PROEL ACEX2 User manual

OWNER’S MANUAL
STEREO COMPRESSOR
ACEX2

1. IMPORTANT SAFETY INSTRUCTIONS
CAUTION: To reduce the risk of electric shock do not remove cover (or back panel). No
user serviceable parts inside. Refer servicing to qualified personnel only.
WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to
rain or moisture.
This symbol is intended to alert the user of the presence of uninsulated
dangerous voltage within the product enclosure that may be of sufficient
magnitude to constitute a risk of electric shock to persons.
This symbol is intended to alert the user of the presence of important
operating and maintenance (servicing) instruction in the literature
accompanying the appliance. Please carefully read the owner’s manual.
INSTRUCTIONS:
All safety and operating instructions should be read before the product is operated.
Retain these instructions:
All safety and operating instructions should be retained for future reference.
This owner’s manual should be considered as a part of the product and it must accompany it
every time, and delivered to the new user when this product is sold. In this way the new owner will
be aware of all the installations, operating and safety instructions.
Heed all warnings:
All warnings on the product and in owner’s manual should be adhered to.
Heed all warnings.
Follow all instructions:
All operating and user’s instructions must be followed.

Sentences preceded by symbol contain important safety instruction. Please read it carefully.
DETAILED SAFETY INSTRUCTIONS.
Water and moisture:
This apparatus should not be used near water (i.e. bathtub, kitchen sink, swimming pools,
etc.)
Ventilation:
This apparatus should be placed in position that doesn’t interfere with correct ventilation. This
unit, for example, should not be placed on a bed, sofa cover o similar surfaces that could
cover ventilation openings, or placed in a built-in installation, such a bookcase or a cabinet
that could block air flow trough ventilation openings.
Heat:
This apparatus should be placed away from heat sources, like radiators, heat registers, stoves
or other products (including amplifiers) that produce heat.
Power sources:
• This apparatus should be connected only to power source type specified in this owner’s
manual or on the unit.
• If the supplied AC power cable plug is different from wall socket, please contact an
electrician to change the AC power plug.
Grounding or Polarization:
• All precautions must be observed in order to avoid grounding or polarization defeating.
• Unit metal parts are grounded through the AC power cord.
• If the AC power outlet doesn’t have grounding, consult an electrician for outlet grounding.
Power cord protection:
The power cord should be routed in a way it will not be walked on or pinched by items placed
upon or against it, paying particular attention to cords at plugs, convenience receptacles and
wall outlet.
Cleaning:
• You can clean the unit with a compressed air flow or a wet cloth.
• Don’t clean the unit using solvents like trichloroethylene, thinners, alcohol, or other fluids
with very strong volatility and flammability.
Non use periods:
The unit AC power cord should be unplugged from the outlet if it’s unused for a long period.

Objects or liquid entry inside the unit:
Be careful that no objects fall or liquid is spilled inside the unit through ventilation openings.
Safe power line use:
• Keep firmly the plug and the wall outlet while disconnecting the unit from AC power.
• If you’re not going to use the unit for a long period of time, please unplug the power cord
from AC power outlet.
• To avoid unit power cord damaging, please don’t strain the AC power cable and don’t
bundle it.
• In order to avoid unit power cord damaging, please be sure that the power cord is not
walked on or pinched by heavy objects.
Unit relocation:
Before any unit relocation please control the unit is turned off. The power cord must be
unplugged by the wall outlet, and all the connections wires should be disconnected as well.
Don’t open this unit:
Don’t attempt to open or to repair this unit by yourself. For any problem solution not described
in this owner’s manual, please refer to qualified personnel only or consult us or your National
Distributor. Any improper operation could result in fire or electric shock.
Damages requiring services:
• Don’t attempt to do operations not described in this user’s manual.
• In the following cases please refer to an authorized maintenance center or skilled
personnel:
- When the unit works improperly or it doesn’t work at all.
- If power cord or plug are damaged.
- If liquid has spilled, or objects have fallen into the unit.
- The unit has been exposed to rain.
- The unit doesn’t operate normally o it exhibits a marked change in performance.
- If the product has dropped or it has been damaged in any way.
Maintenance:
The user shouldn’t attempt maintenance operation not described in this user’s manual. Every
maintenance operation should be done by qualified personnel only.
IMPORTANT SAFETY INSTRUCTIONS:
• Install this unit following owner’s manual instructions.
• Don’t install, connect or disconnect power supply when the unit is powered, otherwise
there’s an high risk of electric shock.
• Don’t open the unit, there are no user serviceable parts inside.
• If you detect a particular smell from the unit, please turn it off immediately and disconnect
the AC power cord.
• Don’t block the unit ventilation openings.
• Avoid using this unit in overload for a long period.
• Don’t force commands (switches, controls, etc.)

