Mastering Tracks In The Browser

MasteringBox Logo

One of the things that can really make your music stand out from the crowd and give it a professional sheen is high quality mastering. Mastering is a very different process from mixing which many amateur musicians who record their own tracks unfortunately often ignore. A fantastic place to start to learn about the art of mastering is Bob Katz’ book Mastering Audio: The Art and the Science, which some people (myself included) consider to be the mastering bible for audio engineers.

Of course a well mastered track requires not only a dedicated mastering studio, where every nuance within the track can be heard clearly, but also a highly trained mastering engineer. This of course is not cheap and well beyond the reach of the typical hobbyist or musician starting out. Even high-quality mastering plugins such as the Waves L3 Ultra-Maximizer, which was a favorite of mine, starts at about $350. Mastering plugins are typically comprised of a high quality multi-band compressor, EQ and peak limiter, which allows you to balance the final mix to an extent and increase the loudness (which can unfortunately be easily abused).

MasteringBox is a company, based in Spain that aims to provide an extremely simple, low-cost alternative for musicians that want to get that polished sound on their final tracks, without going to the expense of hiring a mastering service.

The emphasis is on simple, as the service is implemented as a drag-and-drop interface into the browser, with simple customizable controls. After about 30 seconds, out comes the mastered track, which you can preview and either download or tweak some more to your preference.

Screenshot of

MasteringBox has a simple drag and drop interface for your audio files

MasteringBOX provides a simple way to Master your tracks, providing better sound and proper loudness to your mix with a drag&drop and easy to use Mastering. You can achieve great results that can compare to professional studio work.

Now there’s a wide new range of possibilities for producers and musicians: Just upload your song, DJ mix or even a live recording, and have it Mastered in less than a minute.

The service offers a free tier which provides loudness controls only and unlimited MP3 masters, while the pro service starts at €7 per month for up to 3 WAV masters, with ID3 tagging and EQ controls. The Unlimited tier allows unlimited WAV masters for €14 per month.

For such a simple and fast interface the results are impressive. They are quick to point out that in no way will it replace a good mastering engineer and mastering studio, but it is a great alternative for those that don’t have those resources. It is also sophisticated enough to recognize when the uploaded track has already had a limiter applied on the mastering bus or if the uploaded track is clipping. It will advise you to try again with a non-limited track that is not clipping.

I discussed some of the details with the MasteringBox team to learn more about their process, techonology and philosophy.

Audiograins: You mention that the site and algorithm was created by a team of sound engineers with years of experience. Can you share some of the backgrounds of your team and how you came together?

MasteringBox: As a musician and sound engineer over the years I met a lot of artists, sound technicians, mastering engineers, etc. I studied Telecommunications on UPV university, I specialized in acoustic and I also got to know a lot of interesting people that were also linked to audio.

The idea of this project started 2 years after I finished my studies, I had already 7 years of experience
working as an audio and mastering engineer, one day I had to master a lot of tracks and I had to be done for the same day. That day the idea started, if we could design a piece of software that could automatically master the tracks? Maybe not for projects with higher budget, but for many others where money can be a problem. I started making calls and meeting my colleagues, most thought the project was very interesting so I selected a team and we started working together.

AG: Can you talk about the mastering philosophy you employ in the process and the approach you took for processing? Can you talk about what you’re looking for when you analyze a track and how that affects the outcome of the mastered track?

MB: Our philosophy was to provide a professional mastering service that was easy to use and affordable to everyone, to accomplish that, we focused on analyzing the track first to then be able to do a good mastering, we first analyze dynamics (Peak, RMS, Crest factor, clipping and other — more complex analysis), and then we analyze the spectral response, what a human can see in the typical spectral viewer is tracked perfectly by the computer, finally we had to tell it what to do depending on the situation based on different parameters, it is not easy but I think we did a good job and I’m sure we will still improve it more.

MasteringBOX is just a tool, we are not in favor of overcompressing, in fact the word speaks for itself, OVER-compressing. There has been a lot of discussion on the “loudness war”, when using MasteringBOX anyone can choose the loudness he wants and hear how it changes the sound, if you think it’s overcompressed then just lower the loudness fader, if you like it louder, it’s your choice, not ours.

Screenshot of MasteringBox Loudness and EQ controls

MasteringBox Loudness and EQ Controls

AG: What sort of tracks (style/genre/instrumentation level etc) will see the most benefit from your processing?

MB: I think most type of tracks will get a lot of benefit, right now we’ve had very good feedback for multiple styles such us pop, rock, EDM, rap, RnB or classic music. Instrumental music is usually easier to master, not only for MasteringBOX.

AG: The site has a nice slick interface, especially using some nice HTML5 features such as the drag and drop file selection etc. Do you use any web audio API features for the track preview?

MB: We use jQuery, javascript and HTML5 in the track preview, the preview is just a music player with an A/B comparison, not too complicated.

Screenshot of

MasteringBox Preview of a mastered track

AG: What formats do you support? I was able to successfully upload wav, mp3 and aac. Do you support any other formats for decoding before processing (e.g. FLAC would be an obvious choice due to being a lossless codec)

MB: We support all audio formats, we’ve tested the vast majority of them and we are very happy with the high percentage of compatibility.

AG: The overall speed of the processing is very impressive, can you talk about how important optimizing the upload and especially the processing time was for your service and can you share some of the details of how you achieved that?

MB: Optimizing Speed was important to us, although it was more important to achieve a good mastering result. The upload speed is good because our server has a good internet connection, that simple.

We did make sure to optimize speed in the mastering step, this is why we just master part of the song in the preview, so the user is able to listen to the master quickly. Speed was achieved by debugging the code again and again to make it work better, we also have a powerful server that can process multiple masters at the same time, this is crucial to make the average processing times faster.

My thanks to the MasteringBox team for taking the time to answer my questions. Try it out for yourself (it is after all free) and see how the results are for your music. You can also check out their blog for mastering tips and tricks.

Share this post
  , , , , ,

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.