Norsonic Nor250 Operator's manual

Nor250
Hemi-dodecahedron Loudspeaker
Nor270
Dodecahedron Loudspeaker
Nor280
Power Amplifi er
user
documentation
noise excitation
equipment
Im280_1Ed1R1En

2
Noise Excitation Equipment – February 2007 Edition
Nor250/Nor270/Nor280 User Guide
Im280_1Ed1R1En
Norsonic is a registered trademark of Norsonic AS. All
other brand or product names are trademarks or registered
trademarks of their respective companies.
Every effort has been made to supply complete and accurate
information. However, Norsonic AS assumes no responsi-
bility for the use of – nor for the consequential damages
of the use of – this information and/or the instrumentation
described herein. Furthermore Norsonic AS assumes no
responsibility for any infringement of the intellectual property
rights of third parties, wherever applicable, which would
result from such use.
Norsonic AS reserves the right to amend any of the informa-
tion given in this manual in order to take account of new
developments.
If you wish to communicate with us, our address is:
Norsonic AS, P.O. Box 24, N-3421 Lierskogen, Norway
Tel: [phone], Fax: [phone]
Find us on the web:
www.norsonic.com
e-mail: [email protected]
Copyright © Norsonic AS 1998–2005
All rights reserved

0
4 Dodecahedron Loudspeakers
Nor270 & Nor270H
0
6 Hemi-dodecahedron Loudspeaker
Nor250
0
8 Signal Sockets
0
8 The Nor280 Power Amplifi er
11 Specifi cations
Noise Excitation Systems
Contents
10'4"
16'8"

4
Dodecahedron Loudspeakers Nor-270 & Nor-270H
A multitude of applications within the fi eld
of building acoustics requires the use of iso-
tropic sound sources. The loudspeakers Nor-
270/270H have been designed to comply with
these requirements and satisfi es the ISO 140-
3 Annex C (Laboratory measurements) and
ISO 140-4 Annex A (Field measurements).
The difference between the two lies in the
sound power output level which is 120dB for
Nor270 and 123dB for Nor270H.
The speakers come with a tripod ensuring
correct placement so that unwanted refl ec-
tions and structural transmissions are kept
at a minimum.
The rugged speaker cabinets are made of fi bre
glass and the speaker elements themselves
are protected by grids to further enhance
the concept.
Connecting to a Power Amplifi er
Verify that your amplifi er has been designed
to match the speaker. The Nor270/270H are
available in several impedance fl avours – the
impedance applicable to yours is stated on
the speaker cabinet unless they are of the
standard version
Both the Nor270 and 270H have been de-
signed for continuous operation for more
than one hour at full power..
The speaker input socket accepts Speakon
NL4FC connectors – see overleaf for more
on this.
A mounting rod (Ø=1”) makes tripod mount-
ing easy and safe.
Specifi cations
Nor270 Nor270H
Sound power output (Lin.): 120 dB 123 dB
Speakers: 12×6.5” 12×6.5”
Power rating (max.): 250 W
RMS
400 W
RMS
Impedance: 6
Ω
2.7
Ω
Other impedance values also available, contact factory for details
Diameter: 450mm 450mm
Weight: 12.5kg 20kg
Tripod mounting-rod diameter 1” 1”
Accessories included: Speakon NL4FC plug; 5m assembled cable,
if ordered with Nor-280
Directivity of the Nor-270 according to ISO 140: maximum deviation from mean for gliding 30°
arc. Upper and lower curves are the ISO 140 tolerances.
-10
-8
-6
-4
-2
0
2
4
6
8
10
100
125
160
200
250
315
400
500
630
800
1
k
1.25k
1.6k
2
k
2.5k
3.15k
4
k
5
k
Max.Difference Leq,360 - Leq,30 (dB)

5
The sound power level vs. frequency of the
loudspeakers Nor270 (upper graph) and
Nor270H (lower graph) when used with
power amplifi er Nor280.
The amplifi er has an equalisation circuitry de-
signed to boost the high and low frequencies
to improve the system performance when used
for building acoustics. Both graphs include the
sound power spectrum with and without the
effects of the equalisation circuitry.
The loudspeaker Nor-270/270H
70
80
90
100
110
120
130
5
0
6
3
8
0
100
125
160
200
250
315
400
500
630
800
1k
1.25k
1.6k
2k
2.5k
3.15k
4k
5k
L-netw
Sound Power Level L
w
[dB]
270 + 260 + equal.
270 + 260
70
80
90
100
110
120
130
5
0
6
3
8
0
100
125
160
200
250
315
400
500
630
800
1k
1.25k
1.6k
2k
2.5k
3.15k
4k
5k
L-netw
Sound Power Level Lw [dB]
270H + 260H + equal.
270H + 260H
270H+280+equal
270H+280
270+280+equal
270+280

