Smart Research C2 Series

The C2 compressor houses two independant mono compressors, or in STEREO mode, the left-hand controls operate both audio channels, with the right-hand controls not used, giving true Stereo operation.

The C2M version has one set of controls and two audio channels for Stereo use.

The C2R is a dual channel remote expander for building up to 8 channel systems controlled from one C2M or C2.


The characteristic sound of this unit arises mostly from the fast response at the onset of compression, which when delayed to occur around the mid range attack settings (after 0.3 to 3 milliseconds) results in a window through which transients can still pass. When used accross a mix, or with any dynamic programme, this has the effect of adding 'punch', as the sidechain 'breathes' around these transients, while still controlling overall levels. CRUSH mode has been developed as an extension of this 'musicality', adding to and accentuating the factors involved in producing the character of the unit. CRUSH may sound surprising to those interested in more gentle applications, being capable of exaggerated compression effects, but in conjunction with the fast limit settings also introduced with this unit, it allows the C2 to be used for a much wider range of applications than the C1.


External fader level control input, (to order) (stereo mastering etc).
Extra dual channel slave units, for multichannel applications, (film / surround formats etc.).

Sidechain High Pass filter cables:

Fast attack and limit settings for protective limiting.
Crush mode gives f.e.t 'overcompression' with tailored frequency response, and higher distortion, for 'huge' dynamic effects.
External sidechain inputs, (for ducking etc.)
Power fail bypass for broadcast or live sound.
Ratios 1.5:1, 2:1, 3:1, 4:1, 10:1 and Limit.
Attack 0, 0.1, 0.3, 1, 3, 10, and 30 m/sec.
Release 0.1, 0.3, 0.6, 1.2, and 2.4 seconds.

Reduces sensitivity to low frequency compression. The C2 input is split through 150Hz -6dB/octave High Pass filter to feed the External Sidechain input. The C2 operates as normal, untill the 'External Sidechain' switches selected. (External signals can still be connected if required, with or without the filters)


New generation of Voltage Controlled Amplifiers.
High slew rate amplifiers, with hybrid f.e.t/ transistor inputs (Analog Devices).
High current push-pull transistor outputs.
Total symmetry throughout signal path.
No electrolytic capacitors used in main signal path.
All inputs and outputs balanced.

C2 Family Specifications:

Power: 100v-240v AC selectable, 30 watts.
Noise floor: Below -104 dBm (flat 20Hz-20Khz).
Distortion: Below 0.005% (1K/+4 THD 20Hz-20Khz)
Frequency Response: Within 1/2dB from 20Hz to 100Khz.
Depth in rack: 258mm.
Main input: Balanced, impedance 1K8 per leg.
Sidechain i/p: Balanced, impedance 10K per leg.
Output: Discrete transistor. Above +26dBm into 600 ohm load.
Threshold: Adjustable -20 to +20dBm.
Make-up gain: Adjustable 0 to +20dBm.

C2 Family Performance Graphs


C2 Stereo/Dual Mono Compressor: AU$ 3,550.00 plus GST
C2M Stereo/Mono Compressor: AU$ 2,820.00 plus GST
HPF-Y sidechain filter cable for C2: AU$ 95.00 plus GST

Smart Research C1

Original black front panel version of C2 compressor. (Two sets of controls and two audio channels, but no sidechain inputs, or crush facility). Popular in UK and US west coast studios.


C1 Specifications:

Power: 100v-240v AC selectable, 30 watts.
Noise floor: Below -92 dBm (flat 20Hz-20Khz).
Distortion: Below 0.025% (1K/+4 THD 20Hz-20Khz)
Frequency Response: Within 1/2dB from 20Hz to 20Khz.
Depth in rack: 240mm.
Main input: Balanced, impedance 10K per leg.
Output: Unbalanced (p2 hot default). Above +21dBm.
Threshold: Adjustable -15 to +15dBm.
Make-up gain: Adjustable 0 to +15dBm.


C1 Stereo/Dual Mono Compressor: AU$ 2,820.00 plus GST

Smart Research C1LA

For 25 years Smart Research compressors have been used across many mixes: with artists as diverse as the Rolling Stones to the Three Tenors. The C1LA shares this history by including the same electronics and settings as the original C1, but with several new features.

The C1LA is a two channel Compressor/Limiter, released to commemorate the 25th anniversary of our origi-nal C1 Stereo/Dual Mono unit, and the 50th anniversary of our North American distributer, Sunset Sound. It is a versatile unit, housed in a two-module wide 500-series plug-in format, with three main modes of operation offering a range of possibilities. It can be used for all stereo or single channel signal applications: as a main mix bus compressor; for submixes; or for tracking either mono or stereo sources.

