18
Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
Figure 10: Filter coefficients in Helike 1.0 UA-E3010 .json file
The first three positions represent the numerator coefficients (feedforward coefficients, b0-b2), while the
last two positions represent the denominator coefficients (feedback coefficients, a1, a2). The same
sequence is used for the crossover coefficients. Note that the feedback coefficient a0 is assumed to be 1 in
this implementation. It cannot be changed and is therefore not listed in the configuration file.
An example of a custom filter implementation can be found in section 11.3.
8.3.
DRC CONFIGURATION
Besides the filtering functions, a software dynamic range compressor is built into the Helike 1.0 UA-E3010
firmware. It consists of a leveler and a limiter that are both applied to the audio input signal.
To use this function,
set the parameters “levelerDrcEnabled” and “limiterDrcEnabled” to true and configure
the settings as desired. The parameters of the DRC are shown in Figure 11, together with descriptions of
the used units.
Figure 11: Leveler and limiter settings
