- Publisher: APU Software
- Product: APU Loudness Contour
- Version: 4.2.4-BTCR
- Format: VST/AU/AAX
- Requirements: Windows 10 or higher
APU Loudness Contour is a loudness monitoring plugin that keeps your mixes tonally balanced at any volume using ISO 226 equal-loudness curves. It offers real-time LUFS, RMS, and peak metering, with a free, fully functional version so you can experience it before purchasing — available for macOS, Windows, and Linux.
Professional Loudness Monitoring for Music, Broadcast, and Post-Production
APU Loudness Contour is built for mixing, mastering, and broadcast engineers who need accurate tonal balance across any listening level. Using ISO 226 equal-loudness curves, it accounts for the human ear’s changing sensitivity across frequencies, delivering precise LUFS, RMS, and peak metering in real time. Compatible with macOS, Windows, and Linux in VST3, AU, and AAX formats, it supports stereo and surround workflows. You can evaluate it in your own projects before buying, ensuring it meets your workflow needs.
Key Features
- Equal-loudness curve processing based on ISO 226 standards
- Real-time loudness monitoring: LUFS, RMS, and peak metering
- Customizable target curves for various broadcast and music standards
- Stereo and surround sound support
- Cross-platform: macOS, Windows, and Linux
- Multiple formats: VST3, AU, and AAX
Frequently Asked Questions
What is loudness contour in audio?
A loudness contour is a visual and analytical representation of how the perceived loudness of audio changes across the frequency spectrum at different listening levels, based on the human ear’s sensitivity to bass, midrange, and treble.
How does a loudness contour plugin work?
It measures the incoming signal, applies an equal-loudness contour model, and displays the perceived loudness across frequencies in real time so engineers can make precise tonal adjustments.
Why is loudness contour important for mixing and mastering?
Because mixes can sound very different at different volumes, loudness contour helps ensure consistent tonal balance on any playback system.
Can I use APU Loudness Contour before buying?
Yes — you can download the fully functional version and use it in your projects before purchasing.