Early attempts at loudspeaker array modeling used optical models of the various horns, to estimate sound coverage. No attempt was made to simulate low freq. sound coverage or loudspeaker interaction. With the introduction of digital computers, large institutions could greatly decrease the time it took to conduct the many calculations needed to predict RT in a real venue. Since the late 80s, Macs and PCs have been used to run pro-sound modeling programs, still based on optical/light modeling, to simulate sound.
But “sound isn't light, and Geometric acoustics (GA) does not capture the wave effects that dominate what we hear in a space The GUI's and graphics have far outpaced the accuracy of the acoustics model. It's not just number crunching - there are far too many numbers. Each software has unique algorithms to simulate the acoustic behavior. GA should never be referred to as having high accuracy. Even so, speaker array modeling is a very worthwhile exercise,” says Pat Brown, of prosoundtraining.com.
JBL’s CADP was the first, very basic, personal computer-based simulation, with an attempt to show loudspeaker interaction, but the graphic display was rudimentary (too few data points). Bose next introduced Modeler, an advanced acoustic and loudspeaker modeling program; it took advantage of the advanced graphics of Mac computers, to significantly advance the state-of-the-art, with much higher-resolution coverage mapping and a 3D view of the venue. Modeler was wide-range, intuitive to use, and allowed the system designer to see the direct sound coverage from any perspective desired, and it displayed a Ray-Trace study of echo paths along with RT (Reverberation Time). Early releases ran only on Apple’s Mac. computers and had a variety of loudspeaker brands, models and acoustical materials included in its database; but later releases focused on the, then very limited, Bose pro-sound speakers (reducing its usefulness).
For more on pro-sound modeling programs see Dr. Honeycutt’s articles at https://www.audioxpress.com/tags/Richard-Honeycutt.
Acoustic/loudspeaker modeling program & PC advancements
Other live-sound loudspeaker factories soon followed suit. Altec’s Acousti-CAD failed with their demise. JBL pro. responded with CADP2, their 2nd gen. simulation program for PCs; it was also, an intuitive high-resolution 3D program, to allow the system designer to see the direct sound coverage in any perspective desired and displayed a Ray-Trace study of echo paths along with RT calculations. Early releases also had a variety of loudspeaker brands/models and acoustical materials included in the database. Ray-Trace study of echo paths and RT could be simulated.
The Cluster Computer & PHD modeling programs fell from favor. The EASE program, developed by the German firm ADA (Acoustic Design Ahnert), came out next. It was not related to a specific product speaker brand (product line), so it was quickly adopted as a generic/ universal design tool for use with several brands of loudspeakers. As personal computer processing power increased over the decades, and as the developers were able to build on the progress made by others before them, more advanced large-room acoustics prediction and sound coverage modeling programs became available from several companies, offering improved prediction and signal processing algorithms.
Some more full-featured programs allow auralization of multiple room models and listener positions. Auralization allows a designer to demonstrate audible sound clips, to buyers, what the proposed sound reinforcement system will sound like in different locations, in a venue, and in various acoustical conditions (with or w/out treatment). Modeler remains one of the most intuitive of these to use; it currently provides estimated STI (Speech Transmission Index) and now runs on PCs with Windows. The Yamaha Y-S³ Sound System Simulator has a limited set of features, but it does auralization of point-source loudspeakers and is very easy to use. Well-featured array-specific modeling & control programs from most major array venders, provide mechanical CAD views, with rigging and weight data for their specific loudspeaker array models.
Universal Solutions for Array Modeling
Although not the most intuitive, EASE provided a wide range of loudspeaker brands and acoustic materials in their database. So, it became the dominant array program in the West, for high-resolution 3D array and acoustic modeling, to compare predicted sound coverage (AKA a “heat map”) and related room acoustics and STI simulation. EASE is no longer as dominant, as there are many array modeling & room modeling programs now available. CATT Acoustics has been dominant in Europe, with ODEON having significant market share and ULYSSES less popular.
Managing Director of AFMG Services NA Bruce Olson said. “The advent of line arrays and the need to configure them has resulted in a drastic expansion in the capabilities of line array simulation tools. These tools are available from a broad spectrum of manufacturers, some developed in-house, as well as more universal tools such as EASE Focus 3.”
Speaker data for EASE must be in the EASE GLL format, rather than the deprecated SPK and DLL file formats. CATT accepts CLF (common loudspeaker format). Many of the programs use a proprietary data format, although some use the CLF or can import other speaker data formats. Leaving another universal option, the use of 3D CAD programs, such as SketchUp, or the less popular AutoCAD, to draw a room (shown below), to then submit the room file to a few competing loudspeaker vendors, to model sound coverage.
