RC LEVELIZA User manual

Copyright
Unit 9 Luccombe Business Centre,
L
EVELIZA
User Manual
Copyright
2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre,
Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
EVELIZA
User Manual
- July 2018
Milton Abbas, Blandford Forum, Dorset DT11 OBD
Page 1 of 8

Copyright 2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre, Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
Page 2 of 8
If you have just purchased a LEVELIZA then thank you very much for doing so, and
I do hope you enjoy the benefits of using this new and revolutionary product
Best regards, Jon and the RC Audio Systems team
Application of the LEVEL ZA
The LEVELIZA is intended to be inserted into a full range audio signal. When the average perceived
loudness of the signal exceeds the threshold set on the LEVELIZA, the unit will gently attenuate and
"ride the gain" to try to maintain the average perceived loudness around the threshold level.
In this regard the LEVELIZA is a unique device, and the only simple plug and play solution to achieve
a consistent average level throughout an event from an inconsistent source (such as a DJ) without
need for an engineer to ride the gain throughout the event and without the compromises in
performance and dynamic range associated with other limiter/leveller/compressor/AGC options.
The LEVELIZA is not a limiter. It will not protect amplifiers or speakers from clipping/overload, and
system limiters should still be used as normal to offer such protection.
The LEVELIZA is not a compressor, it will not compress, expand or otherwise affect the dynamic
range of the music signal, it ust slowly rides the gain with the ob ective of trying to maintain a
consistent average perceived volume level over a period of time.
Because the LEVELIZA is only interested in the perceived loudness of the music, it is not as
concerned with low bass and sub frequencies as these have less affect on our human ear's
perception of loudness than the other frequencies. For this reason the LEVELIZA is not suitable for
use in controlling low bass & sub frequencies.

Copyright 2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre, Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
Page 3 of 8
Features and Controls
The LEVELIZA has two independent channels, and each channel has ust three controls.
• The first control is "input gain" that can be used if desired to manually attenuate the input.
• The second control is to set the "threshold" for the desired maximum output level.
• The third control is the "assertiveness". This control would usually be set to minimum in
normal use, in which case the unit will consider the average perceived volume levels over a
few minutes and try to work at an inaudible rate to correct the levels as necessary. On
occasions where the threshold level is being set/ascertained/calibrated, or if large
fluctuations in level between different music sources are expected, the assertiveness can be
turned up high and the unit will work much faster to maintain the correct perceived volume
levels. The engineer also has the flexibility to choose a level of assertiveness in between if it
is considered beneficial to a particular application.
In addition to its normal subtle operation the LEVELIZA will automatically work much faster for an
"emergency response" in cases where the music is suddenly turned up considerably over threshold.
It really is designed with the purpose of continuously managing the perceived volume levels ust the
same as a good human engineer would.
There are two displays, one for each channel, and they simply indicates the approximate db of gain
reduction that is currently being applied to that channel.
TAMPER PROOF:- Also, for applications where the engineer does not want the threshold level to be
increased there are additional hidden tamperproof ad ustments that can be set to limit the
maximum output threshold.
Connections
Mains power is connected via a standard IEC cable into the rear of the unit.
Audio inputs - there is an XLR input for each of the unit's two channels. The unit is designed to
operate at standard "line" levels.
Audio outputs - there is an XLR output for each of the unit's two channels.

