 26
Factory presets 27
Remote control of the DSPXmini-HD 28
Remote trigger port 34
Security code lock 35
Clock based control 36
Specifications 37
Preset sheet Appendix A

Warranty
3
Warranty
BW Broadcast warrants the mechanical and electronic components of this product to be free of defects in mate-
rial and workmanship for a period of one (1) year from the original date of purchase, in accordance with the war-
ranty regulations described below. If the product shows any defects within the specified warranty period that are
not due to normal wear and tear and/or improper handling by the user, BW Broadcast shall, at its sole discretion,
either repair or replace the product.
If the warranty claim proves to be justified, the product will be returned to the user freight prepaid.
Warranty claims other than those indicated above are expressly excluded.
Return authorisation number
To obtain warranty service, the buyer (or his authorized dealer) must call BW Broadcast during normal business
hours BEFORE returning the product. All inquiries must be accompanied by a description of the problem. BW
Broadcast will then issue a return authorization number.
Subsequently, the product must be returned in its original shipping carton, together with the return authorization
number to the address indicated by BW Broadcast. Shipments without freight prepaid will not be accepted.
Warranty regulations
Warranty services will be furnished only if the product is accompanied by a copy of the original retail dealer’s
invoice. Any product deemed eligible for repair or replacement by BW Broadcast under the terms of this war-
ranty will be repaired or replaced within 30 days of receipt of the product at BW Broadcast.
If the product needs to be modified or adapted in order to comply with applicable technical or safety standards
on a national or local level, in any country which is not the country for which the product was originally devel-
oped and manufactured, this modification/adaptation shall not be considered a defect in materials or workman-
ship. The warranty does not cover any such modification/adaptation, irrespective of whether it was carried out
properly or not. Under the terms of this warranty, BW Broadcast shall not be held responsible for any cost result-
ing from such a modification/adaptation.
Free inspections and maintenance/repair work are expressly excluded from this warranty, in particular, if caused
by improper handling of the product by the user. This also applies to defects caused by normal wear and tear, in
particular, of faders, potentiometers, keys/buttons and similar parts.
Damages/defects caused by the following conditions are not covered by this warranty:
Misuse, neglect or failure to operate the unit in compliance with the instructions given in BW Broadcast user or
service manuals.
Connection or operation of the unit in any way that does not comply with the technical or safety regulations
applicable in the country where the product is used.
Damages/defects caused by force majeure or any other condition that is beyond the control of BW Broadcast.
Any repair or opening of the unit carried out by unauthorized personnel (user included) will void the warranty.
If an inspection of the product by BW Broadcast shows that the defect in question is not covered by the war-
ranty, the inspection costs are payable by the customer.
Products which do not meet the terms of this warranty will be repaired exclusively at the buyer’s expense. BW
Broadcast will inform the buyer of any such circumstance. If the buyer fails to submit a written repair order within
6 weeks after notification, BW Broadcast will return the unit C.O.D. with a separate invoice for freight and pack-
ing. Such costs will also be invoiced separately when the buyer has sent in a written repair order.
Warranty transferability
This warranty is extended exclusively to the original buyer (customer of retail dealer) and is not transferable to
anyone who may subsequently purchase this product. No other person (retail dealer, etc.) shall be entitled to
give any warranty promise on behalf of BW Broadcast.
Claims for damages
Failure of BW Broadcast to provide proper warranty service shall not entitle the buyer to claim (consequential)
damages. In no event shall the liability of BW Broadcast exceed the invoiced value of the product.
Other warranty rights and national law
This warranty does not exclude or limit the buyer’s statutory rights provided by national law, in particular, any
such rights against the seller that arise from a legally effective purchase contract. The warranty regulations men-
tioned herein are applicable unless they constitute an infringement of national warranty law.

