LUFS, -1dB TP cosa?!? Il loudness spiegato semplicemente - TUTORIAL

Logic Pro X Italia

20 May 202016:25

Summary

TLDRThe transcript discusses the concept of Loudness Unit (LUFS) and its importance in audio production and broadcasting. It explains the difference between Real-time Measurement (RMS) and LUFS, emphasizing that LUFS is a more accurate measure of perceived volume over the entire track, accounting for silent parts. The speaker also touches on the issue of dynamic range compression and its impact on audio quality, as well as the use of Orbán Loudness Meter for measuring LUFS. The conversation highlights the need for proper loudness standards to ensure consistent volume levels across different media platforms.

Takeaways

📊 The acronym LUX stands for Loudness Unit in Reference Scale, which is a measure of perceived audio volume.
🔊 Loudness (Loudness Unit) is subjective and represents the perceived volume of audio, while Peak Level is the maximum point reached by the audio signal.
📉 The RMS (Root Mean Square) value defines the average level between the maximum and minimum values, effectively representing the perceived volume.
📈 The Dynamic Range, also known as the Loudness Factor or Crest Factor, has been flattened in modern audio to trick the ear into perceiving a higher volume.
📌 The 'Loudness War' refers to the trend of reducing dynamic range to achieve a louder perceived volume, which can lead to audio quality degradation.
🚫 To control volume changes, especially in broadcasting, a new measurement unit called LUFS (Loudness Units relative to Full Scale) has been introduced with a standard limit of -23 LUFS.
🔄 LUFS is different from RMS in that it is a real-time measurement, while LUFS is an average calculated over the entire piece of audio.
🔇 The Orbán Loudness Meter is a free tool that can measure the LUFS of an audio file, providing a more accurate representation of perceived volume.
🎚️ Equalization and other audio processing can significantly affect the LUFS measurement, not just the volume level.
📉 True Peak levels are important to consider when distributing music, as they can affect how audio is perceived on different platforms and can lead to volume reduction or compression.
🔍 Sample rate conversion and interpolation can introduce small errors in digital-to-analog conversion, which should be monitored to maintain audio quality.

Q & A

What does the acronym LUX stand for in the context of audio?
-LUX stands for Loudness Unit in Reference to Full Scale. It is a measure of perceived audio volume.
What is the difference between Loudness and Peak level in audio?
-Loudness is the subjective perception of volume, while the Peak level is the maximum point that the audio signal reaches. The RMS (Root Mean Square) value defines the average level between the maximum and minimum, which is essentially the perceived volume.
What is the Dynamic Range and its significance in audio?
-Dynamic Range, also known as the crest factor, is the difference between the loudest and softest parts of an audio signal. It is significant because it affects the perceived quality and depth of the audio.
What is the Loudness War and how does it affect audio quality?
-The Loudness War refers to the trend of increasing the average volume of audio recordings to make them stand out, which leads to a flattened dynamic range. This can result in audio that sounds overly compressed and lacking in dynamic contrast.
What is the purpose of the LUFS (Loudness Units relative to Full Scale) measurement?
-LUFS is a standardized unit of measurement for audio loudness, which helps to ensure consistent volume levels across different media, improving the listening experience and preventing volume surprises.
How does the Orbán Loudness Meter work?
-The Orbán Loudness Meter is a tool that measures the integrated loudness (LUX) of an audio file. It calculates the average loudness over the entire piece, taking into account the settings that ignore very low levels in the calculation.
What is the relationship between LUFS and RMS measurements?
-While LUFS and RMS are related, they are not the same. RMS is a real-time measurement of the current audio level, whereas LUFS is a calculated average over the entire audio piece, which can provide a more realistic representation of perceived volume.
How does equalization affect loudness measurements?
-Equalization can significantly influence loudness measurements because it alters the balance of frequencies within the audio. This can affect how the overall loudness is perceived and measured.
What is the True Peak level and why is it important?
-True Peak level refers to the highest point of the audio waveform, which can exceed the digital 0 dB level due to sample interpolation. It is important because exceeding true peak levels can cause distortion and is a factor in meeting the loudness standards for various platforms.
What is the purpose of the 'interpolation of samples' measurement in audio?
-The 'interpolation of samples' measurement helps to identify any distortion that occurs during the conversion from digital to analog signals. It is crucial for maintaining audio quality and ensuring that the audio does not clip or distort during playback.
How can one ensure their audio meets the loudness standards for distribution?
-To ensure audio meets loudness standards, one can use tools like the Orbán Loudness Meter or other LUFS meters to measure and adjust the audio levels accordingly. It's also important to be aware of the specific loudness requirements of the platforms where the audio will be distributed.

