I'm developing an app on Android which uses OpenSL to record and play audio. Due to the measurement nature of the App itself, I need to have access to the raw input of the microphone. I have already configured the AudioRecorder with the SL_ANDROID_KEY_RECORDING_PRESET, but despite this in some device it seems that a low-pass filtering takes place before the audio reaches the recorder (for example Galaxy Note 3). I also tried to retrieve the equalizer interface of the recorder through the dynamic interface manager but when I try to set new presets on it I always receive the SL_RESULT_CONTROL_LOST error.
Am I doing everything necessary to access the raw signal or I have to assume the existence of an hardware pre-filtering? How can I fix the SL_RESULT_CONTROL_LOST issue?
Thank you in advance!