XL8i Architects and Engineering Specification

XL8i: Audio Mixing System

The system shall comprise of robust steel, 19" rack mountable, modular units that can be interconnected via dual redundant cables to provide an audio signal distribution network with signal processing and mixing capability. A central control surface shall be provided consisting of multiple modules housed in a robust steel chassis that can be located well away from the rest of the system and connected by dual redundant multi-channel digital fibre or copper "snake". The entire system shall be fault tolerant such that no single interconnecting cable fault can stop the system operating to its full capacity. All external interfacing, internal processing and system controls shall be modular such that loss of power to any single module only affects that module allowing the remainder of the system to operate normally. The operational status of all the system modules and interconnections shall be continuously monitored and reported at the control surface.

The system shall be capable of mixing 96 primary input channels simultaneously to 51 main bus output channels, with equalisation and dynamic processing on every channel and the ability to add insert points to any of the channels as desired. 16 freely patchable effects processors shall be included plus 16 effects return channel paths that can be mixed to 19 of the output channels.

The system shall be capable of sourcing inputs and driving outputs from multiple locations so that for example all inputs can source their signal from a hard disk recorder for sound checking but switch over to microphone feeds for the main live show event.

The system shall have the option of a number of different system I/O boxes with either fixed or configurable I/O card options.

DL451: XL8i Input/Output Unit

The input/output unit shall be a 3U rack box with universal mains power supply and that interfaces 24 bi-directional system signals to external equipment via integral sub modules that can be loaded in optional configurations to conform to a variety of input and output requirements including:

Sub module with 8 balanced mic or line inputs, 8 balanced line outputs on female 25 way D Type and remote status indication for 48V and output mute available on male 25 way D Type.
Sub module with balanced line input and output on 16 gold plated TRS Jacks
Sub module with AES3 input and output on 8 gold plated XLRs
Sub module with 8 way balanced line outputs on gold plated XLRs
Sub module with 8 way balanced line or mic inputs on gold plated XLRs

Bi-directional digital AES50 protocol system connections shall be provided on dual redundant XLR Ethernet connectors.

MIDI and 8 GPIO inputs and output shall be provided.

Control of gain and all preamplifier functions on the 8 way balanced XLR mic/line inputs shall be available remotely from the system control surface.

The XLR mic/line preamplifiers shall meet or exceed the following specifications:

Input Impedance	10K
Analogue Gain Trim	-5dB to 40dB
Digital Console Gain Trim (additional to above)	-40dB to 20dB
Total Gain Range	-45dB to 60dB
Maximum Input Signal Level	+26dBu
100Hz CMRR at 0dB Analogue Gain	80dB
1kHz CMRR at 0dB Analogue Gain	80dB
100Hz CMRR at 40dB Analogue Gain	90dB
1kHz CMRR at 40dB Analogue Gain	90dB
150R EIN at 40dB gain measured at analogue outputs A & B	-88dBu
150R EIN at 0dB gain measured after A/D and D/A conversion	-127dBu
Crosstalk at 1kHz on physically adjacent channels	-100dB
Crosstalk at 10kHz on physically adjacent channels	-100dB
Distortion at 1kHz with 0dBu gain and 0dB output	0.01%
Distortion at 1kHz with 40dBu gain and 0dB output	0.03%
Distortion at 10kHz with 0dBu gain and 0dB output	0.01%
Distortion at 10kHz with 40dBu gain and 0dB output	0.031%
Freq Response ref 1K at A & B analogue outputs	20 - 20kHz +0 to -0.5dB
The D Type connected mic/line preamplifiers shall meet or exceed the following specifications:
Input Impedance	10K
Analogue Gain Trim	-2.5dB to 45dB
Digital Console Gain Trim (additional to above)	-40dB to 20dB
Total Gain Range	-42.5dB to 66dB
Maximum Input Signal Level	+24dBu
100Hz CMRR at 0dB Analogue Gain	80dB
1kHz CMRR at 0dB Analogue Gain	80dB
100Hz CMRR at 40dB Analogue Gain	90dB
1kHz CMRR at 40dB Analogue Gain	90dB
150R EIN at 0dB gain measured after A/D and D/A conversion	-89dBu
150R EIN at 40dB gain measured after A/D and D/A conversion	-127dBu
Crosstalk at 1kHz on physically adjacent channels	-100dB
Crosstalk at 10kHz on physically adjacent channels	-100dB
Distortion at 1kHz with 0dBu gain and 0dB output	0.01%
Distortion at 1kHz with 40dBu gain and 0dB output	0.03%
Distortion at 10kHz with 0dBu gain and 0dB output	0.01%
Distortion at 10kHz with 40dBu gain and 0dB output	0.031%
Freq Response ref 1K at digital output	20 - 20kHz +0 to -0.5dB
The line preamplifiers shall meet or exceed the following specifications:
Input Impedance	10K
Maximum Input Signal Level	+21dBu
100Hz CMRR at 0dB Analogue Gain	60dB
1kHz CMRR at 0dB Analogue Gain	60dB
150R EIN at 0dB gain measured after A/D and D/A conversion	-89dBu
Crosstalk at 1kHz on physically adjacent channels	-100dB
Crosstalk at 10kHz on physically adjacent channels	-100dB
Distortion at 1kHz with 0dBu gain and 0dB output	0.01%
Distortion at 10kHz with 0dBu gain and 0dB output	0.01%
Freq Response ref 1K at digital output	20 - 20kHz +0 to -0.5dB
The line outputs shall meet or exceed the following specifications:
Output Impedance	50R
Max Output Level	+21dBu
Crosstalk at 1kHz on physically adjacent channels	-100dB
Crosstalk at 10kHz on physically adjacent channels	-100dB
Distortion at 1kHz with 0dBu gain and 0dB output	0.01%
Distortion at 10kHz with 0dBu gain and 0dB output	0.01%
Freq Response ref 1K at digital input	20 - 20kHz +0 to -0.5dB
The AES3 sub module shall meet or exceed the following specifications:
Protocol	AES3
Channel Count	4 x stereo in and out
Sample Rate	48 or 96 or auto tracking to input
Word Length	16, 20 or 24 bit
The input/output unit system shall meet or exceed the following specifications:
Digital Output Protocol (dual redundant)	AES50
Digital Input Protocol (dual redundant)	AES50
Remote Control Protocol	Embedded in AES50
Channel Count	24
Sample Rate	96kHz
Word Length	24 bit
MIDI Connections	in, out through on 5 pin DIN
GPIO in	opto-isolated 25pin D Type
GPIO out	opto-isolated 25pin D Type
Dimensions	3U x 410mm Weight 12.6kg