Mix Glue ?The essence of the C1LA sound is determined by its dynamic performance: the way it reacts around tran-sients creating its signature. In many situations, best results can be from medium-slow attack; and medium-fast release settings passing transients present in a signal. The compression law and timing as the sidechain reacts and recovers adds ʻpunchʼ by shaping the transients, whilst also controlling overall levels. The ʻSOFTʼmode in the C1LA also adds a new compression curve, acting not just at the threshold knee, but across a broad input range of about 15dB.

A Tri-Mode C1 Each channel can either be used independently, or in Stereo mode both are summed into the sidechain to eliminate any image shift, as in the C1. The C1LA also has the ability to DC-Link the sidechain signals in Stereo mode, allowing for more movement, while still preserving the stereo image. And for those who prefer to compress both sides of a mix without linking: when operating independently both channelʼs controls are ganged.


3 operating modes: Independent/ganged; Stereo linked/Sum; and Stereo Linked/DC
Meter: Input, Output, (VU) and Gain Reduction (PPM) for L or R
3 sidechain filters : 65, 130, or 205Hz
Automatic distortion null circuitry
Normal and half-threshold ranges
ʻSoftʼ compression curve reshapes a 15dB range
Total of 12 Attack and 12 Release settings
Total of 4 ʻAutoʼ settings
Dual, balanced bantam jacks for external sidechain inputs
All settings and circuitry from original C1 Dual/Stereo Compressor


The Meter and its associated switches allow for several options. With all switches out, the meter adopts a right hand zero position, and shows the amount of gain reduction (compression) being applied on the outer black PPM scale markings (for the left channel). This replicates the meter function and PPM response in the original C1 unit. To the right of the meter, the VU switch changes to the white scale, giving a reading of either the output signal, or below this, pressing the IP switch toggles to show the input signal. In this mode the meter is working with a standard VU scale and response, with left hand zero, and still from the left channel. Any of the above readings can be moved to right channel using the MET R (Meter Right) switch.

Clip Indicator

Independently of the meter selection, the CLIP indicator permanently monitors four separate points to show if signal is approaching overload anywhere in the unit. As gain can be positive or negative through a channel VCA, both input and outputs of both channels are monitored. The C1LA level ceiling is +21.5dBu (though this can be increased by fitting optional transformers) and the CLIP indicator threshold is +20dBu.


Input Impedance: 10K
External Sidechain Input Impedance: 10K
Output Impedance: 30R
Operating Level (and zero VU): +4dBu
Maximum Input/Output Level: +21.5dBu
Clipping Indicator: +20dBu
Threshold Ranges: +/-15dBu, and +/-7.5dBu
Make Up Range: 0 to +15dBu
Frequency Response: +/- 0.5 dB from 20Hz to 50kHz.

Mechanical: Two module widths in API 500 series format racks.
Power Requirements: +/-15 to18v DC (critical voltages are internally regulated)
Current consumption 114mA per rail under full load (Nominal 90mA)


C1LA Stereo/Dual Ganged Compressor AU$ 2.095.00 plus GST

Smart Guitar D.i System

Designed to solve many instrument recording and D.i problems. For instance, one guitar feeding down long cables to 3 amps in a different area, without hums or change of tone. Includes: Balanced line driver for long cables; speaker level D.i input, and one unity gain Di Box/Splitter for two D.i or Amp feeds. Conceived at Real World Studios, to solve the problem of a guitarist wanting to play in the control room and have amplifiers set up in a live room sometimes several hundred feet away. Prototypes were also used at Virgin/ EMI Townhouse and Manor studios. Since then producers and artists such as Tom Lord Alge, Peter Gabriel, Paul Weller, and Tears for Fears have bought systems. Four systems were used to cure problems for Peter Gabriel's live show, where two stages had to be inter -connected with 300 feet of cable carrying guitar signals from radios to effects pedals on both stages and back to amps on the main stage without degradation, (allowing each stage to be patched independently).

Smart Guitar D.i System - Deluxe version

As above, but including: Balanced line driver for long cables; speaker level D.i input, 4 unity gain Di Box/Splitter for up to 8 D.i's or Amp feeds.

Block Diagram of Deluxe TRANSMIT box
(normal version does not have Di/Splitters)

lock Diagram of Deluxe RECEIVE box
(normal version has only one Di/Splitter channel)


Smart Guitar D.i System AU$ 460.00 plus GST
Smart Guitar D.i System - Deluxe version AU$ 595.00 plus GST

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