Safety Instructions
4
DETAILED SAFETY INSTRUCTIONS:
All the safety and operation instructions should be read before the appliance is operated.
Retain Instructions:
The safety and operating instructions should be retained for future reference.
Heed Warnings:
All warnings on the appliance and in the operating instructions should be adhered to.
Follow instructions:
All operation and user instructions should be followed.
Water and Moisture:
The appliance should not be used near water (e.g. near a bathtub, washbowl, kitchen sink, laundry tub, in a
wet basement, or near a swimming pool etc.).
The appliance should not be exposed to dripping or splashing and objects filled with liquids should not be
placed on the appliance.
Ventilation:
The appliance should be situated so that its location or position does not interfere with its proper ventilation.
For example, the appliance should not be situated on a bed, sofa rug, or similar surface that may block the
ventilation openings, or placed in a built-in installation, such as a bookcase or cabinet that may impede the
flow of air through the ventilation openings.
Heat:
The appliance should be situated away from heat sources such as radiators, heat registers, stoves, or other
appliance (including amplifiers) that produce heat.
Power Source:
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 and plugs, convenience receptacles and the point
where they exit from the appliance.
Cleaning:
The appliance should be cleaned only as recommended by the manufacturer.
Non-use Periods:
The power cord of the appliance should be unplugged from the outlet when left unused for a long period of
time.
This symbol, wherever it appears,
alerts you to the presence of
uninsulated dangerous voltage inside
the enclosure—voltage that may be
sufficient to constitute a risk of shock.
This symbol, wherever it appears, alerts
you to important operating and mainte-
nance instructions in the accompanying
literature. Read the manual.
CAUTION: To reduce the risk of electrical shock, do not
remove the cover. No user serviceable parts inside. refer
servicing to qualified personnel.
WARNING: To reduce the risk of fire or electrical shock, do
not expose this appliance to rain or moisture.
Safety InStructIonS

Safety Instructions
5
Object and Liquid Entry:
Care should be taken so that objects do not fall and liquids are not spilled into the enclosure through open-
ings.
Damage Requiring Service:
The appliance should be serviced by qualified service personnel when:
- The power supply cord or the plug has been damaged; or
- Objects have fallen, or liquid has been spilled into the appliance; or
- The appliance has been exposed to rain; or
- The appliance does not appear to operate normally or exhibits a marked change in performance; or
- The appliance has been dropped, or the enclosure damaged.
Servicing:
The user should not attempt to service the appliance beyond that is described in the Operating Instructions.
All other servicing should be referred to qualified service personnel.
CE CONFORMANCE: This device complies with the requirements of the EEC Council
Directives: 93/68/EEC (CE Marking); 73/23/EEC (Safety – low voltage directive);
2004/108/EC (electromagnetic compatibility). Conformity is declared to those standards:
EN50081-1, EN50082-1.
WARNING: This equipment generates, uses, and can radiate radio frequency energy.
If not installed and used in accordance with the instructions in this manual it may cause
interference to radio communications. It has been tested and found to comply with the
limits for a Class A computing device (pursuant to subpart J of Part 15 FCC Rules),
designed to provide reasonable protection against such interference when operated in
a commercial environment. Operation of this equipment in a residential area is likely to
cause interference, at which case, the user, at his own expense, will be required to take
whatever measures may be required to correct the interference.
CANADA WARNING: This digital apparatus does not exceed the Class A limits for radio noise emis-
sions set out in the Radio Interference Regulations of the Canadian Department of Communications.
Le present appareil numerique n'emet pas de bruits radioelectriques depassant les limits applicables
aux brouillage radioelectrique edicte par le ministere des Communications de Canada.

Forward
6
forWard
Thank you for your purchase of the DSPXmini-HD digital audio broadcast processor.
Over the last decade the staff at BW Broadcast have observed broadcast processors from afar with fascination
and intrigue and shared a keen interest in digital audio processing. In January 2002 we decided on a whim that it
was time to have a go at designing our own digital audio processor. We knew that if we were going to design an
audio processor we had to do it the BW way and make the processor the most cost effective fully featured all-in-
one broadcast processor on the planet. The one aim, to make an audio processor that offered all of the features
found in the other more costly processors but at a fraction of the price. That processor was the DSPX!
Why DSPX? Like most products the concept is conceived nameless. The name DSPX came about for several
reasons. Firstly, the BW team couldn't decide on a name we liked so the concept became DSP processor X. As
the project developed it soon became clear that the processor was to be a processor for all seasons and so in
true algebraic fashion X represents many things. DSPX was born.
The DSPX became very popular but we were getting a lot of inquires for a more cost-effective solution. And so,
the DSPXmini was born as a scaled down version of DSPX with some reduced features like no LED metering,
no analog and headphones outputs.
The DSPXmini-HD before you is a processor designed specifically with digital audio broadcasting in mind. This
includes over-the-air digital broadcasting systems such as DAB, DAB+, HD Radio™ (IBOC) AM or FM, DRM,
DRM+, FMeXtra™ as well as Internet based broadcasting (streaming). By incorporating proven 4-band AGC, 4-
band limiter, linear filters for maximum transparency and precision low IMD codec-aware look-ahead limiting that
reduces coding artifacts, DSPXmini-HD offers consistency, cleanliness and adjustability never before seen in a
small processor like this.
Once again, thank you for your purchase; we hope you enjoy the DSPXmini-HD!
BW Broadcast Team

