BOGEN NQ-SMS1810-SCG Nyquist Suspended Ceiling Grid Sound Masking Speaker User Guide
- June 12, 2024
- BOGEN
Table of Contents
- Sound Masking Design Goals
- Sound Masking Applications
- Acoustics
- Sound Masking System Design
- Speaker Selection and Layout
- Wiring for 25- or 70-Volt Systems/Schematics
- Sound Masking System Design Example
- Configuring the Nyquist System for Sound Masking
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
NQ-SMS1810-SCG Nyquist Suspended Ceiling Grid Sound Masking Speaker
User Guide
Sound Masking Design Goals
The primary goals of sound masking are to reduce distractions caused by
unwanted sound and to provide conversational or speech privacy. Distractions
are reduced by increasing the background noise while reducing the range of
fluctuations in sound levels within a targeted area. Speech privacy is
provided by increasing the background noise surrounding the target area,
effectively distorting and muffling sounds and voices emanating from within.
Sound masking creates an evenly distributed and diffused sound field in which
listeners are unable to detect the source. This “random” noise obfuscates most
sounds within the environment—such as a conversation or typing— thereby
reducing disturbances and providing a level of privacy, even within an open
space.
Sound Masking Applications
Coverage and Planning
Sound masking can be useful in many environments such as:
- Commercial facilities, including both open and closed offices.
- Medical facilities, particularly to satisfy regulations that mandate protection of patient health information.
- Educational institutions, in administrative offices, consultation rooms, libraries, student centers, and areas where focused study is required.
- Secure facilities, such as legal offices, court rooms, accounting firms, and military facilities.
Areas where sound masking should not be utilized are:
- Training and audio/visual presentation rooms, where intelligibility is important.
- Bathrooms (for security purposes, unless requested by customer).
- Areas used by the hearing or sight impaired.
Sound masking is usually not applied in conference rooms and closed offices
where clear and reliable communication is important. For these environments,
privacy can be enhanced by applying sound masking to the adjacent hallway or
open office/space, thereby providing improved privacy from people outside the
“protected” area (see Figure 1).
An exception when sound masking may be needed within a closed office is where
the walls between it and the adjoining offices only extend up to the drop
ceiling, not the structural ceiling, leaving the ceiling plenum (i.e., the
space between the drop ceiling and the structural ceiling) open and acting as
an air duct. This would allow sound to travel between each office through
return air grilles, compromising privacy. Sound masking applied in a closed
office would also prevent distractions from noise traveling outside open
spaces into the closed office via the plenum space in the ceiling (see Figure
2).
Acoustics
A critical factor in the success of a sound masking system is first addressing the physical acoustics of the target area. The goal is to decrease the level of unwanted sound to which people are exposed, thereby decreasing the level of unwanted sound to mask (see Figure 3 and Figure 4).
Where possible, minimize direct line-of-sight transmission between workspaces/cubicles (see Figures 5 and 6) by adding or replacing partition walls, using the appropriate height and material.
To minimize voice and sound reflection and reduce environmental sound in the target area (see Figure 7 and Figure 8):
- Change flooring material from hard surfaces such as hardwood or tiles to carpets.
- Replace standard flat-panel ceiling lights with parabolic recessed light fixtures.
- Use absorbent material in ceiling tiles and on cubical walls.
Sound Masking System Design
Speaker Options
NQ-SMS1810-SCG : Nyquist Suspended Ceiling Grid Sound Masking Speaker
The NQ-
SMS1810-SCG includes a ceiling grid mount and a sound masking speaker
assembly, which consists of an 8” dual-cone loudspeaker with a 10-ounce magnet
and a 25V/70V, 4W max., rotary tap selector. A seismic safety cable is
supplied to secure the speaker to a solid object in the plenum space.
Installation: Place upward-facing on top of a 24”-wide ceiling tile on a
conventional suspended ceiling grid.
NQ-SMS1810-VF: Nyquist Variable Firing Sound Masking Speaker
The assembly for the NQ-SMS1810-VF comes with an 8” dual-cone loudspeaker with
a 10-ounce magnet and a 25V/70V, 4W max., rotary tap selector. It includes two
multi-position hangers for multiple mounting configurations and also comes
with a chain kit.
