ProSoundWeb | SynAudCon

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.

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 #20: System & room interactions. If one could listen to only the direct sound of a loudspeaker, the world would be a very different place! Unfortunately, free field listening, where you have NO reflections, room modes or ambient noise, is hard to achieve in everyday life, so we listen to loudspeakers in real rooms. Sam Berkow provides a detail discussion and data.

Article #19: Amplifier-to-Loudspeaker Interface.
Is there anything special about hooking an amplifier to a loudspeaker? Here is a brief look at some parameters that can affect the sonic performance of this important interface.

Article #18: Acoustic measurement primer, part 2.
Picking up where part 1 left off, this article shows interpretation of impulse response and how to apply this information to your system.

Article #17: Acoustic measurement primer.
In part 1 of a new series, Pat Brown provides a logical way to get "up and running" with modern sound measuring instruments. Plenty of examples and graphics are included.

Article #16: Dynamic range and signal-to-noise.
Adequate signal-to-noise ratio is one of the characteristics of a professionally designed and installed sound reinforcement system. Pat Brown explains that terms "dynamic range" and "signal-to-noise ratio" are often used interchangeably, but a closer look reveals that they are not exactly the same thing. And, he shares how to put this knowledge into practice.

Article #15: The Nyquist Plot.
Don Davis offers a thorough discussion of the Nyquist Plot, which he terms the most informative frequency domain plot. He also explains how to correctly determine this data, and what it means. Plenty of graphics as well!

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.

Article #13: Measuring AC with a TEF analyzer.
Jim Brown provides an excellent discussion and a simple, effective method for measuring AC line voltage from a wall outlet using a TEF analyzer.

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

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 #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 #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 #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 #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.