Embodiments relate to an audio system that performs equalization of audio signals based on one or more diffuse field head-related transfer functions (HRTFs) and device-specific data. User-specific data and device-specific data (i.e., transducer-specific data) are applied to an acoustic model to predict an acoustic response for a user. An equalization filter is then determined using the acoustic response and the one or more diffuse field HRTFs. The equalization filter is applied to a processed version of an audio signal to create a modified version of the audio signal. The modified version of the audio signal is presented to the user via a transducer array of the audio system. The audio system can further include a microphone assembly that reduces the Helmholtz resonance effect.