Installation: Connect the two multi-position hangers to the structural ceiling
to hang above the suspended ceiling deck. It can face upwards, downwards, or
sideways.
CSD2X2 and CSD1X2: Drop-In Ceiling Speaker
The CSD2X2 or CSD1X2 replaces a conventional ceiling tile and faces downward.
Installation: Mount the CSD2X2 or CSD1X2 parallel to the floor plane in a
24”-wide suspended ceiling tile grid facing downward.
Refer to Table 1 for additional devices that work in conjunction with the
above speakers.
Nyquist 2-Channel Audio Power
Amplifiers| Nyquist 4-Channel Audio Power
Amplifiers| Volume control wall unit (for closed
offices and conference rooms)
---|---|---
• NQ-A2060-G2
• NQ-A2120-G2
• NQ-A2300-G2| • NQ-A4060-G2
• NQ-A4120-G2
• NQ-A4300-G2| • AT10A 10W Attenuator
• AT35A 35W Attenuator
Note: 15–20% headroom is recommended for the masking amplifiers.
Note: Any Bogen high-impedance downward-facing ceiling speaker can be
used for sound masking applications.
Table 1: Other available devices
Speaker Selection and Layout
Buildings with Suspended Ceilings
The ceiling plenum is the most common location to install sound-masking
speakers. The specific type of speaker to use depends on the plenum’s depth
and available space.
A typical office has a height of 9’ from the floor to the visible face of
drop-ceiling tiles. The plenum extends upwards from the top of the drop
ceiling to the structural ceiling (hard deck) above. In this kind of
construction, either install NQ- SMS1810-SCG on top of the ceiling tile grid
to avoid a cluttered plenum (see Figure 9) or, using the chain kit, hang NQ-
SMS1810-VF upward-facing from the structural ceiling, with the bottom of each
speaker about 6” to 8” above the suspended ceiling grid (see Figure 10).
Figure 9: NQ-SMS1810-SCG placement with a typical plenum height.
For optimal masking with either layout, speakers should be placed in a grid
pattern (see Figure 13). Since sound mixes well in the open plenum space, this
will give an even coverage of sound masking. The taller the plenum space, the
further apart the speakers should be and the higher the wattage should be set
for the transformer taps.
The shorter the plenum space, the closer the speakers should be to one
another.
If the plenum depth exceeds 6’, hang upward-facing NQ-SMS1810-VF speakers 2’
to 4’ from the structural ceiling (hard deck).
When there is acoustic absorption material or thermal insulation on the
structural ceiling, hang downward-facing NQ-SMS1810-VF speakers 2’ to 4’ from
the structural ceiling (see Figure 11). Adjacent speakers must be incoherent 1
(i.e., different) and therefore a two-channel system is required (see Two-
Channel Wiring).
CSD2X2 speakers can be used when the plenum is shallow (less than 1’ in
height) and/or contains obstructions which would prevent an even coverage of
sound masking and cause difficulty in installation (see Figure 12).
Adjacent speakers must be incoherent and therefore a two-channel system is
required (see Two-Channel Wiring).
Figure 11: NQ- S1810SM-VF installed in plenum space with insulation.
Buildings with Open Ceilings
With an open-plenum ceiling, hang the NQ-SMS1810-VF facing upward 2’ to 4’
away from the structural ceiling.
When there is acoustic absorption material or thermal insulation on the
structural ceiling, hang downward-facing NQ-SMS1810-VF speakers 2’ to 4’ from
the structural ceiling. Adjacent speakers must be incoherent and, therefore, a
two- channel system is required (see Two-Channel Wiring).
In the rare case of an interior with a sloped ceiling, hang NQ-SMS1810-VF
facing sideways into the sloped ceiling.
If an obstacle prevents the installation of a speaker, the speaker can be
moved to an appropriate space but the speakers on either side should be spaced
out accordingly to maintain optimum sound masking. For example, if a speaker
needs to be moved three feet away from its intended installation point, then
the next speaker moves two feet away from its original position, and the next
speaker one foot away from its original position.
