20130501
20120922
20120914
SLE Post 4: Lighting Designers
Leroy Bennett is a production and lighting designer who has worked with Prince, Queen, Bon Jovi, Van Halen, Nine Inch Nails, Red Hot Chili Peppers, Marilyn Manson, Tim McGraw, Paul McCartney, Guns 'N Roses, Kelly Clarkson, Bruno Mars, Lady Gaga, Josh Groban, Big Bang, and many other artists. He has also worked on other productions such as award shows by VH1, MTV, Parnelli, and Sundance, as well as Disney on Ice productions and television programs. He has been in the industry since the 70's-80's, and continues to work on some of the best productions.
This year, Leroy Bennett designed the stage and lights for Big Bang's Alive Tour. An amazing crew worked on this production, organized by Live Nation Entertainment. The director was Laurieann Gibson, and the FOH engineer was Ken "Pooch" Van Druten, who has mixed Linkin Park, Eminem, Jay-Z, Beastie Boys, Kiss and many others.
Mark Workman has been touring for 29 years as a lighting designer and tour manager. He has worked with Slayer, Megadeth, System of a Down, and many others. He does many metal and rock shows, and the artists he work with appreciate his understanding of the music.
Stephen Pollard is a lighting and set designer who has worked on tours with Simple Minds, U2, Linkin Park, Adele and many others. He has also designed architectural lights, and lights and sets for television, corporate and industrial events. He has collaborate with other designers, for example on the Linkin Park Minutes to Midnight World Tour 2008, he worked with AJ Pen and Mike Shinoda on the set design.
Looking at the works of the many designers is not just to "draw inspiration", but to study the way colors, positions, movements and other parameters are used. Lighting is used to support the performance and the music, to create the emotion and enhance the experience. Design cannot really be taught, but by observing and analyzing the work of others, the experimentation process has a direction from which to begin. Also, lighting, video, set design and many other aspects have to work closely to create the entire visual experience.
This year, Leroy Bennett designed the stage and lights for Big Bang's Alive Tour. An amazing crew worked on this production, organized by Live Nation Entertainment. The director was Laurieann Gibson, and the FOH engineer was Ken "Pooch" Van Druten, who has mixed Linkin Park, Eminem, Jay-Z, Beastie Boys, Kiss and many others.
Mark Workman has been touring for 29 years as a lighting designer and tour manager. He has worked with Slayer, Megadeth, System of a Down, and many others. He does many metal and rock shows, and the artists he work with appreciate his understanding of the music.
Travis Shirley has worked with Enrique Iglesias, Smashing Pumpkins, Rufus Wainwright, Linkin Park, and many others. He was a student at Full Sail University.
Stephen Pollard is a lighting and set designer who has worked on tours with Simple Minds, U2, Linkin Park, Adele and many others. He has also designed architectural lights, and lights and sets for television, corporate and industrial events. He has collaborate with other designers, for example on the Linkin Park Minutes to Midnight World Tour 2008, he worked with AJ Pen and Mike Shinoda on the set design.
Five Stealth video screens with motion control hovered above the set, which itself was floating over a rolling platform that housed monitors and back line. The way in which the set design worked with the lighting and video made the visual experience really interesting.
Looking at the works of the many designers is not just to "draw inspiration", but to study the way colors, positions, movements and other parameters are used. Lighting is used to support the performance and the music, to create the emotion and enhance the experience. Design cannot really be taught, but by observing and analyzing the work of others, the experimentation process has a direction from which to begin. Also, lighting, video, set design and many other aspects have to work closely to create the entire visual experience.
20120907
SLE Post 3: Manufacturers
Consoles and fixtures are the main tools in a system using automated lights.
Some lighting console manufacturers include Avolites, ABD Lighting, Compulite, Barco/High End, ETC, Jands Vista, ChamSys, MA Lighting, Zero88, and Martin Professional.
High End Systems, a Barco Company, has the Wholehog 3 console, and MA Lighting has the GrandMA 2. These are the two systems that will be explored this month. Also, I have been on the Avolites previously - the Pearl 2000 and Pearl Tiger.
As for fixtures, manufacturers include Martin, Philips Vari*Lite, Robe, Barco/High End, PRG, Coemar, and Clay Paky, among many others.
Martin has its MAC series, Vari*Lite its VL series, Robe its Robin series, ColorWash and ColorSpot, High End its Intellaspot, PRG its AutoPar, Best Boy and Bad Boy, and Clay Paky its Alpha series.
