EM Acoustics S-48 Operational manual

S-48 Subwoofer
Product User Manual
v2 November 2019
LOUDSPEAKERS REDEFINED

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Contents
DECLARATION OF CONFORMITY ................................................................................................................4!
1.0 - Introduction ............................................................................................................................................. 5!
Unpacking.......................................................................................................................................................5!
2.0 – S-48 Subwoofer .....................................................................................................................................6!
S-48.................................................................................................................................................................. 6!
3.0 – Simulation................................................................................................................................................. 7!
Ease Focus 3 ................................................................................................................................................. 7!
4.0 - Safety Considerations..........................................................................................................................8!
General Considerations in use................................................................................................................8!
Personal Injury.........................................................................................................................................8!
Ground Stacking......................................................................................................................................8!
Rigging and Suspension.......................................................................................................................9!
Material Damage from Magnetism ...................................................................................................9!
5.0 – Rigging & Mounting Options .......................................................................................................... 10!
5.1 – S-48 Cabinet Hardware Overview ........................................................................................... 10!
5.2 – Stacking S-48 subwoofers.......................................................................................................... 11!
5.4 – Flying the S-48 subwoofer......................................................................................................... 11!
6.0 – Powering the System........................................................................................................................ 12!
6.1 - Amplifier and Processing Requirements............................................................................... 12!
6.1.1 - Connections............................................................................................................................. 12!
6.1.2 - Connector Options................................................................................................................. 12!
6.1.3 – Amplifier Requirements ...................................................................................................... 13!
6.1.4 – Processing Requirements................................................................................................... 13!
6.2 - Presets and Settings .................................................................................................................... 14!
6.2.1 – Standard S-48 Preset........................................................................................................... 14!
6.2.2 - Geometric Delay..................................................................................................................... 14!
6.2.3 - Applying EQ.............................................................................................................................. 14!
6.3 - Use with the DQ Series Advanced System Amplifiers ..................................................... 15!
6.3.1 - Connections............................................................................................................................. 15!
6.3.2 - Preset Recall............................................................................................................................ 15!
6.4 - System Connectivity..................................................................................................................... 16!
6.4.1 - Cable Length and Specification........................................................................................ 16!

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6.4.2 – Crossover Cable Use ............................................................................................................. 16!
7.0 – Servicing Information........................................................................................................................ 17!
7.1 – S-48: Removing the grilles........................................................................................................ 17!
7.2 – S-48: Removing the front drive units.................................................................................... 18!
7.3 – S-48: Removing the rear drive units...................................................................................... 19!
Appendix A – Technical Specifications.................................................................................................. 21!
S-48 compound isobaric subwoofer.................................................................................................. 21!
Appendix C – Spare Parts List ................................................................................................................... 23!
Appendix D – Warranty Information ....................................................................................................... 24!
Limited Warranty ................................................................................................................................. 24!
Warranty Coverage ............................................................................................................................. 24!
Returning your EM Acoustics loudspeaker................................................................................. 24!

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DECLARATION OF CONFORMITY
The products contained within this manual conform to the
requirements of the EMC Directive 89/336/EEC, amended by
92/31/EEC and to the requirements of the Low Voltage Directive
73/23/EEC amended by 93/68/EEC.
EMC Emission EN55103-1:1996
Immunity EN55103-2:1996
Electrical Safety EN60065:1993
RECYCLING
This product and its packaging constitute the applicable product according
to the WEEE directive. Please ensure that at the end of the working life of
this product, it is disposed of sensibly in accordance with local and national
recycling regulations. The packaging supplied with this product is
recyclable. Please retain all packaging, however if disposing of this
packaging please ensure that you comply with local recycling regulations.
These products also all comply to the RoHS Directive 2002/95/EC.