Important: Masking speakers should not be installed within three feet of a
rectangular metal air duct.
Determining Speaker Placement
Recommended speaker placement is determined by the speaker position,
orientation, and the calculated acoustic path (P), which is the distance the
sound travels from the speaker to the floor.
The formula used to calculate the acoustic path (P) is determined by the
presence of a drop ceiling, the speaker orientation, the speaker type, and the
plenum height, as shown in the following table. The variables A and B
correspond to the distances between the floor and structural ceiling (A) and
between the suspended ceiling and structural ceiling (B).
Drop ceiling| Speaker type| Speaker orientation|
Plenum depth| Calculated Acoustic Path (P)
---|---|---|---|---
No| NQ-SMS1810-VF| Upward| —| P = A + 4
No| NQ-SMS1810-VF| Downward| —| P = A − 2
Yes| NQ-SMS1810-VF| Upward Bottom of speaker 6” above ceiling grid| 2’ to 6’|
P = A + B − 1
Yes| NQ-SMS1810-VF| Upward Speaker 4’ below structural ceiling| > 6’| P = A +
4
Yes| NQ-SMS1810-VF| Downward| —| P = A − 2
Yes| NQ-SMS1810-SCG| Upward| —| P = A + B
Yes| CSD| Downward| —| P = A − B
Table 2: Acoustic path calculation formulas
Once the acoustic path (P) has been calculated, use the following table to determine the correct spacing distance (d) to leave between speakers.
Calculated acoustic path (P)| Speaker spacing for VF and
SCG (±1’)| Speaker spacing for CSD (±2’)
---|---|---
8’–10’| 9’| 8’
10’–12’| 10’| 10’
12’–14’| 11’| 12’
14’–16’| 12’
16’–18’| 13’
18’–20’| 14’
20’–22’| 15’
22’–24’| 16’
24’–26’| 17’
26’| see comments below
Table 3: Speaker spacing based on calculated acoustic path and speaker type
If P exceeds 26’, consider changing the speaker orientation and/or type and
using the relevant formulas to obtain a smaller value for P. If P is still
greater than 26’ after trying all other options, use CSD speakers or install
VF speakers facing downward at 18’ to 20’ from the floor at a spacing distance
(d) of 14’.
For example, if upward-facing SCG speakers result in P = A + B = 27’, we may
get a smaller P value using upward-facing VF speakers (P = A + 4, assuming B >
4), downward-facing VF speakers (P = A − 2), or even CSD speakers (P = A − B,
assuming a drop ceiling).
Once the speaker spacing distance d’ has been determined, the speaker layout
is relatively simple. Layout starts in one corner of the room. The first
speaker should be installed c’ from the corner of the room—where c is between
2’ and one half the spacing distance (d)—with each additional speaker inthe
first row installed d’ from the previous one. Move down d’ and install the
next row of speakers, with speakers again installed in increments of d’ from
the first. Each additional row will continue the same pattern until the whole
area is covered (see Figure 13).
Enclosed offices and most small enclosed spaces follow the same placement rule
except when using CSD speakers.
Even in spaces of less than 200 sq. ft., use a minimum of two CSDs, located
diagonally from each other, to prevent hot spots.
Figure 13: The distance between each speaker and its adjacent speakers is d’
(±1’ or ±2’, depending on speaker type).
The distance between outer speakers and the wall is c’, a value between 2’ and
½d’.
Determining Speaker Power Tap
CSD speakers should be tapped at 1W when the drop ceiling is less than 14’
tall and 2W when it is 14’ or taller. VF and SCG speakers should be tapped at
2W for speakers spaced less than 14’ apart and 4W for speakers spaced more
than 14’ apart.
Wiring for 25- or 70-Volt Systems/Schematics
Multiple-Wire Runs
When more than 10 speakers are required, multiple runs can be wired in
parallel, with no more than 10 speakers per run (see Figure 14). This reduces
the overall resistance, allowing the amplifier more head room, increasing the
number of speakers the amplifier can handle, and providing coverage for both
small and large areas.