Introduction
7
IntroductIon tothe dSPXmInI-hd
The BW Broadcast DSPXmini-HD is a new generation of digital audio signal processor that can be used to proc-
ess audio ready for digital broadcasting such as HD Radio, DAB or Internet streaming. Using the latest multi-
band DSP technology the DSPXmini-HD offers a versatile and powerful tool in creating a loud punchy on-air
presence.
The DSPXmini-HD has been designed and built from scratch using a new approach to the design of a dig-
ital audio processor that incorporates the most up to date components. Cutting edge technologies allow the
DSPXmini-HD to produce similar results to other processors in the market but in a simpler more cost effective
way. The advances we have made have allowed us to pass the savings on to our customers.
What's Under the Lid?
The DSPXmini-HD is driven by a fast 8 bit micro-controller which controls an array of specialised analogue and
digital circuits: These include 24-bit A/D and D/A converters, analogue level control circuitry, 6 x 24 bit DSP's,
an ethernet port, a trigger port, an RS232 port, an LCD screen and memory devices to hold the software and
firmware.
The Processing Architecture!
After input selection the 24-bit digital audio signal is passed through conditioning circuitry before being split to
four bands by linear phase time aligned filters. Each band is processed by multiband RMS leveller which corrects
for input level variations and also improves consistency. Each band is further processed by dynamic audio lim-
iter. The following precision look-ahead limting ensures your signal is kept to a strict maximum while maintaining
clean and natural sound.
The easy to use front panel control system with LCD afford the user with ease of use and setup.
Comprehensive control of every processing parameter is available to the user both from the front panel control
system and by remote (computer) control.
At a fraction of the size, weight and price of its rivals, the DSPXmini-HD is a clear winner.
Dynamic, fresh & innovative...
... The DSPXmini-HD

Connections
8
LOAD PRESET
REMOTE
AES/EBU
EDIT
UP
LOAD
SAVE
DSPXmini
OUTPUT
PROCESS
INPUT
UP
LOAD
U1=BASS FACE INS
DEL
DONE
ENTER PASSCODE
INS
DEL
DONE
ENTER NEW PASSCODE
3779
U2=ROUND FACE
U3=CLASSICAL 3
(A)
SAVE PRESET UP
GO
U1=BASS FACE
U2=ROUND FACE
U3=CLASSICAL 3
(A)
INS
DEL
DONE
NAME PRESET U2
MY PRESET 3
UP
LOAD
SAVE
DSPXmini
OUTPUT
PROCESS
INPUT
DSPXmini-H D
ANALOGUE
INPUTS
AES / EBU
INPUT
RS232
&
TRIGGER PORT
LAN
PORT
GND
LIFT
MAINS POWER INPUT
STATUS
LEDS
SOFT
KEYS
CONTROL
KNOB
DSPXmini-HD FRONT AND REAR PANELS
SYNC
INPUT
ANALOGUE
OUTPUTS
AES / EBU
OUTPUT

Meters And Status LEDs
9
dSPXmInI-hd meterIng
The DSPXmini-HD metering is accesable at any time by pressing the middle soft key on the front panel. It
shows instant IO meters as well as all processing metering.
I/O metering
The input meters show the level of the input audio. The meters are ‘hooked in’ to the DSP code after the input
level selection and mode options.
The output meters represent the level in dB below full scale output. This output level is the peak output level of
the processing and has nothing to do with the actual output level set by the analogue and digital output level
options.
The output meters show a smaller dynamic range compared to the input ones. This reflects the smaller dynamic
range of the audio once processed by the DSPXmini-HD. If we were to have used the same scale as the input
metering we would not see a lot of activity on the bars.
The IO meters follows an approximation of the PPM level of the audio waveform.
Multi-band AGC
The first four gain reduction meters show the gain reduction of the multi-band AGC. The range shown is -21dB
to +21dB in 3dB steps.
There is only one meter per stereo channel and the value shown is the largest gain reduction of the left and right
channels. Under normal operation (with a stereo audio feed) this is fine but you may observe strange metering if
the channels are not very balanced in level.
Multi-band limiter
The second four gain reduction meters show the gain reduction of the multi-band limiter. The range shown is
0dB to -15dB in 1dB steps.
There is only one meter per stereo channel and the value shown is the largest gain reduction of the left and right
channels. Under normal operation (with a stereo audio feed) this is fine but you may observe strange metering if
the channels are not very balanced in level.
StatuS LedS
The DSPXmini-HD front panel contains three status LEDS.
REMOTE: Indicates that the DSPXmini-HD is currently talking to a remote computer. This will flash dur-
ing an update of the firmware or remote control with the remote control application.
AES/EBU: Indicates the presence of a valid AES/EBU signal connected to the digital audio input of the
DSPXmini-HD.
EDIT: Indicates that you are currently editing a parameter
LOAD PRESET
REMOTE
AES/EBU
EDIT
UP
LOAD
SAVE
DSPXmini
OUTPUT
PROCESS
INPUT
UP
LOAD
U1=BASS FACE INS
DEL
DONE
ENTER PASSCODE
INS
DEL
DONE
ENTER NEW PASSCODE
3779
U2=ROUND FACE
U3=CLASSICAL 3
(A)
SAVE PRESET UP
GO
U1=BASS FACE
U2=ROUND FACE
U3=CLASSICAL 3
(A)
INS
DEL
DONE
NAME PRESET U2
MY PRESET 3
UP
LOAD
SAVE
DSPXmini
OUTPUT
PROCESS
INPUT