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1.0 - Introduction
Thank you for purchasing the S-48 subwoofer from EM Acoustics. This product has been
designed and rigorously tested to give you the utmost in sonic performance and many
years of reliable, trouble-free operation. Please take the time to read this user manual
thoroughly to ensure you get the best performance from your system and to ensure you
set it up correctly and safely. If you have any questions or are in any doubt whatsoever
about any aspect of your new product, please do not hesitate to contact us directly or your
local EM Acoustics representative.
The S-48 is a compact compound isobaric subwoofer, intended for a wide variety of low
frequency applications in small installation. The S-48 is equally at home in cafes and bars
or museums and themed attractions – anywhere where cinematic low frequency is required
in a very compact footprint. Four high-excursion 8” drive units allow a surprising amount
of low frequency extension from a compact and lightweight cabinet.
This manual contains all the information you should need on topics of set up, amplifier
connection and basic service. If you feel we have missed anything, or you have a question
not covered by this manual, please visit our website www.emacoustics.co.uk and send us
a message or give us a call – we’re only too happy to help.
Unpacking
Please take care when unpacking your loudspeaker system. Once unpacked, please inspect
each enclosure thoroughly for any transit damage and in the case of any damage please
notify your carrier immediately. It is the responsibility of you, the consignee, to instigate
any claim. Please retain all original packaging in case of future re-shipment.

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2.0 – S-48 Subwoofer
S-48
Low profile VLF installation subwoofer
FEATURES & BENEFITS
•Signature EM Acoustics “maximum headroom” design approach ensures
consistency of performance regardless of SPL level.
•Multiple M10 threaded flying points for temporary and permanent
installation.
•Enclosure coated with 3-step polyurethane process - ensuring the cabinets
are not only weather resistant but more resilient to impact damage.
•Optimised for installation where space is restricted.
•Single amplifier channel required.
KEY SPECIFICATIONS
!
ENCLOSURE TYPE:
DRIVE UNITS:
FREQUENCY RESPONSE:
NOMINAL DISPERSION1:
MAXIMUM SPL:
NOMINAL IMPEDANCE:
DIMENSIONS (HxWxD):
NET/SHIPPING WEIGHT:
!
!
Compound isobaric subwoofer
4 x 8” neodymium LF drive units
35Hz - 150Hz +/-3dB
omniirectional
122dB continuous, 128 dB peak
4 ohms
308 (12.1) x 530 (20.9) x 450 (17.7) mm/(ins)
22/24kg (48.4/52.8lbs)

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3.0 – Simulation
Ease Focus 3
For acoustic reasons it is advised that users familiarize themselves with Ease Focus 3 – this system
provides the user with accurate simulations for setting up S-48 subwoofers.
Ease Focus 3 can be downloaded for free from the AFMG website at http://focus.afmg.eu and is
currently available as a stand-alone application for Windows (XP or Higher) only. It can also be
downloaded directly from the EM Acoustics website with all the current product files embedded.
Tutorials for Ease Focus 3 are available from with the application itself.
For training on the design and implementation of S-48 subwoofers including the specific use of
Ease Focus 3, please contact your local distributor.

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4.0 - Safety Considerations
General Considerations in use
Loudspeaker systems are potentially dangerous objects if used incorrectly. Please ensure
that you read this section fully, and contact EM Acoustics or your local dealer should you
be in any doubt over correct operation procedures.
Personal Injury
Never stand in the immediate vicinity of loudspeakers when in use at high level.
Professional loudspeaker systems are capable of producing sound pressure levels which
can cause permanent damage to human hearing. Levels in excess of 90dB can cause
hearing damage if people are exposed to them over a long period of time, so care and
attention must be used for both staff and audience members.
When deploying loudspeaker systems on the ground or when flown, please take careful
note of the following important safety considerations:
• Only use accessories and flying hardware supplied or approved by EM Acoustics for
flying or transporting loudspeaker systems. Pay close attention to specific
instructions, especially those considering maximum load capabilities as detailed in
the appropriate user manuals or on the legend labels on the accessories
themselves.
• Ensure all additional accessories, fasteners and secondary safeties are of an
appropriate size, working load limit and safety factor.
• All loudspeakers and accessories should be regularly inspected for signs of wear
and tear, and any damaged parts should be replaced.
• All load bearing parts and assembly bolts on accessories should be regularly
checked to ensure they are tight and not worn.
Ground Stacking
• Ensure that the floor or stage surface can withstand the weight of the system.
• Wherever possible, avoid high stacks and use ratchet straps to secure loudspeakers
together. Please also remember that vibrations from subwoofer systems can shake
other loudspeakers out of place, which may present a toppling hazard. The use of
ratchet straps and non-slip material is recommended to prevent this.

