BW Broadcast DSPXmini-FM Quick start guide

DSPXmini-FM
Broadcast Audio Processor
Operational Manual
Version 1.2
www.audio-processor.com

DSPXmini-FM operational manual V1.2
2
Table Of Contents
Warranty 3
Safety 4
Forward 6
Introduction to the DSPXmini 7
DSPXmini-FM connections 8
DSPXmini-FM jumper settings 9
DSPXmini-FM metering 10
Status LEDs 10
Quickstart 11
An introduction to audio processing 12
Source material quality 13
DSPXmini-FM placement 13
The DSPXmini-FM and its processing structure 14
Processing block diagram 15
The DSPXmini-FM menu system 16
The Menu structure 16
Setting up the processing on the DSPXmini-FM 20
Getting the sound that you want 24
Managing Presets 27
Factory presets 28
Remote control of the DSPXmini-FM 29
Remote trigger port 35
Security code lock 36
Clock based control 37
Specifications 38

DSPXmini-FM operational manual V1.2
3
Warranty
BW (broadcast warehouse) warrants the mechanical and electronic components of this product to be free of
defects in material and workmanship for a period of one (1) year from the original date of purchase, in accord-
ance with the warranty regulations described below. If the product shows any defects within the specified war-
ranty period that are not due to normal wear and tear and/or improper handling by the user, BW 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 during normal business hours
BEFORE returning the product. All inquiries must be accompanied by a description of the problem. BW 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. 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 under the terms of this warranty will be
repaired or replaced within 30 days of receipt of the product at BW.
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 shall not be held responsible for any cost resulting 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 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.
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 shows that the defect in question is not covered by the warranty, 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
will inform the buyer of any such circumstance. If the buyer fails to submit a written repair order within 6 weeks
after notification, BW will return the unit C.O.D. with a separate invoice for freight and packing. 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.
Claims for damages
Failure of BW to provide proper warranty service shall not entitle the buyer to claim (consequential) damages. In
no event shall the liability of BW 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.

DSPXmini-FM operational manual V1.2
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
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

DSPXmini-FM operational manual V1.2
5
time.
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);
89/336/EEC (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.

DSPXmini-FM operational manual V1.2
6
forWard
Thank you for your purchase of the DSPXmini-FM digital audio broadcast processor.
Over the last decade the staff at BW 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 proc-
essor we had to do it the BW way and make the processor the most cost effective fully featured all-in-one broad-
cast 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 for FM.
And so, the DSPXmini-FM was born, as a scaled down version of DSPX with some reduced features like no
LED metering, no analog outputs and less sophisticated distortion control. By incorporating proven 4-band AGC,
4-band limiter and high-performance digital stereo generator, DSPXmini-FM offers loudness, consistency and
adjustability never before seen in a small processor like this.
Once again, thank you for your purchase; we hope you enjoy the DSPXmini-FM.
DSPX Team

DSPXmini-FM operational manual V1.2
7
IntroductIon tothe dSPXmInI-fm
The BW DSPXmini-FM is a new generation of digital audio signal processor that can be used to process audio
ready for FM. Using the latest multi-band DSP technology the DSPXmini-FM offers a versatile and powerful tool
in creating a loud punchy on-air presence.
The DSPXmini-FM 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-FM 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-FM 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 distortion cancelling clipping ensures your signal is kept to a strict maximum while maintaining
crystal clear sound. A supersonic sample rate DSP stereo encoder provides MPX generation with fantastic stereo
separation.
The easy to use front panel control system wit 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-FM is a clear winner.
Dynamic, fresh & innovative...
... The DSPXmini-FM

DSPXmini-FM operational manual V1.2
8
FUSE
LOAD PRESET
REMOTE
AES/EBU
EDIT
UP
LOAD
SAVE
DSPX
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
DSPX
OUTPUT
PROCESS
INPUT
ANALOGUE
INPUTS
SCA
INPUT
PILOT
OUTPUT
AES / EBU
INPUT
RS232
&
TRIGGER PORT
LAN
PORT
GND
LIFT
MAINS POWER INPUT
STATUS
LEDS
SOFT
KEYS
CONTROL
KNOB
DSPXmini-FM FRONT AND REAR PANELS
MPX
OUTPUT

DSPXmini-FM operational manual V1.2
9
dSPXmInI-fm JumPer SettIngS
The DSPXmini-FM has several internal jumpers. To access them, you will have to lift the top cover after remov-
ing ten screws that hold it.
Setting input clip level
A pair of jumpers are located just behind analog input connectors and are used to set the input clip level
between +24dBu and +12dBu. As shipped form the factory, jumpers are set for +24dBu operation which is suit-
able for standard, professional balanced levels. If the audio levels going to DSPXmini-FM are low and/or com-
ing from unbalanced source, you might want to set the jumpers for +12dBu operation. You can check the levels
going in DSPXmini-FM at any time by bringing up the metering screen (press the middle soft key on the front
panel). If you are unsure, leave these jumpers at factory default.
Ground lift
Ground lift jumper is located just behind Pilot Out connector. It removes circuit ground from chassis ground. If
you are experiencing hum or buzz in your audio, you might want to move this jumper to the lifted position as
indicated on the board.
Jumpers set outwards for +24dBu clip level
(factory default)
Jumpers set inwards for +12dBu clip level
Circuit ground tied to chassis ground
(factory default)

