It's about time we we adhere to some "Standards".
Updated: Apr 11, 2019
Have you ever noticed that when you upload the same master to Soundcloud that you did to Spotify, one sounds louder than the other? Or when you upload your music to YouTube, you suddenly lose a lot of quality?
Loudness standards are a ‘thing’, and in this day and age of online streaming and distribution platforms, standards vary, which can cause some frustration for the modern producer, mixing, or mastering engineer. Here’s a few tips on making sure you don’t fall into this trap when presenting music to your fans.
Firstly, know this! Most online platforms have a Normalisation process. This allows each platform to playback music at a loudness standard so that there are no severe loudness differences when cueing up the next track in your playlist. Normalisation means that that sweetly dynamic jazz track you just played is the same level as that hardcore sludge metal banger next in your playlist. Seems kinda dumb as both songs may as well be on separate ends of the spectrum. But… this offers a ‘standard’ and allows music to be heard at the same level, all the time.
Secondly, WTF is LUFS?
LUFS stands for 'loudness units relative to full scale'. It’s the most accurate way to to measure loudness of audio. To simplify, I think of this as a more accurate RMS value. If you implement LUFS as a reference value each time you go to bounce out your master, you will never fall into the trap we spoke of earlier. A good mastering engineer will know the LUFS standards to work towards, and each platform or print form can be different. For example:
If your music doesn’t match these standards when you go to upload, each platform will normalise you music to suit their own requirements. For example, Spotify will compress/limit your song using an algorithm, if it doesn’t match their standard.
This is what many call ‘The Loudness War’.
The loudness war ideology is ‘the louder your track, the easier it will be to stand out in the radio world’. This isn't necessarily true anymore. Now, listeners’ want dynamics, physicality, and optimum sound quality. Something that online streaming has always struggled to deliver. Here's an example of ZZ Top's Sharp Dressed Man falling victim to the loudness war. The .gif below shows a comparison of the songs wave form. Starting in 1983, when the song was originally released, through to its latest Limiter 'slamming' in 2008. The wave form turns from a nice hairy, dynamic tune averaging around -0.56 dB, to a 'slammed sausage' sitting around -0.1 dB.
So the question is… How loud do my masters have to be?
So here’s a bit of a golden rule before we dive into what the industry determines as being ‘right’. Always mix and master to what you think sounds right. Trust your ears before trusting a numerical value listed on the internet. That aside, here’s a few tips to get your masters up to scratch.
Use a reference to level match your mixes and masters. There’s nothing like using your favourite bangers to mix beside, and there’s a tone of reference plugins out there that can help you quickly A/B between your track and your reference.
If your mixes or masters are louder than -14 LUFS, prepare to be turned down! Go for dynamic and punchy, rather than an over-compressed, distorted master.
Spotify recommends to “target the loudness level of your master at -14 dB integrated LUFS and keep it below -1 dB TP (True Peak) max. This is best for the lossy formats we use (Ogg/Vorbis and AAC) and will ensure no extra distortion is introduced in the transcoding process. If your master is louder than -14 dB integrated LUFS, make sure it stays below -2 dB TP (True Peak) max to avoid extra distortion. This is because louder tracks are more susceptible to extra distortion in the transcoding process.”
What about Soundcloud?
Soundcloud is a little different. Soundcloud doesn’t normalise your playback volume like our friends over at Spotify. They do the dirty, and transcode all uploads to 128kbps MP3s for the purpose of faster streaming. And if your track is loud already, this will without doubt cause some clip distortion.
Good one Soundcloud… way to sacrifices quality for the impatient consumer. #sarcasm
Louder tracks with higher peaks will be affected the worst if put through this algorithm, which can cause your track to sound crunchy and lack important clarity. The rule of thumb when mastering for Soundcloud… leave at least -1dB TP of headroom and try not to go louder than -7 LUFS for short-term.
Apple has made a plugin called ‘AURoundtripAAC’ which lets you preview your track in a lossy format. It will also tell you if your track will clip once it has been converted for streaming. RoundTripAAC converts to AAC rather than MP3 but it will give you a good reference.
Now, that’s the just of online streaming standards. No let’s look at a physical format. With a huge resurgence in sales over the last two years, vinyl is still the strongest contender as being the most valued musical format offered.
Vinyl is back baby!
So before you go sending the same masters you have for digital services to the press, check out some of these tips to get it right from the get go.