Copyright 2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre, Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
Page 4 of 8
Guidance for set up and use
Of course there are many situations in which a LEVELIZA may be found useful, and in that regard the
user will need to use their udgement in how to best deploy the device.
However, probably the most welcome use of the LEVELIZA is for maintaining consistent levels at a
venue or throughout an event where DJs are performing and there is considerable inconsistency
between the levels produced by the various DJs throughout their sets. For this reason I will provide
some guidance on how we would suggest deploying and using the unit in this situation, as follows:-
Connection
Probably the best way to connect the LEVELIZA is to insert it between the DJ mixer and the PA
desk/sound system, although it could be put elsewhere in the chain if necessary.
Adjustment of the unit
Initially the displays should read "000".
1. We always start with all the control knobs of the LEVEL ZA turned up fully clockwise. In
this position, unless there is a really hot signal, the unit remains inactive and the signal can
pass through freely.
2. Once the music signal is present and the desired level is reached slowly turn down the
threshold knobs until the displays reads "001". This means the level is now ust 1db over
threshold and so the LEVELIZA is attenuating the signal by 1db. If the threshold knob is left
in this position the LEVELIZA will try to hold the average perceived volume around this level
regardless of how much the input signal is increased further.
3. The LEVELIZA is still on maximum assertiveness, so will work hard to respond quickly to
maintain the level. However, in order not to affect the dynamics of the music throughout
the performance a much slower and more relaxed response is required. To achieve this the
assertiveness controls should now be turned right down to "low (normal)" and then the unit
can be left alone to engineer the gain as required, so that the average perceived level of the
event will not exceed the threshold.
We normally leave the "INPUT GAIN" attenuator all the way up all the time, but in case of a very high
signal level it can be used to reduce the input if required.

Copyright 2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre, Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
Page 5 of 8
Are there any special procedures for adjusting the levels or threshold during an event?
When ad usting the threshold or input gain during an event there will be a time lag before realising
the full result of the ad ustment. This is because the LEVELIZA works on average data over
significant periods, especially when the assertiveness is set low for normal operation. For this
reason you should temporarily turn the assertiveness to "high (calibration)" whilst carrying out
ad ustments as then the results can be fully assessed within only a few seconds, then once you are
happy with the new levels and threshold the assertiveness should be turned down again for normal
operation.
What if the DJs produce a level below the threshold?
In that case the unit will stop attenuating and the level at the event will become reduced
accordingly. In cases where this reduced level is unacceptable and a consistent level is required,
even if the DJ plays below threshold, then the LEVELIZA should be set so that it is attenuating more
heavily and therefore the DJs can reduce the signal more before the LEVELIZA stops attenuating.
This can be achieved during the setup above by setting the input gain knobs back to perhaps 1 or 2
o'clock in step one, instead of all the way up. Then, in between step 2 and 3 turn the input gains all
the way up. The LEVELIZA should quickly correct this additional level with some additional
attenuation.
What if the LEVEL ZA is attenuating a lot, maybe 10 or more db?
The sound quality and performance of the LEVELIZA is not affected by the amount it is attenuating.
If the event is sounding good it doesn't make any difference if the LEVELIZA is working at 3 or 5db of
attenuation or at 20db. The only significance of a high attenuation is that the DJs would need to
then reduce their levels a lot more before the event became quieter, and depending on the
requirements of the event this might be either a good or a bad thing.

Copyright 2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre, Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
Page 6 of 8
n what situations would you increase the assertiveness?
If there is a large and sudden fluctuation in operating levels, perhaps a change of DJ or music source,
then with the assertiveness in the normal "low" operating position the LEVELIZA would take some
time to recalibrate. In such situations it can be beneficial to increase the assertiveness temporarily
to the "high (calibration)" position until the large fluctuations/changeover have passed so that the
LEVELIZA works fast to re-calibrate itself and maintain the levels consistently throughout the
changeover.ne example we have experienced is when a new DJ has pointed out that the DJ mixer is
operating well into the red and they would like to bring it back to correct levels, but want us to
cooperate by bringing the system gain back up to match at the same time. In this case we've turned
up the assertiveness, they've then gained back by 10db and the LEVELIZA has quickly reduced its
attenuation by 10db to match, then we put the assertiveness back to "low (normal)" again. Without
turning up the assertiveness in this situation the LEVELIZA wouldn't know that the sudden reduction
wasn't deliberately part of the show, therefore it would take a lot longer to release its attenuation.
Also, if the music source is unusually inconsistent in level and a more consistent output level is
desired then the assertiveness could be increased so that the LEVELIZA worked harder and faster to
maintain the level. As with many things in life, there is always a trade off to consider. A higher
assertiveness will work harder to keep a more consistent level, but at the expense of the dynamic
range of the show as it could to some extent spoil music by ironing out the level differences between
the louder and quieter sections of a piece of music. Equally if the assertiveness was too low then it
wouldn't perform well enough at maintaining the show at a consistent average level. Following
many trials we've set the LEVELIZA's "low (normal)" assertiveness to be about the optimum
assertiveness managing the levels at most events or in most situations, but of course there will be
times, including as mentioned above, where a higher assertiveness is beneficial.

