Sound System Measurements using Time Delay Spectrometry

This web site is part of a project done for Dr. Baraniuk's ELEC 301 class (Fall 2000) at Rice University.


The Problem | How TDS Works | Applications | Other Measurement Techniques | Future Projects


What is TDS?

TDS, or Time Delay Spectrometry, is a technique that can be used to measure the system response of electro-acoustical systems (such as a loudspeakers) in "real-world" reverberant environments. The technique can also be expanded to measure the system response of an acoustic environment such as an auditorium or concert hall. TDS lends itself naturally to obtaining three dimensional TEF (time-energy-frequency) plots of system response. Although the mathematical and conceptual basis behind TDS have been known for quite some time, the TDS technique itself is usually credited to the late Dr. Richard Heyser, who first published the technique in the 1967 Journal of the Audio Engineering Society.

This Project

This investigation presents a broad overview of some of the electro-acoustical measuring techniques used by real-world electrical engineers, acousticians, and sound system designers. We focused on researching TDS, but in no way limited our research efforts in that direction. After searching for a unified source of information on electro-acoustical measuring techniques, we found few sources of information that gave us a broad overview about the mechanisms and practical applications of the various techniques that we have tried to present.

So, we decided to try to do it ourselves. Our attempt is by no means complete, and this investigation will definitely continue in the years to come. Hopefully, we will be allowed to update this web-site to make corrections, add information, and perhaps even add practical case studies for real-world problems.

Think globally, act locally, and don't work too hard. ;-)

And don't forget to get into it!

BTW, we used a software package called Mac the Scope™ to make our measurements.


The group consists of (in alphabetical order, of course):

Lisa Alford (the short one)

--research, posterboard layout, conceptual lifeguard

Adam Brickman (meow)

--research, posterboard layout, sequential concept explainer

John Glassmire (mmm . . . beer)

--research, posterboard layout, graphics, all-around workhorse

Tejus Gohil (the fat one)

--research, TDS measurements, web-page, ultra-global nut


The Problem | How TDS Works | Applications | Other Measurement Techniques | Future Projects