BHI NEMS Specification sheet

Page 1NEMS operating manual
Noise Eliminating Marine
Speaker
1077-102D Issue A
bhibhi
bhibhi
bhi
Operation and Installation Manual
NEMS

Page 2 NEMS operating manual
No user serviceable parts inside. Warranty void if speaker
opened.
Prolonged exposure to high sound levels may lead to hearing
damage. bhi accept no responsibility to damage to hearing
through incorrect operation of this equipment.
Although this product is waterproof it isn’t designed to be
submerged.
Copyright
Thispublication,includingallphotographsandillustrations
is protected under international copyright laws, with all
rights reserved. Neither this manual, nor any of the
material within, may be copied or reproduced without the
written consent of bhi Ltd.
Disclaimer
The information in this document is subject to change
without notice. bhi Ltd. makes no representations or
warranties with respect to the contents hereof and
specifically disclaims any implied warranties of
merchantability or fitness for any particular purpose.
Furthermore, bhi Ltd. reserves the right to revise this
publication and to make changes from time to time in the
content hereof without obligation of bhi Ltd. to notify any
person of such revision or changes.
Important Information.

Page 3NEMS operating manual
1 Overview
1.1 bhi 4
1.2 Introduction 4
1.3 Audio DSP Noise cancellation 5
1.4 Unpacking 6
2 Installation
2.1 Installation overview 7
2.2 Mounting 8
2.3 Audio connection 8
2.4 Power connection 10
3.Operation
3.1 Setup and operation 11
4. Specification
4.1 Specifications 12
5. Troubleshooting
5.1 Troubleshooting guide 13
6. Other bhi products
6.1 NES10-2 dsp speaker 14
6.2 NES5 dsp speaker 14
6.3 NEIM1031 In line module 15
6.4 NEIM1031 In line module accessories 15
6.5 DSP modules 15
6.6 1042 switch box 16
6.7 Audio adapters 16
6.8 Other bhi products 17
Table of contents

Page 4 NEMS operating manual
The speaker mounts like any standard external speaker and is
powered by any 12 – 18 Vdc unregulated power source. The
speaker is fitted with a fused power lead.
The speaker is supplied with a 1.2 metre long audio lead
terminated in a 3.5mm mono jack plug.
Note:
This product is designed for speech only, and isn’t suitable for
music broadcasts, unless the noise cancellation is switched off.
1.1 bhi
bhi Ltd are specialists in the design, development and
manufactureof DigitalSignalProcessing (DSP) noise cancelling
products and other specialist electronics.
1.2 Introduction
The bhi NEMS Noise Eliminating Marine Speaker greatly
improves the clarity and intelligibility of speech in radio
communications. Itissuitableforuseinmanyapplicationswhere
high background noise and interference mean that you cannot
clearly hear what is being said. The NEMS enables the user to
listen and concentrate “stress-free”.
The NEMS is compact and easy to install. It incorporates DSP
technology and is fully adaptive to any change in noise levels
and interference, requiring no further adjustment.
When the power is switched of the NEMS’s circuitry is
disconnected and the speaker behaves as a normal extension
speaker.
1. Overview
1. Overview

Page 5NEMS operating manual
1.3 Audio DSP Noise cancellation.
The bhi DSP processes the incoming audio signal and then
differentiates the speech from the noise. The unwanted noise
and interference are then attenuated to leave only the speech.
The following diagrams are taken from actual audio signals and
illustrate how the audio signal is being processed.
Figure 1. Audio signal before processing.
Figure 2. Audio signal after processing.
Original signal.
Speech with a lot of
background noise
Speech Noise
Processed speech.
Speech with reduced
noise
1. Overview

Page 6 NEMS operating manual
1.4 Unpacking
Check that the following items are included in the package:
•NEMS Speaker complete with mounting bracket.
•Audio lead
•Customer feedback card
Please report any missing items or damage to your supplier as
soon as possible.
1. Overview

Page 7NEMS operating manual
2. Installation
2.1 Overview
The following diagrams show the main components of the
NEMS noise cancelling loudspeaker.
Noise
cancelling/power
on/off switch
Fused
power
lead
Audio
connections
(beneath cover)
Bracket
locking screw
Figure 3. NEMS features.
2. Installation.

Page 8 NEMS operating manual
2.3 Audio connection
Before fitting the audio lead, ensure that the radio has a 3.5mm
mono extension speaker socket for the NEMS to connect to. If
theradio has adifferentconnector then anadapterwill be require
(see your dealer or bhi for more information). The free end of
the lead is connected to the NEMS as shown in figure 5.
Audio
connections
(cover removed)
Fused power
lead
Mounting
bracket
Figure 4. NEMS rear view.
2.2 NEMS mounting
The NEMS needs to be mounted so that it can be connected to
a 12 - 18Vdc power source, and the radio. Locate a suitable rigid
position to mount the NEMS speaker. The NEMS is mounted by
holes in the adjustable metal bracket. The bracket swivels to
allow the NEMS to be adjusted to suit the listener.
Fix the speaker using suitable fixings (not supplied), it may be
necessary to remove the bracket to assist installation.
2. Installation.

