• ASC48

Advanced System Controller
The Advanced System Controller
from Linea Research is a highperformance and easy to use signal
processor for sound systems. With
processing for 4 inputs and 8outputs it takes advantage of thelatest analogue to digitalconversion and DSP technologies todeliver flawless audio that outclasses its competition. The
advanced 96kHz DSP provides anarray of unique and genuinely
useful features. Because all aspectsof the DSP algorithms are designed
and hand crafted in house by Linea,
they are not available on products
from any other manufacturer. For
example, LIR linear phase crossover

filters which are as easy to use as
more conventional filter shapes andhave less latency than FIR filters.
Also, the powerful VX Limiter suite
which sports Peak, RMS andExcursion limiting, as well as
multiband limiting for passive 2way enclosures.

•Four input channels and eight output channels•

No compromise audio performance•

Unique, precise, 96kHz Digital Signal Processing•

4x Analog, 2x AES3 and 8x Dante™ / AES67 (factory fitted option) inputs•

8x Analog or 4x Stereo AES3 and 8x Dante™ / AES67 (factory fitted option) outputs•

Ethernet remote control via Linea’s System Engineer PC application•Full front panel user interface offers simple intuitive local operation•

3rd party control via contact closure ports allow easy system integration•Fully designed and engineered by Linea’s in-house development team•

Manufactured and tested entirely in the UK

Supporting analogue AES3 and Dante™ inputs and having both analogue, AES3 and Dante™ outputs, all under full
remote control, makes the ASC48 suitable for use in the most demanding applications, especially when flexibility isparamount.
When used as a loudspeaker management system or digital crossover, the ASC48 brings state-of-the-art facilities
and performance, however the ability to receive, process and transmit audio without it leaving the digital domain
makes the ASC48 an ideal central controller for large systems, even when amplifiers with in-built DSP are being
employed.
Ethernet is used for remote control while a front panel, optimised for use in challenging environments, allows full
local control of all features. Control via Linea’s intuitive System Engineer application provides many convenient andtime saving features such as very flexible management of presets, and Overlay grouping of Mutes, Gains, Delays andEQ across an entire system.

Key Features
The ASC48 includes Linea Research minimal signal path design, and a 96kHz sampling frequency provides for anominally flat response beyond 40kHz. Three rotary encoders, illuminated buttons and graphical display provide arapid, intuitive and user-friendly control interface. Powerful Drive Module concept which allows for abstraction
from device centric to speaker based control. High speed capable and flexible Ethernet communications thatsupports DHCP, static-IP and auto-IP and direct connection to a computer without the need for a router or aswitch.
Class-leading sonic performance achieved by the use of state of the art converters, Analogue Devices SHARC DSP
and highly advanced DSP algorithms. Unique LIR linear phase crossover shapes giving FIR-like performance withless latency and without the need to design coefficients. Also, Linear phase HF system EQ profiling which provides
perfect integration between enclosures. Output EQ is complemented by 768 tap FIRs.
Innovative limiter suite which includes: VX limiter providing dynamic control for passive 2-way enclosures, anXmax excursion limiter with sliding High Pass Filter which retains dynamic impact whilst effectively protecting
drivers, Tmax transducer thermal modelling provides regulation limiters, addressing long term overload andovershoot limiter governing the amplitude of transient signals, retaining average power whilst constraining peaks.
AES3 inputs and outputs switchable in pairs as standard, with the option of a Dante audio networking card which
provides 8 inputs and 8 outputs.

Sonic Purity
Independent listening tests have confirmed that the Linea Research ASC48 performs as well as the very top brands
often costing many times more than the ASC48. This is testament to our ‘Minimum Signal Path’ philosophy, ourcareful choice of converters, and our many years of expertise in DSP algorithm design for professional audio.
The ASC48 uses 96kHz sampling and a powerful SHARC Digital signal Processor (DSP) running our proprietary LMD(Linea Micro Detail) algorithms. All this adds up to deliver the ultimate in sonic transparency and a stunning open
natural sound quality.

Crossover Shapes
As well as the standard Butterworth, Bessel, Linkwitz-Riley and Hardman filters, Linear research offers a unique“Linea Impulse Response” (LIR) crossover filter which gives a Linear Phase crossover that has a constant delay
regardless of frequency (unlike other types of crossover which delay different frequencies to a different extent,
thus smearing the arrival time).
The LIR crossover can thus be described as having a flat Group Delay response, and thus entirely free of Group
Delay Distortion, this is exactly the same as can be provided by common FIR filtering but without the design
complications and latency inherent with the FIR technique. The shape of the LIR crossover filter is similar to a 4thorder Linkwitz-Riley filter, and maintains zero phase difference between the adjacent bands across the crossover
region to keep the polar response rock steady. As we also employ phase matching on our Bessel filters; adjacentbands are in-phase throughout the crossover region.

High-Pass Filtering
To avoid unnecessary inter-band phase shifts common in many competing products, we provide high-pass filteringon the inputs rather than forcing you to apply ‘system’ high-pass filtering on the low crossover bands.
Our white-paper “High-Pass Filtering in Two-Way Systems” explains why this is important.

