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Klark Teknik SQ1 8 Channel Compressor / Limiter / Expander

Product Code: KLSQ1DYNAM
Manufacturer: Klark Teknik

Free mainland UK shipping available for this product

Our Price £529.99INC

Available within 5-7 working days

The constantly-changing hardware requirements of technical riders are just one of the many issues audio rental companies and live music venues have to deal with. Having to retain a comprehensive inventory of different devices, as well as reconfiguring outboard processing racks is a costly, time-consuming task, further complicated by the number of hardware options available.

The solution: KLARK TEKNIK Square ONE dynamics.Eight channels of flexible, configurable, high-performance dynamics processing in one 3U package. The right brand, the right combination, the right investment, every time.

Default Compressor

RMS sensing type. With both mode switches inactive the compressor behaves in the default Soft Knee and RMS mode. This gives the slowest (and most subtle) feel to the compressor envelopes. The soft knee curvature combines with the adaptive RMS attack and release times to produce gentle envelope curvatures that are ideal for compressing sung vocals but which can still be aggressive enough to limit transients when needed. The knee curvature also reduces the adaptive nature of the RMS detection slightly, providing a little more manual control of the envelope timings than is the case below. When Hard Knee is activated the compressor operates in a more clinical way with a more defined transition between under threshold and over threshold; this is better suited to limiting style compression. A small amount of soft knee is still retained keeping the sound reasonably natural but no modification of the envelope occurs. This means that attacks are more aggressive, but it also allows the adaptive nature of the RMS detection to operate to its fullest extent. This mode is good for natural sounding limiting of speech.

"Vintage" Compressor

Peak sensing type. When Hard Knee and Vintage are activated the compressor operates with more precise envelope control and a defined transition between under and over threshold. This mode uses faster peak sensing (not RMS) like many older compressor designs with exponential attack and release. This produces aggressive compression that gives good fast control, and/or limiting, of extremely dynamic material. It can also be used to add colour to low frequency signals making it ideal for controlling instruments like bass guitar. When Vintage is active alone, the compressor employs a dual time constant, linear attack profile. The soft knee blurring of threshold occurs, (as in RMS mode), however, the effect is greatly accentuated and this produces extremely subtle attack and release curves during the onset of compression that are largely independent of the envelope control settings. As the compressor is driven harder (i.e. signals further over threshold) the soft knee effect reduces, gradually returning manual control of the attack and release times to optimise capture of larger transients etc. Thus, like the RMS modes, this compressor mode is very adaptive making set up of the envelope controls relatively easy. The peak sensing, however, increases harmonic overtones, which add a "vintage" brightness and sparkle to the programme, producing extremely transparent, lively sounding compression of acoustic instruments.

Broadband frequency-conscious compressor

Setup as per compressor, in either RMS or "VINTAGE" modes. Activate FILTER in wide mode, sweep to desired frequency & apply frequency-dependant compression as required

Hi-Q frequency-conscious compressor (De-esser)

Setup as per compressor, in either RMS or "VINTAGE" modes. Activate FILTER in NARROW mode, sweep to desired frequency & apply frequency-dependant compression as required. Excellent for reducing sibilance or other undesirable artefacts from vocals, or for removing specific resonances from instruments or programme material.


Set compressor to "VINTAGE" (peak) mode, hard knee, fastest ATTACK, with the RATIO at infinity to one. Adjust RELEASE to suit programme. Set THRESHOLD for onset of process.


Switch to "GATE" mode, set THRESHOLD, ATTACK, HOLD, and RELEASE times to suit programme, control dynamic range expansion using "RANGE" control. Use sidechain FILTER for frequency-dependant expansion, i.e dynamic noise reduction.


Switch to "GATE" mode, set THRESHOLD, ATTACK, HOLD, and RELEASE times to suit programme, set attenuation depth using "RANGE" control. Use SIDECHAIN FILTER to "tune" the gate to open at selected frequency - "wide" or "NARROW" modes. The attack characteristic of the gate is exponential. This ensures that, even at extremely fast attack settings, the attack envelope seamlessly blends into the audio waveform, ensuring that no undesirable audio artefacts (clicks) are created.

i-TS (intelligent threshold shift)

This operates in conjunction with the gate hold function, to reduce chattering within the gate. Chattering is the undesirable condition that occurs when signals (especially low frequency ones) are very close to the gate threshold. In this situation the gate can become indecisive and repeatedly open and shut on the programme. i-TS ensures that the gate remains open by automatically adjusting the threshold downwards the moment the signal goes over the threshold setting. When the signal eventually falls below the (new) temporarily adjusted threshold, the i-TS re-sets, ready for the next gate opening. This hysteresis means more decisive operation of the gate, ensuring that gating is rock solid. Attacks start instantly and consistently, even on signals that are only slightly over threshold.

Stereo & multiple-channel operation

Channels can be linked (in all modes) for stereo, or multi-channel operation. When any number of channels are linked, the linked channels all adopt the mode of the left-hand channel of the linked group. This channel's settings now control all the members of that group, only the make-up gain and Side chain filter are independent.

Solo Buss

Monitor the sidechain filter during the performance, using the dedicated SOLO OUTPUT. Connect the SOLO OUTPUT to a spare input channel, line return, FX return, etc. on your mixing console. Any SOLO button press will route that processors' SIDECHAIN MONITOR to the SOLO OUTPUT, allowing monitoring of the sidechain filter without interrupting the audio output of the processor. If the SOLO IN PLACE mode is active, the SOLO IN PLACE LED will illuminate. In this mode the SIDECHAIN MONITOR signal will replace the audio output when the SOLO button is pressed.