Quickstart
10
QuIck Start
1. Install the processor into the rack.
2. Connect AC power to the unit and turn on the power.
3. Connect the analogue and / or digital audio inputs.
4. Select the analogue or digital input as the source of the processing with the 'INPUT SELECTION' parameter
which can be found in the 'INPUT' menu. Apply audio and observe the input meters. For analogue inputs, adjust
the 'INPUT’ menus 'INPUT LEVEL CONTROL' so that the input meters do not clip. We recommend setting the
mixing board or audio source to full level output (even clipping) prior to adjusting this control. This ensures that
the processor's A/D converters will not clip under any conditions.
5. Connect the audio analog and/or digital outputs as required and set the output levels for the analogue and dig-
ital outputs to match the equipment that the processor is connected to.
7. Press the 'LOAD' soft key and select a preset from the list!

Introduction To Audio Processing
11
IntroductIon toaudIo ProceSSIng
Most audio processors use a combination of compression, limiting and clipping to 'funnel' the dynamic range
down, reducing the peak to average ratio in each stage. A cascaded arrangement of compressor, limiter and
clipper produces the best results. The first stage of processing usually operates in a slow manner, the process-
ing getting progressively faster and more aggressive as the audio passes through the chain. The instantaneous
peak clipper or look-ahead limiter is the final stage of the chain and sets the final peak level.
The images below illustrate a section of audio as it passes through a typical audio processor.
The first image to the right is an unprocessed section of audio.
The images that follow represent compression of the input wave-
form, followed by limiting and then finally peak clipping.
Compression
Compression reduces the dynamic range of the audio waveform
slowly in a manner similar to a trained operator riding the gain.
Compression is usually performed on the RMS level of the audio
waveform and the ratio of compression is usually adjustable.
Compression is usually gated to prevent gain riding and suck-up
of noise during silence or quiet periods.
Limiting
Limiting is a faster form of compression that employs faster time
constants and higher ratios to produce a denser sound while
controlling peaks based upon the peak level of the audio wave-
form. Excessive limiting can create a busier packed wall of sound
effect.
Clipping
Clipping the audio waveform will not produce any audible side
effects if performed in moderation. Excessive clipping will pro-
duce a form of distortion that produces a tearing or ripping
sound. Clipping can also be used as an effective method of high
frequency peak control when used in conjunction with distortion
controlling filtering.
Look-ahead limiting
Often used instead of a clipper in systems that feed bit rate reducing audio codecs, look-ahead limiting exam-
ines the audio waveform and prepares a gain control signal in advance of the delayed audio waveform arriving.
This prevents overshoots while minimising distortion. A look-ahead limiter behaves in the same way as a soft
clipper. Competent look-ahead limiters will usually be of the multi-band variety.