Presets
The ASC48 uses Drive Module presets, which are defined as a number of outputs driven from one DSP input. Thissystem allows for better flexibility and greater functionality when loading and storing presets. Drive Modules allow
for a less processor-centric and more speaker-orientated system design. The ASC48 allows 50 drive module
presets to be stored.
Presets are stored permanently inside the ASC48 and so will always be available even if the ASC48 is not being
used with the System Engineer application. The OEM can easily create a library of locked ‘factory’ presets fromwhich the user can create their own variants.

System Engineer Application
Thanks to the power of Obcom, System Engineer becomes much more than just a remote control panel for an
ASC48. System Engineer and any connected device(s) become intimately intertwined, faithfully duplicating any
control adjustments whether they are made in System Engineer or on the front panel of the device itself. Adjust again control on the device and watch the gain value in System Engineer smoothly slide in sympathy. They simply
cannot get out of ‘sync’. You can also update the firmware in the unit via System Engineer – even via the network.
Each input and each output can be named in System Engineer. These names not only appear for the User on theSystem Engineer control panels, but also show when scrolling through the inputs and outputs on the device itself.
Should you wish to change the factory presets in the field, modified Factory files can be distributed and loaded by
the user without disturbing the user presets, and without the user being able to access the factory settings in thefactory presets.
The full ASC48 control panels in System Engineer:Refresher Flyer Rear -02

THIS UNIT MUST BE EARTHED

NETWORKEDAUDIO
INTERFACEETHERNETAUXPORT
X Y

MAINS 100-230V 50-60Hz 30W

7 AES3 7&8

65 AES3 5&6

4
OUTPUTS

3 AES3 3&4

2

1 AES3 1&2

43AES3 3&4

2
INPUTS

1AES3 1&2

General Specifications
Audio output channels

8x Analogue / 4x Stereo AES3 and 8x Dante™ / AES67 (factory fitted option)

Audio input channels

4x Analogue / 2x Stereo AES3 and 8x Dante™ / AES67 (factory fitted option)

Digital Signal Processing

High performance 96kHz DSP on all inputs and outputs
Ethernet network
Contact closure port

External Control and Monitoring

Audio Performance
Input impedance<10k Ohm balanced

Output impedance<100R impedance balanced

Maximum input level+20dBuMaximum output level+18dBu into 600R

Sample rate

96kHz

AES3 Input sample rate

28kHz – 108kHz

AES3 Output sample rate

96kHz

Frequency Response

10Hz – 40kHz (Frequency response reduces to 23kHz on outputs with FIR enabled)

Input dynamic range>120dBa typical

Output dynamic range>118dBa typical

Total harmonic distortion, THD<0.008% typical (20Hz – 20kHz)

Digital Signal Processing
Resolution

40 bit, Linea Research proprietary algorithms

Sample rate

96kHz throughout
4x Analogue, 2x Stereo AES & 4x Stereo Dante™ inputs can be routed to four DSP
drive modules

Physical inputs to DSP drive modules
Drive module input processing

Input signal routing, Delay, Gain, HPF, Phase, Mute
EQ: 2x low shelf, 6x PEQ / band pass and FIR shelving filters

Drive module output processing

Source, Delay, Gain, Phase, Mute, Crossover filters, VX limiters
EQ: low shelf, 8x PEQ / band pass and shelving filters / 768 tap FIR

Preset management

10 snapshots for device wide setup, 50 presets for loudspeaker settings
Presets can be recalled to sets of outputs or individual outputs as required

Unique high-performance processing
Overlays

Twelve additional independent overlays of EQ, Delay and Gain
Flexible grouping for effective control of many amplifier channels in large systems

Class leading VX limiters

See the ‘speaker protection systems’ section

Hardman crossover filters

Better out of band rejection than Linkwitz-Riley

LIR crossover filters

Unique Linear Phase alignments without the compromises of FIR filters

Power Supply
Mains required

85V to 230VAC, 50Hz - 60Hz

Mains power

30W

Nominal mains input voltage range

85V to 230V nominal

Mains input frequency range

50Hz to 60Hz

Physical
InputsAnalogue/AES3 IN – 4x female Neutrik™

Outputs

Analogue/AES3 OUT – 8x male Neutrik™

Mains input connector

3 pin IEC

Dante™ Primary and Secondary

2x Shielded RJ45

Contact closure inputs

Phoenix™ pluggable terminal block (mating plug supplied)

Front panel display

Backlit, graphical, high contrast, daylight visibleFront panel encoders

Three, detented, velocity sensitive

Front panel push buttons

Large, tactile, illuminated

LED indicators

Bright, easily differentiatedEnclosureStandard 19” 1U (44mm), 254mm (10”) deep

Net Weight

2.7kg (6 Lbs)

For more information about the ASC48 Advanced System Controller or Linea’s other high-performance
audio products, please contact us or your local dealer.
Linea Research Ltd
Units 1 & 2 Aylesford Court
Works Road
Letchworth Garden City
Herts, U.K.
SG6 1LP
Tel: +44(0)1462 893 500
Tel: +1 949 436 4745 (USA Office)
Email: info@linea-research.co.uk

www.linea-research.co.uk
E&OE FEBRUARY 2020 V1.3