But “sound isn't light, and Geometric acoustics (GA) does not capture the wave effects that dominate what we hear in a space The GUI's and graphics have far outpaced the accuracy of the acoustics model. It's not just number crunching - there are far too many numbers. Each software has unique algorithms to simulate the acoustic behavior. GA should never be referred to as having high accuracy. Even so, speaker array modeling is a very worthwhile exercise,” says Pat Brown, of prosoundtraining.com.
JBL’s CADP was the first, very basic, personal computer-based simulation, with an attempt to show loudspeaker interaction, but the graphic display was rudimentary (too few data points). Bose next introduced Modeler, an advanced acoustic and loudspeaker modeling program; it took advantage of the advanced graphics of Mac computers, to significantly advance the state-of-the-art, with much higher-resolution coverage mapping and a 3D view of the venue. Modeler was wide-range, intuitive to use, and allowed the system designer to see the direct sound coverage from any perspective desired, and it displayed a Ray-Trace study of echo paths along with RT (Reverberation Time). Early releases ran only on Apple’s Mac. computers and had a variety of loudspeaker brands, models and acoustical materials included in its database; but later releases focused on the, then very limited, Bose pro-sound speakers (reducing its usefulness).
For more on pro-sound modeling programs see Dr. Honeycutt’s articles at https://www.audioxpress.com/tags/Richard-Honeycutt.
Acoustic/loudspeaker modeling program & PC advancements
Other live-sound loudspeaker factories soon followed suit. Altec’s Acousti-CAD failed with their demise. JBL pro. responded with CADP2, their 2nd gen. simulation program for PCs; it was also, an intuitive high-resolution 3D program, to allow the system designer to see the direct sound coverage in any perspective desired and displayed a Ray-Trace study of echo paths along with RT calculations. Early releases also had a variety of loudspeaker brands/models and acoustical materials included in the database. Ray-Trace study of echo paths and RT could be simulated.
The Cluster Computer & PHD modeling programs fell from favor. The EASE program, developed by the German firm ADA (Acoustic Design Ahnert), came out next. It was not related to a specific product speaker brand (product line), so it was quickly adopted as a generic/ universal design tool for use with several brands of loudspeakers. As personal computer processing power increased over the decades, and as the developers were able to build on the progress made by others before them, more advanced large-room acoustics prediction and sound coverage modeling programs became available from several companies, offering improved prediction and signal processing algorithms.
Some more full-featured programs allow auralization of multiple room models and listener positions. Auralization allows a designer to demonstrate audible sound clips, to buyers, what the proposed sound reinforcement system will sound like in different locations, in a venue, and in various acoustical conditions (with or w/out treatment). Modeler remains one of the most intuitive of these to use; it currently provides estimated STI (Speech Transmission Index) and now runs on PCs with Windows. The Yamaha Y-S³ Sound System Simulator has a limited set of features, but it does auralization of point-source loudspeakers and is very easy to use. Well-featured array-specific modeling & control programs from most major array venders, provide mechanical CAD views, with rigging and weight data for their specific loudspeaker array models.
Universal Solutions for Array Modeling
Although not the most intuitive, EASE provided a wide range of loudspeaker brands and acoustic materials in their database. So, it became the dominant array program in the West, for high-resolution 3D array and acoustic modeling, to compare predicted sound coverage (AKA a “heat map”) and related room acoustics and STI simulation. EASE is no longer as dominant, as there are many array modeling & room modeling programs now available. CATT Acoustics has been dominant in Europe, with ODEON having significant market share and ULYSSES less popular.
Managing Director of AFMG Services NA Bruce Olson said. “The advent of line arrays and the need to configure them has resulted in a drastic expansion in the capabilities of line array simulation tools. These tools are available from a broad spectrum of manufacturers, some developed in-house, as well as more universal tools such as EASE Focus 3.”
Speaker data for EASE must be in the EASE GLL format, rather than the deprecated SPK and DLL file formats. CATT accepts CLF (common loudspeaker format). Many of the programs use a proprietary data format, although some use the CLF or can import other speaker data formats. Leaving another universal option, the use of 3D CAD programs, such as SketchUp, or the less popular AutoCAD, to draw a room (shown below), to then submit the room file to a few competing loudspeaker vendors, to model sound coverage.
