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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 unaffected.  This represents the Release time and again must be 

carefully set so as to prevent audible artefacts. 

 

Note the level 

difference marked as 

‘Overshoot’.  This 
phenomenon cannot be 

avoided because the 

compressor has no way 
of knowing when the 

signal will reach the 

threshold, and so 

cannot ‘prepare in 
advance’ for this 

happening.   

 
 

 

Consequently, there will always be a brief period before it can react, even at the 

minimum attack setting (fastest rate of gain reduction application). 

 

 

What makes the XTA Compressor different? 

 

Being a totally digital dynamics processor, the 

C2

 

has several advantages over 

conventional compressor designs.  By inserting a short delay into the sidechain signal 

path, the compressor is able to ‘look ahead’ and anticipate peaks before they occur.  
This gives it the ability to prevent the overshoot that is unavoidable with analogue 

compressors.  In this way, the compressor behaves in a more predictable and 

controllable manner, with no compromises in performance. 

 
It is quite common practice to insert some EQ into the sidechain of a compressor to 

make it ‘frequency conscious’.  This would normally involve patching an external 

equaliser through the external sidechain loop (or external key), tying up a valuable 
resource in the process.  the  

C2

 

’s compressor has a band of fully featured 

parametric equalisation built into the sidechain.  Each band can be swept from 20Hz 

to 20kHz and is selectable as either a parametric filter, or a shelving filter.  

Additionally, the filters can be bypassed, so that, in conjunction with the ‘Key Listen’ 

facility, its effect on the sidechain can be quickly and accurately determined. 

 

Modelling all the dynamics processing digitally allows the time constants set by the 

user to be one hundred per cent accurate all the time, with no drift due to 
atmospheric changes.  The ability to link the two channels together also permits 

completely accurate stereo tracking. 

 

Summary of Contents for C2

Page 1: ......

Page 2: ...he meters show level in dB from the clipping point of the unit when the METER switch is set to IN the meters show level in dB from clipping the input converter Set to OUT they show headroom available...

Page 3: ...How does a Compressor work 12 What makes the XTA Compressor different 13 C2 Configurations 14 Compressor Mode 16 DE Eq Mode 17 Sidechain Equalisation How and When to Use it 18 When would Sidechain EQ...

Page 4: ...E CHOC ELECTRIQUE NE PAS ENLEVER NE PAS EXPOSER A LA PLUIE NI A L HUMITE It should not be necessary to remove any protective earth or signal cable shield connections Do not defeat the purpose of the p...

Page 5: ...d and engineered for cutting edge performance and world class reliability If you would like further information about this or any other XTA product please contact us We look forward to hearing from yo...

Page 6: ...which are intelligently adjusted depending on the setting of other controls namely the sidechain EQ frequency when in De EQ mode Sidechain EQ built in for the compressor switchable to lo hi shelf and...

Page 7: ...to 16 1 very heavy compression Knee Key Cycles through Hard knee compression begins at the selected ratio as soon as the threshold is exceeded Medium compression is less pronounced just above threshol...

Page 8: ...shelf mode LISTEN Key Switches the output of the sidechain filter into the main signal path so that the required range of frequencies may be more easily selected LED flashes as a reminder that this is...

Page 9: ...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 sockets are provided for each channel All ar...

Page 10: ...er to the fact that several keys require a press and hold action to initiate them These keys relate to functions that could accidentally introduce large changes of level at the outputs causing undesir...

Page 11: ...are connected together to record the CD for example the unit with the lowest dynamic range sets the dynamic range for the entire system In the example above the dynamic range available is limited to...

Page 12: ...l has risen very sharply hence the sudden jump to a level above the threshold This signal is potentially too high and must be reduced in level to a more acceptable value The difference between the ori...

Page 13: ...is able to look ahead and anticipate peaks before they occur This gives it the ability to prevent the overshoot that is unavoidable with analogue compressors In this way the compressor behaves in a m...

Page 14: ...in EQ Sections The signal used for controlling the main path may be equalised prior to its use as a control signal this enables it to be made more or less sensitive to certain frequencies changing the...

Page 15: ...ction meter which will show the instantaneous amount of compression being applied are the keys to matching the levels Limiter Module Separate to the compressor is a fully independent limiter module Th...

Page 16: ...ignal may be monitored by engaging the LISTEN function In this mode the sidechain control signal may be equalised to make it more or less sensitive to certain frequencies This will in turn affect the...

Page 17: ...st a band of frequencies but in De EQ mode these filters are only used to home in on a band to make the signal more sensitive in this area This filtered signal is then used to control the threshold at...

Page 18: ...useful to be able to de sensitise the sidechain to certain frequency bands to prevent excessive activity at inappropriate times Maximising loudness without dulling the mix Loudness as opposed to volu...

Page 19: ...more accurate control of the amount of bass removed The curve imposed by a high pass filter is shown in orange and that of a shelving filter in red This highlights the advantage to incorporating more...

Page 20: ...frequency conscious compression is to control or tame a certain band of frequencies within the program material Insertion of EQ into the sidechain will make the compressor respond to the required band...

Page 21: ...f one of the channels on his desk reach an unacceptably high level he will turn it down appropriately There is a hidden sidechain in operation even in this case The main signal path is fed through the...

Page 22: ...the first peak above the threshold as it is very fast and short but has caught up shortly afterwards keeping all other peaks under control As it is unable to predict what is coming this will always be...

Page 23: ...sor will achieve similar results but with the penalty of delaying the main signal by the amount of look ahead delay introduced Note that the C2 does not have to use this look ahead delay in many cases...

Page 24: ...ortion if care is not taken with the settings The best way to ensure that the signal is not being excessively distorted is to make good use of the ACTIVE button constantly comparing the original signa...

Page 25: ...above and 6dB below the threshold reducing the severity of the compressor This shows on the graph as a flattening at the threshold rather than a sharp bend The C2 offers three preset knee settings Ha...

Page 26: ...peration is not made apparent by the unit s front panel controls it does go a long way to guaranteeing that the compression will never sound terrible Enabling the AUTO system by HOLDING the AUTO key w...

Page 27: ...that option not a safe operating level Always ensure that this clipping point is no lower than that for the following equipment in the signal chain and allow extra margin if equalisation sections are...

Page 28: ...helf or Narrow 0 83 Oct wide 1 25 Oct parametric response Centre corner Freq 20Hz to 20k Gain 6 9 or 15dB and Off Sidechain monitor available Limiters Threshold 10dBu to 22dBu Attack 1mS preset Releas...

Page 29: ...service facility Defects caused by unauthorised modifications misuse negligence act of God or accident or any use of this product that is not in accordance with the instructions provided by XTA are no...

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