PreSonus StudioLive AI Series - Manual (Page 38)

4 Universal Control-AI and VSL-AI
4.7 Enabling Smaart Analysis (GEQ and PEQ)
StudioLive ™ AI Software Library
Reference Manual
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4. Slowly bring the aux output level up until you hear (and see) feedback.
Note: Ringing out stage monitors will produce feedback. If you are not careful,
you can produce a lot of feedback. Do not make sudden gain boosts; go
slowly and carefully to avoid causing any damage to speakers and ears.
5. Feedback will show up as a solid line on the spectrograph and as
a line peak on the RTA. Use the dynamic threshold to adjust how
bright, and at what input level, the frequency information plots.
6. Lower the GEQ fader for the offending frequency in 3 dB
increments to attenuate it out of your stage monitor.
Power User Tip: Bring back the level on the GEQ slider to the point just before feedback
so you don’t take out too much frequency content and sacrifice overall timbre.
Because the speaker is pointed at the mic, stage-monitor feedback typically occurs
in the higher frequencies, which also is where intelligibility comes from. Maximizing
your intelligibility and gain structure results in clearer-sounding monitors.
You can apply this process to the main system, as well. This is especially useful
with applications requiring lavaliere or podium mics. These types of microphones
are typically omnidirectional condensers and are very prone to feedback.
In a main system, feedback is typically in the mid to low range. The
frequencies that are regenerating and creating a feedback loop
are those frequencies that are wrapping around the main system
due to the loss of directional control of lower frequencies.
When you are ringing out a system, and more than two or three feedback
loops are happening simultaneously, you have reached the level where
stability can no longer be achieved. Try bringing down the overall output level
or find a physical solution, such as moving the speaker or microphone.
4.7.4 Using the Smaart RTA While Mixing
The RTA and spectrograph have useful applications beyond recognizing feedback
spikes. The ability to analyze frequency content—specifically, being able to
visualize the exact frequencies you are hearing in order to home in on problem
areas— makes the RTA a secret weapon for many a mix engineer. The Smaart
Spectra tools also lend themselves very well to ear training and give you confidence
that you are choosing the right frequencies when making adjustments.
Because the RTA/spectrograph is analyzing the bus signal digitally, room and speaker
anomalies are taken out of the equation. This provides a pure measurement of
your mix because you are measuring what is happening inside your StudioLive.
A spectrograph shows the broadband information of a signal, making it easy to
view the fundamental frequency of a source, as well as its harmonic structure.
The RTA is a view of amplitude and frequency content over a specified plane.
With the spectrograph, you can view what is happening in your signal now, at the
same time you are viewing what happened moments before. In contrast, there
is no history information for the RTA: Once an event happens, it goes away.
Power User Tip: Both the RTA and Spectrograph views are useful in understanding what
the spectral content of an instrument is when creating space for that instrument in a
mix. How you use these tools to achieve an objective is a matter of your subjective, or
creative, goals. Trust your ears and use the Spectra tools to verify what you are hearing.
For example, let’s say you are mixing a particularly edgy-sounding lead guitar
that is competing with the male vocal and distracting from the overall good
tone of the instrument. By using the RTA in the Fat Channel, you can quickly
identify the offending frequency by looking for spikes in the RTA. This saves
time and frustration by taking some of the guesswork out of equalization.
Power User Tip: It should be noted that neither a spectrograph nor an RTA can
be used as a substitute for careful listening. While these tools provide a great
visual analysis of your mix, critical listening must always be your main guide.