The WiiM Pro Plus is equipped with the latest generation AKM 4493SEQ premium DAC, renowned for its exceptionally low distortion and wide dynamic range, a result of AKM’s advanced Velvet Sound Technology. This DAC supports high-resolution audio sources up to 768 kHz PCM, making it ideal for audiophiles. It achieves an impressive 120 dB (A-wt) SNR and a THD+N of just 0.00032% (-110 dB) across a range from 44.1k to 192k.


The choice of filter can significantly influence your listening experience, affecting the accuracy of frequency reproduction, phase distortion, and control of ringing artifacts. The extent to which these differences are noticeable can vary based on the recording quality, your audio system, and personal auditory preferences. 

Six DAC Digital Filter Types


Each digital filter in the AKM 4493SEQ DAC uniquely shapes the sound quality. Here's a brief overview:


1. Sharp Roll-Off Filter


  • Key Feature: Steep roll-off, attenuating frequencies just outside the desired range.
  • Benefit: Reduces aliasing effectively but may introduce ringing artifacts.
  • Suitable Audience: Those seeking precise signal reproduction, especially in complex tracks.


2. Slow Roll-Off Filter


  • Key Feature: Gradual roll-off slope.
  • Benefit: Less ringing and phase distortion, offering a natural sound; slightly less effective against aliasing.
  • Suitable Audience: Listeners who prefer a smoother, more natural audio quality.


3. Short Delay Sharp Roll-Off Filter


  • Key Feature: Sharp roll-off with reduced signal delay.
  • Benefit: Limits pre-ringing while maintaining clear frequency attenuation.
  • Suitable Audience: Those sensitive to timing and phase but desiring clear audio reproduction.


4. Short Delay Slow Roll-Off Filter


  • Key Feature: Slow roll-off with minimized delay.
  • Benefit: Natural sound with less phase distortion and reduced pre-ringing.
  • Suitable Audience: Listeners valuing natural sound and phase coherence.


5. Super Slow Roll-Off Filter (NOS)


  • Key Feature: Even gentler roll-off slope.
  • Benefit: Minimizes phase shift and ringing, ensuring smooth sound.
  • Suitable Audience: Audiophiles who favor a very smooth, natural listening experience.


6. Low Dispersion Short Delay Filter


  • Key Feature: Balances time dispersion and roll-off sharpness.
  • Benefit: Reduces both pre- and post-ringing for a balanced sound.
  • Suitable Audience: Those seeking a balanced sound with minimal phase distortion.

Configuration of DAC Digital Filter Type


  1. Open the WiiM Home app.

  2. Go to the Devices tab and tap the Device Settings icon for your WiiM Pro Plus.

  3. Select the Audio Output setting.

  4. Select Line Out as audio output and then select your preferred DAC Digital Filter Type. The default type is Sharp Roll-Off Filter.