Ecler QEM16-2, QEM30-1 Instruction Manual

INSTRUCTION MANUAL
MANUAL DE INSTRUCCIONES
NOTICE D’EMPLOI
BEDIENUNGSANLEITUNG

QEM16-2
QEM30-1

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INSTRUCTION MANUAL QEM16-2/30-1

1. IMPORTANT REMARK 04

1.1. Precautions 04

2. INTRODUCTION 04

3. INSTALLATION 05

3.1. Placement and setup 05

3.2. Connections 05

4. OPERATION AND USE 06

4.1. Power up 06

4.2. Level adjustment 06

4.3. General level adjustment 06

4.4. Clipping indicator 06

5. CONSIDERATIONS 07

5.1. Ground loops 07

5.2. Audio connections 07

5.3. Background noise 07

5.4. Cleaning 07

6. TECHNICAL CHARACTERISTICS 25

7. DIAGRAMS 26

7.1. Function list 26

7.2. Function diagram 28

7.3. Block diagram 29

All numbers subject to variation due to production tolerances. ECLER S.A. reserves the right to make changes or
improvements in manufacturing or design which may affect specifications.

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1. IMPORTANT REMARK
Congratulations. Now, you own the result of a thoughtful design and a careful manufacturing.

We thank you for trusting on us and choosing our equalizer QEM16-2 / QEM30-1.
In order to achieve maximum operativity and efficiency with your QEM, it is VERY
IMPORTANT, before you plug it in, that you read carefully and take into consideration what is specified
in this manual.
In order to guarantee an optimum and trouble-free operation of this device, we recommend
that the possible fixes be carried out by our authorized Technical Services.

1.1. Precautions
This apparatus must be earthed through its mains cable.

Do not expose the unit to rain or water splashes, and do not place liquid containers or
incandescent objects like candles on top of the unit.

Should any connection / disconnection task be done, always disconnect the unit from the mains
supply.

There are no user serviceable parts inside the unit.

2. INTRODUCTION

The QEM16-2 and QEM30-1 equalizers have been specially designed for professional field
applications. Therefore, they can be perfectly used for live P.A., recording studios, radio and T.V.
broadcasting studios, discotheques, night clubs, pubs, disco bars, etc. Also, they are well suited for Hi­Fi fans which already know how to use professional equipment.
The second generation QEM16-2 and QEM30-1 are a direct evolution from the first
generation QEM16-2 y QEM30-1 units.
Constant-Q QEM equalizers are a solid step forward into the improvement and updating of
equalizing units.

What is constant-Q?
Constant-Q systems make bandwidth independent of selected gain. That is, the selectivity of

the equalization does not change because of the applied gain for each band. In traditional graphic
equalization systems, the filter bandwidth -its Q factor- increases as the band gain decreases (its
selectivity decreases).
The QEM16-2 has 16 bands per channel (9,10), following ISO normalization, with ±12dB gain
controls for each of them. It also has general gain linear faders per channel (1,5) and clipping indicators
(3,7) (CLIP).
The QEM30-1 has 30 bands on 1 channel (21), following ISO normalization, with ±12dB gain
controls for each of them. It also has a general gain linear fader (26) and a clipping indicator (28), as
well as a high-pass (23) and low-pass filter controls (22) and ON/OFF switches (25) for them.
All two models have a FLAT switch (2,6,27), which bypasses all filters when ON, giving a true
flat frequency response.

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3. INSTALLATION

3.1. Placement an Setup

In professional installations, QEM equalizers should be preferably placed in the same rack as
active filters (crossovers) and power amplifiers. In this case, it may be necessary to remove their rubber
feet.
In live P.A. applications where hosepipes between control (mixing desk) and stage are used,
QEMs should be placed near the mixing desk, thus easily allowing to perform adjustments by the
mixing engineer.
QEM equalizers have a very low power consumption, so they do not need any fan cooling;
nevertheless, you should avoid exposing them to extreme temperatures and you should try to place
them in a place as dry and dust-free as possible.
It is very important not to place them near noise sources, as transformers, dimmers, motors,
etc... and their power supply cables. Because of this same reason, under not any circumstance should
you remove the metal cover from the unit.
The QEM16-2 and QEM30-1 can be mounted in a 19" (482.6mm) standard rack, taking up
two unit heigth (88mm). The device is also provided with plastic washers for a clean and scratch-free
mounting, keeping the rack-mounting ears in good condition.