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Rigging and Suspension
Please see Chapter 5 for further information on the detailed rigging options for your
loudspeaker system.
WARNING: The overhead suspension of loudspeakers is a very serious issue with
potentially lethal consequences should anything go wrong. Rigging should only be
carried out by experienced personnel following safe working practice. Should you be
in any doubt whatsoever, please contact your local dealer who will be able to refer you
to a suitable rigging company.
Material Damage from Magnetism
Loudspeakers produce a static magnetic field at all times – even when not in use. Certain
devices are susceptible to external magnetism, and as such a safe distance should be
maintained to prevent damage. It is recommended that a safe distance of 0.5m (1.5ft) is
maintained from loudspeakers when stored, transported and in use, from devices such as
computer hard drives, magnetic media, bank cards to remove the risk of corruption. Larger
distances may be required for some older cathode ray tube displays.

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5.0 – Rigging & Mounting Options
5.1 – S-48 Cabinet Hardware Overview
[1]
[2]
1
M10 threaded flying point
2
Rear access door
[1]

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5.2 – Stacking S-48 subwoofers
The S-48 is not directly intended to be stacked, as it is envisaged that they would be used
in distributed systems.Should stacks be required, ensure they are secured with straps or
similar.
5.4 – Flying the S-48 subwoofer
The S-48 has a total of 16 M10 threaded fittings internal to the cabinet woodwork – each
one has an M10 countersunk socket bolt fitted in the factory. Various methods for
installation can be used – from forged shoulder eyebolts and steel wires to hook clamps.
Any of the S-48 points can be used for suspension, however due to the location of the
points and the location of the Centre of Gravity, four points are needed to ensure the S-48
sits straight and level.
Always ensure that a secondary safety is used when suspending any loudspeaker.
Step 1.
Using a 6mm Allen key, remove the relevant
countersunk M10 bolts on the cabinet where you will be
attaching your chosen suspension method.
Step 2.
Secure your chosen attachment method to the
loudspeaker. Ensure all fittings are tight before
suspending the loudspeaker.

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6.0 – Powering the System
The S-48 subwoofer can be powered from any amplifier & DSP combinations with the
relevant high & low pass filter, and limiter settings.However, due to the self-contained
nature of the package, the use of DQ Series advanced system amplifiers is highly
recommended. The use of DQ Series amplifiers provides a neat and flexible system that
will encompass all requirements for the system to function correctly, as well as providing
user control for room EQ and system alignment.
6.1 - Amplifier and Processing Requirements
6.1.1 - Connections
The S-48 requires only a single amplifier channel. Inputs to the S-48 enclosure are on
Neutrik SpeakON NL4 as illustrated below.
Two-core cable should be used for connecting S-48 subwoofers, and the connections are
as follows:
SpeakON connection 1+ 1- 2+ 2-
Drive unit connection LF + LF - Link Through Link Through
6.1.2 - Connector Options
The S-48 is supplied as standard with two NL4 connectors. For more demanding
environments, S-48 subwoofers can be supplied with other options by special order –
please contact EM Acoustics to discuss your requirement.