6
Hemi-dodecahedron Loudspeaker Nor250
A powerful sound source designed for build-
ing acoustics measurements per ISO 140-4
Annex A (Field measurements), ISO 354,
ASTM E-90, E-336. The source provides
uniform sound radiation. When used with
the power amplifi er Nor280 the high sound
power level ensures accurate descriptors in
measurement conditions that include high
background levels, high sound insulation
properties and large room volumes.
The Nor280 power amplifi er comes with an
equalisation circuitry that can be switched
on or off, designed to boost the high and
low frequencies to improve the Nor250/260
system performance.
The loudspeaker is designed to operate at
full power for more than one hour continu-
ously.
Specifi cations
Sound power output:
Using the
Nor280 with pink noise, and
equalisation: 120 dB (Lin)
Power rating:
250 W
RMS
(maximum)
Impedance:
48
Ω
, 12
Ω
, 5.4
Ω
(the latter
matches Nor280), specify on order
Dimensions:
415 × 235 [mm] (d × h)
Speakers:
6 × 6.5”
Weight
: 11.7 kg (26 lbs.)
Accessories included:
Speakon NL4FC
plug; 5m assembled cable, if ordered
with Nor280
Accessories available:
Nor1327A
carrying case for Nor250 speaker and
Nor280 amplifi er
The Nor250 Quick Lock connector…
1. Insert
2. Turn right (locks
automatically), con-
tact is made after
turning
3. Pull lever
4. Turn left
5. Pull plugg
Insert…
Remove…
Strain relief bushing
– don’t loosen!

7
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























Typical third octave band noise
directivity pattern for 100 Hz,
630 Hz and 3 150 Hz centre
frequencies in the vertical plane
Typical Nor250 third octave band frequency
response when fed with pink noise from the
Nor280 power amplifi er, with and without the
equalisation circuitry activated. Equalisation is
used to boost the spectrum extremes for better
system performance when used for building
acoustics
Typical third octave band noise
directivity pattern for 100 Hz,
630 Hz and 3 150 Hz centre
frequencies in the horizontal
plane, measured at 15° eleva-
tion
If you need to assemble cable and the Quick
Lock connector, connect as follows:
1+ and 2+ are to be connected together.
1– and 2– are to be connected together.
70
80
90
100
110
120
130
5
0
6
3
8
0
100
125
160
200
250
315
400
500
630
800
1k
1.25k
1.6k
2k
2.5k
3.15k
4k
5k
L-netw
Sound Power Level L
w
[dB]
250 + 260 + equal.
250 + 260
250+280+equal
250+280

8
The Nor280 Power Amplifi er
The Nor280 is a rugged, lightweight and
powerful class D amplifier. It is specially
designed for building acoustics applications.
Its output stage is designed to drive almost
any type of load.
The amplifi er comes with a built in noise
generator as standard and as an option it
can be fi tted with a wireless remote control
for switching the signal on/off.
To optimise the power where it is needed a
unique built in equalization network com-
pensates for the falling frequency response of
the speaker system in both the low and high
frequency areas. The equalisation network
also ensures that it is less than 5 dB differ-
ence between two adjacent 1/3 octave bands.
A part of the amplifi ers input stage is a high
pass fi lter that removes low frequency signals
that lie below the required frequency range
for building acoustic measurements and a low
pass fi lter that removes all frequencies above
12kHz. This feature protects the speakers
from distortion and concentrates power into
the frequency bands where it is needed.
The output of the amplifi er is short circuit
protected and an automatic system will guard
against overheating and high signal voltages
through the input. The built in cooling fan is
normally not required but will run at high
room temperatures or during prolonged use
of the amplifi er at full power . It will how-
ever, immediately switch off when the input
signal goes off; this feature makes the unit
well suited to reverberation measurements
in areas of low background noise.
Front panel layout
The front panel consist of a source selector,
a level attenuator, a switch selecting the
equaliser on/off, input and output connectors,
mains connector, mains fuse and switch, an
error indicator and a remote indicator.
Source selector
The Source selector has four positions:
• Line. Selects the input signal connector
and disconnects the internal noise gen-
erator. This allows the use of an external
signal source. Input sensitivity is 1 Vrms
for full power output.
• Pink. Selects pink noise from the internal
noise generator.
• Red/White. Selects Red/White noise from
the internal noise generator.
• White. Selects White noise from the
internal noise generator.
Level selector
The Level selector attenuates the output level
in 5 dB steps from 0 dB (full power) to 35dB.
The fi nal position switches the signal off.
Equalizer switch
The equalizer switch selects the equaliza-
tion network on/off. The switch should be
left in the on position when using Nor250,
Nor270 or Nor270H loudspeakers for maxi-
mum power to the speaker system. It also
ensures that there is less than 5 dB between
each adjacent 1/3 octave band (free fi eld
conditions) when using any of the above
mentioned speakers, as required by annex C
in the ISO140/3 standard.
The equalization network is adapted to the
Nor250, Nor270 and Nor270H loudspeakers.
When using other speakers, it is recom-
mended to switch the equalizer off, or use
the network with care in order not to damage

