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ECE 40020 Sound Reinforcement System Design Spring 2014
Sound System Design Project Report Evaluation
Group Members Time Spent* Initials Score**
Matt Jordan 29 MJ
Rahul Sarma 55 RS
Ishaan Kohli 17 IK
*documented in Activity Log Sheet for each team member, included as Appendix A **may be different for each team member, based on amount of effort proportionally invested
CRITERION SCORE WGT. PTS.
Engineering design process 0 1 2 3 4 5 6 7 8 9 10 2
System design constraint analysis 0 1 2 3 4 5 6 7 8 9 10 2
Design constraint satisfaction 0 1 2 3 4 5 6 7 8 9 10 2
Component selection 0 1 2 3 4 5 6 7 8 9 10 2
Technical content / creativity 0 1 2 3 4 5 6 7 8 9 10 1
Writing style / professionalism 0 1 2 3 4 5 6 7 8 9 10 1
TOTAL
Instructor comments: ______________________________________________________________________________
______________________________________________________________________________
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ECE 40020 Sound Reinforcement System Design Spring 2014
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ECE 40020 Sound Reinforcement System Design Spring 2014
TABLE OF CONTENTS
Abstract
1.0 Engineering Design Process 1
2.0 Design Constraint Analysis 3
3.0 Design Constraint Satisfaction 6
4.0 Equipment Selection 8
4.1 Power Amplifier Requirements and Selection 8
4.2 Signal Processing Requirements and Selection 9
4.3 Mixing Console Requirements and Selection 10
4.4 Microphone Requirements and Selection 11
4.5 Rack Requirements and Design 12
4.6 Cabling and Wiring Requirements 13
5.0 Summary and Recommendations 14
6.0 References 15
Appendix A: Activity Logs 16
Appendix B: Venue Illustrations 20
Appendix C: Loudspeaker Placement and EASE Simulation Results 22
Appendix D: Signal Path Wiring Diagram 27
Appendix E: Rack Design and Power Sequencing/Distribution 29
Appendix F: System Component List and Street Price Cost Estimate 32
Appendix G: Manufacturer Data Sheets 34
ECE 40020 Sound Reinforcement System Design Spring 2014
ECE 40020 Sound Reinforcement System Design Spring 2014
Abstract This report documents the design of a complete sound reinforcement system tailored for a generic,
4000-seat fan-shaped multi-purpose auditorium, with (approximately) 3000 seats on the main floor
and 1000 seats on the first (and only) balcony. Room dimensions and configuration should be chosen
based on the specified seating capacity.
The primary system design constraints are as follows:
▪ minimum SPL of 105 dB at back row of seating
▪ no more than ±5 dB variation in SPL over the entire seating space for the 1 KHz, 2 KHz, 4
KHz, and 8 KHz frequency bands
▪ frequency response of 40 – 16,000 Hz ± 5 dB
▪ %ALCONS no greater than 10% over entire seating space
▪ minimum 48-channel mixing console
▪ minimum of 4 separate monitor mixes (and corresponding monitor loudspeaker systems – may
choose an in-ear monitoring system as an alternative)
▪ support for a minimum of 20 compatible wireless microphone channels (include
transmitters/receivers for at least 20 channels)
▪ good assortment of general-purpose wired and wireless microphone systems for speaking,
individual vocalists, a variety of musical instruments, choral performances
▪ digital media recording/playback capability
▪ all equipment mounted in rack cabinet(s)
▪ budget of $500,000
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1. Engineering Design Process
The biggest advantage of designing an auditorium from scratch is that the venue can be
designed around the sound reinforcement system in order to extract the best possible
performance out of the selected equipment. The horizontal coverage angle of the speakers as
well as the coverage depth were factored into the overall venue dimensions. The venue was
constantly modified and altered throughout the design process in order to fit the system requirements
and work well together with the sound reinforcement system. Although the first iteration of our venue
had a length greater than 55 meters, it soon became quite apparent that a longer venue would need
multiple delay systems to provide even coverage. This increased spectral variance throughout the
venue to more than ± 5 dB over the entire operating range, which was not ideal. Shortening the length
of the venue to under 45 meters worked wonders for the loudspeaker coverage, allowing us to use 2
flying arrays above the stage to effectively cover the entire audience area with only the help of front
fills.