In FSL-1 we use various Martin fixtures, Vari*Lite VL 500Ds, and High End's Technobeams. Previously, (almost) all I had gotten to use were Robe ColorWash 575 ATs and ColorSpot 575 ATs.
Some lighting console manufacturers include Avolites, ABD Lighting, Compulite, Barco/High End, ETC, Jands Vista, ChamSys, MA Lighting, Zero88, and Martin Professional.
High End Systems, a Barco Company, has the Wholehog 3 console, and MA Lighting has the GrandMA 2. These are the two systems that will be explored this month. Also, I have been on the Avolites previously - the Pearl 2000 and Pearl Tiger.
As for fixtures, manufacturers include Martin, Philips Vari*Lite, Robe, Barco/High End, PRG, Coemar, and Clay Paky, among many others.
Martin has its MAC series, Vari*Lite its VL series, Robe its Robin series, ColorWash and ColorSpot, High End its Intellaspot, PRG its AutoPar, Best Boy and Bad Boy, and Clay Paky its Alpha series.
In FSL-1 we use various Martin fixtures, Vari*Lite VL 500Ds, and High End's Technobeams. Previously, (almost) all I had gotten to use were Robe ColorWash 575 ATs and ColorSpot 575 ATs.
Regardless of make/model, a lighting console/board/desk is an electrical device that allows us to control multiple fixtures. DMX512, which is the most commonly used electronic control protocol, is how control data is transmitted from the console to the fixtures, usually over DMX cables with 5-pin XLR connectors.
Intelligent lights, also known as automated or moving lights, again regardless of make/model, allow versatility and multiple functions. The luminaires use multiple channels of DMX for features such as pan, tilt, dimmer, shutter, gobo select and rotation, color wheel, CMY full color mixing, prism facet and rotation, effects wheel, gobo animation wheel, zoom, focus, iris, lamp on and off, fixture reset, and remote patching channel.
Movers give us more attributes per fixture that can be controlled from the console, as compared to conventional lights, where everything but intensity has to be pre-set.
Movers can now integrate digital projection capabilities, combining lighting and video projection through the addition of video content control. Control from laptops, using USB to DMX, are more common now. Also, transmitting data over ethernet (RJ45) still is being further developed.
The tools have fixed capabilities, and it is up to designers and programmers to expand on these.
20120901
SLE Post 2: Architectural Lighting Design - Tokyo
Two new spaces that have opened this year in Tokyo are the Tokyo Skytree tower and the Gundam Front.
The Tokyo Skytree opened to the public on May 22, 2012. Standing at 634 meters (2080.05 feet) tall, the Skytree is the tallest tower, and the second tallest structure in the world. The base of the tower has a similar structure to that of a tripod, and the cylindrical structure has seismic proofing in the form of oil dampers that can absorb half the energy from an earthquake. The exterior lattice is painted "Skytree White", based on a traditional Japanese color called aijiro (bluish white).
There are 2 illumination patterns, "粋" (Iki) which represents the spirit of Edo and the Sumida River which is right by the tower, and "雅" (Miyabi) which represents the aesthetic sense. These are used in alternation on a daily basis. Iki uses a pale blue while Miyabi uses Edo purple with gold.
The Tokyo Skytree opened to the public on May 22, 2012. Standing at 634 meters (2080.05 feet) tall, the Skytree is the tallest tower, and the second tallest structure in the world. The base of the tower has a similar structure to that of a tripod, and the cylindrical structure has seismic proofing in the form of oil dampers that can absorb half the energy from an earthquake. The exterior lattice is painted "Skytree White", based on a traditional Japanese color called aijiro (bluish white).
There are 2 illumination patterns, "粋" (Iki) which represents the spirit of Edo and the Sumida River which is right by the tower, and "雅" (Miyabi) which represents the aesthetic sense. These are used in alternation on a daily basis. Iki uses a pale blue while Miyabi uses Edo purple with gold.
.JPG)
.JPG)
.JPG){kind=link}
An environmentally friendly All-LED lighting system was used. Compared to the combined use of HID and LED lights, "Iki" consumes 43% less energy, and "Miyabi" 38%. Panasonic provided 1,995 units of EVERLEDS for the Tokyo Skytree. The lights can be controlled in intervals of 1/30th of a second.
