Notes On Operation - RME Audio ADI-96 PRO User Manual

11.5 Notes on Operation

The most important application using a Spectrum Analyser is the visualisation of frequencies
and levels found in music or speech. What you see is what your hear! The Analyser shows
levels and frequencies even at the edge of the human ear's abilities. The visual display helps to
train your ears, and avoids serious mistakes when mixing to the master tape. Usual studio
monitors won't let you hear frequencies below 100 Hz. Simply look on the Audio Analyser to
see what's going on in the underground!
Reading the display is not easy for novices because of the huge amount of information it
shows. But after some training you'll agree that this tool is a precious help in every day work.
Analysis of Music
Attack and Release time are the most important parameters when trying to achieve a display
similar to what you hear. At a very fast attack setting the Analyser will show even shortest
peaks down to one sample. But these are only audible when present in several bands and last-
ing for more than a millisecond. That's why 7 ms Rise Time results in a much better display
behaviour. The release time should be set to three different values. A very fast display (1 s) is
recommended for example when trying to see the bass which normally hides behind the bass
drum. At 2 s the display will be more easier to read and is more friendly to your eyes. Some
special applications (like averaging the sound impression or noise measurements) require val-
ues around 10 to 20 seconds.
Special Display Modes
The Audio Analyser offers two different envelope modes. Let's look at this example: You want
to study the frequency distribution of a bass drum sample.
Method 1: Route the bass drum sample to the Analyser and store the display's contents by
hitting Freeze in the right moment. Much more convenient is
Method 2: Use Instant Hold to activate the envelope mode. Play the bass drum sample one
time. Thanks to the infinite release time the analyser's result won't vanish from the screen.
Method 3 is mainly used with music. At active Instant Hold and display mode Peak Hold the
music is shown as usual, but the peak display above the bars won't be reset. When playing
back a 3 minute Pop song an envelope of all frequencies and levels which occured is shown.
Sound Measurements
The combination Equalizer/Analyser is used to correct the misalignment of speakers and room.
A test signal (pink noise) is send from the speakers into a special measurement microphone
placed at the engineer's preferred listening position. At a release time of 20 seconds, Riste
Time 200 ms and active Point mode a display of the overall frequency response is shown. The
external Equalizer is now used to correct this curve to a straight line.
Special Applications
At the highest display range (50 dB) and lowest Top Level setting (-70 dB) the Analyser dis-
plays all signals down to -120 dBFS. This allows to examine the hum and noise present in the
studio's environment. Disturbing frequencies can be classified and removed more exactly. In
Left minus Right mode only the stereo signals of a complete mix are shown. This gives some
interesting information on the mixing technique.
User's Guide ADI-96 PRO © RME
31