After this, the venue dimensions were continually tweaked in order to get sufficient under-
balcony coverage. For this reason, the depth of the balcony was reduced and the entire balcony was
moved higher in order to prevent any interference from the edge of the balcony. In order to reduce the
length of the venue and still meet the seating requirements of the venue, the width was increased
considerably. The wide, fan shaped design had another advantage, which was that it allowed each
array sufficient horizontal coverage without them interacting with each other and causing undesirable
lobes. The center aisle was made as wide as possible in order to minimize the speaker overlap in the
center of the venue. Care was take to ensure that there were no parallel surfaces in the entire hall,
which will prevent standing waves from adversely affecting the sound reinforcement system. In
particular, flutter echoes, which normally occur between spaced parallel walls, will be minimized due
to this venue design.
Initially, all of the surface materials where highly absorptive, which resulted in an ALCONS
(Articulation loss of consonance) level of 3.4%. Such a low ALCONS level had the potential to
sound unnatural, since the ideal recommended ALCONS level for live system reinforcement is
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between 4 -7%. Another important consideration we had to take into account is that the highly
absorbent materials drastically reduced the high frequency coverage of the system. Since a single
array was being used to cover the entire audience area, it was critical for the surface materials to
support good high frequency coverage and compensate for losses due to pink shift. For this reason,
materials towards the back of the auditorium were modified to allow a bit more high frequency
reflection. Acoustic tiling on the ceiling was replaced with a wooden slotted ceiling that diffuses
sound without absorbing it, increasing the “liveness” of the venue.
Seats at the back of the auditorium under the balcony were chosen to be made of wood as
opposed to the leather seats in other audience areas. This allowed for even speech intelligibility
across the venue, with high frequencies being absorbed near the stage but gently reflected at the back
of the hall. The back walls were made out of engineered concrete blocks that are both absorbers and
diffusers. This was important to prevent direct sound from reflecting straight back onto the stage and
affecting performers and also audience members, to whom the delay between direct and reflected
sound will be painfully apparent. The front of the balcony was lined with Auralex bass traps in order
to prevent undesired low frequency interactions. This was a more practical approach than using split
mains to cover the venue, which would have required extra mounting hardware`The floor between
audience areas was concrete with carpet, and the side walls were concrete with thin drapes, this
prevented too much absorption while still preventing the ALCONS level from becoming too high.
The final obtained ALCONS level was a desirable 6.8%, which meets the design requirements but
also strikes the balance between live and dead sound.
The biggest issue we faced in this system design was the availability of EASE data from
loudspeaker manufacturers. There is no standardized resolution between manufacturers, nor does
every manufacturer have EASE data for all of their products. Also, modifying the EASE
preconfigured auditorium was a challenge; there was a point when the changes made the venue
completely unrecognizable, and the limitations of EASE 3D extrusion modeling became quite
apparent. It was finally decided to build a new venue from scratch to accommodate the new
architectural constraints that we had discovered during the design phase.
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Rahul was in charge of the venue design, loudspeaker selection and placement and EASE
simulations. It was important for all of those tasks to be coherent, which is why it made sense for one
person to do all of them. To overcome the EASE resolution compatibility issue, Rahul chose all the
speakers from the same manufacturer (JBL) so that the resolution of all speakers modeled in the
venue are consistent. He also modified the venue to suit the speaker system, and then worked with
gain tapering, adjusting splay angles and equalization of the individual array elements to get the most
even coverage. His task also included selecting and modifying all the materials in order to go hand in
hand with the venue and the sound reinforcement system. It was clear early on that Matt undertook
the challenging task of fully understanding the components and processes involved in using a fully
digital networking based system. This involved detailed research into Cobranet and other digital
protocols. He identified the power conditioning and sequencing requirements of the system based on
which he designed the racks. He also created the signal flow diagrams for this report, to show the
power sequencing application as well as the overall signal flow of the sound reinforcement system.
Ishaan picked out and researched suitable mixing consoles as well as microphones for the right
applications. He worked to find a reliable console for live sound mixing that would be compatible
with Cobranet and reduce the overall latency of the system. The remaining tasks were worked on
together as a group.
