Problem
A cross-platform export contains sub-bass that survives the master but becomes distorted after mobile-oriented encoding, making music-heavy intros sound clipped.
Solution
Root Cause / Diagnostic:
Sub-bass energy below 40 Hz consumes massive electrical headroom and amplifier power without being physically reproducible on small mobile phone speakers. When lossy audio codecs encode intense sub-bass into low-bitrate AAC, the extreme low-frequency excursion causes digital intersample peaks, driving the platform encoder into harsh square-wave clipping.
Actionable Fix:
1. Apply an 18 dB/octave high-pass filter (HPF) on the master output bus, rolling off all sub-audible frequencies below 35 Hz to 45 Hz.
2. Insert a saturator or harmonic exciter (such as Waves Renaissance Bass) to generate 2nd and 3rd order harmonics (80 Hz–180 Hz) so bass remains audible on mobile hardware.
3. Audit True Peak metering on the master channel to ensure no transient exceeds -1.0 dBTP after low-cut filtering is applied.
Pro Tip:
Cutting frequencies below 40 Hz creates 1.5 to 2 dB of clean dynamic headroom, allowing dialogue and musical punch to sit noticeably louder without distortion.
Sub-bass energy below 40 Hz consumes massive electrical headroom and amplifier power without being physically reproducible on small mobile phone speakers. When lossy audio codecs encode intense sub-bass into low-bitrate AAC, the extreme low-frequency excursion causes digital intersample peaks, driving the platform encoder into harsh square-wave clipping.
Actionable Fix:
1. Apply an 18 dB/octave high-pass filter (HPF) on the master output bus, rolling off all sub-audible frequencies below 35 Hz to 45 Hz.
2. Insert a saturator or harmonic exciter (such as Waves Renaissance Bass) to generate 2nd and 3rd order harmonics (80 Hz–180 Hz) so bass remains audible on mobile hardware.
3. Audit True Peak metering on the master channel to ensure no transient exceeds -1.0 dBTP after low-cut filtering is applied.
Pro Tip:
Cutting frequencies below 40 Hz creates 1.5 to 2 dB of clean dynamic headroom, allowing dialogue and musical punch to sit noticeably louder without distortion.