Besides the illumination of the main structure, there also is a ring of "Tick-tack" lights on the perimeter of the upper observatory decks that are in a constant chase, the "Snow cap" at the apex, and illumination of the steel-frame to highlight the concave and convex curves of the tower.
The Skytree's lighting consultant was Hirohito Totsune of Sirius Lighting Office Inc, who oversaw the project. The lighting designers included Koichi Kaiho and Naoko Shinohara.
Gundam Front Tokyo opened on April 19, 2012. The world's first permanent Gundam entertainment facility is located in DiverCity Tokyo Plaza, Odaiba, and right in front of the mall stands a 18 meter tall Real Grade 1:1 scale RX-78-2 Gundam statue (RG1/1 RX-78-2 GUNDAM Ver.GFT).
Every night, a 7 minute long display called "Gundam Stand Atop Tokyo" has the Gundam coming to life. Behind the Gundam, on the wall of the DiverCity mall, is a 32 by 11.5 meter (105'x37') video screen, which acts as the backdrop.
Architectural lighting design is very different from concert and theatrical lighting. However, the aesthetic appeal and energy efficiency is just as important, or even more important than the functional light in many new buildings and structures. Especially with the Skytree and the Gundam Front, we see how lighting is used in ways that can also be applied to concert lighting.
-----------------------------------------------------------
Another interesting use of Panasonic's EVERLEDS:
Other insane happenings at the Skytree:
20120827
SLE Post 1: AJ Pen - Linkin Park "A Thousand Suns" Tour LD
AJ Pen has worked with Linkin Park, Avril Lavigne, Audioslave, The Goo Goo Dolls, Marilyn Manson, and Sum 41, among many others. He took the position of of Chief Lighting Director for Linkin Park in 2003, and has been working with the band ever since.
For the Australian shows on the "A Thousand Suns" Tour during late 2010, the equipment featured included 41 units of Vari*Lite VLX Wash, and 12 units of Vari*Lite VL*3500 Wash as follow spots and backlights. The VLX LED wash lights are capable of a chase at 1500 beats per minute, faster than many other fixtures he compared them with. The VLX units were only introduced in the Australian shows. Some of the other lighting fixtures used include (24) Martin Atomic 3000 DMX strobes, (18) MAC III Profile, (7) Mac 2000 Performance.
As for the console, the Martin M1 was used. A MacBook was used to connect all the equipment for control. The lighting show was pre-programmed, and MIDI data was used to control the lighting cues. The parts of the music that needed lighting effects were placed on a MIDI track on a DAW, in this case Ableton Live, and that information is what the cues follow. Lockstep, run on the Mac, allowed SMPTE-MTC timecode conversion was used to sync up all the devices. The band had backing tracks running on ProTools, and the Ableton Live session chased the ProTools SMPTE timecode. The Martin Ether2DMX router, which translates Artnet into DMX in/out universes, was used to interface devices. Also, there were multiple follow spot operators manually following the performers on stage.
Seth Robinson programmed the show, and also designed an application using Cycling '74's Max that took MIDI information and timecode, and translated those into MIDI show control for the Martin M1.
AJ used MIDI controllers for data input. These were used when programming, and for the odd bits of live control. AJ also mentioned that the modulation wheel gave more intuitive control than a fader.
AJ was also involved in the set design, along with Stephen Pollard and Mike Shinoda.
I think that having a show run on its own, entirely pre-programmed, is now a common thing especially with shows that have somewhat of a set timeline. Letting technology take over ensures the accuracy of the synchronization between the performers and the visual aids. This also emphasizes the importance of pre-production and planning, understanding the material, and communication.
20120819
SPS Post 4: DiGiCo SD10
SD10: Live Digital Console with Stealth Digital Processing™
The DiGiCo SD10 is capable of 96-channels with full processing, 12 of which can be configured as full Flexi Channels, allowing a total of 108 simultaneous input channels; 48 assignable busses - mono or stereo groups or auxes; 16x16 output matrix (up from 16x12); Dual Solo buss; Smart Key Macros, accessed via four layers of ten backlit keys; Snapshot control with relative update and offline facility; Onboard insertable FX and graphic EQs; the addition of 16 DiGiTuBes.
It has a 15" touch screen, and 37 motorized faders with high resolution bar graph meters. The surface is made of anodized aluminum overlaid with polycarbonate panels. Every fader, button and control knob is back-lit for working in dim conditions, and at the same time, the touch screen is bright enough under daylight conditions. The scribble strips are user-definable, and use RGB backlit LCDs.