DSPXmini-FM operational manual V1.2
10
dSPXmInI-fm meterIng
The DSPXmini-FM 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-FM. 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 multiplex output metering represents the composite outputs peak level. This is a representation of the out-
put in relation to the peak composite level of the processing and not the actual level set by the multiplex output
level control.
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-FM front panel contains three status LEDS.
REMOTE: Indicates that the DSPXmini-FM is currently talking to a remote computer. This will flash during
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-FM.
EDIT: Indicates that you are currently editing a parameter
FUSE
LOW HIGH
MIDHMIDL LOW HIGH MIDHMIDL
WB
LRLRMPX
CLIP CLIPCLIP
GATE
INPUT AGC OUTPUTLIMITERS
REMOTE
AES/EBU
EDIT
0
-3
-6
-9
-12
-18
-24
-30
-36
-42
-48
-56
-2
-4
-6
-8
-10
-12
-14
-16
-18
-20
-22
-24
-2
-4
-6
-8
-10
-12
-14
-16
-18
-20
-22
-24
0
-3
-6
-9
-12
-18
-24
-30
-36
-42
-48
-56
110
100
90
80
70
60
50
40
30
20
10
PILOT
dB
dB
dB
dB %
RS232
DSP X
UP
LOAD
SAVE
DSPX
OUTPUT
PROCESS
HOLD
INPUT

DSPXmini-FM operational manual V1.2
11
QuIck Start
1. Install the DSPXmini-FM into the rack
2. Connect AC power to the unit, and turn on the power.
3. Connect the analogue or digital audio input.
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.
5. Select the pre-emphasis setting for your region (input menu). 75uS for USA and 50uS for Europe.
6. Navigate to the ‘STEREO’ menu and adjust the ‘MPX OUTPUT LEVEL’ to match the transmitter (or link
device) that follows the DSPXmini-FM. Adjust for 100% modulation with audio.
7. Press the 'LOAD' soft key and select a preset from the list!
8. You're on the air!
Further information on each parameter is contained in the 'menu structure' and 'setting up the processing' sec-
tions of this manual.

DSPXmini-FM operational manual V1.2
12
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.

DSPXmini-FM operational manual V1.2
13
Source materIaL QuaLIty
The DSPXmini-FM has the ability to substantially improve the quality of your ON-AIR broadcast. However
the DSPXmini-FM can only work with what you provide it. The best performance will be obtained when the
DSPXmini-FM is fed with very clean source material. After dynamic multi-band re-equalisation is performed, poor
quality source material will sound poorer when processed with the DSPXmini-FM.
We strongly advise against the use of MP3's and other compressed audio formats for audio storage. If you must
use compressed audio we advise rates of 256 Kbps and higher. 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-FM can violate the frequency masking characteristics of the bit reduction process,
creating distortion that was inaudible prior to the DSPXmini-FM processing.
dSPXmInI-fm PLacement
We recommend that the DSPXmini-FM be placed as close to transmitter as possible. Ideally DSPXmini-FM
should be connected directly to the transmitter. Composite studio to transmitter links may introduce additional
overshoots, therefore increasing peak level and reducing average modulation.

DSPXmini-FM operational manual V1.2
14
the dSPXmInI-fm and ItS ProceSSIng Structure
The DSPXmini-FM broadcast audio processor is intended to be used for processing audio prior to broadcast on
FM .
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-FM. It employs distortion controlled clippers to limit the peaks of the signal. Distortion
controlled clipping is the best method for preserving as much high frequency energy as possible, important when
the high frequency loss characteristics of the FM broadcast de-emphasis curve is taking into account. Distortion
controlled clipping produces harmonic distortion which if used moderately can produce a sizzling bright sound
but can result in a ripping or tearing sound if used excessively (overdriven).
the ProceSSIng Path
Input selection and conditioning
The DSPXmini-FM offers the user input selection (analog or digital input) and pre-emphasis selection.
Bass enhancement
The DSPXmini-FM 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-FM 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-FM 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.
Bass clipper
The DSPXmini-FM peak limits (clips) and linear phase filters the low frequencies before being fed to the final
clipper stages.
Distortion controlled clipper
The DSPXmini-FM main clipper uses sophisticated algorithms to produce tightly peak controlled output and
maximum distortion control.
Stereo encoder
The DSPXmini-FM's DSP stereo encoder takes its inputs after peak processing. The stereo encoder is highly
over-sampled and offers superb stereo performance. A composite clipping function is provided for those who
wish to use it.

