How to avoid over-compressing your mix
( Or, how to NOT smash it to hell ! )
Loudness has always been an important topic in mixing, and especially mastering – never more so than today.
Knowing how loud is too loud has always been difficult. I’ve written before about how we hear loudness, and different software solutions for measuring loudness - but now, everything has been made far easier.
Recently a new tool has been released, purpose-designed for measuring the loudness of music. You can now see at a glance how loud your mix is, make informed decisions about compression and limiting, and choose to make your recordings punchy, loud and competitive.
And best of all – it’s free. (*)
(*) Kind of
This tool is the TT Dynamic Range Meter, released by the Pleasurize Music Foundation. It comes in two flavours – the one in the animation on the right is the real-time plugin version, available for both Mac and PC now, in AU, RTAS and VST versions.
There is also a second, off-line version of the meter, which generates an overall DR dynamic range measurement for a complete WAV file or CD and allows you to generate a log file, which can be submitted to the (unofficial) Dynamic Range Database.
The real-time plugin version shows peak and RMS level metering for the left and right channels, but also a measurement of the dynamic range – the difference between the loudest and quietest parts of the music – in the centre, labelled “DR“.
Broadly speaking, the idea is to keep the dynamic range as wide as possible – up to a point, at least.
(Actually, it’s more complicated than that. “Loudness War” sound suffers from limited crest factor, low RMS variability and in the worst cases distortion. We’ve chosen “limited dynamic range” as an intuitive way to describe all this, but for a more rigorous technical analysis, click here.)
Both loudness and dynamic range are measured in Decibels (dB) and as a rule of thumb, anything with an overall dynamic range of 12dB or more (“DR12″) will sound great, dynamically – and in this case, the central DR meters of the plugin will stay green much of the time. Louder material will sometimes have less range than this – any less than 8dB will start to sound very aggressive and crushed, and the DR meters start to fade from green to orange to red to represent this.
So, to ensure you aren’t over-compressing your mix - keep the meters in the green for most of the time. Not all of the time, but a track where they are always red is almost certainly pushed too hard.
It’s that simple !
(Well actually, it’s not quite that simple. Firstly, if you’re making electronic music, or using lots of synths and sample loops, the sounds you have may already have quite a limited dynamic range. And so does a flute, for that matter ! So, if your mix is only DR10 without any extra compression, don’t worry – that’s the way it is naturally. And also, this rule-of-thumb applies to mixes. If you are using the meter in mastering, pushing up into the orange and occasionally red is probably OK – but use your ears and remember there is always a compromise.)
One of the cleverest things about the DR meter is that it works independently of the overall level of the music. So, something very loud, crushed and distorted, like, say – oh, I don’t know – Metallica’s “Death Magnetic”, for example – will be in the red, almost all the time - even if you turn it down.
This means you can objectively compare how squashed different recordings are, regardless of the overall level. Which in turn makes it a great mixing tool – if you over-compress everything in your mix, the meters will show you’re in the red, even if the overall level isn’t that high, yet.
Try it yourself – fire it up and watch how the meters react to your favourite recordings. Remember though they may have been pushed to a higher level in the mastering. Try comparing older CDs from the late eighties and earlier 90s – usually the overall level will be lower, and compared to releases from the last few years they will be more dynamic, ie. the dynamic range DR values will be larger.
Don’t be fooled into thinking that you need a narrow dynamic range for a “loud” sound – to see why this isn’t true, just click here.
It’s important to note though that the realtime DR meter only gives the loudness at an instant. And, it’s quite permissible (and necessary) to push into the red at some points. To get an overall measurement of a tracks loudness, you should use the off-line version.
Both meters are free, but to get them you need to be an “Active Member” of the PMF – meaning, you need to contribute a small amount to the Foundation. For individuals this is very affordable, and the TT Meters alone are well worth the price of admission, in my opinion. In addition to the meters you also get access to members-only areas of the site, and the right to use the DR logos.
I strongly recommend the Pleasurize Music Foundation website – there is lots of good information and they have ambitious plans, including getting all music labels to agree to a standard minimum DR14 measurement on all albums, as measured by the offline metering tool.
If they succeed, this would mean standardisation of levels across CDs in the same way there is in the cinema, and an end to the “Loudness War” madness. I’m cautious about their chances for success – in particular I think DR14 as an average is unnecessarily ambitious, but it’s an interesting idea, and one I wish them every success with – and making the fantastic Dynamic Range Meter plugin available is a great step forward and a very clever move, in my opinion.
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