The console is to be used with D-Rack, SD-Rack Stage rack and local I/O. The local I/O on rear of console has 8 mic ins, 8 line outs, 8 mono AES I/O, 2 MADI connections with redundant cabling connections, 16 GPI & GPO connections, with option to expand to 32 GPI and GPO, word clock synchronization with external devices.
There is the option feature set that can convert the SD10 into the SD 10B, specifically designed for broadcast.
Interfacing options include MADI, Optocore, Dante and analog connectivity. Up to 14 racks and five redundant-engined consoles on an optical loop can be connected.
For recording, there is DiGiCo's MADI-based multitrack recording I/O, a fully integrated system that allows all internal and Waves effects to be recorded as well.
SD10 Nitrous gives an expanded amount of processing power for EQ, compressors, FX. No fewer than 10 Dynamic EQ processors can run simultaneously, allowing expansion and compression on all 4-bands of the parametric EQ. Stealth Digital Processing allows for 24 graphic EQs to be inserted and controlled, 10 Stealth stereo effects units to be used from the 33 available, and allows for the processing units to be switched from scene to scene.
For even more effects, there is Waves integration available. With the Waves SoundGrid module added and the DiGiCo SD10 console linked to external computer, there will be the ability to use 16 ultra-low latency Waves stereo processor racks, plus TDM plugins after registration.
There is the ability to take the surface into an "offline" mode, and edit snapshots without affecting audio. The 40 user-definable Macros and snapshot flexibility help workflow efficiency.
It has two internal "Hot Swap" power supply units for redundancy, and two 75Ω redundant BNC connections for using the MADI protocol for digital audio transmission.
The console is similar to the SD7 in the way it uses Super FPGA technology with floating point processing for smoothness, accuracy and dynamic range. It can be said that the SD10 is at a level between the smaller SD8 and large-format SD7, in terms of both price and features.
I feel that this console has the layout that DiGiCo users and accustomed to, with added expandability and interfacing options, and yet will be more affordable than the industry-leading SD7. For a mid-range production, the SD10 would be a good option to consider.
The DiGiCo SD10 is capable of 96-channels with full processing, 12 of which can be configured as full Flexi Channels, allowing a total of 108 simultaneous input channels; 48 assignable busses - mono or stereo groups or auxes; 16x16 output matrix (up from 16x12); Dual Solo buss; Smart Key Macros, accessed via four layers of ten backlit keys; Snapshot control with relative update and offline facility; Onboard insertable FX and graphic EQs; the addition of 16 DiGiTuBes.
It has a 15" touch screen, and 37 motorized faders with high resolution bar graph meters. The surface is made of anodized aluminum overlaid with polycarbonate panels. Every fader, button and control knob is back-lit for working in dim conditions, and at the same time, the touch screen is bright enough under daylight conditions. The scribble strips are user-definable, and use RGB backlit LCDs.
The console is to be used with D-Rack, SD-Rack Stage rack and local I/O. The local I/O on rear of console has 8 mic ins, 8 line outs, 8 mono AES I/O, 2 MADI connections with redundant cabling connections, 16 GPI & GPO connections, with option to expand to 32 GPI and GPO, word clock synchronization with external devices.
There is the option feature set that can convert the SD10 into the SD 10B, specifically designed for broadcast.
Interfacing options include MADI, Optocore, Dante and analog connectivity. Up to 14 racks and five redundant-engined consoles on an optical loop can be connected.
For recording, there is DiGiCo's MADI-based multitrack recording I/O, a fully integrated system that allows all internal and Waves effects to be recorded as well.
SD10 Nitrous gives an expanded amount of processing power for EQ, compressors, FX. No fewer than 10 Dynamic EQ processors can run simultaneously, allowing expansion and compression on all 4-bands of the parametric EQ. Stealth Digital Processing allows for 24 graphic EQs to be inserted and controlled, 10 Stealth stereo effects units to be used from the 33 available, and allows for the processing units to be switched from scene to scene.
For even more effects, there is Waves integration available. With the Waves SoundGrid module added and the DiGiCo SD10 console linked to external computer, there will be the ability to use 16 ultra-low latency Waves stereo processor racks, plus TDM plugins after registration.
There is the ability to take the surface into an "offline" mode, and edit snapshots without affecting audio. The 40 user-definable Macros and snapshot flexibility help workflow efficiency.