Loudspeaker Array Modeling Trends
A current trend in Array Modeling is loudspeaker factories offering Line Array Calculator (AKA shooter), programs for free. These basic modeling programs, (many are based on EASE Focus) are commonly used by concert sound engineers, to improve sound coverage for concert touring and temporary music events, but are typically not able to model acoustics. There are also a few simple estimation and coverage aps. for selecting ceiling speakers for installation projects, such as: EASE Address, that only show coverage from ceiling speakers (in Overhead/Plan View).
These days it seems that most array simulation is done on one of the several Line Array Calculators, like EASE Focus. These 2D programs tend to be available for free; many of them were only showing a 2D side view (see FOCUS Figure below) but 3D views are now available. But free sound modeling simulators (AKA Line Array Calculators), as shown in the Figures above and below; are not able to do any array-room interaction nor acoustic simulation.
A current trend in Array Modeling is loudspeaker factories offering Line Array Calculator (AKA shooter), programs for free. These basic modeling programs, (many are based on EASE Focus) are commonly used by concert sound engineers, to improve sound coverage for concert touring and temporary music events, but are typically not able to model acoustics. There are also a few simple estimation and coverage aps. for selecting ceiling speakers for installation projects, such as: EASE Address, that only show coverage from ceiling speakers (in Overhead/Plan View).
These days it seems that most array simulation is done on one of the several Line Array Calculators, like EASE Focus. These 2D programs tend to be available for free; many of them were only showing a 2D side view (see FOCUS Figure below) but 3D views are now available. But free sound modeling simulators (AKA Line Array Calculators), as shown in the Figures above and below; are not able to do any array-room interaction nor acoustic simulation.
Charlie Hughes, Principle Engineer of Excelsior Audio added. “There is just no excuse to not model at least the direct coverage of a loudspeaker system on the audience area of a venue. There are many programs available for this that are free or relatively low cost. Problems can often be revealed at design time, rather than installation time, by doing this. Also, perform measurements on site to verify that the expected coverage is being achieved. If it’s not, there might be a problem with loudspeaker aiming or DSP settings.”
Line Array Calculators are set-up programs, offering a relatively simple, intuitive modelling tool, while supplying the required prediction data for good system performance. They consider the direct-field response, but not acoustics.
A good sound system alone, regardless of a brand name, does not assure good sound quality. A sound system is not complete without adequate (program appropriate) room acoustics. Sound systems can rarely cope with serious defects in a room design, and a more powerful system commonly makes such defects worse. Proper architectural acoustics design includes a well modeled room, and the study of how speaker arrays interact with the architectural acoustics (control of long echoes), to prevent costly architectural acoustic flaws, before a venue is built.
Advanced Analysis of Array Performance and Acoustical Modeling
Richard A. Honeycutt, Ph.D. explained “With CATT, EASE, or ODEON, I can look at the actual RT in 1/3 octave bands, using modeling methods that have been tested against measurements. I can look at objective acoustical measures including clarity, definition, sound strength, speech intelligibility (STI, %ALcons), and echo disturbance for speech and music per the Deitsch/Kraak evaluation method and criteria. I can objectively evaluate room support for congregational singing in a church. I can examine acoustical stage support for a choir or singing group that does not depend upon stage monitors. If echoes are a problem, I can identify their source so they can be eliminated. I know of no programs provided by loudspeaker vendors that will do these things. In short, I can do acoustical analysis. If all I wanted to do was look at loudspeaker coverage, I could do that with the free programs. But a good acoustical design requires much more than that.” For a more advanced understanding of the variables and choices entailed in proper acoustic design for performance and worship, read a book like Dr. Honeycutt’s, Acoustics in Performance.
For advanced analysis of array performance in an acoustical venue and/or to design/study critical acoustical projects, such as concert halls, many acoustical design consultants use an acoustic modeler/simulator, such as CATT-Acoustic, EASE (shown below) or ODEON; they are all world-wide standards for acoustic simulation, for both inside rooms and open areas. An acoustical venue can be defined using a CAD module, absorption or scattering coefficients can be assigned to surfaces and sound sources, as well as listener positions can easily be added to a 3D model. All three simulation programs offer various program modules to choose from (priced separately or as a multi-thousand-dollar package). Visit their web sites to determine which version and/or additional modules is the right choice for your advanced Acoustic and Array design needs.
Sound contractors still use the full-featured EASE program, due to its large database of acoustical materials and loudspeaker brands, that can be compared in a venue model.
It seems that AFMG was focusing (pun intended) its resources on advancing the more basic and free/popular EASE Focus modeling software, as the simulation of Cardioid sub arrays & FIRmaker optimization technology is now included with EASE Focus. The more robust EASE program is now receiving attention with the expected release of a new version in the next year.
