Marc Daniel Nelson shares a background vocal mixing technique that he discovered by accident, which has since become a staple in his mixing arsenal.
This approach involves using the FabFilter Pro-MB as an expander to emphasize the higher frequencies (between 2 kHz and 15 kHz) of the background vocals, thereby enhancing their brightness, punchiness, and presence in a distinct manner.
To ensure the background vocals remain supportive and do not overshadow the lead, Nelson incorporates two stages of de-essing and employs a Klanghelm MJUC compressor with a high-pass filter in the sidechain, set to around 400 Hz.
This technique creates a sense of space and airiness around the vocals, yielding a polished pop sound that is especially effective for dense arrangements with a high track count.