It has two internal "Hot Swap" power supply units for redundancy, and two 75Ω redundant BNC connections for using the MADI protocol for digital audio transmission.
The console is similar to the SD7 in the way it uses Super FPGA technology with floating point processing for smoothness, accuracy and dynamic range. It can be said that the SD10 is at a level between the smaller SD8 and large-format SD7, in terms of both price and features.
I feel that this console has the layout that DiGiCo users and accustomed to, with added expandability and interfacing options, and yet will be more affordable than the industry-leading SD7. For a mid-range production, the SD10 would be a good option to consider.
20120813
SPS Post 3: Understanding Spec Sheets
Pat Brown: Understanding Specification Sheets: What Do The Charts & Graphs Really Mean?
Specification sheets are important when we need to measure, analyze and describe the sound system and its components. They help in planning, and selecting components.
There are two types of variables found on a specification sheet - dependent and independent. Dependent variables change, and vary over time. Independent variables have fixed values. Most graphs and charts show the relationship between two variables, one dependent and one independent.
In general, the horizontal axis or x-axis represents the independent variable, while the vertical axis or y-axis represents the dependent variable.
Even though we see a joint line across most 2-dimensional plots and graphs, the values on each axis are actually sampled and measured at points called "data points". The points are joined by a line just for ease of reading.
Common graphs an audio engineer will come across include:
When the independent variable on the X-axis is frequency, the Y-value is said to be "frequency dependent". When the independent variable is time, the Y-value will be "time dependent". This means that all the variables on the Y-axis do not have a fixed value, varying and depending on the X-value at which it is measured.
An example of a frequency-dependent variable is relative level. On a graphic equalizer, we can see a graph or plot on the face of the device. the horizontal axis represents frequency while each adjustment made to the settings is changing relative level at whichever frequency band.
Other variables that are time-dependent include loudness, temperature and background noise.
Graphs show trends in data, giving us a visual aid in understanding the characteristics of the equipment. Graphs give us measured values so that we have a reference. It still is up to the engineer or technician to analyze that data, understand it, and apply it.
Another important thing to think about is how precise the data is, and at what resolution the data points were measured. The resolution needs to be appropriate for the data, such that all significant data points are represented, and yet we do not need to go too far with the resolution as there will be a point of "diminishing return", where the points are insignificant and do not serve our purposes.
Graphs and plots provided by manufacturers do not fully describe the product, they describe certain aspects of the equipment such that we can understand its behavior and compare it with similar products.
"One-number" ratings often over-simplify data, for example, instead of providing the user with the full graph, only the value measured at a frequency of 1kHz is given. If the product is purchased based solely on this information, the user will later realize that at all other frequencies outside of 1kHz, the performance of the equipment is unpredictable and perhaps not up to expectations.
Spectrum plots alone are still not enough to fully describe the behavior of equipment. For example, the loudspeaker response depends on frequency, but the amplitude x frequency graph only shows us the response measured on-axis. Depending on the Q value, with Q = 1 meaning omni-directional, the intensity on-axis will be the Q-value times the average radiated intensity. The higher the Q-value, the higher the axial intensity in relation to the average radiated intensity. Q is interchangeable with DI or directivity index, derived by DI (dB) = 10 . log Q.
Specification sheets help us determine if a certain product suits our needs for a certain application. We still need to measure and listen in order to evaluate the performance of the product, and purchases should only be made after doing both.
Specification sheets are important when we need to measure, analyze and describe the sound system and its components. They help in planning, and selecting components.
There are two types of variables found on a specification sheet - dependent and independent. Dependent variables change, and vary over time. Independent variables have fixed values. Most graphs and charts show the relationship between two variables, one dependent and one independent.
In general, the horizontal axis or x-axis represents the independent variable, while the vertical axis or y-axis represents the dependent variable.
Even though we see a joint line across most 2-dimensional plots and graphs, the values on each axis are actually sampled and measured at points called "data points". The points are joined by a line just for ease of reading.
Common graphs an audio engineer will come across include:
Y-Axis---------------------------------X-AxisEach graph shows a Y-value as a function of an X-value.
Amplitude--------------------------Frequency
Impedance--------------------------Frequency
Directivity--------------------------Frequency
Phase--------------------------------Frequency
Amplitude----------------------------Time
Level-----------------------------------Time
When the independent variable on the X-axis is frequency, the Y-value is said to be "frequency dependent". When the independent variable is time, the Y-value will be "time dependent". This means that all the variables on the Y-axis do not have a fixed value, varying and depending on the X-value at which it is measured.