Figure 14: Installation with multiple wire runs is recommended for more than ten speakers.
Two-Channel Wiring
A two-channel, acoustically incoherent wiring design (see Figure 15) is
required for direct radiating speakers (e.g., CSD or NQ-SMS1810-VF when
installed facing downward). Adjacent speakers receive signals from different
sound masking sources, thereby avoiding comb filtering (i.e., acoustic
interference). It is critical to make sure that the sound masking from each
channel has the same spectrum preset and level.
Ideally, the two channels should come from two different amplifiers, ensuring
the signals will be different. When it is not practical to have multiple
amplifiers, add phase shift to one of the channels to achieve the same result
(see Viewing Station Configuration Settings in the Nyquist System
Administrator Guide and refer to the Add Phase Shift station setting).
Wire-Related Losses
Wire is an important but often ignored component of a sound masking system.
Because all wire has resistance, some of the voltage at the source is lost or
dropped in the wire before it reaches the target destination. The voltage lost
in the wires is affected by the resistance and gauge of the wire and the
electrical current flowing through the wire. This is classic Ohm’s law in
action. If the voltage lost in the cables is not anticipated, the final volume
level at the passive speaker may not meet the requirement.
The sound masking system can be run as 25V or 70V. A 70V system can use
significantly longer cables, but requires twice the number of amplifiers due
to bridging. There are separate charts for 25V and 70V transformer
distribution systems that specify the maximum cable lengths that should be
allowed. Attempt to keep the system power lost in the wires below 10%;
however, less power at the speaker is the only negative effect that larger
losses
have on the system. Clarity, intelligibility, and frequency response are
unaffected by larger losses in the wiring of transformer distribution systems.
Once the number of speakers to be wired together in a run has been decided,
estimate how long the wire run will be from the first to the last speaker in
each run. Include the lead-in wire length from the amplifier to the first
speaker in each run in the overall run length. For each run, sum up the
speaker power and cable lengths. Using that information, refer to the Wire
Loss Chart to ensure that the wire gauge is sufficient to support the power
and cable length for the run. It may be necessary to increase the wire gauge,
split the speaker loads, or shorten the wire run lengths if they exceed the
chart maximums.
70V – Load Power Per Wire Run (Watts) | |
---|---|
Wire Gauge | 5 |
200
16| 10,000| 7,000| 4,600| 2,300| 1,400| 700| 350
18| 9,000| 4,500| 2,800| 1,400| 830| 415| 205
20| 5,500| 2,700| 1,800| 900| 540| 270| 135
22| 3,400| 1,700| 1,100| 550| 330| 115| 60
24| 2,100| 1,000| 700| 350| 350| 105| 50
| Maximum Wire Run Cable Length (ft.) (10% of power lost in wire)
Shielded Pair, Stranded Cable
Figure 16: 70V Wire Loss Chart
| 25V – Load Power Per Wire Run (Watts)
---|---
Wire Gauge| 5| 10| 15| 30| 50| 100|
200
16| 1,280| 640| 425| 215| 125| 60| 30
18| 800| 400| 265| 130| 80| 40| 20
20| 505| 250| 165| 80| 50| 25| 12
22| 315| 155| 105| 50| 30| 15| 7
24| 200| 100| 65| 30| 20| 10| 5
| Maximum Wire Run Cable Length (ft.) (10% of power lost in wire)
Shielded Pair, Stranded Cable
Figure 17: 25V Wire Loss Chart
Sound Masking Zoning Choices
There are a number of factors that must be considered in mapping out the sound
masking zones for each physical location. Their acoustic attributes and
administrative functions, as well as the available speaker types, are all
factors that must be considered.
Areas with different structural and acoustical features should be assigned to
distinct sound masking zones. For example, closed vs. open offices, areas with
alternating suspended ceilings, and open offices with extreme panel height
differences. Areas with different administrative functions should also be
assigned to different sound masking zones, such as cafeterias, open offices,
reception areas, closed offices, and conference rooms. It is usually best to
also separate areas using different types of speakers, such as upward-facing
vs. downward-facing speakers, into distinct masking zones.