9
output stage or a speaker system with a
nominal impedance less than 2 ohm is
connected.
• Over temperature. If the temperature ex-
ceeds the temperature limit, the amplifi er
is turned off and the cooling fan is turned
on at full speed.
The signal is turned on again as soon as the
error condition is removed.
Please note that the fan is turned on if
the temperature inside the amplifier ex-
ceeds 35 ºC and the input signal exceeds
100mVrms. The amplifi er however is still well
suited for reverberation time measurements
in areas of low background noise since the
fan is turned off when the input signal drops
below 100mVrms.
Remote on LED
The remote on LED indication is normally
illuminated. If the wireless remote on/off
control option is added, the output to the
speaker can be switched on/off from the small
remote hand switch. The remote on indicator
is turned off if the output is switched off from
the remote switch.
Input connector.
The input connector is a 3 pin female XLR.
The input stage is balanced in order to remove
infl uence from external noise such as hum
and crosstalk. A BNC to XLR adaptor is a part
of the delivery schedule. It is recommended
to use a XLR cable from the Nor280 to the
external signal, and convert it to a BNC or
other single ended cable system as close to
the signal source as possible. This ensures
a minimum influence from external hum
and noise.
Indication of remote
control status
– signal On/Off
Selector for
output level.
The equalizer circuit
may be switched
On/Off
Signal source
selector
Fuse compartment
Mains power switch
Error indicator
Indicates overload
and shutdown due
to over-temperature
Signal input
connector
Output connector
(loudspeaker)
Mains connector
Front panel of Nor280
the speaker.
The high and low pass fi lter is always a part
of the signal path regardless of the setting of
the equalization switch.
Error indicator
The error indicator is illuminated and the
output signal is turned off when one of the
following error conditions occurs:
• Short circuit. If the output current ex-
ceeds 35Amp due to a short circuit of the

10
Using Nor280 with the speakers Nor223/229/250/270/270H
The power amplifi er Nor-280 is extremely powerful, so care must be taken not to destroy
loudspeaker systems connected to it. The below table provides an indication of maximum
permissible amplifi er input signal.
The following settings should
not
be exceeded:
Signal type Nor223
1
Nor229
2
Nor250/270/270H
White/pink noise 0 dB –3 dB 0 dB
Octave & third octave fi ltered
pink noise, f< 200 Hz –3 dB –6 dB –3 dB
Octave & third octave fi ltered
pink noise, f> 200 Hz 0 dB –3 dB 0 dB
Red/white noise with
equalisation On/Off –3 dB/0 dB –6 dB/–3 dB –3 dB/0 dB
All dB values are dB re. 1V
RMS
1
assuming an impedance of 5.4
Ω
2
assuming an impedance of 6
Ω
The frequency response of the
equalisation circuitry of the
Nor280 Power Amplifi er
Output connector
The output connector is a 4 pole Speakon
NL4MP type. 1+ and 2+ are connected
together to form the + output, and 1- and
2- are connected together to form the
– output.
Warning:
The balanced speaker outputs are
both “hot” with a common DC voltage separate
from ground. Shorting one of the terminals to
ground results in an over-current situation.
Connecting to a speaker
Switch on the amplifi er and set the signal
attenuator to off. Select the noise source or
connect the signal input to the amplifi er.
Connect the amplifi er to the speaker.
Caution ! Consult the table on this page
for selecting the level of the noise. If your
speaker is not listed, precaution must be
taken in order not to damage the speaker
system.
Increase the signal to the desired level.
Precaution should be taken against hearing
loss – wear hearing protectors!
Noise Generator
The built in noise generator is a random type
with a repetition period in excess of 4 hours.
It features 3 different noise types; Pink, Red/
White and White. The output can be attenu-
ated in 5 dB steps by the level selector from
0 to –35dB in addition to signal off.
Wireless remote control
Option 1, wireless remote control of signal
on/off, enables the user to control the on/off
without being present in the source room.
The output to the speaker can be switched
on/off from the small remote hand switch.
Typical range is 100m in free fi eld but will
also transmit through a concrete wall/fl oor.
The remote on LED indication is normally
illuminated. The remote on indicator is
turned off if the output is switched off from
the remote switch.