An example of a frequency-dependent variable is relative level. On a graphic equalizer, we can see a graph or plot on the face of the device. the horizontal axis represents frequency while each adjustment made to the settings is changing relative level at whichever frequency band.
Other variables that are time-dependent include loudness, temperature and background noise.
Graphs show trends in data, giving us a visual aid in understanding the characteristics of the equipment. Graphs give us measured values so that we have a reference. It still is up to the engineer or technician to analyze that data, understand it, and apply it.
Another important thing to think about is how precise the data is, and at what resolution the data points were measured. The resolution needs to be appropriate for the data, such that all significant data points are represented, and yet we do not need to go too far with the resolution as there will be a point of "diminishing return", where the points are insignificant and do not serve our purposes.
Graphs and plots provided by manufacturers do not fully describe the product, they describe certain aspects of the equipment such that we can understand its behavior and compare it with similar products.
"One-number" ratings often over-simplify data, for example, instead of providing the user with the full graph, only the value measured at a frequency of 1kHz is given. If the product is purchased based solely on this information, the user will later realize that at all other frequencies outside of 1kHz, the performance of the equipment is unpredictable and perhaps not up to expectations.
Spectrum plots alone are still not enough to fully describe the behavior of equipment. For example, the loudspeaker response depends on frequency, but the amplitude x frequency graph only shows us the response measured on-axis. Depending on the Q value, with Q = 1 meaning omni-directional, the intensity on-axis will be the Q-value times the average radiated intensity. The higher the Q-value, the higher the axial intensity in relation to the average radiated intensity. Q is interchangeable with DI or directivity index, derived by DI (dB) = 10 . log Q.
Specification sheets help us determine if a certain product suits our needs for a certain application. We still need to measure and listen in order to evaluate the performance of the product, and purchases should only be made after doing both.
20120806
SPS Post 2: System Design - Speakers
Pat Brown: Illuminating The Audience With Beautiful, Consistent Audio Coverage
As human perception of sound is highly subjective and differs from person to person, there is no true standard on how to make a room sound right.
However, Pat Brown has a list of items that are a must for a sound system, his "Big 5".
The sources of problems are often the transducers - the microphones and speakers. These are the "weakest links" in the signal flow chain.
Speaker selection and placement is highly important for two reasons:
1) Among the two transducers, more is budgeted for speakers than microphones when designing a system.
2) Speakers are the next most important thing to room acoustics in the way elements of the sound system affect the sound in a field.
In a permanent install, speaker selection and placement is of extreme importance, as there is little that can be done to correct issues if these are not first done right. Coverage should be as equal as possible across all seats, in terms of amplitude over distance/position. The best way to check is by playing back speech over the system, and walking around to listen, instead of using metering tools.
As for directivity or coverage angle, the farther away the speaker is from the listener, the more confined the angle must be. This can be determined, in general, by physical size of the speaker larger speakers have more directivity. This can be observed with lights, as changing distance and focus work the same way as distance and directivity of a speaker.
Directivity is also important in ensuring sound does not spill onto areas without audience, especially back onto the stage.
First determine possible placements, which will determine required directivity, and thus determine if a larger or smaller speaker is required. Look for the closest possible placement, so that smaller speakers can be used.
The problem is that directivity is "frequency dependent", so suitable placements for subs versus high cabs will differ. Also, with multiple speakers, the sources interfere with each other to produce "drop outs" and narrow coverage. Much care has to be taken in calculating the way in which arrays, closely placed speakers, will interact.
There are tools such as modeling programs, but these are not effective if the user does not have the required experience and knowledge. Besides the acoustical consultant, hiring an audio system consultant is also important.
For quality sound and speech intelligibility, at an even level across all seating areas, much planning is required, such that each element in the system is selected and placed right, satisfying the "Big 5".
I feel that this article points out the importance of getting the system right instead of trying to fix issues later, and also the importance of getting a specialist for each area when planning and designing a system. Getting a system installed right will cost more at first, but will minimize future issues.
As human perception of sound is highly subjective and differs from person to person, there is no true standard on how to make a room sound right.
However, Pat Brown has a list of items that are a must for a sound system, his "Big 5".