2. Design Constraint Analysis
The Meyer Sound LYON system was initially chosen to be the loudspeaker system for our
venue. The Galileo Loudspeaker Management system is widely considered to be one of the best
systems for DSP and array management, and we decided very early on to use it along with the Meyer
Sound family of speakers to create desirable sound reinforcement for our venue. Unfortunately,
Meyer sound does not have EASE data for all their loudspeakers, and we were forced to abandon the
LYON system. This was extremely disappointing, especially since we had designed our initial venue
around the coverage patterns of LYON. We then switched to the M series of speakers with the MILO
high power curvilinear speakers for the main arrays. However, in the room designed for LYON, the
power output of MILO was too low and we were unable to get reliable coverage above 100 dB at all
listening positions. Modifying the venue did not help much, since we still had to make sure we had a
minimum seating space of 4000 seats. Introducing multiple MILO arrays as side fills and under
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balcony fills created a new problem. The spectral variance across seating areas varies considerably
with the addition of more sound sources. As a result we were forced to discard Meyer Sound
altogether and instead try out other, more powerful line array systems from JBL, EV and QSC.
Eventually, despite its lower resolution EASE data, we chose to use the JBL VerTec series array due
to its high SPL outputs. Since we were able to consistently simulate Total SPL levels greater than 120
dB at the back rows of the auditorium, we were able to manage without delay systems other than
front fills.
Initially, we had placed the more compact MILO arrays closer to and above the stage.
However, this was not a possibility with the large VerTec Array; its larger and more conspicuous
presence would certainly be undesirable in the middle of the stage. In fact, we widened the stage and
moved the arrays to the corners of the stage in order to prevent the arrays from ruining the aesthetics
of the venue. While aware that this does affect the horizontal localization of sources on stage, it was a
necessary compromise in order to preserve the functionality of the venue. Despite being a heavier
array, the J.B.L. VerTec series come with integrated mounting hardware for the patented J.B.L.
S.A.F.E. mounting mechanism, which has multiple features to ensure safety. For example, mounting
line array elements require the use of quick release pins to connect them together that will not
unfasten until an element has been loaded and fully secured in the array.
By selecting a fully powered speaker system with networked audio capabilities, we were able
to make this an extremely economical system to wire and configure. Running multiple channels of
audio over single ethernet cables dramatically reduces the overall number of points of susceptibility
in the system. Each line array element also features a completely modular I/O back panel which
basically future-proofs the loudspeaker system. JBL constantly offer updates and improvements to
hardware and software, allowing their products to be upgraded and kept up to modern standards.
Although the current networked system provided in this report passes audio over a single network
cable and does not have built in redundancy, it will not be very expensive to upgrade the network
architecture to include redundancies. One possibility is the creation of a mesh/self-healing network
that will automatically switch to working network paths. The mixing console was chosen due to its
Cobranet compatibility, this will allow it full network control without any issues of latency that non
compatible devices that operate using different protocols like AES will face. By using digital audio,
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the signal is less susceptible to noise and interference as well as signal degradation over distance. An
I/O stage rack is provided so that long XLR snakes will not have to be run over the length of the
auditorium.
Microphones were chosen based on their suitability and durability for live applications. Shure
SM 57 and SM 58 microphones are solid, reliable and great sounding dynamic microphones that will
serve as long term instrument and vocal amplification requirements. Although drums can be
amplified with regular instrument microphones, we felt that it would be useful to have microphones
that are designed specifically for this purpose would be a big advantage. Normally, drum miking is a
complicated process that requires careful consideration regarding mic pickup patterns, phase
differences and appropriate acoustic separation. A Heil HDK 8 piece drum microphone kit will
reduce the difficulty of matching microphones to individual drum elements and lower the required
proficiency level of the sound board operator.
Electrical safety has to be given priority; despite cutting down on cabling requirements and
cost, there are many components in the system that need AC power and will have to be addressed.
For this reason, a few basic safety points need to be considered (Center for Safety in the Arts, 1997).
All AC circuits must be grounded, and circuits from portable switchboards need to have over current
protection. All electrical outlets should be recessed, and back feeding of circuits should not be
allowed. Following these few basic rules in the system implementation and operation will prevent
any untoward incidents that compromise the safety of all individuals involved. Appropriate power
sequencing and conditioning is also important in a system with a great deal of expensive pro-audio
equipment. This has been addressed in the rack design, with appropriate power conditioning and
sequencing from Furman built in to the system.
3. Design Constraint Satisfaction
With the large VerTec Array, its conspicuous form would certainly be undesirable in the
middle of the stage. As a result, we widened the stage and moved the arrays to the corners in order to
prevent the arrays from ruining the aesthetics of the venue. Each array is placed 15 meters from the
floor level and spaced 16 meters apart. They are angled 15 degrees away from the horizontal (away
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from each other). The topmost element in the array is pointed 3 degrees up to cover the entire balcony
seating area.
