Syn-Aud-Con Tech Topics Exclusively On PSW

For several years, Pat Brown has been writing superior technical articles on a wide range of audio topics. As leader of Syn-Aud-Con and a highly experienced system designer/installer, Pat has an enviable knowledge base that he willingly shares with audio professionals the world over.

Pat’s articles have primarily appeared in Syn-Aud-Con publications such as the newsletter and Tech Topic supplements, in addition to leading trade journals.

Pat Brown (left) leading a class.

We’re so pleased at PSW to be able to present these articles as a valuable reference and educational resource. Our thanks to Pat and Brenda Brown for selflessly allowing us to do so in the pursuit of learning and better systems. Note that we’ll be offering additional articles from Pat on a regular basis.

Article #1: Troubleshooting Radio Frequency Interference (RFI) Problems -
You turn on the sound system and hear a radio station - what's up with that? Radio Frequency Interference (RFI), one of the most common and troublesome system problems, can usually be solved via a logical, methodical approach. Pat Brown explains the tools and procedures to help eliminate RFI difficulties.

Article #2: Getting Acquainted With the Bessel Array -
A Bessel Array makes use of multiple loudspeakers to radiate in a pattern similar to one of the loudspeakers used individually. Sound familiar? It's one of the base concepts of the "line array" concept. Pat talks about the setup and numerous advantages of Bessel Arrays, which can help solve array problems in a simple and cost-effective manner.

Article #3: A Practical Example of the Limiting Distance
It can be difficult to localize a sound source, particularly in rooms with highly reverberant fields such as large high school gymnasiums. Pat defines key factors in this equation and stresses the importance of absorptive materials to assist in solving the problem.

Article #4: Alternatives To High Voltage Distribution
There's more than one way to distribute power, as Pat shows with an examination of distributed amplification systems. An explanation of the workings of traditional power amps is also covered.

Article #5: Low-Frequency Directivity And Arrays
Lack of low-frequency directivity is a problem plaguing many sound systems. Pat looks at the theory of low-frequency arrays and offers a range of possible configurations, explaining the characteristics of each.

Article #6: Truth Is Timeless
A discussion of various aspects of distortion involving Pat, as well as points made by Paul Klipsh and Don & Carolyn Davis almost four decades ago. A definition of non-linear distortion and more.

Article #7: Understanding Differential Inputs
Electricity, that unseen force that powers much of the world around us, is
an abstract concept to most people because we can’t see it or touch it
safely. Pat uses mechanical analogies to great effect in explaining
electrical aspects like avoiding extraneous noise pickup in a system.

Article #8: Electrical Power Required
The crest factor of an audio signal is the dB difference between the peaks
and the RMS value of the signal. The RMS (Root Mean Square) is defined as
the “heating value” of the signal - the voltage that would generate the same
heat as a DC (Direct Current) signal, over the same time. The RMS value of a
complex signal must be read with an RMS voltmeter. This straight discussion
continues as Pat discusses power.

Article #9: Apples With Apples
It can be said that the most fundamental process regarding the reception and evaluation of sound is that of comparison. Pat explains methods for difference measurements using mics and PC-based analysis tools, backed up by charts.

Article #10: Using %Alcons to Aim a Line Array
When implemented properly, line arrays can prove an excellent solution in helping to attain good speech intelligibility in highly reverberant spaces. Using %Alcons measurements can help lead to further optimization. How to do it, and a real-world example.

Article #11: Meaningful Metering
Sure, having visual feedback regarding system operating levels is handy, but what are the meters really saying? Pat details methods of monitoring a waveform, each with its own pros and cons. Includes examples using available meters.

Article #12: Measuring Sound
Selecting the FFT Size. Sam Berkow & Pat Brown address a parameter common to most all computer-based measurement systems - the FFT size. What, why, how, and with graphic examples.

Article #13: A Simple Implementation of the Impedance Balanced Output
Rick Chinn's discussion of transformerless output circuits, remarks on output stage topology, balanced and unbalanced connectors, and his view on the best solution.

Article #14: Measuring Z with an RTA. Since the impedance of a loudspeaker is a frequency- dependent parameter, it must be measured at multiple frequencies to get a true picture of what the amplifier is “seeing” at its output terminals. While very sophisticated methods and instruments exist, you can get a pretty good idea about the impedance curve of a loudspeaker with a standard real-time analyzer. Pat Brown explains how.

Related Article: A Conversation With Don & Carolyn Davis