• To obtain good speakers wire contacts, please tighten the screw terminals firmly.
• For safety reason, don’t defeat the grounding connection. Grounding is useful for user
safety.
• Use only connectors and accessories suggested by the manufacturer. .
• This unit should be placed in a rack (see INSTALLATION) and kept far from:
 Wet places
 Direct exposure to heat sources (like sun light)
 Non properly ventilated places
• Disconnect the power cord during storms or when the unit is not used.
• In order to prevent fire and electric shock risks, it’s necessary to keep the unit far
from sprinkling and drops. Please don’t put cups, vases or other object containing liquids
over the unit. In case of interferences from source signal, THD value will raise over 10%.
Don’t place this unit in a bookshelf o in other places with small room.
• PROEL S.P.A. is not responsible for any damage that occurs due to a wrong unit
installation.
Thank you for choosing one of Proel products, and for your confidence
towards our brand, synonymous of professionalism, accuracy, high quality
and reliability. All our products are CE approved and designed for
continuous use in professional installation systems.
Description
This unit has been designed to manage the dynamics of two audio signal
channels to be amplified.
FEATURES
• Advanced design and manufacturing accuracy.
• Compact dimensions, 1RU.
• Expander/gate section with level control and processing LED.
• Fully featured compressor section.
• Choice between automatic or manual attack/release times.
• In/out switch for compressed/not-compressed signals comparison.
• Enhancer section to recover brightness lost with compression.
• Balanced XLR and 6.3mm. (1/4”) TRS jacks input connectors.
• Balanced XLR and 6.3mm. (1/4”) TRS jacks output connectors.
• Unbalanced 6.3mm. (1/4”) TRS jacks SIDECHAIN connector.
• IEC standard AC power supply socket and AC voltage selector.
• DC 24V DC power supply terminals provided.

Front panel description
fig. 1
1. Gate/expander section THRESHOLD level.
2. Gate/expander section CLOSE LED.
3. EFFECT switch for compressor section activation.
4. Compressor section THRESHOLD level.
5. Compressor section RATIO control.
6. Compressor section ATTACK time manual control.
7. Compressor section RELEASE time manual control.
8. Selection switch to choose AUTO or manual attack/release time.
9. Compressor section OUTPUT level control.
10. CH1 & CH2 GAIN REDUCTION meters.
11. Enhancer section PROCESS control.
Rear panel description
fig. 2
1. AC IEC socket and fuse-holder.
2. AC voltage selector.
3. DC power supply terminals.
4. XLR & 6.3mm. (1/4”) TRS jack INPUT connectors.
5. XLR & 6.3mm. (1/4”) TRS jack OUTPUT connectors.
6. Unbalanced 6.3mm. (1/4”) TRS jacks SIDECHAIN connector.

Installation
1. Input/output connections.
This unit has two independent input/output channels (CH1 and CH2).
Each channel is supplied with a balanced XLR and a balanced 6.3mm
(1/4”) TRS jack. The TRS jacks can be used in an unbalanced way by
just connecting tip and sleeve (TS connection) only.