DL471 and DL461: XL8i Processing Unit

The system shall include the ability to site its components at multiple locations with multi-channel digital signal interconnections providing all audio routing between them.

The system shall incorporate two dual redundant digital routers at either end of a 192 channel bi-directional digital audio cable systems that can run up to 100 meters on CAT-5E cable or 500 meters on fibre optic cable.

For local distribution the system shall use multiple CAT-5E cables to carry 24 channels of AES50 protocol digital audio bi-directionally over cable up to 100 meters long.

The main router units shall form a 240 channel bi-directional routing matrix to and from, the processing units, the 192 channel long haul digital audio connection, and 10 other AES50 ports, that provide up to 240 channels of external connectivity.

The processing units shall be formed as modular 1U 19" rack boxes with universal mains power supplies and connected to both each other and the main dual redundant audio router systems, housed in 3U 19" rack boxes also with universal mains power supplies. The control surface shall be connected to, and physically contain, another set of dual redundant routers.

The processor units shall be operated in N+1 mode with a hot spare always available and with a ring topology interconnection system such that the system can operate at full capacity with either a missing connection or inactive processor unit. Audio data interconnections shall be made with both routers within the redundant pair to ensure fault tolerance.

The routers shall meet or exceed the following specifications:

 

Digital Audio Protocol (dual redundant)	AES50
Input/Output & Split Unit Control Protocol	Embedded in AES50
Sample Rate	96kHz
Word Length	24 bit
Processor Control Protocol	Ethernet
Long Haul "snake"	HyperMac Fibre or CAT-5E
Sync	AES3 in & out plus 75R word clock in & out
External Data Transition Tunnel	2 x Ethernet

DL471 and DL461: XL8 Processing Unit

The system shall include the ability to site its components at multiple locations with multi-channel digital signal interconnections providing all audio routing between them.

The system shall incorporate two dual redundant digital routers at either end of a 192 channel bi-directional digital audio cable systems that can run up to 100 meters on CAT-5E cable or 500 meters on fibre optic cable.

For local distribution the system shall use multiple CAT-5E cables to carry 24 channels of AES50 protocol digital audio bi-directionally over cable up to 100 meters long.

The main router units shall form a 240 channel bi-directional routing matrix to and from, the processing units, the 192 channel long haul digital audio connection, and 10 other AES50 ports, that provide up to 240 channels of external connectivity.

The processing units shall be formed as modular 1U 19" rack boxes with universal mains power supplies and connected to both each other and the main dual redundant audio router systems, housed in 3U 19" rack boxes also with universal mains power supplies. The control surface shall be connected to, and physically contain, another set of dual redundant routers.

The processor units shall be operated in N+1 mode with a hot spare always available and with a ring topology interconnection system such that the system can operate at full capacity with either a missing connection or inactive processor unit. Audio data interconnections shall be made with both routers within the redundant pair to ensure fault tolerance.