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6.1.3 – Amplifier Requirements
The S-48 is a powerful subwoofer, making use of some of the most advanced drive units
available in the industry today. It is good practice to ensure that your amplifier can deliver
at least double the RMS power handling of the loudspeaker to ensure full headroom, and
as such the amplifier requirement is:
Product RMS Power Handling Recommended Min. Amplifier Power
S-48 600W @ 4 ohms 1200W @ 4 ohms
A loudspeaker is far more likely to be damaged by an under-powered amplifier working
too hard, than an over-powered amplifier working well within its limits.
All of the DQ Series advanced system amplifiers can be used to power the S-48.
The following table shows the maximum number of S-48 that can be connected per
channel on the various different amplifiers:
Amplifier Max S-12 per channel
DQ6 1
DQ10 2
DQ20 4
6.1.4 – Processing Requirements
The S-48 requires active high and low pass filters, and appropriate limiter settings. If not
using DQ Series amplifiers, or the DSC48 Digital System Controller, then a suitable DSP
system must be used in conjunction with your S-48 to prevent damage to the subwoofer.
Check the EM Acoustics website for the most up-to-date DSP settings for the S-48.

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6.2 - Presets and Settings
6.2.1 – Standard S-48 Preset
When used with a DQ Series amplifier S-48 subwoofers require only a single amplifier
channel, and as such the preset recalled will only require one output from your DQ Series
amplifier.
6.2.2 - Geometric Delay
Appropriate delay will need to be applied to account for physical location differences
between different elements of your system – for example time-aligning subwoofers to the
main system. The use of SMAART or similar can make this task a great deal simpler and
faster.
6.2.3 - Applying EQ
The presets are intended to be a starting point for your system and will almost certainly
require tuning on-site dependent on room characteristics, the rest of your system design
and the system voicing you are aiming for. The S-48 is designed with a significant amount
of system headroom, so applying EQ is perfectly acceptable.

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The four amplifier channels appear on four
speakON connectors on the rear of the DQ
Series amplifiers. S-48 subwoofers require
one amplifier channel.
6.3 - Use with the DQ Series Advanced System Amplifiers
The S-48 will perform best when using DQ Series advanced system amplifiers, as not only are they
state-of-the-art amplifiers, but the onboard DSP provides appropriate high/low pass filter settings
and limiters to get the best from your subwoofers. Please refer to the DQ Series User Manual for
detailed information on using the amplifiers and the System Engineer software.
6.3.1 - Connections
6.3.2 - Preset Recall
The S-48 preset is pre-installed on the DQ amplifiers, and as such can be used following
the normal preset recall procedure. The presets available are:
S-48.Sub Standard S-48 subwoofer preset
As mentioned above, these presets are intended to be a starting point and additional work
may be required depending on the venue, the style of content and the end result you are
looking for.

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4-core cable from amplifier to subwoofer.
Signal for subwoofer on pins 1+/1-, signal fullrange
loudspeaker on pins 2+/2-.
4-core “crossover” cable wired as detailed below used to link
between subwoofer and fullrange loudspeaker. This will
ensure the fullrange loudspeaker is fed from the signal carried
on pins 2+/2- of the original cable
6.4 - System Connectivity
6.4.1 - Cable Length and Specification
All cables add to the system impedance, and as such careful selection is required depending on your
amplifier setup and overall system impedance. Cables with a cross sectional area of less than
2.5mm2should not be used. Recommended maximum cable lengths are given below:
Conductor Area Maximum Recommended Cable Length
2 ohms 4 ohms 8 ohms
2.5mm2(14 AWG) 15m 30m 60m
4.0mm2(12 AWG) 20m 40m 80m
6.0mm2(10 AWG) 30m 60m 120m
6.4.2 – Crossover Cable Use
The use of a pin-swap or “crossover” cable can allow for neater cable solutions when
sending different amplifier signals to the same location. Because pins 2+/2- are linked
through inside all EM Acoustics loudspeakers, using a 4-core cable to one loudspeaker
(carrying two different signals) allows a crossover cable to be used to link out of the first
loudspeaker into another, thereby feeding it from a separate signal.
Crossover cable specifications
Connector A Pin Connector B Pin
1+ 2+
1- 2-
2+ 1+
2- 1-

