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Mastering is becoming more and more important as recording budgets are dwindling and mixes are often in need of help to make them sound as good as possible and meet the loudness challenge dictated by the market.

In an ideal world with perfect mixes, the job of Mastering is a technical one: to create Masters for CD, Vinyl or Online Distribution that meets exact specifications of each format. There, the Mastering Engineer would leave the mix more or less untouched, only applying subtle EQ or compression to ensure good translation on most listening systems and coherence of the tracks in the context of an album.

But over the past two decades, the role of the Mastering Engineer (ME) has evolved into a more "creative" process involving obscure or "secret" techniques used to enhance mixes. "Bigger/ more powerful sounding, louder, punchier, more polished, more airy..." are some of the terms used to describe what is often expected from the Mastering process. MEs now have to draw from a whole range of skills to improve or correct the presentation of mixes while often being asked to create very loud masters to compete with current commercial levels.

One of the many skills of top MEs is to know how to preserve the integrity of a mix. Sometimes "less is more" and being able to do this often shows the difference between great & average MEs. Inexperienced MEs often can't resist the temptation to use too many too many processes that end up ruining the mix. Stereo widener, multi band compressors, limiters are often used and abused creating more damage than improvements.

Mastering is sometimes confused with Mixing. Mastering starts when the mixes are completed and sound as good as possible. When mixes exhibit serious flaws it is more effective to remix the tracks and address the issues rather than try a fix at the mastering stage. Mastering can only apply global correction, and problems like poor instrument separation, badly controlled volume of individual instruments or voice, excessive sibilance, distortion/clipping cannot usually be fixed during mastering.

A common mistake is to send in for mastering mixes that have been made as loud as commercially mastered releases. When this is done using a limiter on a high setting, this squashes all the waveforms and softens transients , doing a lot of damage to the mix (verses sounding louder than the choruses, drums loosing attack & volume...). If it is done by cranking up the faders so that everything goes over 0db (clipping) this results in digital distortion which cannot be removed and will become more apparent after mastering. Louder & more punchy masters are usually better achieved from clean mixes with no clipping and with plenty of dynamics.

Most MEs recommend removing limiters & compressors from the Master bus and leaving at least 3db of headroom. This is to avoid clipping. Here, we think that master buss processor can be left in provided you are satisfied that they help the overall sound rather than damage the dynamics and that there are not used just for loudness. When in doubt, we suggest you do a separate version without the compressor and/or limiter, and give us the choice of which version to use.

While we can do Stems Mastering, this technique is not often used in mastering. It adds time & cost to the mastering as it is similar to mixing, and we generally don't recommend it as the results are rarely better than working from a good stereo mix. It is only worth considering if you are unsure about a mix and don't have the option to adjust the mix.

Formats submission
We recommended 24bit 44.1Khz Wav that can be sent online (you can use the upload link on the main page or file delivery services such as, on a USB stick, a hard drive, Data CD or DVD (audio CD truncates higher bit files to 16bit).

We can work from most formats and it is generally better to send files in the format & bit rate that was used for mixing.

We normally include CD-Text and ISRC codes when available (see PPL). These need to be supplied by email with the titles typed exactly as you want them to show (use of Capital letters, hyphens, contractions, spelling...).

CD-Text (only displayed on CD-Text equipped CD players) is not to be confused with info submitted to the Gracenote database (usually via the iTunes software) which is what enables computers connected to the Internet to access title tracks and album & Artists' names. Mastering engineers do not submit track details to Gracenote. This is done by the label.

Delivery Formats
For Albums and EPs we either supply a Red Book P&Q CD Master (also called PMCD) with a CD Listening Copy (Reference CD), or a DDP Master. DDP (Disc Description Protocol) is a file that can be sent over the internet & FTP, or burned onto a DVD-R. A properly made and verified P&Q CD-R Master and a DDP are identical in terms of quality of the manufactured CD. DDP is often the more convenient way of sending CD Masters to both clients and CD Manufacturers.

For Vinyl release, we supply a Vinyl CD-R Master or 24 bit Wav files optimised for cutting.

Mastered For iTunes
(MFiT) files are normally supplied as 24 bit 44,1khz created using the Apple MFIT tools and following the MFiT guidelines (higher headroom, no clipping, increased dynamic range, higher resolution than 16/44). Please note that not all digital distributors accept higher resolution files or that they may charge more to do so. MFIT files are designed to get the best quality possible out of the new enhanced iTunes AAC Plus codec and are sold on iTunes with the MFiT Badge.

(Text copyright Flow Mastering)