The JBL VerTec 4889 ADP-CN was chosen to be the main array element due to its high
power output. The VerTec 4888 DP-CN was used for frontfill sound reinforcement due to its smaller
enclosure but similar coverage patter to the 4889 ADP-CN. The JBL VerTec 4880 ADP-CN powered
subwoofer was chosen as it is the same size as the VerTec 4889 and works with the same rigging and
support structures. This selection of loudspeakers has a much higher SPL output than the Meyer
Sound MILO speakers that were initially considered; they were not able to consistently provide an
SPL level above 105 at all seating positions.
Despite being a heavier array, the J.B.L. VerTec series come with integrated mounting
hardware for the patented J.B.L. S.A.F.E. mounting mechanism, which has multiple features to
ensure safety. For example, it features quick release pins that connect between each array element,
and they will not release until an element has been loaded and fully secured in the array.
All S.A.F.E. hardware is designed, engineered, and certified with a 6:1 Safety Ratio, which means the
that the support structure must be capable of supporting 6 times the weight of the array. The preferred
way for flying array elements to be connected to each other include connecting the top truss of one
element to another using 2 connecting bars on each side attached with a quick release pin. For curved
arrays, as is the case here, a Locking Steel Caribiner (ASF-LSC) will also be required to allow high
splay angles.
The support structure for the J arrays had to take into account safety, usability and venue
aesthetics. Using a pair of line array towers and a truss that goes across the front of the stage is a
common option at multipurpose venues, since the truss can also be used for lighting requirements.
(Craig Leerman) However, venue aesthetics were a big consideration and hence this method was
ruled out. Construction lifts are often used to fly loudspeakers at outdoor venues where rigging has to
be done in a limited mount of time. We decided that the venue required a more permanent solution,
one that would be aesthetically pleasing in the venue. Since the venue is being designed and built
from scratch, we can incorporate a permanent installation of the sound reinforcement system. For this
reason, the J arrays will be “dead hang flown”, which means that the J array will be connected to a
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structural ceiling beam without a motor or lift. However, it is important that the structural integrity of
these beams are designed and evaluated by an experienced civil engineer before arrays are mounted.
Access to the arrays can be through personnel lifts or scaffolding.
In order to satisfy the design constraints, the splay angle between speakers had to be adjusted
and each individual array element required equalization. This was especially true for the speakers that
were higher up in the array that required high frequency reinforcement for the longer travelling sound
waves. For the the top 5 array elements, frequencies above 2kHz were boosted between 3 and 6 dB to
compensate for pink shift loss. Splay angle was also kept to a minimum for this reason. As you can
see from the EASE simulation - the painstaking venue design, speaker selection, positioning, and
equalization resulted in very even coverage over the 1kHz, 2kHz, 4kHz, and 8kHz frequency bands.
The venue has a total of 4200 seats, and all of the design constraints are met, including minimum
SPL, spectral variance and %ALCONS level. There was a noticeable amount of acoustic power
addition in the center of the venue, and although this increases the overall system efficiency, it
resulted in slightly uneven SPL coverage of the venue. For this reason, the aisle was designed to be in
the center of the venue and 4 meters wide. This means that maximum acoustic power addition will
occur in the aisles and allow the audience areas to be covered evenly, resulting in a total SPL
coverage of ±2 dB SPL across all seating areas. This is well within the system design requirement of
±5 dB SPL. This is especially impressive as the venue is being covered only with 2 main arrays and
front fills.
4. Equipment Selection
1.1. Power Amplifier Requirements and Selection
Selecting the amplifiers for this design was a very short process. We chose to utilize an
entirely active system which means that the amplification and digital signal processing were
completed within each individual speaker. All of the alternatives considered were actively amplified
as well. By selecting actively powered speakers the amplifier requirements are sure to be met because
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the manufacturer obviously designed the amplifier and speaker to be paired together. The only
requirement for us to consider then is the AC power demands.
The included amplifiers are JBL Drivepack DP-3 amplifiers. They employ a highly efficient
class I amplifier topology that allows it to be run at higher levels with less energy use because the
reactive energy is used again instead of dissipating it as heat. This also keeps the speakers much
cooler. For the front fill and our main arrays the DP-3 at load outputs 6000W Peak and 3000W
Continuous, while when used in the subwoofers the DP-3 outputs 6900W Peak and 3500W
Continuous. Electrical wattage calculations are not necessary as the amplifiers are integrated with the
speaker.
