Liberty Instruments, Inc.    Technical Articles  LAUD User info
Contact Us  Time, Frequency, Phase and Delay  (reprinted from
Speaker Builder Magazine)  Signal theory is a topic which
intimidates many audiophiles. We generally have a good grasp of
the concept of time and feel comfortable discussing frequency.
But many consider phase and signal delay to be magical
quantities in some sort of esoteric alchemy, understandable only
with great effort and through extensive mathematical
abstraction. In this article I will attempt to present a
relatively simple treatment of these subjects, with emphasis on
their importance in loudspeaker design and testing.  First, lets
make sure that we all agree about the meaning of time domain
data and frequencies. Time domain data is any quantitiy that
varies with time, which in the case of loudspeakers is usually a
sound pressure or signal voltage. Music (as viewed on an
oscilloscope) is an example, as are the other various signals
(impulses, MLSs, sweeps, tone bursts, noise) u