The routers shall meet or exceed the following specifications:

 

Digital Audio Protocol (dual redundant)	AES50
Input/Output & Split Unit Control Protocol	Embedded in AES50
Sample Rate	96kHz
Word Length	24 bit
Processor Control Protocol	Ethernet
Long Haul "snake"	HyperMac Fibre or CAT-5E
Sync	AES3 in & out plus 75R word clock in & out
External Data Transition Tunnel	2 X Ethernet
Dimensions	3U x 410mm Weight 11.5kg
The processors shall meet or exceed the following specifications:
Digital Audio Protocol (dual redundant)	AES50
Sample Rate	96kHz
External Word Length	24 bit
Internal Maths Word Length	32 bit floating point
Processor Control Protocol	Ethernet
Dimensions	1U x 410mm Weight 6.7kg
The available audio processing shall include:
Input Channel Functions:
Input Channel Hi Pass	10Hz to 400Hz swept slope selectable 12dB/Oct or 24dB/Oct
Input Channel Lo Pass	2kHz to 20kHz swept slope selectable 6dB/Oct or 12dB/Oct
Input Channel Treble	Parametric Operation Frequency 1kHz to 25kHz swept Gain +16dB to –16dB BW 0.1 Oct to 3 Oct
	Shelf Operation Frequency 1kHz to 25kHz swept Gain +16dB to –16dB Soft, Classic or Bright (minimum harmonic disruption) curves
Input Channel Hi Mid	Parametric Operation Frequency 320Hz to 8kHz swept Gain +16dB to –16dB BW 0.1 Oct to 3 Oct
Input Channel Lo Mid	Parametric Operation Frequency 80Hz to 2kHz swept Gain +16dB to –16dB BW 0.1 Oct to 3 Oct
Input Channel Bass	Parametric Operation Frequency 16Hz to 400Hz swept Gain +16dB to –16dB BW 0.1 Oct to 3 Oct
	Shelf Operation Frequency 16Hz to 400Hz swept Gain +16dB to –16dB Warm, Classic or Deep (minimum harmonic disruption) curves
Input Channel Compressor	Peak, Linear, RMS, Vintage modes Thresh -50dBu to +20dBu Attack 200uS to 20mS Release 50mS to 3 Sec Ratio 25:1 to 1:1 Knee 4dB, 12dB or 40dB Gain 0dB to +24dB
	Side chain source selectable + filter Frequency 50Hz to 15kHz swept Bandwidth 1/3, 1 or 2 Oct
Input Channel Gate	Peak mode Thresh -50dBu to +20dBu Attack 10uS to 20mS Hold 5mS to 2 Sec Release 2mS to 2 Sec Range 100dB to 0dB
	Side chain source selectable + filter Frequency 50Hz to 15kHz swept Bandwidth 1/3, 1 or 2 Oct
Output Channel Functions:
Output Channel Band 6	Parametric Operation Frequency 16Hz to 25kHz swept Gain +16dB to –16dB BW 0.1 Oct to 3 Oct
	Lo Pass Operation Frequency 16Hz to 25kHz swept Slope 6dB/Oct or 12dB/Oct
	Shelf Operation Frequency 16Hz to 25kHz swept Gain +16dB to –16dB Mode soft curve
Output Channel bands 3,4,5	Parametric Operation Frequency 16Hz to 25kHz swept Gain +16dB to –16dB BW 0.1 Oct to 3 Oct
Output Channel Band 2	Parametric Operation Frequency 16Hz to 25kHz swept Gain +16dB to –16dB BW 0.1 Oct to 3 Oct
	Hi Pass Operation Frequency 16Hz to 25kHz swept Slope 24dB/Oct
Output Channel Band 1	Parametric Operation Frequency 16Hz to 25kHz swept Gain +16dB to –16dB. BW 0.1 Oct to 3 Oct
	Hi Pass Operation. Frequency 16Hz to 25kHz swept Slope 6dB/Oct or 12dB/Oct.
	Shelf Operation Frequency 16Hz to 25kHz swept Gain +16dB to –16dB Mode soft curve
Output Channel GEQ	16 available in place of PEQ (above) 31 Bands. 1/3 Oct. Proportional Q Lo Pass Frequency 2kHz to 20kHz swept Slope 6dB/Oct or 12dB/Oct Hi Pass Frequency 20Hz to 500Hz swept Slope 6dB/Oct or 12dB/Oct
Output Channel Dynamic	Pk, Linear, RMS, Vintage, Shimmer modes Thresh -50dBu to +20dBu Attack 200uS to 20mS Release 50mS to 3 Sec Ratio 25:1 to 1:1 Knee 4dB, 12dB or 40dB Gain 0dB to +24dB Dry mix 0% to 100%
	Side chain source selectable + filter Frequency 50Hz to 15kHz swept Bandwidth 1/3, 1 or 2 Oct
	Output Clipper Thresh 0dBu to +24dBu
Effects Channel Functions:
Stereo Effects Channel	16 available configurable as Stereo or mono in, stereo out Modulated delay effects Complex delay, reverbs Advanced dynamics RTA and advanced measurements
Effects Channel Stereo GEQ	16 available in place of effects (above) 31 Bands. 1/3 Oct. Proportional Q Lo Pass Frequency 2kHz to 20kHz swept Slope 6dB/Oct or 12dB/Oct Hi Pass Frequency 20Hz to 500Hz swept Slope 6dB/Oct or 12dB/Oct

