Recommended Tools
Loudness Leveler
Maintain -24 LUFS with steady real-time target tracking.
Loudness Compressor
Shape dynamics toward -24 LUFS with built-in True Peak control.
Loudness Limiter
Drive audio to -24 LUFS while respecting -2 dBTP.
Dynamics Optimizer
Analyze offline for precise -24 LUFS delivery.
Loudness Meter
Verify -24 LUFS and -2 dBTP targets.
About this Target
Standard for US broadcast, typically focused on dialogue anchoring.
The CALM Act in the US requires commercials to be the same volume as the programming they accompany. ATSC A/85 specifies a target of -24 LUFS. This standard focuses heavily on 'Dialogue Normalization' (Dialnorm). For music delivery to TV, adhering to -24 LUFS ensures your track matches the anchor level of the dialogue in the broadcast.
Guide: Loudness Leveler
The APU Loudness Leveler is a strong fit when you want to hold a program close to the ATSC A/85, US TV target continuously rather than force it there with conventional compression or hard limiting.
Instead of mapping one loudness range onto another, the Leveler follows a target zone in real time and applies correction only when the program drifts away from where you want it.
A practical starting point is to load a Leveling - Present or Leveling - Deep preset, then select the ATSC A/85, US TV target range preset to initialize the target loudness and limiter ceiling.
From there, adjust Target Tolerance to control how tightly the audio is held around -24 LUFS. Present tends to work well for general-purpose material, while Deep is useful when you want the correction to follow the larger contour of the audio instead of every phrase-level change.
The built-in Tail Guard mode helps prevent the leveler from amplifying breaths and other relatively quiet moments at the end of phrases, which can lead to a more natural sound. When Tail Guard is enabled, the leveler holds gain correction during these moments, allowing them to sit more naturally in the mix.
The built-in limiter then handles final peak containment at -2 dBTP, which makes the Leveler especially useful for podcasts, dialog-heavy material, streams, and other sources that benefit from steady loudness tracking instead of obvious peak chopping.
Guide: Loudness Compressor
The APU Loudness Compressor is a complete loudness solution that combines dynamic range control with a built-in True Peak limiter.
This allows you to achieve the ATSC A/85, US TV target by increasing density and "glue" rather than just chopping off peaks.
Workflow:
1. Use the Source Range "Learn" function to automatically detect the dynamic range of your input audio. This function
utilizes the LRA algorithm to determine the optimal source range for compression/expansion.
2. Select the ATSC A/85, US TV preset in the Target Range. This sets the compressor's target to -24 LUFS and the limiter ceiling to -2 dBTP.
Note: Hold Ctrl (Cmd on Mac) and click + drag the middle of the target range slider up or down to expand or contract the target range around the center
point. Great for maintaining a consistent loudness target while adjusting dynamic range.
Guide: Loudness Limiter
For the most direct path to compliance, the APU Loudness Limiter can be used as a standalone maximizing solution.
It simultaneously targets the specific LUFS loudness and True Peak limit required by ATSC A/85, US TV.
Simply select the ATSC A/85, US TV target range preset. This configures the limiter ceilings to -24 LUFS and -2 dBTP.
Drive the input gain until the momentary LUFS meter stabilizes around the target. The limiter's transparent lookahead algorithm ensures the
audio never exceeds the allowable True Peak level while also enforcing a soft ceiling on the momentary loudness.
Soften up the limiter some more by switching to Short term loudness mode for a slower, more musical response. Short term is based on
a 3 second average and is less sensitive to transient spikes, making it ideal for transparent music mastering.
Guide: Dynamics Optimizer
If you prefer an automated, offline approach, the APU Dynamics Optimizer analyzes your entire audio
file and applies optimal normalization and limiting to meet the ATSC A/85, US TV target in one pass.
This tool provides the highest accuracy as it can "see" the entire file before processing. Select the ATSC A/85, US TV target range preset
to quickly set the target loudness to exactly -24 LUFS and -2 dBTP, and the Optimizer will calculate the precise gain adjustments needed to
achieve compliance while maintaining dynamic integrity.
Metering for ATSC A/85, US TV
Compliance with ATSC A/85 often focuses on the 'anchor element' (usually dialogue). When metering, ensure that the speech sections center around -24 LUFS. The Integrated LUFS measurement serves as the verification for the CALM Act compliance.
Monitoring both Momentary and Integrated LUFS helps ensure your audio consistently meets the ATSC A/85, US TV loudness target.
The APU Loudness Meter provides real-time feedback on your audio's loudness levels, allowing you to make informed adjustments
during the mastering process.
In the screenshots below, we can see the Momentary LUFS meter hovering around the target of -24 LUFS, indicating compliance with the ATSC A/85, US TV target.
The statistics panel gives quick access to Integrated LUFS, LRA and other metrics.