You’ll need separate masters. Separate masters are required for CD replication or digital distribution and for vinyl records. Although, in the majority, the mastering processing can be the same for both, as the crucial differences between them are practical (ie. the level and extent of limiting, the word length, and the sequencing of the files). A digital master for CD has to have a 16-bit word length, and it can be as loud and as limited as the client’s taste or insecurity dictates; with the vinyl master there is a physical limit to what can be fed to the cutting head of the lathe, and so heavily clipped masters are not welcome and can only be accommodated, if at all, by serious level reduction.
The optimum source for vinyl is 24-bit, keeping it dynamic, and limited either extremely lightly or not at all. And for the delivery, you’ll need to send your mastering engineer 2 .wav files. One for each side of the record.
When preparing your mixes, and to save a lot of headache, assure that your audio is within these standards (supplied by Second Line Vinyl):
STEP 1: All bass frequencies must be centered (below 150 Hz). Phase issues in the bass frequencies can cause a collapse of the groove, causing a skip. STEP 2: Tame sibilance. Too much sibilance will cause distortion on playback. This should be addressed at the mix level for best results. Additional de-essing during the pre-mastering stage and cutting process may be possible. STEP 3: Avoid excessive high frequencies. Frequencies above 15 kHz just cause distortion. Do not boost frequencies above 10 kHz. STEP 4: Try to avoid using psychoacoustic processors to an excessive degree. STEP 5: If your recording substantially differs from natural sounds, which is caused by spreading out the energy in the acoustic zone, there is a risk of audible changes to the sound during the transcription. This is due to the limitations of mechanical recording processes and can for example be caused by singing adjusted by processors or electronically generated effects. STEP 6: Do not “clip” waveforms. This technique is often used in CD mastering to achieve a hot level, but will translate to distortion when cut. If a re‐cut is requested on a record cut with clipped audio, it will be fully billable. STEP 7: Avoid too much limiting. Too much brick wall limiting can cause distortion in the cut. Re‐cuts requested due to distortion on material that has been excessively brick walled (rms over ‐10) will incur additional costs if not resolved before manufacturing. STEP 8: A distorted master will likely sound more distorted when transferred to vinyl. Watch the distortion on the mix. STEP 9: Keep in mind that due to the limitations of vinyl, by the time you reach the inside of the record the frequency response is down ‐3db at 15 kHz. Sequence your master accordingly. It is best to put quiet songs or ballads on the inside. Try to avoid sequencing the loudest song as the last track. STEP 10: Try not to exceed the maximum recommended playing lengths per side, as longer playing times will lead to a dramatic decrease in recording level and dynamics. On the other hand, the requirements of extremely high recording levels decrease the possible playing time (see the table in the next section for recommended playing times for all formats) STEP 11: Try to avoid 7" vinyl formats at 33 1/3 rpm as the possibilities of the recording and reproduction are most limited at this format. If there is no other solution you have to take into account that the final product will be in some way compromised. Low groove speed limits the recording level and causes a higher decrease of the high frequencies into the middle of the record and can also cause higher distortion levels. STEP 12: All audio should be provided on a CD‐R master or uploaded to us in a .wav or .aiff format.
33 RPM VS 45 RPM
The RIAA (Recording Industry Association of America) adopted certain standards for the recording and manufacturing of phono records with regards to the recording levels and the assumption that the standard level will be 0-dB under certain conditions. The chart below will show variations due to time, speed, and size.
Mastering audio for Soundcloud, iTunes, Spotify and Youtube. (2016). Retrieved from https://www.masteringthemix.com/blogs/learn/76296773-mastering-audio-for-soundcloud-itunes-spotify-and-youtube
Mastering & loudness – FAQ – Spotify for Artists. (2019). Retrieved from https://artists.spotify.com/faq/mastering-and-loudness#will-spotify-play-my-track-at-the-level-it's-mastered
James, E. (2015). Q. How does mastering differ for vinyl and digital releases? |. Retrieved from https://www.soundonsound.com/sound-advice/q-how-does-mastering-differ-vinyl-and-digital-releases
A Guide to Mastering For Vinyl — Second Line Vinyl. (2019). Retrieved from https://www.secondlinevinyl.com/a-guide-to-mastering-for-vinyl
Loudness war. (2019). Retrieved from https://en.wikipedia.org/wiki/Loudness_war