Assignment 2 –Audio Systems Design and
Evaluation
Audio Systems and Measurement – DESC9090
Architecture Design and Planning, University of Sydney

Contact for
assignment:
Luis Miranda Jofre luis.mirandajofre@sydney.edu.au

Assessment Title: Design and Evaluation of Audio Systems
Individual or group: Individual
Weight of final grade: 40% (First task 6%, second task 3%, final report 31%)
Due date & time: 19 Nov

Deliverables: - ~2000 word written assignment (3000 words maximum)
- EASE packed project

1. General Objectives
Upon successful completion of this assignment, students should have a good understanding
of the processes and requirements involved in the design and evaluation of a professional
sound reinforcement system. The assignment requires the student to design a sound system
for a space and reflect on principles used in the design of such systems. More importantly,
students are required to analyse the response of their system and highlight deficiencies and
achievements and show critical thinking based on electroacoustic principles and typical
design metrics.

2. Materials
Students will be provided with the following:
a) An EASE packed project with a performing room model. The model shall not be
altered geometrically or acoustically in any way. The location of the loudspeakers in
the model can be altered and augmented with additional locations.*
b) Models for two manufacturers to aid you in designing the sound system
c) Additional readings relating to sound system evaluation.

*Make sure that you open the provided zip file from within EASE just as you would any
other file. You can open the file from EASE without being unzipped.

3. Tasks
The tasks for this assignment are, in brief:
a) Design a sound system which will be demonstrated by your EASE project delivery.
b) Write an assignment that talks about your design at length.



4. Design Targets
The following design targets are set for the system.
Parameter Design Target Reporting On Calculation
Method
Notes
Coverage
Uniformity
125 Hz – 8 kHz (6 dB
range or coverage
envelope)
Distribution
on all areas
Mapping
Module – Use
Direct Field
Following
ANSI/InfoComm
Standard A102.01-
2017
Spectral
Balance
SB-A Seats Aura Calculation
– Use Direct
Field
Following AVIXA
Standard
A103.01:201X (Draft)
SPL (Total) 110 dB(A) min
(remember you need
to sum all bands)
Seats Aura Calculation Lower target than FI
FIFA requirements in
Football stadiums –
Technical
recommendations
and requirements
SPL
(Direct)*
40 Hz – 100 Hz sub
augmentation
Cannot be done in
EASE
STI 0.55 min (male) Seats Aura Calculation Following FIFA
requirements in
Football stadiums –
Technical
recommendations
and requirements

As part of the first task in section 3, it is expected that you will go through iterations to
deliver results as close to these targets as possible.

The AURA results are to be calculated as: Particles – Intermediate Resolution and Length –
Standard, Fast. You need to tick Consider Noise Levels and Signal Masking in the Options
tab of your calculation.

It is expected that, at some locations, these results will be unachievable. The written
assignment should show that you have a good understanding of why this would be the
case.

*For the low frequency augmentation you need to nominate a product and their location.
EASE does not include calculations for lower frequency bands.



5. Suggested Written Assignment Structure
The following structure is recommended for the written assignment. Suggestions of topics
to consider when writing your assignment are included.

Introduction
Giving a brief overview of your assignment.

System design
Including details of your sound system including:
• Speaker system
• Details of arrays including locations, number of elements and configuration
• Any additional details (required EQ, etc.)
• Include low frequency augmentation

Results
Results and their relationship to design targets. Make sure you include appropriate
summaries for your results. Statistical descriptors included in the obtained EASE reports are
encouraged. Understanding statistical descriptors is greatly encouraged.

Analysis
This is the most important section of your assignment. For this section I expect you to talk
about some or all of these topics:
• Consistency of coverage – Is the entire hall covered evenly? Is it covered evenly at all
frequencies or is there a frequency dependent behaviour associated to this? A good
analysis tool for this are the mapping files. For numerical results the distribution
values, average and standard deviation descriptors are useful. If this is not achieved,
why is this the case? Is it frequency range specific interactions between multiple
loudspeakers? Is it inconsistencies in the loudspeaker coverage across frequencies? If
you are using line arrays, is this influenced by their configuration and element
number?
• Frequency response – Is the frequency response appropriate? Is it better to have a
flat frequency response or should some frequencies be emphasised? Good indicators
of these are the average response again, as well as individual responses from several
seats.
• Acoustics of the venue – Although not something that can be improved as part of this
assignment, the acoustic response of the venue will influence the response of the
system. Are the acoustics of the room supporting the performance of the system?
What are the acoustical characteristics? To correctly assess the acoustics of the room,
a calculation involving ray tracing is required. It is recommended that the students
use Aura calculations for this. This can be done at the same time as the calculations to
provide the system response. If you are reporting on acoustic metrics, is it correct to
use a single source or multiple sources?
• STI –STI is a very good indicator of not only, the speech intelligibility of the system,
but also of the overall performance of the system and it’s interaction with the
acoustic environment. The first question you need to ask is: does the system provide
enough speech intelligibility? Is the intelligibility evenly distributed across the entire
venue? If we have a low speech intelligibility: is it related to low values of the MTF? Is

it related to Signal to Noise Ratio? Is it related to the masking effect? This can be
analysed using the seat response. Further acoustic analysis can be performed by using
the ray tracing modules. Make sure you use correct results using auditory masking.
• Additional speech metrics – Are there additional metrics that can help you to
understand if the system will perform as it should. Consider looking at other metrics
included in EASE such as C50, C80 and Echo Criterion.
• Low frequency augmentation – EASE cannot perform calculations at lower
frequencies. Using alternative tools, demonstrate that the low frequency system will
be sufficient for the proposed loudspeaker system. Consider showing interactions
between low frequency loudspeakers and how this can be overcome.