All successful sound systems must:He suggests that for existing sound reproduction systems, the best way to find out if there are problems is by listening to the complaints of the audience. There is likely to be an issue with something on the list when there are problems such as inability to hear, loss of intelligibility, or imbalances within frequency response at various locations within the house.
1) Provide even sound coverage of all audience areas
2) Provide adequate loudness before distortion
3) Provide adequate loudness before acoustic feedback
4) Be easy to understand
5) Reproduce musical sources with adequate clarity and fidelity
The sources of problems are often the transducers - the microphones and speakers. These are the "weakest links" in the signal flow chain.
Speaker selection and placement is highly important for two reasons:
1) Among the two transducers, more is budgeted for speakers than microphones when designing a system.
2) Speakers are the next most important thing to room acoustics in the way elements of the sound system affect the sound in a field.
In a permanent install, speaker selection and placement is of extreme importance, as there is little that can be done to correct issues if these are not first done right. Coverage should be as equal as possible across all seats, in terms of amplitude over distance/position. The best way to check is by playing back speech over the system, and walking around to listen, instead of using metering tools.
As for directivity or coverage angle, the farther away the speaker is from the listener, the more confined the angle must be. This can be determined, in general, by physical size of the speaker larger speakers have more directivity. This can be observed with lights, as changing distance and focus work the same way as distance and directivity of a speaker.
Directivity is also important in ensuring sound does not spill onto areas without audience, especially back onto the stage.
First determine possible placements, which will determine required directivity, and thus determine if a larger or smaller speaker is required. Look for the closest possible placement, so that smaller speakers can be used.
The problem is that directivity is "frequency dependent", so suitable placements for subs versus high cabs will differ. Also, with multiple speakers, the sources interfere with each other to produce "drop outs" and narrow coverage. Much care has to be taken in calculating the way in which arrays, closely placed speakers, will interact.
There are tools such as modeling programs, but these are not effective if the user does not have the required experience and knowledge. Besides the acoustical consultant, hiring an audio system consultant is also important.
For quality sound and speech intelligibility, at an even level across all seating areas, much planning is required, such that each element in the system is selected and placed right, satisfying the "Big 5".
I feel that this article points out the importance of getting the system right instead of trying to fix issues later, and also the importance of getting a specialist for each area when planning and designing a system. Getting a system installed right will cost more at first, but will minimize future issues.
20120801
SPS Post 1: Equalization
Pat Brown: The Bigger Picture on Equalization
In setting up a sound system, there is tuning and optimization to think about. The precision of the design and implementation of each element of a P.A. is critical. Shaping the sound is of utmost importance.
Typically, when using equalization on sound systems, third-octave "continuous" equalizers are used to create a flat frequency response. A signal, usually pink noise, is run through the system, while a measurement microphone is placed "on-axis", at the best spot or critical distance, while a RTA (real-time analyzer) is used to view frequencies that need to be cut or boosted.
The problem with this process is that not everyone in the house will be at that sweet spot, on-axis and in the direct field of the sound sources. Therefore, the author suggests changing the approach to equalization on a sound system.
One suggestion is to take the "common denominator", which means taking measurements at various locations in the house and averaging out the EQ curves. However, with the microphone being placed at different positions, the sound field changes, and the balance between sound arriving directly from the source and from the reverberant field is changed with each measurement. The addition or subtraction of reflections in each measurement must be "excluded" before taking the average. This makes the "spacial average" technique difficult to put into practice, since frequencies, especially the mids-to-highs, will be randomly affected by the position in the house.
Another suggestion Pat Brown has is to consider the fact that sound radiates outwards 3-dimensionally. The "3-dimensional radiation balloon" needs to be studied to avoid issues with off-axis seats in the house. He also suggests using "precision signal delay" or leaving notches or dips at certain frequencies "simply ignored", and therefore dealing with phase or time relationships instead of using EQ filters.
Even though the first thing to do with tuning a system is equalization on the direct field, boosting or cutting a frequency simply based on the measurement taken on-axis in the direct field may cause problems to be aggravated at other off-axis listening positions, thus much consideration needs to be taken.
Even before thinking about using EQ to fix issues, careful, precise measurements have to be made such that the loudspeakers are placed in the right spot for the room.
Pat Brown recommends that technicians look at the data file that already has been created by the CLF (Common Loudspeaker Format) group, which will allow one to calculate the average frequency response over a "range of angles" even before setting up and measuring the pink noise signal. Since the direct field does not really depend on the way the room is, the data found on the site (www.clfgroup.org) can be used to get the "common denominator" curve for the direct field, as mentioned above in his first suggestion.