Sound Masking Levels
Introducing a New Sound Masking System It is advisable to introduce a sound
masking system slowly. Turn the system on at 10 dB below the final target
level and bring it up to its final level over a period of 20 to 30 days,
allowing time for office staff to adjust to the extra ambient sound (see Sound
Masking Zones in the Nyquist System Administrator Guide, particularly the Slow
Ramp Days setting).
Finding the Right Balance
In general, louder sound masking levels provide more speech privacy. However,
in the real world of an open office space, there is a limit to how much speech
privacy one can have. If the masking sound is set higher than a reasonable
level, issues may arise. Office workers will talk louder and any speech
privacy gained will be lost. A comfortable sound pressure level (SPL) range
for sound masking in a relatively quiet office area is 46 dBA to 52 dBA. Using
47 dBA as a starting point, raise or lower the masking level based on the
existing background noise level.
It is critical to avoid sudden sound level changes throughout the facility.
Keep sound levels balanced between different zones, as well as masked and
unmasked areas. If there is an unmasked open area nearby, the adjacent
corridor or space should have speakers that gradually reduce the masking
level. A cost-efficient way is to adjust the speaker power tap setting to
create a spatial gradient of masking levels as one enters the open area.
Adjust overall zone output levels using the masking zone’s Output Gain to
obtain uniform levels throughout masked areas. If there are multiple stations
within a zone (a station, in this context, represents an amplifier output
channel), adjust the output level of each station via the Output Power field
of the Edit Station view, which allows adjustments of ±6 dB (see Editing
Station Configuration Settings in the Nyquist System Administrator Guide). Do
not rely on the amplifier’s DSP output levels to make adjustments to the
channel.
Measuring Sound Levels
Masking sound levels should be measured using a sound pressure level meter
with A-weighting in each open area and in each closed room where a sound
masking speaker is installed. Measure SPL at a height off the floor of 4.0’ to
4.7’ (i.e., approximately ear height when seated). Measurements should be
made across several locations in larger areas. Adjust the masking sound levels
to within ±3 dB of the target level.
Emergency Muting
If applying sound masking to an area with an existing paging system, the sound
masking should not interfere with the paging system. To compensate for the
masking noise, the normal paging system level should be increased by +3 dB.
The masking noise will immediately be muted by the Nyquist system whenever an
Alarm tone, Disable-Audio command, or an Emergency or Emergency-All-Call
announcement occurs. Once the announcement or alarm has completed, the
masking sound will be automatically ramped back up to its previous level over
a period of five (5) minutes (known as fast ramping). This also occurs
whenever the masking zone signal has been disabled and re-enabled, as well as
after a system reboot, power outage, or system maintenance.
Note: Sound masking is not muted for an Emergency announcement or Alarm
that is being played to a specific zone.
Sound Masking Spectrum
In addition to the sound masking level, the sound masking spectrum is also
very important. Because sound masking is intended primarily for speech
privacy, it is only the frequency range of speech that is critical, so the
masking sound is adjusted using high- and low-pass filters to minimize sounds
outside that range.
High-frequency sound is considered “hissy” and uncomfortable, but high
frequency sound is also more effective at providing speech privacy. This
results in a tradeoff between performance and acceptability. Using a sound
spectrum that rolls off approximately 5 dB per octave provides a good balance
between effectiveness and comfort. A well-designed HVAC (i.e., air
conditioning) system generates a significant level of low-frequency sound. To
avoid adding an unwanted rumbling sound, the masking sound covers the higher,
speech-like frequencies but reduces frequencies below 160 Hz.
The ideal sound masking level and spectrum are strongly affected by the
acoustic conditions of the room, such as the panel height, ceiling tile
material, furniture, flooring, etc. Bogen provides a number of spectrum preset
options corresponding to these various conditions, applications, and
preferences.