Outlines

00:00

Understanding Loudness (🔊)

The paragraph discusses the concept of loudness (LUFS) and its importance in audio production. It explains that loudness is a subjective perception of volume and introduces the term LUFS (Loudness Unit relative to Full Scale). The speaker attempts to clarify the meaning of LUFS and its relevance in the context of audio levels and dynamic range. The paragraph also touches on the issue of loudness normalization and the 'loudness war,' which refers to the trend of increasing audio levels to make them more competitive, potentially at the expense of audio quality.

05:02

LUFS and RMS: The Difference (📊)

This paragraph delves into the distinction between LUFS and RMS (Root Mean Square). It explains that while RMS is a real-time measurement of audio levels, LUFS is an average calculated over the entire piece of music. The speaker emphasizes the practicality of LUFS for broadcast and streaming, as it accounts for the overall perceived volume, including silent parts that are not considered in the RMS calculation. The paragraph also mentions the use of a loudness meter to measure LUFS and the importance of adhering to broadcast standards.

10:04

Adjusting Music for Distribution (🎧)

The speaker addresses the process of preparing music for distribution, focusing on the loudness requirements of various platforms. It mentions the importance of adhering to LUFS standards, such as -14 LUFS for YouTube, and the use of a loudness meter to adjust audio levels accordingly. The paragraph also discusses the impact of equalization on loudness measurement and the need to consider sample rate conversion and its potential for introducing distortion, known as 'sample clipping.' The speaker recommends using specific plugins and tools to measure and manage these parameters.

15:06

The Impact of Loudness on Audio Quality (🎵)

The final paragraph highlights the consequences of not adhering to loudness standards. It suggests that older music and CDs may not have been optimized for current loudness expectations, leading to a perceived drop in quality when played on modern platforms. The speaker encourages listeners to experiment with different music and to be aware of the potential for volume reduction or compression on various music distribution platforms. The paragraph concludes with a recommendation to use online tools for measuring the loudness of audio files and a reminder of the importance of maintaining audio quality.

Mindmap

Keywords

💡Loudness

Loudness refers to the perceived volume of sound, which is subjective and varies from person to person. In the context of the video, it is discussed in relation to the Loudness Unit (LU) and how it is measured. The video emphasizes the importance of managing loudness to avoid sudden volume changes, which can be jarring for listeners, especially in broadcasting environments like television and radio.

💡Loudness Unit (LU)

The Loudness Unit is a measure used to quantify the perceived volume of audio. It is derived from the acronym 'LU' which stands for 'loudness unit in reference.' The video explains that LU is not directly related to the peak level of audio but rather to the perceived volume, which is influenced by factors such as the dynamic range and the average level of the audio signal.

💡Dynamic Range

Dynamic range is the difference between the loudest and softest sounds in an audio signal. The video discusses how the 'loudness wars' have led to a compression of dynamic range, resulting in audio files that are perceived as louder but may lack the quality and depth of a wider dynamic range. This compression can lead to a 'flattening' of the audio, which can be detrimental to the listening experience.