DSPXmini-FM operational manual V1.2
15


!.!,/'



$)')4!,


!$

32# 

,/7

!'#

-)$
!'#



()'(
!'#

).054 -"!'# 

,0&

"0&

"0&

(0&

"!33 0%!+
02%

-)$
!'#
,/7
,)-
-)$
,)-


()'(
,)-

-",)- 
-)$
,)-


,0&

"!33#,)0


,0&




/54054 -08 
0),/4/54
$!

-08
#/-0
#,)0 0),/4

3#!).

-08/54
$308MINI&-02/#%33).'",/#+$)!'2!-
#,)0

DSPXmini-FM operational manual V1.2
16
menu overvIeW
This section presents an overview of the four main menus
and thier submenus and any parameters that are contained
within them.
INPUT: Contains controls that affect input selection and pre-
emphasis.
PROCESS: Contains all the controls that affect the process-
ing. From here you can fine-tune your sound.
STEREO: Contains all the controls that affect MPX output.
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.
SOFTKEYS: The DSPXmini-FM has three context sensitive
soft keys that help access commonly used features. These
intuitive softkeys are primarily designed to aid in the selec-
tion, loading and saving of presets, as well as displaying the
metering screen. More information on the softkey functions
are contained in the appropriate sections of this manual.
menu Structure
MENU: INPUT
INPUT SOURCE
PRE-EMPHASIS
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
BAND1MIX
BAND2MIX
BAND3MIX
BAND4MIX
MENU: CLIPPERS
BASS CLIP
HF CLIPPING
MAIN CLIP DRIVE
CLIPPER HARDNESS
CLIPPER OVERSHOOT CONTROL
COMPOSITE CLIPPER
MENU: STEREO
LEVEL
PILOT LEVEL
PILOT OUTPUT
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

DSPXmini-FM operational manual V1.2
17
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.
Pre-emphasis: This parameter allows you to activate pre-emphasis when the DSPXmini-FM is being used to
process for FM broadcast. The available options are 50uS, 75uS and OFF
The 'PROCESS' menu allows access to all of the processing blocks that make up the DSPXmini-FM.
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-FM.
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 the processors clipping
peak control 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.
'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

DSPXmini-FM operational manual V1.2
18
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 peak clipping 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 'CLIPPER' menu contains the clipping controls that form the final peak limiting stages of the DSPXmini-
FM.
'BASSCLIP' Controls the clip level of the mix of Bands 1 and 2. The clip level range is -6dB to 0dB refer-
enced to the main clippers output level.
'HFCLIPPLING' This control redistributes high frequency peak control between the limiters and the HF
clipper. The range is 0 to 17 with 0 equating to full control by the limiters and higher numbers producing
less control by the limiters on a frequency dependent basis, leaving control by the HF clipper. This control
is similar to a variable de-emphasis control in the limiters side-chain control signals.
'MAIN CLIP DRIVE' Controls the drive into the main output clipper that defines the systems peak clipping
ceiling. Adjustable over a -6dB to +6dB range.
'MAIN CLIPPER HARDNESS' Another distortion controlling mechanism that helps to reduce IMD in the
final clipper. The range is 1 to 10 with 10 producing the least distortion control. A setting of 10 effectively
bypasses this control.
'OVERSHOOT CONTROL' Controls how much the main clipper will pass overshoots to the composite
clipper. The range of overshoot control is 1 to 10 with lower numbers allowing more overshoots through
to the composite clipper.
'COMPOSITE CLIP Controls the drive into the composite clipper which effectively sets the amount of
composite clipping. The range of composite clipping is -0.5dB to +2dB.
The 'STEREO' menu contains all of the controls relevant to the DSP stereo encoder that generates the
multiplex signal.
'LEVEL' Controls the output level of the composite MPX output. Range is 0dBu to +12dBU
'PILOT LEVEL' This parameter sets the level of the composite signals 19 Khz pilot tone. The adjustable
range is 6% to 12% and an OFF setting for mono applications.
'PILOT OUTPUT' This controls the 19KHz pilot output reference signal which is available on the DSPXmini-
FM back panel. Options are enabled and disabled
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-FM’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.

DSPXmini-FM operational manual V1.2
19
The 'SYSTEM' menu contains all the system controls (non processing) such as remote control and secu-
rity
'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-FM version number and design credits.
'BOOTLOAD' This option is used to FLASH update the software and firmware inside the DSPXmini-FM.
Further information on using this option is described in the documentation supplied with the upgrade.

DSPXmini-FM operational manual V1.2
20
SettIng uP the ProceSSIng on the dSPXmInI-fm
This section has more detailed information on setting up the DSPXmini-FM’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-FM 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-FM employs an RMS based level detector for superior performance. This
enables the DSPXmini-FM 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