The following is a list of available spectrum preset options:
Closed-plan space| Recommended for private office or small conference room
with some reflective surfaces, absorptive ceiling, and furnishings.
---|---
Ideal open-plan space| Suitable for open offices with 5-foot or higher cubical
panels, absorptive ceilings and furnishings, and proper layout.
Good open-plan space| Suitable for open office with 4- to 5-foot high cubical
panels, some reflective surfaces, and moderate furniture absorption.
Non-ideal open plan space| Recommended for open office with no cubical panels
or with cubical panels under 4-foot high, reflective surfaces, and moderate
furniture absorption.
NCB contour| Noise Criterion Balanced (NCB) Contour may be used to evaluate
the acceptability of masking sound in various non- industrial environments.
NRC Canada Contour| A cost-effective open-plan environment masking spectrum
published by the National Research Council, Canada.
NC40 Contour| Noise Criterion (NC) 40 Contour may be used to evaluate the
acceptability of masking sound in an open office environment.
Sound Masking System Design Example
Here is a scenario where a sound masking system installation is requested for
an office complex.
Assume the following conditions:
- The building has two large open offices, several closed offices, and a few conference rooms.
- The building has suspended ceilings.
- Some areas have sound absorption materials in the ceiling plenum.
- The suspended ceiling height is lower than 12 feet.
- The plenum depth is between one and three feet.
The final sound masking design is shown (see Figure 18) to make it easier to
visualize as each area is analyzed and an optimal design determined.
Office Areas
There are four distinct areas in which sound masking is to be incorporated:
Zone 1: Open Office Area X
Open Office Area X is approximately 8600 sq. ft., therefore requiring 50
upward-facing NQ-SMS1810-VF speakers installed in the plenum area 13’ apart
across the length of the room and 14’ apart across the width of the room.
The NQ-A4120-G2 amplifier can provide 120W per channel when operating at 25V.
Allowing 20% headroom, each channel should not exceed 96W. At 2W per 25V
speaker, this allows for a maximum of 48 speakers per channel.
Since a single channel cannot support all 50 speakers, two channels (A and B)
are used, assigning 25 speakers to each channel.
Channels A and B of an NQ-A4120-G2 amplifier are assigned to Sound Masking
Zone 1.
Zone 2: Closed Offices
There are several private closed offices ranging in size from 90 to 200 sq.
ft. One upward-facing NQ-SMS1810-VF speaker tapped to 2W is used in addition
to an optional wall-mount volume control for each office.
Channel C of the NQ-A4120-G2 amplifier is assigned to Sound Masking Zone 2.
Zone 3: Open Office Area Y
Due to acoustic material above the drop ceiling tile (e.g., a layer of
fiberglass sheet), CSD2X2s are the only option for Open Office Area Y. At
approximately 1200 sq. ft., 16 speakers are installed within the drop ceiling
(see Figure 19). Two- channel wiring is also mandated. Speakers are installed
8’ apart from each other and tapped to 1W.
Alternate speakers will receive signals from two channels from two separate
amplifiers, as shown in Figure 20.
Channel D of NQ-A4120-G2 and Channel A of a separate NQ-A2120-G2 are assigned
to Sound Masking Zone 3.
Figure 19: 1200 sq. ft. open space area with 16 CSD2X2 speakers.
Zone 4: Hallway Outside Conference Room
To provide speech privacy during meetings, three NQ-SMS1810-SCG speakers
tapped to 2W are installed 12’ apart in the plenum of the hallway ceiling. The
speakers are placed 4’ away from the conference room wall. A wallmounted AT10A
attenuator is also installed inside the conference room to adjust the masking
sound level. Sound masking will be turned on during meetings and off at other
times.
Channel B of the NQ-A2120-G2 is assigned to Sound Masking Zone 4.
The final layout is shown in Figure 20.
Configuring the Nyquist System for Sound Masking
Once the speakers in the design example are installed and connected to the appropriate amplifier channels, there are several tasks that must be performed on the Nyquist System to configure the system.