Page 9NEMS operating manual
Figure 5. Audio connections.
Remove the audio connector cover from the rear of the speaker.
Insert the audio cable through the hole in the cover. The piano
keyconnectorsareopenedbypressingthebottomofthecoloured
lever. Insert the wires into the correct speaker connection as
shown in the above diagram. Ensure that the blade of the
connector is clamping the exposed strands of the wire and not
the insulation. Push the cover over the connections.
Run the audio cable to the radio. Ensure the radio is switched off
and connect the 3.5mm mono jack plug to the socket marked
extension speaker (using any adapter if required).
2. Installation.
Audio
Cable
Rear view
of speaker
Wiring
cover
Piano
key
connectors
Connect the Red wire to the +Ve Red connector.
Connect the white wire to the -ve Black connector.

Page 10 NEMS operating manual
2.4 Power connection
The NEMS is fitted with a fused power lead. The NEMS requires
12 - 18Vdc to operate. If the supply voltage is higher than this it
willbenecessarytouseapoweradapter(notsupplied),toconvert
the voltage to within
these limits.
The cable with the
white stripe is the
positive lead. Connect
the cable to the
power supply.
If the power lead is
shortened ensure the
fuse holder is still
connected.
Figure 6. Connection overview.
2. Installation.
Note:
If any of the cables pass through
walls, bulkheads etc. ensure that
they adequately protected
from damage. Also ensure
the wires are properly
secured and do not present
a trip hazard.
Audio lead
into
extension
speaker socket
12 - 18Vdc
white stripe = +ve
NEMS
Cover
Fuse
Radio

Page 11NEMS operating manual
3. Operation
3. Operation
3.1 Operation
The NEMS speaker provides noise cancellation when power is
appliedtothespeaker andit isswitchedon. Removingthe power,
or switching the NEMS off will remove the noise cancellation
and the speaker circuitry will be bypassed. In this mode the
speaker acts as a normal extension speaker.
To check the operation tune the radio into a band where there is
a lot of background noise (turn the squelch off). Turn on the
NEMS, the red led will illuminate in the switch.
The level of noise will drop after a short delay as the DSPadapts
to the noise present on the audio signal. Turn the switch off and
the noise will return.
If the NEMS doesn’t operate as expected the please turn to
section 5 - troubleshooting.
Note:
If a slight pop is heard when the speaker is switched on this is
nothing to worry about and is normal.
There is no need to turn the noise cancelling off if the noise
levels reduce, as the DSP is fully adaptive and will learn the new
noise conditions, and will not interfere with the audio signal.
3.2 Remote operation.
If the NEMS on/off switch is inaccessible due to the chosen
mounting position it is possible to install another switch in the
power line. Leave the NEMS power switch on, and control the
power and noise cancellation with this new switch.

Page 12 NEMS operating manual
4. Specifications
4. Specifications
4.1 ELECTRICAL CHARACTERISTICS
(Vs=16V, Tamb= 25ii
ii
iC unless otherwise stated)
Symbol Parameter Test Conditions Min. Typ. Max. Units
VsSupply voltage 12 16 18 V
PoOutput power d = 10%
f = 1KHz 12V
1.7 16V 18V
3.17 Vs
W
BFrequency response
(-3dB) Po= 1W
RL= 8W50 4300 Hz
d Distortion f = 1KHz
PO= 0.2 - 2.4W 0.8 %
RiInput resistance 21 22 23 W
TsSystem delay 26 mS
Noise reduction 20 dB
To ne re d uc tio n 2 1 d B

Page 13NEMS operating manual
5. Troubleshooting
5. Troubleshooting
No Audio
No
Yes
Check audio
connections
Switch
Radio on
Switch on
NEMS
Power LED
on? Check power
Connection
No
Switch
NEMS
off
Can
Audio be
heard now?
Radio switched
on?
Audio
Now?
Finish
Faulty
No
Yes
No
Yes
Yes
Figure 7. Fault finding chart.
No audio out from the
speaker.

