D-fend SA300 User Manual - page 17
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D-fend™ SA300 User Manual
Mounting Recommendation
For maximum cooling potential, it is recommended to operate D-fend with the cooling fins positioned in a vertical
orientation as illustrated in the drawing below.
Failure to provide adequate exposure to ambient air may limit the performance or life expectancy of the device.
Advanced Programming
This section of the manual provides information on how to use and operate the Advanced Programming portion of the GUI
(graphical user interface) provided with your SA300 and give you some tips and advice on tweaking the settings. At the end
of this section we will go over the recommended starting settings for our four example systems that we have shown you
earlier in the manual, and the process you should use to best tweak the settings.
Some words to the wise before we dig In:
When configuring the SA300 to protect your speaker system, we encourage you to begin with ¼ of the rated power of the
load connected to the SA300. This is very conservative in many instances and it will be up to you to make the ultimate
decision on how much protection you want vs. how much output you need. The SA300 is a tool to help you protect your
system and allow you to run it very hard without fear of blowing something up if it is set correctly. The SA300 needs to be
configured so the system can be run at its limits and the SA300 does not have any sonic impact on the musicality of the
system. It will take some trial and error to find the limits. If you find you are continually hitting the set limits then there is a
possibility you have either set the limits too low, or you have simply reached the limits of your system.
Let’s dig in and get your system properly protected.
First, some background on the SA300’s internal workings will help you better understand the settings we need to enter
into the SA300. The Advanced Programming portion of the GUI provides direct access to all three internal signal flow
paths used by the SA300 during run-time operation: the high frequency path (HF), the all-pass path (AP), and the
low frequency path (LF). As the audio signal is received into the SA300 it is sampled and then the inbound waveform’s
spectrum is analyzed over these three paths. After filtration, the three signal paths provide you with different limiter blocks
available for configuration. Specifically, the HF path provides an RMS limiter and a peak limiter; the AP path provides an
RMS limiter block; and the LF path provides a peak limiter block. All of these limiter blocks make use of standard limiting
parameters: threshold, attack, and release.