How do I improve how my mixes sound on SoundCloud and YouTube?
By Rob Stewart - JustMastering.com - Last updated on August 7, 2017
- While mp3 and other streaming audio technology has limitations, it is possible to improve how your mixes sound over these formats.
- Loudness normalization is being used more widely, giving more reason to create mixes with wide open dynamics.
I often receive questions about how to improve sound quality on streaming music and video sites such as SoundCloud, and YouTube. This article addresses those questions and it can apply to SoundCloud, YouTube, Spotify, Apple Music, Tidal and any other streaming service that uses a lossy audio-based streaming format.
There are a few things to note about music streaming services:
- they are all different (some sites simply have higher quality sound than others)
- they use lossy encoding formats for streaming out of necessity, so the trick is how to work within the limits of the lossy format
- some use loudness normalization, meaning if your mix is too loud, the service will reduce its gain to align to a target
- your recording quality and mix quality will have the biggest impact on the resulting sound quality after encoding
- that last point is worth repeating - your recording and mix quality have the most significant impact on the resulting sound quality
Is there such a thing as Mastering for SoundCloud or YouTube?
I personally do not set out to master a track specifically "for SoundCloud" or "for YouTube". I follow the recommended practices for Mastered for iTunes which - in my view - apply to any lossy format (such as avoiding clipping and distortion, and keeping peaks below -1 to -1.5dBFS).
Streaming formats used by SoundCloud, YouTube and other websites will be here for awhile, so it is important to understand how to make the best of these formats. The spin-off benefit to improving your sound on SoundCloud and YouTube, is that - in general - you will achieve better recordings and mixes, too!
Improve the sound of your mixes on SoundCloud and Spotify
This advice applies to any music streaming site. If you do an internet search about the sound quality of SoundCloud, you will find many forum discussions where countless people are expressing their frustration at how their mixes sound after they post them to SoundCloud. I sincerely believe it is not SoundCloud's fault. It is possible to achieve a relatively high sound quality on SoundCloud and other streaming audio sites. In fact, I like SoundCloud's platform so much that I use it to house some of my mastering samples for this website.
At the time of this writing, SoundCloud converts all uploads to 128kbps Mp3 format for streaming purposes. There are some significant sonic limitations with 128kbps Mp3 format, however, those limitations are a necessary evil because of today's internet bandwidth limitations. Despite those limitations, it is possible to achieve a high sound quality when streaming music on SoundCloud.
First, it is important to understand a little bit about how Mp3 compression works. Without getting too deep into details, Mp3 uses something called "perceptual coding" to compress audio. At a very high level, all that means is that the encoder analyzes your music and removes pieces of it that it doesn't think you can hear (elements that are hidden by more prominent elements in the mix). For example, at 128kbps, the encoder will remove anything above 16kHz (many people cannot hear too far beyond that point). The algorithm also looks for parts of the mix that are masked by stronger elements. To get a sense for pieces that get removed, please check my "Issues With Lossy Formats" article.
Bearing this in mind, here are my recommendations for achieving the very best sound quality when posting your mixes to SoundCloud:
- Create the cleanest recordings possible, prior to mixing (avoid distortion, significant background noise etc). Noise, distortion, rumble and other non-musical information in your recording will create more work for the encoder. Strive for the purest, clearest recordings. You can always add color selectively to certain tracks but avoid capturing dense, congested color or "mojo" on every single track. Remember that less is more, and the contrast of "clean" and "colored" tracks in your mix is what will make it interesting, while making the encoder's job a little easier.
- Follow my critical mix tips. Remember, because of the points above, the more you can do to achieve a clear, lively, and dynamic mix, the more chance it will sound good when converted to Mp3 128kbps. Keep your mix open, dynamic and clean.
- Avoid heavy use of saturation and distortion. Distortion is often wide-bandwidth in nature which presents several problems for perceptual coding (i.e. how does it know what parts of the distortion are intended to be "musical" and which are not and could be removed?).
- Avoid overly dense or congested mixes. Make sure that you construct mixes in such a way that each of the elements are clearly defined (have their own space in the mix) and that there is no congestion. The most challenging scenario is a mix with several with heavily distorted guitars. In that case, it's necessary to carve out enough sonic space for each guitar so that they can clearly be heard. If they sound like they are blending into one big guitar sound, then the Mp3 encoder will likely have a big challenge.