Source Quality
Source materIaL QuaLIty
The DSPXmini-HD has the ability to substantially improve the quality of your ON-AIR digital broadcast. However
it can only work with what you provide it. The best performance will be obtained when the processor is fed
with very clean source material. DSPXmini-HD can improve audio somewhat (especially intelligibility) through
dynamic multi-band re-equalisation, but it can't improve audio quality in terms of distortion - poor quality source
material will only sound poorer after processing.
We strongly advise against the use of MP3's and any other loss-less compressed audio formats for audio stor-
age. Linear formats are always to be preferred. Compressed audio formats employ frequency masking data
reduction techniques to reduce the bit-rate. Through re-equalisation the DSPXmini-HD can violate the frequency
masking characteristics codec relied on, "revealing" distortion that was inaudible prior to the DSPXmini-HD
processing.
Additionally, as digital audio broadcasting systems employ perceptual coding as part of the transmission system,
using compressed sources will further decrease audio quality. If audio is stored in the play-out system in com-
pressed format, this already reduced audio information is subjected to yet another coding cycle for transmission,
often with very low target bitrate. The end result is lower audio quality and increased coding artifacts, than there
would be if an uncompressed audio sources were used and cascading codecs avoided.
fInaL LoWPaSS fILterIng
The DSPXmini-HD has a built-in lowpass filter adjustable from 4kHz to 20kHz that limits the amount of high-end
spectrum and energy delivered to the codec. Codecs are especially sensitive at higher frequencies, where most
of the annoying artifacts like "metallic high-end", "phasing" or "squishing" occur. Reducing the amount of high-
end puts less stress on the codec and can lower the amount of codec induced artifacts. The actual setting will
depend on the type of codec and the bitrate used. Lower bitrates require more audio information to be thrown
away by the codec, so lower filter settings would have to be employed to reduce artifacts. If you're using higher
bitrates, you can set lowpass filter more towards 20kHz without causing excessive artifacts. As a rule, low pass
filter frequency should be set at or below codec's half sample rate frequency (i.e. 15 kHz for codec running at 32
kHz sample rate).
outPut LeveL SettIng
DSPXmini-HD has an adjustable output level that can be set to drive subsequent equipment with full scale
digital audio level. However, caution should be made here if the following equipment using perceptual coding
(codec) does not take into account internal codec overshoots. Overshoots can occur in the codec when pre-
sented with the tightly peak-controlled audio such as the one produced by DSPXmini-HD. If the codec does not
provide headroom internally, these overshoots would be clipped leading to increased distortion and artifacts.
Therefore we would advise setting the output level of the processor lower than 0.0 dBfs to leave the headroom
in the transmission system for codec overshoots. The actual output level setting would depend on the amount of
codec overshoot occurring in the system, which depends on the type of codec used and how aggressively you're
processing audio with DSPXmini-HD. Generally, codecs that use spectral band replication (SBR) technology
(such as aacPlus, HDC, Windows Media 11, etc.) have more overshoots than the codecs that don't, especially in
the higher frequencies.
If you're using DSPXmini-HD to process for HD Radio (IBOC), DAB+, DRM or web-streaming, a good starting
point to set the output level would be -2.0 dBfs. This would ensure maximum audio quality at the expense of
slightly reduced level (which the users can always compensate with volume control on their radios).
12

Processing Structure
13
the dSPXmInI-hd and ItS ProceSSIng Structure
The DSPXmini-HD broadcast audio processor is intended to be used for processing audio prior to digital audio
broadcast or streaming.
Before we discuss the processing structure in full we would like to tell you a little about the final peak limiting
stage of the DSPXmini-HD. It employs look-ahead limiting as opposed to clipping. Look-ahead limiting produces
less artifacts than conventional clipping, so will reproduce the original audio more accurately with less bits of
digital information because it is not wasting bits encoding non-audible clipping artefacts. Look-ahead limiting pro-
duces less harmonic distortion but produces IM distortion if over driven resulting in a packed, busy sound.
the ProceSSIng Path
Input selection and conditioning
The DSPXmini-HD offers the user input selection (analog or digital input) and level setting.
Bass enhancement
The DSPXmini-HD offers a bass enhancement via peaking filter that can be set to provide up to 6dB of gain
on one of four frequencies with a choice of 4 Q's. This can be thought of as a simple bass parametric.
Xover
The DSPXmini-HD employs linear-phase time aligned digital FIR filtering to split the audio spectrum into 4
bands while maintaining sonic transparency.
Multi-band AGC
The DSPXmini-HD processes each band with RMS based levellers. Each bands gain control processing
function can be configured in different manners to provide different effects. Adjustable timing constants, drive
and gating afford the user with full control of this important re-equalisation stage of the processor.
Multi-band limiters
Each band has its own dynamic peak limiter. Multiple time constant based detectors are fully adjustable as
well as input drives.
Mixer
The four bands are 'virtually' mixed together at this stage, allowing overall EQ adjustment.
Look-ahead limiter
The DSPXmini-HD look-ahead limiter is one of the most sophisticated available in a broadcast processor.
Output selection, processing and routing
The DSPXmini-HD allows the user to select the output levels for both analog and digital outputs. The digital
output sample rate can also be configured to a variety of settings.