💡Loudness Meter

A loudness meter is a tool used to measure the loudness of audio in LU. The video mentions the Orbán Loudness Meter, which is a free software that provides real-time loudness measurements. It is used to ensure that audio content meets specific loudness standards, such as those for broadcasting, and to avoid issues like clipping or distortion.

💡RMS (Root Mean Square)

RMS, or Root Mean Square, is a statistical measure of the magnitude of a varying quantity and is used to represent the average power of an audio signal. In the video, RMS is compared to LU and is described as a real-time measurement that reflects the perceived volume at any given moment, as opposed to LU, which is an average over the entire audio piece.

💡True Peak

True Peak refers to the highest peak level of an audio signal, which can exceed the digital 0 dBFS level during the conversion from digital to analog. The video mentions that exceeding the true peak level can cause distortion and is something to be monitored during audio production and distribution. It is particularly important for formats like iTunes, which have specific true peak limits.

💡Interpolation of Samples

Interpolation of samples is a process that occurs when digital audio signals are converted to analog. It can introduce a small error, known as a 'glitch,' which can affect the audio quality. The video explains that this issue is more pronounced in certain digital formats and during the conversion process, which is why it's important to monitor and manage it to maintain audio quality.

💡Loudness Normalization

Loudness normalization is the process of adjusting the volume of audio content to meet specific loudness standards. The video discusses the introduction of the LUFS (Loudness Unit relative to Full Scale) as a new unit of measurement to control the perceived volume of audio, ensuring that it does not exceed certain limits, which can be particularly beneficial for broadcasting and streaming services.

💡Loudness Integration

Loudness integration is the process of calculating the overall loudness of an entire audio piece, rather than just individual sections. The video mentions the 'Loudness Integrated' value, which is the average loudness over the entire duration of the audio, and is used to ensure that the audio content is consistent and does not have sudden volume changes.

💡Sample Clipping

Sample clipping occurs when the amplitude of a digital audio sample exceeds the maximum level that can be represented, causing distortion. The video discusses the importance of avoiding clipping to maintain audio quality and how certain plugins and meters can help detect and prevent it.

💡Streaming Services

Streaming services, such as those mentioned in the video, have specific loudness standards to ensure a consistent listening experience for users. The video talks about the need to adjust audio content to meet these standards, which can involve managing loudness, dynamic range, and true peak levels to avoid issues like volume compression or distortion.

Highlights

The acronym LUX stands for Loudness Unit in Reference to Full Scale, which is a measure of perceived audio volume.

Loudness is the subjective perception of audio volume, while peak level is the maximum point reached by the signal.

RMS (Root Mean Square) defines the average value between the maximum and minimum levels, effectively representing the perceived volume.

The dynamic range, or crest factor, has been flattened in the 'loudness war' to trick the ear into perceiving a higher volume.

This flattening can lead to audio quality degradation, as files become overly compressed and lose dynamic range.

To control this issue, a new measurement unit called LUFS (Loudness Units relative to Full Scale) was introduced.

LUFS is a real-time measurement, while LUX is an average calculated over the entire piece of audio.

LUX measurements do not account for very low levels, which can lead to a more accurate representation of the audio's perceived volume.

For broadcasting, a limit of -23 LUFS is often set to prevent sudden volume changes and maintain audio quality.

The Orbán Loudness Meter is a free tool that can measure the LUX of an audio file, providing a real-time loudness measurement.

LUFS values are not solely influenced by volume; equalization also plays a significant role in the loudness measurement.

Online platforms often have specific loudness limits for music distribution, typically around -14 LUFS.

True Peak levels, which are slightly above the RMS levels, are important for digital-to-analog conversion and maintaining audio quality.

Interpolation of digital samples can cause a small defect in the conversion to analog, which is accounted for in some measurement tools.

To ensure audio quality, it's crucial to monitor and adhere to the loudness standards set by various platforms.

There are free online tools available for measuring the loudness of audio files, such as the one mentioned in the transcript.