When mixing live sound, it is essential to be able to see at-a-glance, how the outboard processing is performing. Therefore, each channel of the Square ONE convertible dynamics rack features a 6-segment 3-colour input meter, and a 10-segment attenuation depth meter. The attenuation depth meter operates in both compressor and gate modes. The use of vertically oriented high-intensity LEDs makes for easy peripheral-vision awareness of each channel's status.

Architects and Engineers Specification:

The Dynamics Processor shall provide eight complete channels of either compression or gating, with push button selection and LED status indication of operational mode on an individual channel basis.

The compressor section on each channel shall provide for adjustment of Threshold, Make-Up Gain, Attack and Release times and Ratio. There shall be push button selection of RMS or Vintage Emulation (Peak) response and push button selection of Soft or Hard knee mode on each channel.

The gate section on each channel shall provide for adjustment of Threshold, Attack, Hold and Release times and Range.

The Threshold, Attack and Release controls shall be operable by the same rotary control knobs in compression and gating modes. Control of Ratio and Range shall be performed using the same rotary control knob. There shall be individual rotary control knobs for Make-Up Gain and Hold.

Each channel shall have a six-segment input level meter and a ten-segment attenuation depth meter, which will show the gain reduction being applied in both compression and gating modes.

Each channel shall have a sidechain band-pass filter with a rotary control knob for frequency control and shall be enabled by a push button switch. The band-pass filter shall have two different bandwidth settings, selectable by a push button switch. There shall be provision for an external sidechain input selected by the External Key switch with LED status indication.

The Bypass switch shall set the signal path to unity gain on each channel and provide LED status.

Each channel shall have a Solo switch with LED status indication that sends the sidechain signal to the Solo Bus Output connector.

A Solo Bus Input connector shall allow multiple Dynamics units to be chained together to form a common Solo Bus Output.

The Side Chain Solo In Place switch shall have LED status indication and change the function of each Solo switch; when selected the sidechain signal shall be sent to the channel output connector instead of the Solo Bus Output.

The Dynamics Processor shall have the ability to link the operation of any number of adjacent channels, which shall all be summed into the sidechain of the left-hand linked channel which shall control the gain of each of the linked channels. The selection of either compression or gating for the left-hand linked channel shall override the push button settings for all channels linked to it.

A Power On Led shall be provided.

The Dynamics Processor shall meet or exceed the following specifications:

Distortion: (THD+N) <0.02% @1kHz, +4dBu
Frequency response: +/-0.5dB (20Hz-20kHz)
Dynamic Range: (20Hz-20kHz unweighted) >117dB

Each channel shall have XLR connectors for the input and output and a 1/4" TRS jack socket for the external side chain input. All audio connections shall be electronically balanced.

The Dynamics Processor shall be 19" standard rack mountable and 3U high.

The Dynamics Processor shall be capable of operating from a 100-240V +/- 10% 50/60Hz a.c. power source.

The Dynamics Processor shall be the KLARK TEKNIK Square ONE Dynamics, and no alternative specification option is available.

Technical Specification:

  • Dynamics Inputs Eight
    Type: Electronically balanced XLR (pin 2 hot)
    Impedance (O): 10k

  • Ext Key Inputs Eight
    Type: Electronically balanced TRS Jack (Tip hot)
    Impedance (O): 20k
    Solo Bus Input One
    Type: Electronically balanced XLR (pin 2 hot)
    Impedance (O): 20k
    Dynamics Outputs Eight
    Solo Bus Output: One
    Type: Electronically balanced XLR (pin 2 hot)
    Minimum load impedance: 600O
    Source impedance: <60 O
    Maximum level: +22dBu into >2kO

  • Performance
    Frequency response: 20Hz - 20kHz ±0.5 dBu
    Distortion (THD+N): <0.02% @ 1kHz, +4 dBu
    Noise Floor <-95 dBu @ Unity Gain Dynamic range (20Hz-20kHz unweighted): >117 dB

  • Compressor
    Threshold (Hard Knee): -50dB to +25dBu
    Gain: 0dB to +30dB
    Attack: 100us to 20ms
    Release: 50ms to 2.5s
    Ratio: 8 to 1

  • Gate
    Threshold: -50dB to +25dBu
    Attack: 10µs to 10ms
    Release: 2ms to 2s
    Hold: 2ms to 2s
    Range: 8 to 0dB

  • Sidechain Bandpass filter
    Frequency Range: 40Hz -16kHz
    Slope (Wide): 6dB per Octave

  • Terminations
    Audio: 3-pin XLR and 1/4" TRS jack
    Power: 3-pin IEC

  • Power Requirements
    Voltage: 100V-240V a.c. ± 10%
    Consumption: <35W

  • Dimensions
    Height: 133mm (5.25 inch) - 3U High
    Width: 482mm (19 inch)
    Depth: 205mm (8 inch)

  • Weight
    Nett: 4.4kg
    Shipping: 5.4kg

  • UK Based Company
  • Part of A.C. Entertainment Technologies - has its trading origins over 45 years ago
  • UK Stock Holding
  • UK Warranty
  • Free Delivery Over ?150
  • Great Prices
  • Over 20 Years' Experience
  • Specialist Advice
  • Fast Delivery
  • Finance Options Available

With years of experience supplying Businesses, Government Organisations, Charities, Schools, Colleges and Universities, we invite you to take advantage of our knowledge to help you make an informed choice, ensuring you are purchasing the best music products for your needs. With specialists in PA Systems, Pro Audio & Live Sound equipment on hand to answer calls and emails, you're in the best possible hands.

Contact us now to discuss your requirements or to request a quotation. Additional discounts may apply for educational establishments or size and value of order.

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