- Avoid heavy limiting and dynamic compression. I say this for a few reasons. First, it adds harmonics (distortion, which is wide-bandwith), but second, it can sometimes fill in the sonic spaces that the encoder is looking for with those harmonics, forcing the encoder to make more compromises. Many mix engineers like to compress to "glue" a mix together, and that's certainly valid in some cases, however when it is overdone, there simply isn't enough space in the mix for the encoder to figure out what elements can be safely removed during encoding.
- Keep peaks below -1dBFS, in fact, I'd even recommend -2dBFS if you are working from a 24-bit file. Since many encoding schemes do not handle peaks that are at (or near) 0dBFS very well, you can end up with a lot of distortion on the transients.
- Consider lowering the gain of your mix. Pull the gain on your mix down so that the average levels are below -12 to -16dBFS. Better yet, consider some of the newer "loudness monitoring" options out there such as metering that is based on Loudness Units Full Scale (LUFS), and set the "loudness" of your mix somewhere between -16 and -23LUFS.
- Export your mixes in a lossless format such as *.WAV or *.AIF. If you export to a lossy format such as Mp3 from the start, then SoundCloud will be re-encoding from one lossy format to another (this is called "transcoding" and it degrades the quality even further).
- If (and only IF) none of the steps above have helped, consider low-passing your mix with a 6 or 12dB-per octave roll-off so that energy from 14-15kHz and above is reduced, and high-passing it at around 35-40Hz before uploading it to SoundCloud. In theory, this step should never be necessary, but in the event that there is something unusual happening beyond the lowest/highest extremes, this pre-filtering stage may help improve things.
If you are skeptical about any of my suggestions, above, consider this fact: Mp3 predates the loudness war. It was developed in the early 1990s and was made available for widespread usage in 1995. The song "Tom's Diner" by Suzanne Vega is considered the "Mother of Mp3" because Karlheinz Brandenburg used this song (among several others of course) to fine tune his Mp3 enoding scheme. "Tom's Diner" was released in 1987 - well before the so-called "loudness wars" ever started - and also long before mainstream home recording became as popular and advanced as it is today (in 1987, many home recordists used cassette-based 4-track multi-track machines - how far we've come!!). Mp3 has surely evolved also, but it is important to note mixes with very heavy dynamic compression, saturation and "maximization" - that are often heard today - were more of a rarity in 1987.
Optimize your mixes for YouTube
Everything I mentioned above for SoundCloud also applies to YouTube and other streaming sites, but there are some additional things to note about YouTube specifically.
There are two ways to control sound quality on YouTube, however the key thing to remember with YouTube is that High Definition Video = Highest Available Quality Audio.
The most critical is via the encode process, because that is the one you have direct control over. To achieve the very best sound on YouTube, you need to submit a high definition (HD 720p or 1080p) video file. By choosing a high definition video format, it will encode the audio at the highest possible rate (currently 192kbps at the time of this writing). That in turn gives you the very best possible quality. By contrast, if you chose to upload a standard definition (SD 480p or less for example) file, you will end up with between 24 and 129kbps, which will dramatically impact audio quality. There is some more information here in this article. They also recommend using a 48kHz audio sampling rate for your original video.
The second way to control sound quality is in the control of the viewer. After the file is published on YouTube, the person viewing your video can be guaranteed to get the best sound quality by maximizing the video quality. For example, if they play back your video at 720HD it will sound better than 360SD.
How does Loudness Normalization impact how music sounds on streaming services?
(April 24, 2016 update) As of the time of this update, several streaming services have implemented loudness normalization. For example Apple Music uses "Sound Check" which adjusts all songs to a set target gain level of -16LUFS. Spotify has implemented its own normalization process that aligns everything to -11LUFS and it uses a limiter when necessary to ensure peaks don't go above 0dBFS so by nature this process is more destructive in nature. Other services have other targets so at the present time there is no "standard".
The short answer is that loudness normalization eliminates the perceived "benefit" that high gain will have because if the gain is higher than the streaming services target, it will only get reduced downward to meet that target. Therefore, any processing used to allow you to make high gain mixes and masters is only damaging the audio unnecessarily. This means that now, more than ever, mixes with wide open dynamics will sound clearer and more musical than heavily compressed and limited mixes.