Copyright 2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre, Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
Page 7 of 8
Tamper Proof threshold adjustments
In some situations where a sound system is to be left unattended, or maybe in an installed venue,
the engineer that carefully set the threshold levels may not want anyone else to ad ust these levels
in their absence. For this reason there are some hidden ad ustments that can be set on the
LEVELIZA.
Just ad acent to the threshold knobs there are holes in the front panel. These holes are tapped with
a standard M6 thread, and when we supply the LEVELIZA we cap these holes off with a very short
"black M6 dome socket cap screw". If these screws are removed (with a small allen key) then a
preset ad ustment can be found inside.
The presets, as supplied, are turned fully anticlockwise into their off position. To set these tamper
proof thresholds:-
1. Turn the threshold knobs all the way up - this is important,
2. then (with music playing at desired threshold volume) using a tiny screwdriver turn the
preset ad ustment slowly clockwise until the LEVELIZA starts to attenuate, and hence set the
thresholds as required.
3. Put the security screws back in so that nobody can access the presets.
Once this is done the front panel controls are still fully operational as normal, however the
maximum threshold and hence maximum average volume level that the LEVELIZA will allow to pass
to the sound system is restricted to the levels set on the presets.
There are many different security screws and other screws that require special screwdrivers/tools
available on the market with an M6 thread, so to increase security further the owner can buy their
own unique screws to use instead of the supplied ones cover the presets. However, the threaded
length must not be more than 4mm or there is a risk of damage to the preset and/or circuit board
behind the front panel. Of course longer screws can be bought and carefully cut down to under
4mm.

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Unit 9 Luccombe Business Centre,
Dimensions:
Weight:
Power requirement:
Audio Connections on rear:
Power Connections on rear:
Typical input level:
Maximum input before clip:
Display:
The LEVELIZA comes
with a one year full parts and labour warranty, during which time we will repair
any faults if they should develop affecting
cover damage caused by misuse or abuse or tampe
After the warranty has expired we will continue to support the products into the future, including
offering a repair facility, spare parts and technical support should any customers need any
assistance.
Copyright
2018 - RC Audio Systems Limited
Unit 9 Luccombe Business Centre,
Milton Abbas, Blandford Forum, Dorset DT11 OBD
email:- [email protected]
Specifications
Standard 19 inch 1U rack case by 250mm deep
Approx 3kg
90 - 264 V AC, 47 -
63 hz, up to 60mA current draw
XLR input and output for each channel
Standard IEC power inlet
Designed to be compatible with "lin
e level" pro audio equipment
Unbalanced 10V RMS / Balanced 20V RMS
Gain reduction shown in db for each channel
Warranty
with a one year full parts and labour warranty, during which time we will repair
any faults if they should develop affecting
the performance of the product
. This warranty does not
cover damage caused by misuse or abuse or tampe
ring with the products.
After the warranty has expired we will continue to support the products into the future, including
offering a repair facility, spare parts and technical support should any customers need any
Milton Abbas, Blandford Forum, Dorset DT11 OBD
Page 8 of 8
63 hz, up to 60mA current draw
e level" pro audio equipment
with a one year full parts and labour warranty, during which time we will repair
. This warranty does not
After the warranty has expired we will continue to support the products into the future, including
offering a repair facility, spare parts and technical support should any customers need any