Page 14 NEMS operating manual
6. Other products
6. Other products from bhi
Other noise cancellation products from bhi. Visit www.bhi-ltd.co.uk
for more information.
DSP noise cancellation built into a compact speaker
unit. the unit provides an easy to install solution to
noise reduction
Features:
•Fully adaptive noise cancellation 9 -35dB
•8 user selectable noise cancellation levels
•Mono earpiece socket
•Input sensitivity control
•Noise cancellation On/Off switch
•LED indication of power and noise cancellation
•12-24VDCoperation
•On/Off audio bypass switch.
•Greatly improved signal to noise ratio
•Easy to install with adjustable mounting bracket
•2m audio lead
•Optional extras avaiable.
6.1 NES10-2 MKII Noise Eliminating speaker.
Basic plug and go noise cancelling
speaker preset to 20dB of noise
reduction.
Features:
•Fully adaptive noise cancellation 20dB
•12-24VDCoperation
•Compact robust speaker unit.
•Greatly improved signal to noise ratio
•Easy to install with adjustable mounting bracket
•2m audio lead
6.2 NES5 Noise Eliminating speaker.

Page 15NEMS operating manual
6. Other products from bhi
6.3 NEIM1031 In-line module.
Then NEIM1031 provides a flexible solution to noise reduction. It features
bothamplifiedinputsandoutputs,alongwithline level signal
processing.Theunit also featuresanaudio bypasswhen
the unit is switched off, so there is no need to disconnect
when not in use.
6.4 NEIM1031 accessories.
6.5 DSP modules.
LSPKR
20 Watt extension
speaker for use with the
NEIM1031. Fitted with a
3.5mm mono jack plug.
1031-STAND
Clear Acrylic stand to
mount the NEIM1031.
The NEIM1031 can be
usedhorizontallyorver-
tically
DSP module range.
NEDSP1061-PCB: Low signal level module
NEDSP1061-KBD: Low signal level module
controlled by single button
keyboard.
NEDSP1062 - KBD: Amplified DSP module
controlled by a 2 button
keyboard.
NEDSP1062 - PCB: Basic amplified DSP module
Features:
•Fully adaptive noise cancellation 9 -35dB
•8 user selectable noise cancellation levels
•Mono earpiece socket
•Input sensitivity control
•Noise cancellation On/Off switch
•Line level in/out
•Input overload indication
•Power on/off with audio bypass.

Page 16 NEMS operating manual
6. Other products from bhi
Power adapters:
1030-UKPA 12V DC UK power adapter
1030-EUPA 12 VDC European adapter
1030-VEPL Fused vehicle power adapter
Audio leads:
ALD-001 1.2m 3.5mm - 3.5mm mono lead
ALD-002 2.5m 3.5mm - 3.5mm mono lead
ALD-003 phono -phono plug
ALD-004 3.5mm stereo plug - phono plug
ALD-005 3.5mm mono plug - phono plug
Audio adapters:
ADP-P001 6.35mm plug - 3.5mm mono socket
ADP-P002 6.35mm plug - 3.5mm mono socket
ADP-P003 3.5mm stereo plug - 3.5mm mono socket
ADP-P004 Phono plug - 3.5mm mono socket
ADP-P005 2.5mm mono plug - 3.5mm mono socket
ADP-P006 2.5mm stereo plug - 3.5mm mono socket
ADP-P007 6.35mm stereo plug - 3.5mm stereo socket
ADP-P008 3.5mm stereo - aircraft adapter
ADP-S001 3.5mm mono socket - 3.5mm mono plug
ADP-S002 6.35mm socket - 3.5mm mono plug
ADP-S003 6.35mm stereo socket - 3.5mm mono plug
ADP-S004 2.5mm stereo socket - 3.5mm mono plug
ADP-S005 2.5mm mono socket - 3.5mm mono plug
6.6 Switch Box
Order code: 1042 Switch Box
Need to Connect more than one
piece of equipment to your bhi Noise
Eliminating Speaker or module?
6.7 Adapters and power supplies

Page 17NEMS operating manual
6. Other products from bhi
NCH
Noise Cancelling
Headphones
These headphones feed an
inverted copy of the ambient
noise to cancel it out.
The headphones effectively
remove noise such as blower
noise, ambient noise, jet
engine noise or music from
another room.
The headphones are supplied
with an aircraft
adapter, so you can
nowlistentothefilm,
or CD player
without all the jet
engine noise.
Also supplied
with carry bag.
BBRP
Banner Badge
Applications
• ID badge
• Club badge
• Restaurants
• Receptions
• Gifts
• Stag and Hen nights
• DJs
• etc...
Get the message across
Easy to program using push
buttons on back: no cords, no
wires, no software needed.
Enteryour messageand watch
it scroll across.
What will yours say?
6.8 Other products.

Page 18 NEMS operating manual
Notes:

Page 19NEMS operating manual
Notes:

Page 20 NEMS operating manual
bhi Ltd
P.O. Box 318
Burgess Hill
West Sussex
RH15 9NR
tel: +44 (0)845 217 9926
fax: +44 (0)845 217 9936
www.bhi-ltd.co.uk
bhibhi
bhibhi
bhi
Sound Engineering Solutions
DSP Noise Cancellation
Table of contents
Other BHI Speakers manuals