AS3460
ALC Tuning Guide
Demo Kit Manual
• PUBLIC
UG000480
• v3-00 • 2021-Nov-08
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FB Mic Blocked
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Adaption Guard
They are independent of the earphone's acoustic properties and filter tuning and therefore do not
require any tuning. Explanations on what these corner case algorithms do is provided by the tooltips.
The tuning instructions for the wind noise detection algorithm are provided in a separate document.
7.11
ELF Stage
In some earbud designs, the driver's low frequency response diminishes strongly with increasing
leakage. Especially if a small speaker and no basstube was used. An extra adaptive shelf filter can be
activated in ALC to improve performance on these types of earphones.
To use it, enable the "ELF adaption" in the ALC configuration. A new filter stage, denoted "Special",
will then appear in the tuning tab at the end of the feed forward filter chain. You can then try to run the
auto adapt function.
However, if the process times out with the warning: “ELF band pass could not
produce required attenuation levels”, then please try to
increase the extra low-frequency attenuation or
adjust the adaption region, these settings can be found at "Adaption Region" in the ALC configuration.
If the adaption with ELF stage still does not succeed, it usually means that the ELF stage does not
provide a benefit for this headphone.
If the “Adapt” process does run successfully with the ELF stage enabled, but the noise cancellation
performance at intermittent leakage is not satisfactory, adjust the feed-forward high-pass filter cut-off
frequency marked as “Special”. Then, try different frequency settings running the “Adapt” process
each time until there is a satisfactory level of noise-cancellation performance at intermediate leakage.
