PublicationsAlternative Ways of Viewing Polar Data Synergetic Audio Concepts - Tech Topics (2001) about a my MATLAB program PolarSum. This details a different way to view directivity data. It also describes processing the data with filter functions and adding multiple sources to calculate their combined directivity response.How using textbook crossover filters with typical non-ideal loudspeaker drivers can affect a loudspeaker's performance in the real world.EASE Focus - Line Array 2D Aiming Software A Synergetic Audio Concepts Newsletter (2006) article detailing the features and operation of EASE Focus.EASERA - Calibration for Absolute Levels A brief procedure for calibrating EASERA to display measurements with correct absolute levels.EASERA - Overview and Operation A relatively quick glance at the acoustical measurement and analysis features of EASERA.Graphs of popular crossover filter alignments and how they sum together.How Accurate is Your Directivity Data? A white paper on the anechoic chamber modifications and calibration that were necessary to accurately measure the complex data of directivity balloons of loudspeaker systems. The facility detailed in this paper is operated by NWAA Labs in southern California.A process is described for measuring impedance of loudspeakers at higher drive levels common of typical usage. Most often impedance is measured at very low drive level which may not reveal some problems. This is done with standard, off-the-shelf software and hardware that is relatively inexpensive.A short article on how to do small and large signal impedance measurements with a TEF analyzer. Waterfall (3D) impedance measurements showing how impedance resonances behave as a function of time are also mentioned.A brief explanation of different pick-up patterns of microphones.A brief explanation of phase.
Phase Response & Propagation Delay There are always questions about the “correct” phase response when measuring a loudspeaker or some other band pass device. In this article I examine the correct phase response of a text book device (a band pass filter). I then describe a method to determine the correct propagation delay for an arbitrary device under test so that its true phase response may be measured. This is a great companion / follow-up to the Subwoofer Alignment article.Transcript of Charlie's ProSoundWeb chat from April 2, 2001.A new concept in horn design. This paper was presented at the 107th Audio Engineering Society convention, September 25, 1999.Quadratic Throat Waveguide - White Paper John Murray gives a very good explanation of the Quadratic Throat Waveguide without a lot of the math. This also covers some of the history of the development of conventional constant directivity horns.Does a square wave, or any clipped wave form, contain DC? I examine a square wave and see what causes it to have its square shape. This leads into an easy to understand explanation of phase and its effects in the time and frequency domains. This is a very general introduction to Fourier analysis and the correlation between the time & frequency domains with no math cited.Subwoofer Alignment with a Full Range System I have heard the question “How do I align a subwoofer with a full range loudspeaker system?” asked many times. I thought it might be interesting to delve
into this to see if I could come up with an answer. The task of adding a subwoofer to a loudspeaker system to increase the low frequency bandwidth should
typically entail three primary items.
|
| Excelsior Audio | (704) 675-5435 | info @ excelsior-audio.com |