Overview

The WiiM Ultra, WiiM Amp Ultra, WiiM Amp Pro, and WiiM Amp feature Sub Out, allowing you to connect an active subwoofer for a 2.1 system. However, it can sometimes be difficult to properly synchronize the subwoofer with the main speakers. To simplify this process, we have introduced the Subwoofer Calibration feature.

Note: Currently, only WiiM Ultra and WiiM Amp Ultra support this feature. Support for WiiM Amp Pro and WiiM Amp will be available in a future update.

With a simple tap, the Subwoofer Calibration feature automatically aligns the time delay and volume level between the main speakers and the subwoofer based on measurements at the listening position, helping them work together seamlessly for better sound.

Note: This adjustment is based on differences in speaker distance and internal processing, so all sound reaches you in sync.

Understanding Subwoofer Delay

If your subwoofer uses digital signal processing (DSP), it most likely introduces processing delay. Unfortunately, this delay cannot be eliminated. To compensate, you can add delay to the main speakers using the WiiM Home app.

If your subwoofer does not introduce noticeable delay but is placed farther from your main listening position than your main speakers, you should apply delay to your main speakers.

Subwoofer Calibration Guide

The calibration process uses your phone's microphone to automatically measure and align the time delay and volume level.

Instructions:

  1. Open the WiiM Home app.
  2. Go to the Devices tab > Device Settings > Sub Out > Subwoofer Calibration. Subwoofer Calibration settings in WiiM Home app
  3. Tap Next to start the calibration process.
    During the process, make sure to follow these instructions:
    • Ensure the room is quiet.
    • Rotate the phone 180° (microphone pointing toward speakers).
    • Hold it at ear height.
    • Sit in the sweet spot.
    Holding phone pointing toward speakers at ear height
  4. Once the calibration results appear, tap Done to complete. Successful calibration results page

The calibrated delay and level values will be automatically applied.

Further Adjustment

Calibration adjustment options

If you are not satisfied with the results, you can further adjust time delay, level, or both using any of these options:

  • Option 1: Simply tap Redo Calibration to calibrate both time delay and level again.
  • Option 2: Tap Adjust next to the delay value to manually set a delay value.
    Tips:
    • If the subwoofer is too fast, increase its delay.
    • If the main speakers are too fast, increase their delay.
    Setting manual delay value
  • Option 3: Go to the Sub Out settings and adjust the subwoofer level. Adjusting subwoofer volume level

Troubleshooting

If you encounter an error during the subwoofer calibration process, refer to Troubleshooting Subwoofer Calibration Errors to resolve the issue.