User manual

Audio Analyzer
AM700 Audio Measurement Set User Manual
4-57
NOTE. If measurements on either Channel 1 or Channel 2 are not enabled, stereo
measurements cannot be enabled. Also, if the Channel 1 and Channel 2 sources are
not a stereo pair, stereo measurements are not enabled. For instance, if the Channel
1 source is the High Res generator and the Channel 2 source is the High BW
generator, the inputs are not a stereo pair and stereo measurements cannot be made.
Remember also, that when making channel separation and crosstalk measurements,
setup of the channels is important to obtain the expected results. Crosstalk is a
wideband measurement of the level difference between the undriven channel and the
driven channel, while channel separation is a measurement of the level difference
between the driven channel and the undriven channel with a bandpass filter centered
on the frequency of the driven channel.
As an aid to you, the display provides feedback if a measurement choice you have
defined for a view does not have the needed measurements or channels enabled. An
example of the type of setup error that is possible is where the measurement defined
for a view is of THD or THD+N versus Level and the THD measurement is not
enabled. The error message “THD measurements are disabled” then appears below
the measurement name in the view. Enable the channel and measurements you have
selected for a view as indicated by the error message. In the case of the example
given, press the front panel Menu button, touch the Enables soft key to display the
Channel and measurement enable choices. then touch the THD soft key to enable
THD measurements.
Wow and Flutter makes an NAB type measurement that characterizes the signal
degradation caused by short-term speed variations of analog recording and playback
devices such as tape recorders and turntables. Frequency deviations are converted
into proportional amplitude variations that can be measured. This measurement
requires enough time to make that it should not be enabled except when you want to
make the Wow and Flutter measurement, and other measurements should be
disabled to decrease the time required to made the measurement.
Measurement Operating Information. Wow and Flutter measurements in the AM700
require approximately two seconds per channel to make. If the measurement is only
being made on one channel, faster turn around time for the measurement is obtained
by turning off the unused measurement channel (Channel 1 or Channel 2) in the
Enables. The input signal frequency must be above 1200 Hz. If the dominant
frequency is below that frequency, the measurement will not be made. Also, the
measurement cannot be done using the High Bandwidth inputs of the AM700.
Wow and
Flutter
Measurement