2. SIDECHAIN connection.
This unit has one unbalanced 6.3mm (1/4”) TRS jack to be used as
insert connector to allow an external control, e.g. an equalizer for
frequency conscious operation. The TRS jack must be wired as follows:
Tip to receive external equipment signal, Ring to send unit output
signal, Sleeve for both signals grounding. To do this kind of connection
you need a “Y” cable that splits the ACEX2 TRS connector into two TS
connectors.
3. Power supply connections
• IEC standard AC power supply socket (fig. 2, ref. 1) has a fuse-
holder receptacle.
Warning: In case of fuse substitution, please use a fuse of the
same type and value.
• The operating voltage of the unit (110~120 V or 220~240 V)
depends on the way the dedicated switch is set.
• For 24V DC operations this unit is supplied with appropriate
terminals (fig. 2, ref. 3).
Operations
a. To turn on the unit press the POWER switch ON.
b. To turn off the unit press the POWER switch OFF.
c. Gate/expander section setting. The THRESHOLD (fig. 1, ref. 1)
control adjusts the level within OFF/+10dB range. Signals under the set
value will be cut, allowing noise and unwanted signals reduction, unless
when the THRESHOLD is set OFF. To better understand the way this
section works, please do some tests with noisy signals searching for the
right THRESHOLD setting, with compressor section OUT and enhancer
section control OFF. The CLOSE LED (fig. 1, ref. 2) will indicate this
section operation.
d. Compressor section setting. The EFFECT (fig. 1, ref. 3) switch turns
IN/OUT (activates/deactivates) the compressor section, it’s useful to do
comparisons between the compressed/original signal characteristics.
The THRESHOLD (fig. 1, ref. 4) control adjusts the threshold point of
compressor section within -40/+20dB range. Compression will occur
with signals over threshold value, without affecting less loud signals.
The RATIO (fig. 1, ref. 5) control sets the compression ratio of signals

over the threshold. Try to set THRESHOLD and RATIO with AUTO
ATTACK RELEASE times, searching for the best values, a good
starting point for paging is with threshold around –20dB with a ratio
around 2:1, then do some tests to find the better settings for your
application. ATTACK (fig. 1, ref. 6) sets the response time of the
compressor section to incoming signals over THRESHOLD level, this
control can be adjusted in 0.1-200ms range. RELEASE (fig. 1, ref. 7)
sets the response time when the signal falls under the THRESHOLD
level, this control can be adjusted in 0.05-4sec. range. The AUTO
switch (fig. 1, ref. 8) disables the manual settings of ATTACK and
RELEASE times, so the compressor behaviour will be program
dependent. The OUTPUT level (fig. 1, ref. 9) has a range adjustment
from –20dB up to 20dB. This control can be used to set the level in the
most suitable way for your application and/or recover gain loss due to
compressor activity. You can visually control the compressor gain
reduction for each channel by GAIN REDUCTION meters (fig. 1, ref.
10).
e. Enhancer section setting. This section has just the PROCESS (fig. 1,
ref. 11) control, with range from OFF to 6. This control is useful to
recover signal brightness lost during compression activity, set this
control by your own taste and/or acoustic environment response.
Please note that this section is active only when compression section is
active too.
f. We suggest you to do careful settings during system installation, one
section a time, not more sections simultaneously. Then do some tests
with gate + compressor and compressor + enhancer with small
adjustments, then turn all sections on… you’re ready! We recommend
you to write the settings in a protected file and to find a unit position that
will allow to not authorized personnel to change settings.

Technical specifications
Model ACEX2
Input connectors Active balanced XLR and 6,3 mm (1/4”) TRS jack
Input impedance 60-kOhm balanced
Max input level +21dBu balanced and unbalanced
Output connectors Active balanced XLR and 6,3 mm (1/4”) TRS jack
Output impedance 40-Ohm balanced
Max output level +21dBu balanced and unbalanced
Frequency response 20Hz-20KHz. +0db, -1dB
T.H.D. + N < 0.05 % (@ 1kHz, +4dB)
I.M.D. (SMPTE) 0.01% (@ +10dBu)
Signal to noise ratio > -93dB (@ unity gain)
Signal to noise ratio > -97dB (all sections off)
Crosstalk > -85dB (@ 20kHz)
AC power supply 115 V / 230 V – 60Hz / 50Hz
DC power supply 24V
Dimensions (WxHxD) 483mm x 44mm x 217mm - 19" x 8.54" x 1.75"
Weight 3 Kg – 6.61lbs

This unit complies with CE Directive 89/336/CEE (Electromagnetic compatibility)
and following modifications 92/31/CEE e 93/68/CEE, by European Specifications:
EN 50082-1:1997, EN 55013:1990, EN 55020:1994
This unit complies with CE Directive 73/23/CEE (Low Voltage)
and following modifications 93/68/CEE, by European Specifications:
EN 60065:1998
Disclaimer
Proel SpA pursue a policy of continuous research and development. Proel SpA reserve the right to modify
p
roduct circuitry and appearance at any moment, without prior notice..

PROEL S.p.A.
(World Headquarters - Factory)
Via alla Ruenia 37/43
64027 Sant’Omero (Te) – Italy
Tel: [phone]
Fax: [phone]
E-mail: [email protected]
installation.proelgroup.com