Summary of C2
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Page 2 c2 operators manual c2 quick reference things you need to know… ü bold means hold! Any functions that would produce possible unexpected level changes at the outputs are protected by a ‘press and hold’ action and printed in bold on the panel. These functions are: switching automatic time const...
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C2 operators manual page 3 contents c2 quick reference 2 important safety information 4 thanks 5 unpacking the c2 5 introduction 6 features 6 front panel familiarisation 7 rear panel connections 9 operating the c2 10 switching the unit on and start-up procedure 10 press-and-hold keys 10 minimum and ...
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Page 4 c2 operators manual an example of this equipment has been tested and found to comply with the following european and international standards for electromagnetic compatibility and electrical safety: radiated emissions (eu): en55013-1 (1996) rf immunity (eu): en55103-2 (1996) rf immunity, esd, ...
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C2 operators manual page 5 thanks thank you for choosing the xta c2 dual compressor for your application. Please spend a little time reading through this manual, so that you obtain the best possible performance from the unit. All xta products are carefully designed and engineered for cutting-edge pe...
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Page 6 c2 operators manual introduction the c2 is a powerful dsp based audio dynamics processor, ideally suited for live sound applications, where it combines the accessibility and immediacy of a pure analogue design with the quality and accuracy of a digital design in a compact 1u unit. To achieve ...
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C2 operators manual page 7 front panel familiarisation level meter: dependant on the setting of the ‘meter’ switch, this will display the instantaneous available headroom, at either the input to the channel (analogue to digital converter) or the output from the channel, post limiter (digital to anal...
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Page 8 c2 operators manual make-up gain control: apply extra gain to compensate for the compression gain reduction, helping to maintain the signal at its original level. Mode key: switch between normal compression mode, and de- eq mode, where only the frequency band selected with the sidechain eq is...
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C2 operators manual page 9 rear panel connections power switch: turns the units mains supply off and on. Mains fuse: located in a finger-proof holder adjacent to the mains inlet. A spare fuse is also located in this holder. Mains inlet: connected via a standard iec socket. Audio in-out: 3 pin xlr so...
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Page 10 c2 operators manual operating the c2 operation of the c2 is very straightforward, but there are a few points worth noting which, once understood, will make using the unit even easier. Switching the unit on and start-up procedure after plugging in the power and switching the power on suing th...
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C2 operators manual page 11 compression – what it is and what it can do what does a compressor do? A compressor is designed to do as the name suggests – compress. What it compresses is the dynamic range of the audio fed to it. This means that it is used to control the level of the audio in such a wa...
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Page 12 c2 operators manual what is required is a device that can monitor the signal passed to it, and allow the average level to pass untouched. At a threshold level the device will begin to turn down the level by a certain amount. This amount can be varied, to offer more or less attenuation of sig...
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C2 operators manual page 13 the last region of interest is region 3 where the signal returns once again to below the threshold. The green shaded area represents the recovery time for the compressor to stop applying gain reduction and effectively ‘recognise’ that the signal is to pass through unaffec...
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Page 14 c2 operators manual c2 configurations there are two distinct modes of operation of the c2 - normal compressor mode (augmented by a sidechain equaliser section), and the de-eq mode. To explain the operation of these two modes and clarify the differences between them, they will be broken down ...
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C2 operators manual page 15 gain control section: this element is simple in its operation – the signal to be controlled passes straight through, and the signal fed in from the side can ‘turn down’ the main signal, but is never heard itself. To hear this control signal, it is necessary to monitor the...
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Page 16 c2 operators manual compressor mode below is the block diagram showing how the compressor works. Following the input section, the signal is split into the main path (audio) and the sidechain (control). The main path consists of the gain control element, followed by the make-up gain section, ...
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C2 operators manual page 17 de-eq mode below is the block diagram showing how the de-eq mode works. Following the input section, the signal is split into two paths, which are eventually recombined to form the main signal path again. One signal passes through the equalisation sections that, in this m...
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Page 18 c2 operators manual sidechain equalisation – how and when to use it when would sidechain eq be useful? When it is necessary to adjust the sensitivity of the compressor, tailoring the sidechain signal with equalisation is the only way to achieve this without affecting the main signal path. De...
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C2 operators manual page 19 having used eq to tame the bottom end in the sidechain, the compressor will now be much less sensitive to low frequencies and so won’t start applying gain reduction in response to only bass. Traditional sidechain eq is normally only featured in noise gates, and is limited...
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Page 20 c2 operators manual why is the de-eq mode so useful? Having selected the frequency band to work with, the dynamic eq will listen to this band and act upon it by cutting(compressing) any frequencies present in it that go above the predetermined threshold. Consider the example below where the ...
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C2 operators manual page 21 look ahead delay – pre-emptive action one of the most significant advantages of digital signal processing over analogue is the ability to delay the audio signal precisely and without extensive complex hardware. The entire domain of digital signal processing is based aroun...
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Page 22 c2 operators manual the red waveform represents the input to the dynamics module, with the dotted line showing the threshold for gain control to occur. There are several peaks towards the start of this signal that are above the threshold, and so the dynamics processing should react to these ...
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C2 operators manual page 23 the predelayed sidechain is shown in green, with the main signal in red. As the main signal arrives slightly after the sidechain, the output from the c2 does not suffer from the overshoot problem. Remember that this delay is only in the order of 10 to 60us,and is a predel...
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Page 24 c2 operators manual setting the attack and release times as with all compressors, using too fast attack and release times on low frequency program (such as a bass guitar) will cause the compressor to respond to individual cycles of the signal, rather than the overall envelope. This will resu...
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C2 operators manual page 25 consider a compressor with a relatively high ratio of 8:1. A typical in-out transfer function would be as below 2 . The very sharp introduction of gain reduction is obvious at the threshold point (-20db). The ‘knee ‘ parameter is set to 0db in this example – this correspo...
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Page 26 c2 operators manual using the auto system the automatic system on the c2 is responsible for taking care of the setting of the attack and release times in either compression mode or de-eq mode. By adjusting these times dependant on the use of the use of the sidechain eq, the compression can b...
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C2 operators manual page 27 operating notes operating level with any audio signal processing equipment it is necessary to ensure adequate signal level is used through the device, to avoid sacrificing noise performance. It is suggested that the operating level chosen should give adequate level to jus...
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Page 28 c2 operators manual specifications inputs: 2 electronically balancedu impedance: > 10k ohms. Cmrr : >65db 50hz - 10khz. Outputs: 2 electronically balancedu source imp: min. Load: 600ohm max. Level: +20dbm into 600 ohm frequency resp.:+½db 20hz-20khz dyn range:>110db 20hz-20k unwtd distortion...
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C2 operators manual page 29 warranty this product is warranted against defects in components and workmanship only, for a period of one year from the date of shipment to the end user. During the warranty period, xta will, at it's discretion, either repair or replace products which prove to be defecti...