3.2. Connections

The QEM16-2 and QEM30-1 operates under voltages between 90 and 264 V at 47 to
63Hz. This device features an over dimensioned power supply that adapts to the mains voltage in
any country of the world with no need to make any adjustments. Make sure that the mains wire
(which plugs into 19) is far away from the signal cables in order to avoid any possible audio hum.
In order to protect the equalizer from eventual mains power overload or excessive power
consumption by the internal circuitry, there is a 500mA mains power fuse (18). If this fuse ever gets
blown up, you should replace it for an identical one. Should this new fuse also get blown up, please
contact our Technical Service as soon as possible. YOU MUST NOT EVER PLACE A HIGHER VALUE
FUSE.
The QEM16-2 and QEM30-1 units have XLR connectors for their inputs and outputs.
These models allow balanced and unbalanced connection. Balanced operation lowers
significantly cable noises. Here is the standard way of connection:

1 Ground
Balanced connection 2 Live or Direct signal
3 Cold or Inverted signal

1 Ground
Unbalanced connection 2 Live or Direct signal
3 Ground

There are two main ways of connecting the QEMs:

1.- Between preamplifier and power amplifier.

Connect the preamplifier's or mixer's output to the equalizer's inputs (12,13,30) (marked
INPUT) and its outputs (14,15,31) (marked OUTPUT) to the power amplifier's inputs.

2.- Between SEND/RCV of any mixing unit (INSERT).

This kind of bridge can be found just before the general output MASTER fader, so this control
will not have any influence over the equalizer's operation.
The SEND output must be connected to the INPUTs of the QEM and its OUTPUTs to the
RCV input of the mixing unit.

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4. OPERATION AND USE

4.1. Power up

Once the unit is connected in any of the ways described in 3.2, your QEM is ready to work.
Just push the mains POWER switch (11) and the associated green pilot will light up. Even
though the noise produced by powering up is minimum and it is practically cancelled by placing all
faders at 0dB, it is always advisable to follow the classical power up sequence: signal sources, mixing
unit, equalizers, active filters (crossovers) and, at the end, power amplifiers. The power down sequence
must follow exactly a reverse order. By closely following this sequences, all peaks or transitories
produced by switching on and off devices do not affect the next devices in the chain and, of course,
never reach the loudspeakers, which are extremely sensitive about this.
In order to be able to use the controls we must first verify that the switches marked as FLAT
(2,6,27) are not activated. Once this is checked, all controls can operate and we are able to perform any
adjustment.
If anytime you wish to perform a BYPASS of all equalizer's controls, just push the FLAT
switches. In models QEM16-2 and QEM30-1, if you unplug the mains power connector (turning the unit
off abruptly), the BYPASS will be performed automatically, through an inner relay.

4.2. Level Adjustment

The correct starting point for a proper equalization is having all band gain faders (9,10,21) at
0 position. From this point on, either with a spectrum analyser or by ear, depending on your own taste,
all adjustments can be made.
As a general rule of thumb, it is advisable to avoid abrupt jumps in the response. It is much
better to use two or more contiguous frequency bands in order to achieve a given result.

4.3. General Level Adjustment

Any modification performed over the signal spectrum also affects the overall output level. In
order to compensate for this level change, which could overload the next steps in the audio chain, there
is the possibility to separately adjust each channel's general level by a ±12dB margin through the GAIN
controls (1,5) (the QEM30-1 has only got one GAIN control (26) because it is a mono unit).
By using the FLAT switches, it is possible to verify if the modifications performed are the
desired or right ones; by using them you bypass the equalizer operation (see 4.1).
Taking the original, unequalized, signal as a reference, you can adjust the overall output level
and avoid the risk of saturation in other elements of your equipment.
The QEM30-1 has also got a high-pass and low-pass tunable filters section. In order for these
to work, the FILTERS switch (25) must be pushed on. At this point, the LED on the right side (24) will
light up, indicating that the filters are into operation.
The LO-CUT filter (or high-pass filter) allows to cut or bypass low frequencies of the signal.
With this control (23) it is possible to simulate a "rumble" filter.
The HI-CUT filter (or low-pass filter) performs the reverse effect; that is, it allows to cut high
frequencies of the signal. With this control (22), a "scratch" filter can be simulated. By placing both filters
at their maximum band cuts, we would obtain the sound effect of a telephone line.

4.4. Clipping Indicators

This indicator is physically placed just over the FLAT LED (4,8,29) and it is marked as CLIP
(3,7,28). It will light up when the output signal is 3dB below clipping (+17dBV/600Ω). If, during the usual
equalizer operation, this indicator remains lighting up for a long time, it means we are producing a

distortion on the output signal.

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5. CONSIDERATIONS

5.1. Ground Loops

We must try for the different mechanical and electrical grounds, as well as the chassis and
connections grounds arriving to the equalizer, to be independent from each other.
Ground loops can be easily detected through a low frequency hum noise (50Hz). Depending
on the level of this noise, it can interfere on the music quality.
The LINK switch (16) separates the mechanical ground from the electrical one in the unit, so ­in some cases- this can help you cancel the ground loop.