Block Diagram
14
DSPXmini-HD PROCESSING BLOCK DIAGRAM
ANALOG
DIGITAL
A/D
SRC
LOW
AGC
MID1
AGC
HIGH
AGC
INPUT MB AGC
LPF
BPF BPF HPF
BASS PEAK
MID2
AGC
LOW
LIM
MID1
LIM
HIGH
LIM
MB LIM
MID2
LIM
OUTPUT
DIGITAL
SRC
ANALOG
D/A
SYNC
N-1
DELAY
ATTACK RELEASE
LOOKAHEAD
adj
LPF
BASS CLIP

Menu System Overview
15
menu SyStem overvIeW
This section presents an overview of the four main menus and thier submenus and any parameters that are con-
tained in them.
INPUT: Contains all the controls that affect input selection, level control and signal conditioning.
PROCESS: Contains all the controls that affect the processing.
OUTPUT: Contains all the controls that affect output selection, level control and signal conditioning.
SCHEDULE: Contains all the real time clock controls for switching presets (Dayparting).
SYSTEM: Contains all the system controls (non processing) such as remote control and security.

Menu Structure
16
menu Structure
MENU: INPUT
INPUT SOURCE
ANALOG LEVEL
MENU: PROCESS
MENU: ENHANCE
PEAKING BASS GAIN
PEAKING BASS FREQ
PEAKING BASS Q
MENU: MULTI-BAND AGC
MENUS: BANDS 1-4
DRIVE
ATTACK
DECAY
GATE
MENU: MULTI-BAND LIMITERS
MASTER LIMITER DRIVE
MENUS: BANDS 1-4
DRIVE
LIMITER ATTACK
LIMITER DECAY
COMPRESSOR ATTACK
COMPRESSOR DECAY
MENU: MIXER
BAND 1 MIX LEVEL
BAND 2 MIX LEVEL
BAND 3 MIX LEVEL
BAND 4 MIX LEVEL
MENU: LOOK-AHEAD
BASS CLIP LEVEL
LP FILTER
DRIVE
MENU: OUTPUT
LEVEL
MENU: SCHEDULE (X) REPRESENTS 0-7
TIME
DAYPARTING ON/OFF
TIME CALIBRATION
DAYPARTS 1-4
DP(X) ON/OFF
DP(X) START TIME
DP(X) TIME ON (LENGTH)
DAYPARTS 5-8
DP(X) ON/OFF
DP(X) START TIME
DP(X) TIME ON (LENGTH)
MENU: SYSTEM
LCD CONTRAST
TRIGGER PORT
CODE LOCK
REMOTE SOURCE
MENU: LAN CONFIG
IP
DG (DEFAULT GATEWAY)
SM (SUBNET)
MA1 (MAC ADDRESS PART1)
MA2 (MAC ADDRESS PART2)
PORT
MENU: ABOUT
VERSION
CONCEPT
HARDWARE
CONTROL SYSTEM
PROCESSING
REMOTE APPLICATION
BOOTLOAD