-
Configure six sound masking stations for two amplifiers:
• Four stations for the NQ-A4120-G2
• Two stations for the NQ-A2120-G2 -
Define and configure four masking zones, assigning sound masking stations to each zone:
• Open Office Area X
• Closed Offices
• Open Office Area Y
• Hallway Outside Conference Room -
Initiate sound masking and adjust levels
Add and Configure Amplifiers on the Nyquist System Controller
After the NQ-A4120-G2 and NQ-A2120-G2 amplifiers are connected to the network,
they must be added to the Nyquist system and stations must be created for them
of type Sound Masking via the Station Management view of each amplifier. It
may be helpful to review the Adding Amplifier and Gateway Devices and Adding
and Editing a Sound Masking Zone sections in the Nyquist System Administrator
Guide for detailed instructions.
Note: For this example, ensure that all Amplifier Mode switches on the
amplifiers are set to 25V/4Ω (not bridged), allowing the use of every channel
on each amplifier.
Add the amplifiers to the Nyquist system and configure each channel, as
specified in Table 4.
Device Type | NQ-A4120-G2 | NQ-A2120-G2 |
---|---|---|
Channel | A | B |
Name | A4120-A | A4120-B |
Load Impedance | High (all speakers will be wired at 25V) | |
Output Power | 0 dB (may eventually be adjusted) | |
Add Phase Shift | No | No |
Table 4: Amplifier Station Management channel configurations Station Management channel configurations
Although channels A and B of the NQ-A4120-G2 are connected to the same zone
and are from the same amplifier, two-channel wiring is not needed and Add
Phase Shift is set to No because the NQ-SMS1810-VF speakers on both channels
are upward-facing, which do not need to be phase shifted (as the sound waves
are significantly randomized by reflecting off the structural ceiling). All
other channels can also be No because they do not include more than one
channel from the same amplifier, so there are no phasing issues.
Configure Sound Masking Zones
Now that the amplifiers have been configured for sound masking, the sound
masking zones can be created.
It may be helpful to review the Sound Masking Zones section of the Nyquist
System Administrator Guide, which provides details on how to add and edit
sound masking zones, as well as an overview of sound masking zones in general.
For this example, the properties of the four sound masking zones will be
configured as specified in Table 5.
|
Zone 1
| Zone 2| Zone 3|
Zone 4
---|---|---|---|---
Enabled| No| No| No| No
Number| 1| 2| 3| 4
Name| Open Office Area X| Closed Offices| Open Office Area Y| Hallway Outside
Conference Room
Stations| A4120-A A4120-B| A4120-C| A4120-D A2120-A| A2120-B
Speaker Orientation| Up| Up| Down| Up
Spectrum Preset| Good open-plan space| Closed-plan space| Good open-plan
space| Non-ideal open-plan space
Output Gain| -35 dB| -35 dB| -35 dB| -35 dB
Slow Ramp Days| 30| 30| 30| 30
Table 5: Sound masking zone configurations
Initiate Sound Masking and Adjust
Levels Once all sound masking zones are configured, return to the Sound
Masking Zones page and enable each zone to determine if the sound masking
volume satisfies the sound masking needs. It may be necessary to adjust the
sound masking levels to ensure an even sound distribution, wherein the
direction of the sound source is undetectable and the volume appears
consistent. The levels can be adjusted by modifying the Output Gain for each
masking zone.
Once the levels are satisfactory, select Start Ramping. Sound Masking is now
in effect and will reach the specified level in 30 days.
Assuming that there is an existing paging system in one or more of the sound
masking areas, at some point during those 30 days (e.g., approximately 15
days), the paging and audio distribution cut levels (and optionally the sys-
tem-wide All-Call cut level) should be increased by +3 dB to compensate for
the increased noise level. This can be performed manually via the Nyquist web
interface (Zones configuration) or by creating a routine that includes Change-
Volume actions for each audio type (i.e., Audio Distribution, Zone Paging, and
optionally All-Call) and for any zone that overlaps a sound masking zone,
specifying a cut level +3 dB above the zone’s current level, and scheduling
the routine to occur at the desired time (e.g., approximately 15 days into the
ramping process).