With the second method of looking at the 3-D balloon, the distance between elements needs to be taken into consideration, and the delay created by that positioning. The ballon needs to be "re-shaped" if there are multiple sound sources.
Pat Brown reminds us that humans tend to pick up on frequencies that are too loud, rather than missing frequencies, and thus suggests that technicians avoid over-boosting frequencies. Also, if boosts are avoided when equalizing based on the on-axis measurement, technicians can be sure that there will not be peaks at off-axis positions that will be further worsened.
In conclusion, technicians must consider off-axis locations, avoid boosting when equalizing, and make planning and precise calculation part of the process. Depending on how well the elements in the system match up with their specifications, fine tuning based on observation and using our ears, on top of all the tools we have, is important. DSPs with settings based on CLF data and auto-RTAs can be used, but in the end, it is for the technician to listen and think to make decision that will give the best possible response to every listener in the house.
I feel that the point here is that though there are practices that have become set standards over the years, engineers and technicians should always think, observe and decide, and not just follow the "normal" way of doing things.
In setting up a sound system, there is tuning and optimization to think about. The precision of the design and implementation of each element of a P.A. is critical. Shaping the sound is of utmost importance.
Typically, when using equalization on sound systems, third-octave "continuous" equalizers are used to create a flat frequency response. A signal, usually pink noise, is run through the system, while a measurement microphone is placed "on-axis", at the best spot or critical distance, while a RTA (real-time analyzer) is used to view frequencies that need to be cut or boosted.
The problem with this process is that not everyone in the house will be at that sweet spot, on-axis and in the direct field of the sound sources. Therefore, the author suggests changing the approach to equalization on a sound system.
One suggestion is to take the "common denominator", which means taking measurements at various locations in the house and averaging out the EQ curves. However, with the microphone being placed at different positions, the sound field changes, and the balance between sound arriving directly from the source and from the reverberant field is changed with each measurement. The addition or subtraction of reflections in each measurement must be "excluded" before taking the average. This makes the "spacial average" technique difficult to put into practice, since frequencies, especially the mids-to-highs, will be randomly affected by the position in the house.
Another suggestion Pat Brown has is to consider the fact that sound radiates outwards 3-dimensionally. The "3-dimensional radiation balloon" needs to be studied to avoid issues with off-axis seats in the house. He also suggests using "precision signal delay" or leaving notches or dips at certain frequencies "simply ignored", and therefore dealing with phase or time relationships instead of using EQ filters.
Even though the first thing to do with tuning a system is equalization on the direct field, boosting or cutting a frequency simply based on the measurement taken on-axis in the direct field may cause problems to be aggravated at other off-axis listening positions, thus much consideration needs to be taken.
Even before thinking about using EQ to fix issues, careful, precise measurements have to be made such that the loudspeakers are placed in the right spot for the room.
Pat Brown recommends that technicians look at the data file that already has been created by the CLF (Common Loudspeaker Format) group, which will allow one to calculate the average frequency response over a "range of angles" even before setting up and measuring the pink noise signal. Since the direct field does not really depend on the way the room is, the data found on the site (www.clfgroup.org) can be used to get the "common denominator" curve for the direct field, as mentioned above in his first suggestion.
With the second method of looking at the 3-D balloon, the distance between elements needs to be taken into consideration, and the delay created by that positioning. The ballon needs to be "re-shaped" if there are multiple sound sources.
Pat Brown reminds us that humans tend to pick up on frequencies that are too loud, rather than missing frequencies, and thus suggests that technicians avoid over-boosting frequencies. Also, if boosts are avoided when equalizing based on the on-axis measurement, technicians can be sure that there will not be peaks at off-axis positions that will be further worsened.
In conclusion, technicians must consider off-axis locations, avoid boosting when equalizing, and make planning and precise calculation part of the process. Depending on how well the elements in the system match up with their specifications, fine tuning based on observation and using our ears, on top of all the tools we have, is important. DSPs with settings based on CLF data and auto-RTAs can be used, but in the end, it is for the technician to listen and think to make decision that will give the best possible response to every listener in the house.
I feel that the point here is that though there are practices that have become set standards over the years, engineers and technicians should always think, observe and decide, and not just follow the "normal" way of doing things.
Subscribe to:
Posts (Atom)