The AC requirements are not overly strenuous for the system. The VT4888 and VT4889, used
for front fill and mains respectively, only require 6A while the VT4880, used for subs, require 15A as
the bass bumps draw the heavy power. There are 10 units in each of the two main arrays, 6 units in
each of the two sub arrays, and 3 front fills calling for a total of 318A to be distributed. We are
assuming a US location so this is based off of the provided specifications for 120V operation. Power
distribution, sequencing, and conditioning will be covered in section 4.5.
1.2. Signal Processing Requirements and Selection
Since we are already utilizing the active amplification of the JBL DP-3 module, it was only
logical to use the internal digital signal processing as well. This allows each speaker to have its own
dedicated DSP on the fly, all controlled from the front of house via a CobraNet system. CobraNet is a
digital audio over Ethernet system and makes the decentralized DSP easy, efficient and possible.
The DP-3 offers a wide range of digital sign processing functions. These include a delay of up
to 2 seconds, equalization, level control, limiting, and included signal generation functionality (JBL
2010). All of the functions are remotely controllable via HiQnet System Architect over the CobraNet
network. The compatible software is available for personal computers as well as tablets so the
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operator can adjust the DSP functionality from anywhere in the venue. Up to 50 presets can be stored
so the venue can be quickly adjusted to meet the requirements of multiple acts.
Overall we decided to to implement the on board DSP over more traditional methods for
several reasons. First, we are paying for the functionality regardless since it is included in the same
system providing the active amplification. Second, the DP-3 provides all of the required functionality
and more all while being connected through CobraNet. The CobraNet compatibility is the huge
selling point, however. The ability to control each speaker individually and remotely using only 1
wire to transmit everything is a huge convenience factor that should not be over looked. A signal path
wiring diagram is included in Appendix D.
1.3. Mixing Console Requirements and Selection
The mixing console was primarily based on our needs of connectivity with CobraNet. Since
we chose to have a digital environment for our connectivity between speakers with CobraNet, we
needed a mixer which would support it.
Initially, for our first venue without CobraNet connectivity we chose the Allen and Heath
Ilive-R72 as our mixing console. It was later discovered that this console doesn’t support CobraNet.
Thus, we had to switch our mixing console to something that could support our digitized
environment. The ILIVE-R72 had 12 faders, audio and control over single CAT5 and 8 audio in and
out ports. This console met all the constraints set for the project but it didn’t fulfill our needs.
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After doing a little more research after finalizing our venue and connectivity design, we chose
the Yamaha M7CL mixing console as our final console. This console has 56 inputs and 64 outputs
which satisfy the minimum requirements of at least 48 channel mixing console as specified in the
abstract. This console can be connected to iPads, Laptops for control. Anyone in FOH can monitor
the speakers through the console and adjust the DSP and even record audio using a laptop or an iPad.
The best feature about this console was the CobraNet connectivity to create a digitize
environment for speakers and reduce wiring by a huge amount. We can install 3MY16 CobraNet
cards in the mixers 16 channels, each for 48 digital channels, reducing the wiring significantly. This
mixer also features the HA gain which means that it can adjust the gain of the console’s input
channels head amplifiers over a 72-dB range if needed. The Direct EQ control feature allows the user
control any of the 31 bands on the graphic EQ via the trademark centralogic faders from Yamaha.
The M7CL mixer can be properly placed on a workstation whenever required. The
input/output connectivity is one of the best things for the mixer due to which it was chosen in our
final design
1.4. Microphone Requirements and Selection
Microphone selection was mostly based on the constraints provided and the fact that many
different types of instruments could benefit from various types of microphones. We took in to
account the frequency response, impedance, directionality of the mics etc. For eg: If the mics used for
drums are omnidirectional, that might lead to bleeding in the sound. After looking at the above
specifications, we chose the following microphones for our design:
■ (1) Heil HDK - 8
■ (1) DPA Mic 4099P
■ (10) Shure - SM57
■ (10) Shure - SM58
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The Heil HDK – 8 is a 8 piece drum mic set specifically made for drum sets. This mic set is
perfectly placed in front of the pieces of the drums and aligns perfectly to the height of the pieces.