11
Specifi cations
Output: Short circuit and over temperature protected
Output connector: Speakon NL4MP
Output power: 500Wrms (4ohm) and 250Wrms (8ohm) measured as THD+N<0.1%.
The built-in LP and HP fi lters ensure that the output power matches the Norsonic
Nor250 and Nor270 series of dodecahedron loudspeakers.
Peak power: >1 kW
Output current: Maximum 35 A
Input: Balanced input to avoid ground loops and cross talk to signal cables
Input sensitivity: 1V (0dB)
Input impedance: 10k ohm//220pF
Input connector: 3 pin female XLR
Weight: 3,5Kg (7,7 lb)
Dimensions: 275 x 110 x 246 (mm) (D x W x H)
11 x 4,3 x 9,7 (inch)
Operating
temperature: -20 to + 35 °C
Operating
humidity: 0-90 %RH
Enclosure class: IP20
Mains voltage: 220Vac (190 - 265Vac, 45-55Hz) or
110Vac (90 - 132Vac, 55-65Hz).
Mains fuse: T 3,15A for 220Vac and T 6A for 110Vac
The unit is only safety approved using the following fuses, as appropriate:
Wickman 181 1630 000 (1000pcs) or 002 (10 pcs) (110V) or
Wickman 181 1315 000 (1000pcs) or 002 (10 pcs) (230V)
EMC and safety standards:
EN55103-1, EN55103-2, IEC61340-5 part 1&2, IEC61010, FCC part 15b class A
Licence Exemption:
Europe: The transmitter encoders use ECM compliant radio transmitter modules and com-
plies with ETSI330-220 and ETSI300-683.
USA: The device comples with part 15 of the FCC Rules
Operation is subject to the following two conditions:
1. The device may not cause harmful interference, and
2. This device must acceptany interface received, including interference that may cause
undesired operation.
Schedule of parts
Mains input lead, BNC to XLR female adapter, Output connector or a complete as-
sembled cable 5m if ordered with a Norsonic Nor250, Nor270 or Nor270H dodecahedron
speaker. User manual with conformance certifi cation.
Programming the hand switch
The remote hand switch is pre-pro-
grammed for the supplied Nor280. Sev-
eral hand switches can be programmed
for one or more amplifi ers or vice versa.
The procedure is as follow:
• Switch on the amplifi er.
• Push a small rod (paperclip) into the
tiny hole located to the right above
the mains switch. This activates a
push button
• Press and release the button located
on the remote hand switch
• Repeat the press and release
• Wait 20 seconds
• The hand switch is now programmed
to the new Nor280
Ordering information
Option 1: Wireless remote on/off
switch (must be specifi ed when
ordering)

Declaration of Conformity
We, Norsonic AS, Gunnersbråtan 2, Tranby, Norway, declare under our sole responsibility that the
product:
Nor250; Nor270/270H; Nor280
to which this declaration relates, is in conformity with the following standards or other normative
documents:
Performance complying with:
EMC and safety standards: EN55103-1, EN55103-2, IEC61340-5 part 1&2, IEC61010, FCC part 15b
class A (Nor280 is only safety approved using the specifi ed fuses)
The optional remote control transmitter use ECM compliant radio transmitter modules complies
with ETSI330-220 and ETSI300-683 and part 15 of the FCC Rules, as applicable (see Specifi cations)
This product has been manufactured in compliance with the provisions of the relevant internal Norsonic production standards. All
our products are tested individually before they leave the factory. Calibrated equipment—traceable to national and international
standards—has been used to carry out these tests.
This Declaration of Conformity does not affect our warranty obligations.
The declaration of conformity is given according to EN 45014 and ISO/IEC Guide 22.
Norsonic AS, P.O. Box 24, N-3421 Lierskogen, Norway
Tranby, December 2005
Dagfi nn Jahr
Quality Manager