XL8i Control Surface:

The system shall include a control surface that can monitor and operate all functions within the system and also provide keyboard, video, mouse connectivity to monitor and operate any computer based external systems.

The control surface shall be 1875mm x 1054mm x 421mm and constructed with a robust steel chassis containing multiple bays that can operate independently or as a whole with individual universal mains power supplies.

The control surface shall be clearly split into 3 main control areas presented in a traditional analogue centre masters format and providing control for multiple input channels, creative mixing and multiple outputs with 5 high resolution 12 " daylight visible colour VGA displays.

The control surface shall adhere to the following ergonomic rules:

Surface navigation, at channel paging level, through to individual control cluster sub sections, shall be clear, obvious and fast with navigational visual feedback presented so that it suggests movement side to side, or up and down analogous to analogue console operation.

Control cluster sub sections shall be instantly recognisable from their visual form and colour so that operators are not reliant on reading text labels. Their relative position shall be similar to analogue norms and imply signal flow where appropriate.

Similar sub section types shall have consistent layout across the control surface making them instantly recognisable.

Visual status of all controls shall be provided by motorised controls and/or high-resolution screens with advanced graphic quantization techniques.

All major signal paths shall have comprehensive metering easily viewable and available simultaneously.

All major signal paths shall have audio status information easily viewable and available simultaneously.

Large numbers of 100mm faders shall be accessible simultaneously for mixing.

Mute and Solo functions must be available with all faders.

Controls must not have dual audio parameter functions.

Use of stepped control status feedback (such as LED rings or screens with individual pixels visible) is not allowed.

All channel paths shall have electronic scribble strips with user definable background colour.

8 population groups, with electronic scribble strips as defined above, shall be provided that, when activated, can instantly recall to the control surface a sub set of inputs that have been previously been loaded into the group.

12 VCA master faders shall be provided that operate on user defined selections of input channel fades like traditional analogue consoles and can also be used to populate the control surface effectively providing another 12 population groups that operate as defined above.

A KVM switcher shall be provided so that up to 3 external computer software systems can be controlled from the control surface.

The control surface shall incorporate two dual redundant digital routers for connection to the main system routers located at the other end of a 192 channel bi-directional digital audio cable system that can run up to 100 meters on CAT-5E cable or 500 meters on fibre optic cable.

For local audio distribution the control system shall use multiple CAT-5E cables to carry 24 channels of AES50 protocol digital audio bi-directionally over cable up to 100 meters long.

The control surface routers units shall each form a 192 x 192 channel bi-directional routing matrix to and from, the 192 channel long haul digital audio connection, and 8 AES50 ports.

The control surface shall meet or exceed the following specifications:

 

Digital Audio Protocol	AES50
Input/Output & Split Unit Control Protocol	Embedded in AES50
Sample Rate	96kHz
Word Length	24 bit
Long Haul "snake"	HyperMac Fibre or CAT-5E
Sync	AES3 in & out plus 75R word clock in & out
External Data Transition Tunnel	2 X Ethernet
All the above are dual redundant connections and hardware systems
Weight	160kg

Automation:

The system shall include the ability to store and recall all audio control setting as "scenes" that can be recalled individually or in a defined sequence. The time taken to recall all control settings within a scene shall be less than 25mS (excluding extended cross fade times).

All scenes shall be numbered and have the ability to be named and present the system operator with text prompts or notes as a scrolling list of scenes.

The extent of the data stored in each scene and the extent of the controls recalled by each scene shall be selectable by the user and defined as store and recall "scope" tables per scene such that some areas of the console can be operated manually without automation for some periods during a show.

The number of scenes available shall be in excess of 1000.

Show wide hardware "safe" switches shall be provided to disconnect channels or parts of channels from automation control in addition to and overriding scope settings.

The Automation shall have the capability to send MIDI commands and GPIO signals to/from external devices via connections located in the Input/Output units. External selection of the next scene in a scene list shall also be possible.

Copy and paste facilities shall be provided that allow scenes to be copied, edited and inserted within a scene list and also provides a means to copy channel control settings, in part or as a whole, to other channels.