The DPA mic 4099P is a perfect match for pianos. This microphone has a built in windscreen
and shock mount. It can also be magnetically mounted on the piano frame. It has a supposedly flat
frequency response, high gain before feedback and excellent phase characteristic.
For general musical instruments such as Guitar, Trumpets etc, we chose the ever reliable
Shure SM57’s. These mics has extremely good reputation and a long history to prove it reliability.
We chose to get the Shure SM57 package which includes the mount so that it can be perfectly
mounted. We plan to use the SM57’s for all the other musical instruments that may be present during
the performance.
Finally we chose the Shure SM58 for general vocals and speaking as again they are extremely
reliable. The frequency response for this mic is tailored for vocals with brightened midrange and bass
roll off which makes it perfect for the vocals. Another good feature is the the Pneumatic shock-mount
system which cuts down the handling noise. The frequency response ranges from 50 to 15,000 Hz.
We chose to get 10 of these wonderful mics for vocals and speaking as there is no other contender in
this category to win over the SM 58’s.
We used the Shure in-ear monitors after comparing it with the Clear-Com single ear headset
(XLR-4F). The Shure PSM-1000 system allows up to 20 wireless in ear monitors at once which
vastly surpasses the design requirements.
1.5. Rack Requirements and Design
Like the rest of the design, the rack specifications were quite minimalist. The design does not
call for much hardware due to the active speaker selection with integrated digital signal processing.
This meant that most of the space required came from the power sequencing and conditioning units.
We went with Middle Atlantic racks because they have a good reputation and have high quality units
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available. The BGR-25 and BGR-19 racks that we selected are “furniture grade” according to the
manufacturer. This means that externally they are very aesthetically pleasing so there is no need to try
and hide them away from sight.
Two racks were included with this design. The first rack is stationed in the front of house and
contains 19u’s of space. It will contain a drawers for storage (1u/2u/4u), a 16 port rack mountable
network switch (1u), an EtherCON panel to change EtherCON to unlocked Ethernet cords (1u), and a
Furman PS8R-II power conditioner and sequencer (1u). This rack has 9 empty slots for expansion.
The amount of slots also makes it tall enough for useful desk space in the front of house area All
audio recording and playback functionality is done through the laptop.
The second rack is located back stage and has 25u’s of space available. Inside the rack are 4
Furman ASD-120s for power conditioning and sequencing of the speakers (2u’s each), 1 PS8R-II for
power conditioning and sequencing of the electronics (1u), the PSM-1000 in ear monitor system (1u),
3 microphone pre-amps (1u), a network bridge (1u), a network switch (1u), an EtherCON panel (1u),
and drawers for mic/monitor storage (2u’s each), and a general storage drawer (4u). This is a total of
21u’s occupied with 4u’s of space left that will be used for separation to enhance cooling.
The power sequencers will likely generate the most heat so they will be placed near the top.
After the sequencers there will be a blank space for cooling followed by the wireless monitor
controller. The microphone pre-amps will follow after another blank space for cooling. Under the
pre-amps will be the 2 storage drawers. Lastly the network bridge, network switch, and the
EtherCON panel. This order was chosen to maximize cooling efficiency and to keep the most used
items within reach of a comfortable standing height.
1.6. Cabling and Wiring Requirements
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For this design we tried to make the cabling as condensed as possible. We achieved this goal
through the CobraNet system to transfer audio and control signals over Ethernet instead of using
standard analog cables. With CobraNet it is possible to transfer up to 64 channels of high quality
audio simultaneously on a single wire. The system allows every speaker to be controlled remotely
while only sending 1 line to the front of house.
On the stage we have the ability to capture audio from up to 24 microphones at once and
transmit audio to a max of 20 wireless in ear monitors. The audio at these points is analog and
connects via balanced XLR cables to multiple Yamaha AD8HR where the signals are converted in to
digital audio. The XLR cables were purchased in a variety of lengths (10’/25’/50’) and are run through
under stage multi channel snakes when needed to minimize the tripping hazard. The balanced and
high quality cables will help ensure that sound quality is upheld. From the Yamaha AD8HR the
signals and digitally transferred over to a Yamaha NHB32-C Network Bridge on D-Sub 25 pin
AES/EBU cables. The network bridge takes all of the channels and puts them out on a single Ethernet
cable in full duplex utilizing the CobraNet system.