5.2. Audio connections

Usually, many people do not care about the cables themselves. Many times, because of a
bad connection or bad quality cables, there can be important problems during the music reproduction.

5.3. Background noise

Using active circuitry can mean, depending on the actual configuration, a high noise level.
QEM equalizers have been designed to produce the lowest noise level. Apart from the equalizer's
electronics, noise level will directly depend on the right installation and use of the equalizer.
For instance, if high frequency controls are highly boosted, noise level from the connected
devices at the QEM's inputs, as well as the unit circuitry's noise level, is also boosted or increased.

5.4. Cleaning

The control panel must not be cleaned with any dissolvent, abrasive or petroleum
derivated substance else paint and silk-printing could be damaged.
Whenever cleaning should be necessary use a soft cloth slightly wet with water and
neutral liquid soap. Be careful that no liquid gets into the unit. Never use sharp or erosive objects to
scratch the control panel.

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MANUAL DE INSTRUCCIONES QEM16-2/30-1

1. NOTA IMPORTANTE 09

1.1. Precauciones 09

2. INTRODUCCIÓN 09

3. INSTALACIÓN 10

3.1. Ubicación y montaje 10

3.2. Conexionado 10

4. OPERACIÓN Y USO 11

4.1. Puesta en marcha 11

4.2. Ajuste de niveles 12

4.3. Ajuste nivel general 12

4.4. Indicador de recorte de salida 12

5. CONSIDERACIONES 12

5.1. Bucles de masa 12

5.2. Conexiones de audio 12

5.3. Ruido de fondo 13

5.4. Limpieza 13

6. CARACTERÍSTICAS TÉCNICAS 25

7. DIAGRAMAS 26

7.1. Lista de funciones 26

7.2. Diagrama de funciones 28

7.3. Diagrama de bloques 29

Todos los datos están sujetos a variación debida a tolerancias de producción. ECLER S.A. se reserva el derecho de
realizar cambios o mejoras en la fabricación o diseño que pudieran afectar las especificaciones.

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1. NOTA IMPORTANTE

Enhorabuena. Vd posee el resultado de un cuidado diseño y de una esmerada fabricación.
Agradecemos su confianza por haber elegido nuestro ecualizador QEM16-2 / QEM30-1.
Para conseguir la máxima operatividad del aparato y su máximo rendimiento, es MUY
IMPORTANTE antes de su conexión, leer detenidamente y tener presentes las consideraciones que en
este manual se especifican.
Para garantizar el óptimo funcionamiento de este aparato, recomendamos que su
mantenimiento debe ser realizado por nuestros Servicios Técnicos.

1.1. Precauciones
Este aparato debe ser conectado a tierra mediante su cable de alimentación.

No exponga el aparato a la caída de agua o salpicaduras, no ponga encima objetos con
líquido ni fuentes de llama desnuda, como velas.

En caso de requerir alguna intervención y/o conexión desconexión del aparato debe desconectarse
previamente de la alimentación.
En el interior del aparato no existen elementos manipulables por el usuario.

2. INTRODUCCIÓN

Los ecualizadores QEM16-2 y QEM30-1 están concebidos especialmente para las
aplicaciones en el campo profesional. Así pues, podrá ser instalado perfectamente en las
sonorizaciones en directo, estudios de grabación, estudios de radio y televisión, discotecas, salas de
fiestas, pubs, disco bares. También es adecuado para los entusiastas de la Alta Fidelidad iniciados ya
en el empleo de aparatos profesionales.
Los QEM16-2 y QEM30-1 de segunda generación son una evolución de los QEM16-2 y
QEM30-1 de primera generación.
Los ecualizadores QEM de Q constante son un sólido paso al frente en la mejora y
modernización de las unidades de ecualización.

¿Que es la Q constante?
Los sistemas de Q constante independizan el ancho de la banda del filtro de la ganancia que

hayamos seleccionado. Es decir, la selectividad de la ecualización no varia en función de la ganancia
que se aplica sobre cada banda. En los sistemas tradicionales de ecualización gráfica a medida que se
disminuye la ganancia de la banda, el ancho del filtro -su factor Q- aumenta, con lo cual su selectividad
disminuye.
El QEM16-2 consta de 16 bandas por canal (9-10), según normalización ISO, con posibilidad
de variación en ±12dB en cada una de ellas. Incorpora además potenciómetros deslizantes de
ganancia general por canal (1,5) e indicadores de recorte (3,7) (CLIP).
Dispone también de un filtro conmutable (20) para recortar las frecuencias por debajo de
25Hz.