A commonly overlooked Acoustical issue is control of Noise from HVAC, traffic and adjacent spaces. A Noise Control specialist maybe needed to ensure that the assembly, performance or worship space not only sounds good, but is also quiet
(another type of signal-to-noise-ratio).
Acoustic & Array Modeling Options Summary
Due to decades of experience using acoustic & array modeling/simulation programs, recent talks with several colleagues and demonstrations from array manufactures, to research this article, my conclusion is that there are basically three types of modeling/simulation programs available:
1. The legacy no-cost modeling programs, from sources like Bose and JBL, were relatively accurate for basic large-room acoustic modeling (reverberation time calc.), point-source loudspeaker array coverage, as well as array-room interaction (display echo paths); they were easy to use, but had limited features. Bose has continued to expand the feature set of Modeler (and security key no longer needed). JBL has not continued on with CADP2.
2. The modern, hardware-specific line-array modeling and control software programs (also no cost from most brands of live-sound loudspeakers) are quite useful for regional and touring sound companies that own the same brand of arrays, as they provide array-specific direct-field coverage prediction with control and monitoring functions (such as: beam-steering, cardioid sub-array design, headroom, FIR EQ, mobile aps & mechanical data) not generally available in third-party software. But most of the speaker modeling programs have limited coverage views and cannot predict room acoustics/echoes.
3. The more advanced and modern, but costly, modular modeling programs, such as CATT, EASE, and ODEON, have continued to offer an increasing range of features, for in-depth analysis and design of critical-large acoustic spaces, along with more accuracy for the modeling of array coverage and simulation of speech intelligibility. CATT Acoustic has a method of more accurately modeling coverage of line-arrays at high-frequencies. Modeler seems be the only full-featured acoustic & array simulation program now freely available. However, these advanced acoustic modeling programs do not have the control and monitoring functions of the 2nd group of hardware-specific line-array programs above.
Dr. Honeycutt summarized modeling by saying. “Each acoustical modeling program has advantages and disadvantages, as well as characteristics and quirks that cause a given user to prefer one over the other. With modeling programs, the main differences are in the method of data input, the ability to incorporate scattering and diffraction, the method of presenting data output, acoustical parameters calculated by the program, the availability of manufacturers’ speaker data in a form acceptable to the software, the inclusion of walk-through auralizations, and the accuracy of auralizations. One other aspect is the expectations of the acoustician’s professional partners. Is there a certain format required for models, so that they can be passed back and forth among the acoustician, sound contractor, and perhaps the architect?”
Since no one modeling/simulation program provides all of the above features, it is sometimes necessary to use two different types of programs; such as exporting an array design file, from a specialized line-array modeling program, as EASE data, and then importing it into an acoustical modeling program, to study how the processed line-arrays will interact with the venue’s architectural acoustics. Most of the older sound modeling programs could not (accurately) model low-frequencies. Multiple modeling programs, can now do simulation of cardioid sub arrays.
We will continue to look out for and cover in more detail, the advances in these acoustic & array modeling programs in future articles. Follow-up articles are also being prepared, about several updated array modeling programs, with new features including the simulation of cardioid (AKA directional) sub arrays. We will also look at full-range and sub array polar-plot simulation.
Line Array Calculators are set-up programs, offering a relatively simple, intuitive modelling tool, while supplying the required prediction data for good system performance. They consider the direct-field response, but not acoustics.
A good sound system alone, regardless of a brand name, does not assure good sound quality. A sound system is not complete without adequate (program appropriate) room acoustics. Sound systems can rarely cope with serious defects in a room design, and a more powerful system commonly makes such defects worse. Proper architectural acoustics design includes a well modeled room, and the study of how speaker arrays interact with the architectural acoustics (control of long echoes), to prevent costly architectural acoustic flaws, before a venue is built.
Advanced Analysis of Array Performance and Acoustical Modeling
Richard A. Honeycutt, Ph.D. explained “With CATT, EASE, or ODEON, I can look at the actual RT in 1/3 octave bands, using modeling methods that have been tested against measurements. I can look at objective acoustical measures including clarity, definition, sound strength, speech intelligibility (STI, %ALcons), and echo disturbance for speech and music per the Deitsch/Kraak evaluation method and criteria. I can objectively evaluate room support for congregational singing in a church. I can examine acoustical stage support for a choir or singing group that does not depend upon stage monitors. If echoes are a problem, I can identify their source so they can be eliminated. I know of no programs provided by loudspeaker vendors that will do these things. In short, I can do acoustical analysis. If all I wanted to do was look at loudspeaker coverage, I could do that with the free programs. But a good acoustical design requires much more than that.” For a more advanced understanding of the variables and choices entailed in proper acoustic design for performance and worship, read a book like Dr. Honeycutt’s, Acoustics in Performance.