The CobraNet system connects everything in the auditorium seamlessly. A 16 port network
switch housed stage side is used as the main hub to connect all of the traffic. The network bridge,
mixing table, front of house laptop, and several other switches for the speakers are all connected to
this main hub. There is a star topology of five more 16-port switches connected to the main hub to get
the digital audio to the speakers. Each group of speakers has it’s own switch; the left/right main
arrays, left/right sub arrays, and the front fills. Limiting the number of cables that traverse long
distances is prioritized over utilizing every port in the switches, therefore the switches were placed
near the arrays. This also minimizes the total amount of cabling need.
In general, normal CAT5 Ethernet cables with RJ-45 connectors are used. In some cases, such
as from the main hub to the front of house, there might be tripping hazards which could cause a
normal Ethernet cord to come unplugged. To prevent this from happening we used EtherCON
connections to properly secure the cables in place. EtherCON is a standard Ethernet cable but uses
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the same locking mechanisms at the terminations that XLR cables use to make sure they don’t come
unplugged.
5. Summary and Recommendations
As discussed in the report, we used top of the line powered line array elements from the JBL
VerTec series as our speakers of choice. The venue has been intelligently designed to allow even SPL
coverage and low spectral variance with only 2 main speaker arrays and front fills. Six front fill
speakers were used for the first 10-15 rows to provide even coverage even at the front of the hall. The
overall ALCONS level of 6.8% is extremely good and falls well within the system requirement of
<10% ALCONS.
The Yamaha M7CL mixing console was chosen due to the excellent connectivity with
CobraNet to make it a digitized environment. We also have on board DSP and Amplification. Shure
In-ear monitoring system was used to monitor the sound in the entire venue. An assortment of wired
and wireless microphones for various types of equipment and vocals were chosen while keeping the
constraints in mind. This includes a specific drum microphone kit as well as a number of vocal and
instrument microphones that will be necessary in a multi-purpose auditorium.
Extra money can be used to expand and upgrade the mixing console. The money could also be
invested in the design of scalable and reliable network architecture.To future-proof the system from
future changes in technology, we selected line array elements with modular panels on the back. We
recommend that extra money also be used to regularly upgrade the system without an overhaul of the
entire system. Audio over network cabling is the way of the future, and our upgradable and scalable
system design allows this multipurpose venue to be on the cutting edge of technology for many years
to come.
6. References
ECE 40020 Sound Reinforcement System Design Spring 2014
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Cobranet HOME | CobraNet HOME. (n.d.).CobraNet. Retrieved May 9, 2014, from
http://www.cobranet.info/
JBL Professional. (2010). DPDA Input Module [PDF]. Retrieved from www.jblpro.com.
JBL Professional. (2008). VT4880ADP [PDF]. Retrieved from www.jblpro.com.
JBL Professional. (2008) VT4888DP [PDF]. Retrieved from www.jblpro.com.
JBL Professional (2008). VT4889ADP [PDF]. Retrieved from www.jblpro.com.
Center for Safety in the Arts. "THEATER SAFETY." University of Illinois at Chicago -
UIC. N.p., n.d. Web. 12 May 2014.
Craig Leerman. "Live Sound: Defying Gravity…Safely: Approaches And Best Practices In
Flying Loudspeakers." Pro Sound Web. N.p., n.d. Web. 12 May 2014.
