Advanced Live Sound 201

ALS 201 is an 8 week course that aims to take a novice sound engineer to the next level. It's very hard to pick up the "conventional wisdom" of the industry from an OJT learning situation. Yet everything you are going to learn here is paramount to the overall job of "Sound Engineering." Below is a list and description of the classes in this course.

You don't have to be a mathematician to learn about sound and light. Yet understanding some of the basic concepts and simple rule of thumb calculations will help you greatly. We will examine some of the physics and some simple math that can help.

Waveforms of all types interact. For example, the human mind shapes our perceptions of electromagnetic radiation, i.e., sound and lights. It weaves emotional reactions based on that energy throughout the experience of witnessing a performance. Especially a stirring performance. The spoken word, theater, and concerts are just some of the ways that the science of sound and light impacts our everyday lives.

An overview of the techniques used to distribute power in the entertainment production industry.

Safety is vital in this area, and visual identification of power devices and connectors is essential. Power distribution is paramount to the correct, noise-free operation of your equipment, as well as the safety of you and your artists, and your guests. Alternating current is dangerous unless handled 100% correctly. Learning the safe and acceptable methods to distribute power is fundamental to any production. 99% of all buzzing, humming, 60 cycle noise, etc., is caused by improper grounding and multiple ground paths. Electricity always seeks the path of least resistance. 

Feedback, or acoustic feedback, is the bane of the live sound engineer.

Because we add vast amounts of gain to some microphones, we constantly risk creating feedback in the audio system. In this class, we will learn how to train and use our ears. 

We will also learn how to use technology to tune the acoustic feedback out of amplified audio systems. 

Eliminate feedback before it can happen. Learn how professional audio engineers eliminate feedback from the audio system before any artist walks into the venue. There are straightforward methods that do not involve machinery or analysis by anything but your ears. On the other hand, many valuable devices can pinpoint troublesome frequencies, nodes and anti-nodes, and other wave phenomena that can severely affect your mix. We will examine both approaches in this class.

Mixing Console Overview...Analog and digital consoles are examined and compared. 

With the advent of digital mixing consoles, what seemed like easy operations on a simple analog console can become daunting to perform on a digital mixer. But in reality, they both use the same audio toolbox. In fact, a digital mixer often gives the live sound engineer the same dynamic tools that a studio engineer or a mastering engineer would use to enrich the quality of the sounds in a recording studio environment. However, despite using the same audio toolbox, the two different types of mixers, analog & digital, have inherently different approaches to signal path and gain structure. This course will examine the fundamental physical differences between the two without delving into the subjective or collective value or their quality of sound.

Gain structure, the most misunderstood concept in professional audio engineering.

This is an overview of the logic of Gain Structure to ensure proper throughput in any system. Gain structure is defined as a balance of signals throughout the signal chain of the entire sound system. The signal chain starts at the input stage of an audio mixing console. It could be a microphone, or it could be an iPod that is connected. One type of signal requires high amounts of gain added to it, whereas the latter requires relatively little added gain compared to the microphone.

There are many "gain stages" in a mixing console. Just as there is an input amplifier for the microphone, an output signal is fed from the amplifier to the next gain stage. Balancing the inputs and outputs of all the gain stages in a console is achieved by using metering. The best consoles allow you to meter levels at any spot in the signal chain. This is crucial to what I call Relative Audio Balancing. Voices and instruments vary wildly in timbre and pitch, and making adjustments that make individual sounds relative to one another involves adjusting the gain at different points. Dynamic processing such as limiting or compression is designed to help the engineer keep levels within the acceptable design limits of the circuitry. Input clipping, over-saturation, phase cancellation, and phenomena relative to audio signals "in the wire" are to be avoided at all costs. In this course, we will learn how to manage gain structure effectively. 

Dynamic Processors, can't live with'em, can't live without'em.

Several of the most difficult problems for audio engineers are over-saturation of signal, bleed-through of unwanted sounds, and excessive dynamic range. This class will examine the nature of audio dynamic processors such as noise gates, compressor-limiters, and the concept of side-chain insertion, which allows an engineer to combine these line-level devices in novel ways that solve those problems. Add to that the fact that now most of these "devices" are plug-ins and work strictly in the digital realm. Still...

Audio engineers must know how to control signals and dynamic range through the use of dynamic processing devices. Audio signals can often be affected by a wide range of both internal and external influences. For example, excessive signal level or excessive dynamic range, bleed-through into mics from adjacent sound sources, and Brick-wall limiting functions are all achieved through the use of dynamic processing. Unfortunately, these devices can ruin your sound just as easily as they can fix it! Understanding the operations of these devices, how and where they are connected to other devices, and the proper approach to setting the adjustments to dynamic processing are all topics we will cover in this week's class.

Live audio effects such as reverb, echo, chorus, and delays are examined and explained in terms of content and technique of use.

Audio effects take your mix to the next level by punctuating certain emotional elements of performances. Audio engineers must know how to operate Audio FX while mixing music. A live performance's "raw" sound can have a great deal more emotional impact when subtle effects like echo and reverb are added. Learning to use effects for live audio mixing will take your sound to a whole new space! Audio engineers have used the psycho-acoustic phenomena associated with delays, and echos have been used for years by audio engineers to improve their mixes. Reverb, chorus, and other types of effects can also play an important role in defining the emotional content of songs and performances.

Advanced techniques for mixing and the conventional wisdom of the industry are examined.

The different workflows and sensory inputs must be compared and contrasted. An attempt to gain a deeper understanding of the role of the sound engineer and the methods required to achieve very high levels of satisfaction. Mixing techniques can be one of the hardest things to learn in an OJT learning environment. The role of the sound engineer is much more complex than most people imagine. First and foremost, techniques for controlling a large number of inputs simultaneously are examined in light of my personal experience and industry standards. By definition, the term "conventional wisdom" translates to "adjustable truth." Engineers can easily fall into the trap of relying on the industry's conventional wisdom rather than believing their eyes and ears.