Processing Parameters
17
ProceSSIng ParameterS
The 'INPUT' menu contains options relating to the control and conditioning of the audio inputs.
'SOURCE' This parameter allows you to select the between the analog and digital inputs as the source for
the processing.
'ANALOGUE INPUT A/D CLIP LEVEL' This parameter is only active on units with a serial number of 500 or
greater. For serial numbers less that 500 see 'DSPXmini-HD Jumper Settings'. This parameter allows you
to set the analogue input level with reference to the DSPXmini-HD's A/D Converter. This would normally be
set to +24dBu if driving the DSPXmini-HD from professional audio equipment. When adjusting make sure
that the input audio meters NEVER show clipping under any conditions.
The 'PROCESS' menu allows access to all of the processing blocks that make up the DSPXmini-HD.
There are only sub-menus inside the 'PROCESS' menu. The submenus are laid out in the same configu-
ration as the signal path through the DSPXmini-HD.
The 'ENHANCE' menu contains the low frequency peaking bass equalizer which is used to provide bass
enhancement and help overcome the bass reduction effect of multi-band compression. Four frequencies,
amplitudes and Q's are provided giving you 64 different bass curves to select from. Frequencies selectable:
60Hz, 76Hz, 95Hz and 120Hz. Q's selectable: 0.4, 1, 2 and 4. Gains selectable: 0, 1.5dB, 3dB, 4.5dB, 6dB
The ‘MULTI-BAND AGC’ is designed to re-equalize the program material and create a consistent tonal bal-
ance while maintaining a consistent output level based on the RMS level of the program material.
‘B1-4’
‘DRIVE’ Controls the drive into the AGC. 0dB drive corresponds to a gain reduction of 0dB, the mid-
way point. The drive can be increased or decreased by up to 12dB. You may need to increase the
drive a little as you go up through the bands to compensate for the fact that music has less energy in
the higher frequency spectrum compared to low frequencies.
‘ATTACK’ Controls the attack rate of the AGC, The time the AGC takes to respond to an increase of
input level. The attack time can be varied between 1 and 10 which corresponds to 100mS to 10S on
a semi-exponential scale.
‘DECAY’ Controls the release/decay rate of the AGC, the time the AGC takes to respond to a
decrease of input level. The DECAY time can be varied between 1 and 10 which corresponds to
100mS to 30S on a semi-exponential scale.
‘GATE THRESHOLD’ The gate function prevents ‘suck-up’ of noise during periods of silence or low
level audio. The level can be adjusted to turn on when the input drops to a level from -20dB to -40dB.
The gate can also be switched off or forced on. The gate when turned on will cause the gain reduc-
tion to move towards the resting 0dB level
The 'MULTI-BAND LIMITERS' peak limit each of the bands to prevent distortion in thefinal peak limiting con-
trol system.
‘MASTER LIMITER DRIVE’ Sets the drive into the multi-band limiter. This control allows a +/- 6dB adjust-
ment.
'B1-4'
'DRIVE' Controls the drive into the limiter. The drive can be increased or decreased by up to 12dB.
'PEAK ATTACK' Controls the attack rate of the limiter, the time the limiter takes to respond to an
increase of input level. The attack time can be varied between 1 and 10 which corresponds to 1mS to
200mS on a semi-exponential scale.
'PEAK DECAY' Controls the peak release/decay rate of the limiter, the time the limiter takes to
respond to a decrease of input level. The DECAY time can be varied between 1 and 10 which corre-
sponds to 10mS to 1000mS on a semi-exponential scale.

Processing Parameters
18
'AVG ATTACK' Controls the average attack rate of the limiter. This control is a modifier control that
scales from the peak attack control. The attack time can be varied between 1 and 10 which corre-
spond to peak attack time / 2 to peak attack time / 1000 on a semi-exponential scale. The AVG attack
control determines the dynamics of the dual time constant system and how control is shared between
the peak and average circuits.
'AVG DECAY' Controls the average release/decay rate of the limiter, the time the limiter takes to
respond to a decrease of input level. The DECAY time can be varied between 1 and 10 which corre-
sponds to 200mS to 5000mS on a semi-exponential scale.
'MIXER' menu. Each band can be adjusted over a small range to provide small EQ changes. These controls
are limited in range to prevent excessive drive into the final peak limting stages and excess distortion being
introduced.
BAND1MIX: -3dB to +3dB of level adjustment is available.
BAND2MIX: -3dB to +3dB of level adjustment is available.
BAND3MIX: -3dB to +3dB of level adjustment is available.
BAND4MIX: -3dB to +3dB of level adjustment is available.
The 'LOOK-AHEAD' menu contains the look-ahead limiter controls that form the final peak limiting stages of
the DSPXmini-HD.
'BASS CLIP' Sets the bass clipper threshold. The range is 0 dB to -6 dB below final look-ahead limiter
threshold.
'LP FILTER' A high frequency filter adjustable over a range of 4-20 kHz. This control can be used to tame
the artifacts of subsequent perceptal coding, especially when used with very low bitrates.
'DRIVE' Controls the drive into the main output look-ahead limiter that defines the systems peak output
ceiling. Adjustable over a -6dB to +6dB range.
The 'OUTPUT' menu contains all of the controls relevant to the analog and digital outputs.
The 'ANALOG' menu contains the controls relevant to the analogue outputs.
'OUTPUT LEVEL' Controls the output level of the analogue output. Range is -12dBu to +24dBu
The 'DIGITAL' menu contains the controls relevant to the AES/EBU digital outputs.
'OUTPUT LEVEL' Controls the peak output level of the digital output. Range is -12dBFS to 0dBFS
'SAMPLE RATE' This parameter sets the output sampling rate for the AES/EBU digital output. The avail-
able rates are 32 KHz, 44.1 KHz, 48 KHz, follow digital input rate and follow external sync rate.
The 'SCHEDULE' menu contains all the controls for the dayparting (REAL TIME CLOCK) preset switch-
ing.
'TIME' Sets the time and day of the DSPXmini-HD’s Real Time Clock.
'DAYPARTING ON/OFF: Enables or disables the scheduling.
'DP(X) ON/OFF' Enables or disables an individual daypart schedule.
'DP(X)' Sets the preset to switch to when this daypart is triggered.
'DP(X) START' Sets the start time day and time of the daypart. There is also an ‘ALL days’ option.
'DP(X) LENGTH' Sets the length in minutes that the daypart will run for.
The 'SYSTEM' menu contains all the system controls (non processing) such as remote control and secu-
rity