Appendix A:
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Activity Logs
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Activity Log for: Matt Jordan Role: Wiring, DSP, Amplification, Racks, Power,
Flow Charts
Activity Date Start Time End Time Time Spent
EASE Tutorial 22 April 9:45 11:45 2 Hr
Venue Design 23 April 8:00 11:00 3 Hrs
Poster 28 April 7:00 8:00 1 Hr
Design Showcase 2 May 4:00 5:00 1 Hr
Power sequencing and conditioning 6 May 8:00 11:00 4 Hrs
Team meeting 7 May 7:30 8:30 1 Hr
CobraNet 7-8 May 9:00 2:00 6 Hrs
Presentation preparation 8 May 9:00 11:00 2 Hrs
Work on final report 9 May 12:30 9:30 9 Hrs
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Activity Log for: Rahul Sarma Role: Venue design, Speaker selection & placement, EASE simulations
Activity Date Start Time End Time Time Spent
EASE Tutorial 22 April 9:45 11:45 2 Hr
Venue Design 24 April 11:00 2:00 15Hrs
Poster 28 April 7:00 8:00 1 Hr
Loudspeaker selection 2 May 8:00 16:00 8Hrs
Loudspeaker placement/EASE simulation 6 May 8:00 23:00 15 Hrs
Team meeting 7 May 7:30 8:30 1 Hr
Presentation preparation 8 May 9:00 11:00 2 Hrs
Work on final report 9 May 12:00 17:00 5 Hrs
Work on final report 11 May 8:00 14:00 6 Hrs
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Activity Log for: Ishaan Kohli Role: Microphones and Mixing console
Activity Date Start Time End Time Time Spent
Poster 28 April 7:00 8:00 1 Hr
Microphones 1 May 7:30 8:30 4 Hr
Mixing console 2 May 8:00 16:00 4 Hrs
Team meeting 7 May 7:30 9:30 2 Hrs
Presentation preparation 8 May 9:00 11:00 2 Hrs
Work on final report 9 May 12:00 17:00 4 Hrs
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Appendix B:
Venue Illustrations
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Appendix C:
Loudspeaker Placement and EASE Simulation Results
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Appendix D:
Signal Path Wiring Diagram
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Appendix E:
Rack Design and Power Sequencing/Distribution
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Appendix F:
System Component List and
Street Price Estimate
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D-Link DGS-1016D 16-Port Switch $127.99 6 $767.94
Netgear XSM7224S 24-Port Managed Switch $7,299.95 1 $7,299.95
Yamaha AD8HR A/D Mic Preamp $2,315.99 3 $6,947.97
Yamaha NHB32-C Network Bridge $3,524.95 1 $3,524.95
Yamaha MY16-CII CobraNet Card $764.95 1 $764.95
Shure PSM-1000 In-Ear Wireless Monitors $5,105.00 2 $10,210.00
Furman ASD-120 Power Sequence/Condition $699.95 4 $2,799.80
Furman PS8R II Power Sequence/Condition $269.95 2 $539.90
Middle Atlantic BGR-25 25u Rack $2,038.60 1 $2,038.60
Middle Atlantic BGR-19 19u Rack $1,939.14 1 $1,939.14
Cable Whole Sale 10X6-002SH Cat5e Ethernet Cable $104.63 2 $209.26
Aviom 20-EC-EC EtherCON Rack Panel $175.00 2 $350.00
Kopel 25' XLR $20.00 20 $400.00
Kopel 10' XLR $16.00 20 $320.00
Whirlwind 12 Channel Snake $270.00 2 $540.00
Whirlwind 6 Channel Snake $180.00 2 $360.00
JBL Pro VT4889ADP Main Array Speakers $12,211.00 20 $244,220.00
JBL Pro VT4888DP Front Fill Speakers $9,560.00 6 $57,360.00
JBL Pro VT4880ADP Subwoofer Array Speakers $8,449.00 8 $67,592.00
JBL Pro Frame and rigging $4,300.00 1 $4,300.00
Yamaha M7CL Digital Mixer $11,500.00 1 $11,500.00
Yamaha MY16C-II CobraNet Card $764.95 3 $2,294.85
Heil HDK-8 8 piece drum mic set $1,652.00 1 $1,652.00
DPA 4099P Piano mic set $1,099.00 1 $1,099.00
Shure SM58 Vocal mics $100.00 10 $1,000.00
Shure SM57 Instrument mics $100.00 4 $400.00
TOTAL $430,700.3
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Appendix G:
Manufacturer Data Sheets
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https://www.jblpro.com/pub/technote/ary_safe.pdf http://www.jblpro.com/ProductAttachments/JBL_VT4880ADP.v8.pdf http://www.jblpro.com/ProductAttachments/DPDA_InputModule_SpecSheet.pdf http://www.jblpro.com/ProductAttachments/JBL_VT4889ADP.v7.pdf http://www.jblpro.com/ProductAttachments/DOC_1089.pdf http://www.downloads.netgear.com/files/GDC/GSM5212P/ProSafe_CLI%209-0-2.pdf http://cdn.shure.com/specification_sheet/upload/162/PSM_1000_Spec_Sheet.pdf http://download.yamaha.com/api/asset/file/?language=en&site=ae.yamaha.com&asset_id=46698 http://download.yamaha.com/api/asset/file/?language=en&site=ae.yamaha.com&asset_id=46638 http://www.furmansound.com/pdf/datasheets/ASD-120_datasheet.pdf http://www.furmansound.com/pdf/datasheets/PS-8R_II_datasheet.pdf