Conclusion
Summarise your assignment.

References
Including references in your assignment will help to substantiate any of the above
sections.

6. Some Pointers
• It is expected that adequate coverage will require at least a main system (left and
right), side fills (left and right) and down fills or stage loudspeakers for the nearest
seats to the stage.
• Check levels and delays for all elements of the system that you introduce. Are all the
loudspeaker arrays correctly aligned in time? Is the response of the system the best
response it can provide? Use the standard deviation and distribution values of the
Direct Sound to check the consistency across all areas. Please use the average of the
Direct Sound as an indication of the overall levels across frequencies. Use the Arrival
Time values to check if the delay on the loudspeakers is correct. Check the delay and
frequency response of all arrays.
• Check the configuration of line arrays if you are using them. Are the arrays’ inter-
element angles appropriate? Is the main aiming point of the arrays aimed optimally?
The best check of this is the level plot across several frequencies. This is strongly tied
to the standard deviation and distribution of values in the previous point
• Report on the acoustics of the venue. The previous checks were performed on direct
sound calculations. For this point you will need Aura calculations. Remember that you
need calculation with a ray tracing element to be able to correctly characterise the
acoustics of the venue. In this file you will find a set of 12 seats.
• Report on the STI values obtained for the same Aura calculation 12 seats. Do the
acoustic parameters and STI values seem to be correlated? Please check the tick
boxes on the final tab of the results for the inclusion of background noise and the
calculation with signal masking. How are the STI values influenced by these two
parameters?
• Find useful references. There is a large range of references that can be included on
topics such as sound system arraying, metrics of speech intelligibility and their
criticism, acoustic metrics, etc.


7. Additional Models
Two additional models have been supplied to aid you in your assignment. The software for
these two is proprietary to two brands and can be found in the following links.

L’Acoustics: http://www.l-acoustics.com/products-soundvision-download-138.html
d&b: http://www.dbaudio.com/en/systems/details/arraycalc.html

It should be noted that no support will be provided for this software. I encourage that you
practice your independent thinking and research skills with this.

8. Mini Tasks
There are two mini tasks for this assignment.

8.1 Task 1 – Direct coverage simulation – 29th October
The first task is worth 6% of your FINAL grade. For this task you will submit an initial design
using the proprietary software you will be using (e.g. Soundvision, Arraycalc, etc.). This first
submission will allow me to provide advice on your submission. It will allow me to see that
you are heading towards the right direction.

The submission should include:
• Design file.
• Brief design description as a written document (i.e. number of sources, source
location, rationale for your design, etc.).

To obtain a good grade in this assignment you will need to demonstrate your ability to
research the use of simulation software and show independent research abilities,
particularly in terms of loudspeaker positioning. Impossible to do at the moment in person,
but think about places that you have been in your life. Have a look at photos of venues.

8.2 Task 2 – First round of simulations – 5th November
The second task is worth 6% of your grade. For this task you will submit an initial batch of
calculations in EASE. The results will include only the direct field calculations. This second
submission will allow me to understand that you are being able to position loudspeakers in
EASE and obtain data from the software. A brief document with description of the system
and the results presented should accompany the delivery (e.g. 500 words max).

To obtain a good grade in this assignment you will demonstrate technical proficiency in
EASE and ability to present the results coherently.



9. Grading Scheme
Assignments will be graded using the school’s typical grading scheme. Please note that
Credit is the grade given to assignments of good quality. Distinction and high distinction is
reserved for students’ ability who show outstanding learning outcomes including
independent thinking.
Grade Description
High
Distinction
85 - 100
Work of outstanding quality, demonstrating mastery of the learning outcomes assessed.
The work shows significant innovation, experimentation, critical analysis, synthesis,
insight, creativity, and/or exceptional skill.
Distinction
75 - 84
Work of excellent quality, demonstrating a sound grasp of the learning outcomes
assessed. The work shows innovation, experimentation, critical analysis, synthesis,
insight, creativity, and/or superior skill.
Credit
65 - 74

Work of good quality, demonstrating more than satisfactory achievement of the learning
outcomes assessed, or work of excellent quality for a majority of the learning outcomes
assessed.
Pass
50 - 64
Work demonstrating satisfactory achievement of the learning outcomes assessed.
Fail
1 - 50
Work that does not demonstrate satisfactory achievement of one or more of the
learning outcomes assessed.