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M6x30
countersunk socket screws
7.0 – Servicing Information
All S-48 components can be removed for service purposes if required, using the minimum of tools.
7.1 – S-48: Removing the grilles
TOOLS REQUIRED: 4mm Allen key
1. Lie the enclosure on its’ back and remove the eight M6x30 countersunk socket screws using a 4mm
Allen key, and then lift the grille clear of the cabinet.
2. To replace the grille, position the grilles on the front of the S-48 (logo badge should be in the bottom
left hand corner) and ensure the threaded fittings on the grille are lined up with the mounting holes.
Replace each of the eight M6x30 countersunk bolts and ensure all machine screws are started in their
threads before beginning to tighten. Ensure they are all tightened evenly so that the grille sits
straight and flat and does not rattle.

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M6 Nyloc Nuts
M6 Nyloc Nuts
7.2 – S-48: Removing the front drive units
TOOLS REQUIRED: 13mm socket
1. Complete step 7.1 above to remove the grille.
2. Using a 13mm socket, remove the eight M6 Nyloc nuts that secure each of the drive units. Ensure
that you remove the flat washers as well as the nuts before you remove the drive unit.
3. Disconnect the cables before attempting to remove the drive unit – please take careful note of the
reversed polarity for reconnection (black stripe cable to positive, white cable to negative).
4. To replace the drive unit, carefully sit the drive unit back over to the protruding bolts with the
terminals toward the cable protruding from the baffle. Reconnect the cables to the drive unit (note
the white cable goes to the negative (black) terminal, and the black stripe cable goes to the positive
(red) terminal on the drive unit).
5. Replace the M6 Nyloc nuts and flat washers over each protruding stud (washer between the nut and
the drive unit chassis), and ensure all nuts are started in their threads before tightening. Tighten
opposing nuts, working around the drive unit until all nuts are appropriately tightened.
6. Replace the grille as described above.

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M6x50 hex-head setscrews
M6x50 hex-head setscrews
7.3 – S-48: Removing the rear drive units
TOOLS REQUIRED: 5mm Allen Key & 13mm socket
1. Complete steps 7.1 & 7.2 above to remove the grilles and the front drive unit (s).
2. Using a 5mm Allen key, remove the ten M6x30 socket cap
machine screws securing the rear door. Ensure that you
collect both the spring and flat washers from each bolt
recess before proceeding further. Disconnect the main
cables from the input connector PCB to set the rear door to
one side.
3. Using a 13mm socket, remove the eight M6x50 hex-head set screws that secure each of the drive
units. Ensure that you remove the spring and flat washers as well as the set screws before you
remove the drive unit.
4. Disconnect the cables before attempting to remove the drive unit – please take careful note of the
polarity for reconnection (red cable to positive, black cable to negative).

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5. To replace the drive unit, carefully sit the drive unit back in place with the terminals toward the cable
protruding from the baffle. Ensure all the mounting holes line up properly. Replace the M6x50 set
screws and washers in each hole, and ensure all bolts are started in their threads before tightening.
Tighten opposing bolts, working around the drive unit until all bolts are appropriately tightened.
6. Reconnect the cables to the drive unit (note the white cable goes to the positive (red) terminal, and
the black cable goes to the negative (black) terminal on the drive unit).
7. Reconnect the main cables to the input connector PCB (red to 1+, black to 1-) and re-seat the rear
door in place. Replace the M6 socket cap screws in each bolt hole, ensuring the washers are replaced
correctly (flat washer in contact with the door, spring washer between flat washer and the bolt head).
8. Replace the front drive unit(s) as described in 7.2 above.
9. Replace the grille as described in 7.1 above.