Processing Parameters
19
'LCD CONTRAST' Sets the contrast of the front panel LCD screen. The range is 0 to 25
'TRIGGER PORT' This enables or disables the rear panel trigger (remote) port. The options are enabled and
disabled. More information is available in the trigger port section of this manual.
'CODE LOCK' This enables or disables the security code lock. The options are enabled and disabled. More
information is available in the code lock section of this manual.
'OUTPUT LOCK' This enables or disables the output code lock. The options are enabled and disabled. More
information is available in the code lock section of this manual.
'REMOTE SOURCE' This selects the seria or the NET/LAN port as the remote control method. The default
option is Off.
The 'LAN CONFIG' menu contains the controls relevant to the LAN/NET port.
'IP' Sets the IP address of the LAN port
'DG' Sets the default gateway of the LAN port
'SM Sets the subnet mask of the LAN port
'MA1' Sets the first half of the MAC address of the LAN port
'MA2' Sets the second half of the MAC address of the LAN port
'PORT' Sets the port number of the LAN port
'ABOUT' DSPXmini-HD version number and design credits.
'BOOTLOAD' This option is used to FLASH update the software and firmware inside the DSPXmini-HD.
Further information on using this option is described in the documentation supplied with the upgrade.

Setting Up The Processing
20
SettIng uP the ProceSSIng on the dSPXmInI-hd
This section has more detailed information on setting up the DSPXmini-HD’s processing.
Bass enhancement
The frequency contouring effect of multi-band audio processors often leaves the bass lacking a little. The sum-
mation of the bands tends to give a boost to the presence frequencies and leaves the bass sounding a little thin.
This effect can be compensated somewhat by enhancing the bass prior to multi-band processing.
The DSPXmini-HD has a pseudo parametric style bass equalizer control that allows you to sweet tune the
bass. Four frequencies, amplitudes and Q's are provided giving you 64 different bass curves to select from.
Frequencies selectable: 60Hz, 76Hz, 95Hz and 120Hz. Q's selectable: 0.4, 1, 2 and 4. Gains selectable: 0,
1.5dB, 3dB, 4.5dB, 6dB. A starting setting of 95Hz, Q of 1 and gain of 4.5dB warms the bass up quite nicely but
you are free to experiment to get the bass sound you're after.
Multi-band AGC
The multi-band AGC in the DSPXmini-HD employs an RMS based level detector for superior performance. This
enables the DSPXmini-HD to control input level variations based on the true loudness of the input waveform
unlike other simpler average responding peak detectors used in other digital audio processors. When you couple
the advanced detector with the user adjustable and hidden intelligent controls you really do have a powerful lev-
elling tool.
The Multi-band AGC stage of the DSPX has two main functions.
1. To re-equalise the program material to provide a consistent tonal balance and sonic signature.
2. To prevent excessive limiting by the following peak limiter stages.
Because of the RMS based level detectors the multi-band AGC can re-equalise the sound in a more natural
manner than the peak limiter stages which use peak detectors. As the human ear works on average loudness
rather than peak level the re-equalised audio will sound more natural when dynamic range reduction is per-
formed by RMS based level detectors.
Because the peak to average ratio of the program material can be quite wide it is still necessary to control the
peaks of the audio with the multi-band limiters but unlike most other audio processors the bulk of the work has
been performed by the multi-band AGC and the limiters can be fed with a more controlled level allowing them to
operate in their sweet spot.
Over the course of the next few pages we have included several scope shots clearly illustrating the input and
output of the single band AGC together with the AGC control signal. The effect of the control signal is clearly evi-
dent on the output audio waveform. These scope shots help to visually illustrate the concepts under discussion.
The multi-band AGC stage is designed so that a 0VU input level to the processor will drive the multi-band AGC
to the midway resting level of 0dB.
Individual drive controls are provided as a way of equalizing the audio before processing. This can be used to
add a touch of more presence or bass. Keep in mind that the mutli-band AGC by it's very nature will tend to
compensate any cut or boost you make here.
The attack and decay times of the AGC have a range of 1-10 and this corresponds to time constants of 100mS
to 30S. We suggest an attack somewhere in the region of 3-4 and a decay setting of 1 or 2 positions higher than
that.
AGC attacking and decaying with faster time
constants
AGC attacking and decaying with slower time
constants
The effects of time constant speeds