For advanced analysis of array performance in an acoustical venue and/or to design/study critical acoustical projects, such as concert halls, many acoustical design consultants use an acoustic modeler/simulator, such as CATT-Acoustic, EASE (shown below) or ODEON; they are all world-wide standards for acoustic simulation, for both inside rooms and open areas. An acoustical venue can be defined using a CAD module, absorption or scattering coefficients can be assigned to surfaces and sound sources, as well as listener positions can easily be added to a 3D model. All three simulation programs offer various program modules to choose from (priced separately or as a multi-thousand-dollar package). Visit their web sites to determine which version and/or additional modules is the right choice for your advanced Acoustic and Array design needs.
Sound contractors still use the full-featured EASE program, due to its large database of acoustical materials and loudspeaker brands, that can be compared in a venue model.
It seems that AFMG was focusing (pun intended) its resources on advancing the more basic and free/popular EASE Focus modeling software, as the simulation of Cardioid sub arrays & FIRmaker optimization technology is now included with EASE Focus. The more robust EASE program is now receiving attention with the expected release of a new version in the next year.
A commonly overlooked Acoustical issue is control of Noise from HVAC, traffic and adjacent spaces. A Noise Control specialist maybe needed to ensure that the assembly, performance or worship space not only sounds good, but is also quiet
(another type of signal-to-noise-ratio).
Acoustic & Array Modeling Options Summary
Due to decades of experience using acoustic & array modeling/simulation programs, recent talks with several colleagues and demonstrations from array manufactures, to research this article, my conclusion is that there are basically three types of modeling/simulation programs available:
1. The legacy no-cost modeling programs, from sources like Bose and JBL, were relatively accurate for basic large-room acoustic modeling (reverberation time calc.), point-source loudspeaker array coverage, as well as array-room interaction (display echo paths); they were easy to use, but had limited features. Bose has continued to expand the feature set of Modeler (and security key no longer needed). JBL has not continued on with CADP2.
2. The modern, hardware-specific line-array modeling and control software programs (also no cost from most brands of live-sound loudspeakers) are quite useful for regional and touring sound companies that own the same brand of arrays, as they provide array-specific direct-field coverage prediction with control and monitoring functions (such as: beam-steering, cardioid sub-array design, headroom, FIR EQ, mobile aps & mechanical data) not generally available in third-party software. But most of the speaker modeling programs have limited coverage views and cannot predict room acoustics/echoes.
3. The more advanced and modern, but costly, modular modeling programs, such as CATT, EASE, and ODEON, have continued to offer an increasing range of features, for in-depth analysis and design of critical-large acoustic spaces, along with more accuracy for the modeling of array coverage and simulation of speech intelligibility. CATT Acoustic has a method of more accurately modeling coverage of line-arrays at high-frequencies. Modeler seems be the only full-featured acoustic & array simulation program now freely available. However, these advanced acoustic modeling programs do not have the control and monitoring functions of the 2nd group of hardware-specific line-array programs above.
Dr. Honeycutt summarized modeling by saying. “Each acoustical modeling program has advantages and disadvantages, as well as characteristics and quirks that cause a given user to prefer one over the other. With modeling programs, the main differences are in the method of data input, the ability to incorporate scattering and diffraction, the method of presenting data output, acoustical parameters calculated by the program, the availability of manufacturers’ speaker data in a form acceptable to the software, the inclusion of walk-through auralizations, and the accuracy of auralizations. One other aspect is the expectations of the acoustician’s professional partners. Is there a certain format required for models, so that they can be passed back and forth among the acoustician, sound contractor, and perhaps the architect?”
Since no one modeling/simulation program provides all of the above features, it is sometimes necessary to use two different types of programs; such as exporting an array design file, from a specialized line-array modeling program, as EASE data, and then importing it into an acoustical modeling program, to study how the processed line-arrays will interact with the venue’s architectural acoustics. Most of the older sound modeling programs could not (accurately) model low-frequencies. Multiple modeling programs, can now do simulation of cardioid sub arrays.
We will continue to look out for and cover in more detail, the advances in these acoustic & array modeling programs in future articles. Follow-up articles are also being prepared, about several updated array modeling programs, with new features including the simulation of cardioid (AKA directional) sub arrays. We will also look at full-range and sub array polar-plot simulation.
