Compression #7 - wrapping up

I hope you’ve learned a little bit about compression, what it’s used for and how it’s misused as well.

As a listener you should be able to hear over compression and ask your favorite radio hosts to ease off on it if you ear them overdoing it. You can point them here on this blog if that helps. There’s also tons of reference literature on compressors and compression all over the internet.

Here’s a little audio example that should make you clearly hear the destructive aspects of over-compression:

One way I’ve read compression described was that it was similar to a boxer kicking a boxing bag as opposed to a concrete wall (with no compression). The sound is splattered and rounded the same way. The problem is that music needs concrete walls too!

Radio concerns

Don’t mistake over-compression (which sounds like there’s little difference between the low levels and the high levels of a song and everything seems to have been smashed against a rubber wall) with file compression or streaming compression (as we said earlier, most radios air at 128 or 192 kbps), the effects of file compression is often that the sound is a bit phase-y, like the left and right side of the stereo image are a bit off and you get that impression that the sound source location is hard to pick up, the sound kind of swirl in your ears. Bad but unless the bandwidth gets higher (to 256 or 320 kbps) there’s nothing much to be done. But audio over-compression can and should be avoided.

For radio hosts, compression has its use when it comes to your own mic levels, because you want to be heard loud and clear and this will help evening out your voice and put it on top of any background. However, when it comes to music you should be very wary of your compressor/limiter settings. If in doubt, avoid compression and especially limiting.

Since most music sent to radios is already mastered, no compression should be needed.

If limiting is applied, it should only be used as a brick-wall to avoid digital distortion from peaks that would go over 0 dB, depending on how hot the masters you receive are and how you push your faders. But it should never be reducing more than 1 or 2 dB and it shouldn’t be working all the time… if it does, you’re doing it wrong!

In short, please give a chance to the dynamics of songs you are playing. If the songs you get have already been over compressed that’s not your problem, but some songs are mastered to their best level and they shouldn’t be penalized by over compression after the fact.

Remember how tricky it is to assess the quality of a sound when louder always sound better, so you will be fooled by your own ears thinking you’re making it sound bigger and better. More than anything remember that the ultimate level control is up to the listener, so trying to make things artificially louder is going to be futile in the end, and will only be detrimental to the sound quality. When your radio is played quietly, the effect of over compression will make it sound bad, and there’s no reason for it.

The new loudness standards

There is now a general standard in audio land, and indeed most streaming platforms have adopted it as well as most TV and FM radio broadcasters. The consensus nowadays is to use loudness compensation to bring down everything around -14 LUFS (Loudness Unit Full Scale – I will not go over the details of this norm but there is plenty of literature on the subject all over the internet and I invite you to research a little bit about it).

The fact is that a lot of internet radios and podcasts shows I hear nowadays are playing around -8 LUFS, sometimes even less, sometimes a lot less! Which means that on average they are 6 LUFS (roughly 6 dB) under the generally accepted level of dynamic range. Their sound is over-compressed way more than necessary, and if you remember that a difference of 3 dB is perceived as doubling the level, you will understand that 6 dB of lost dynamics is huge.

Finally, my advice to all radios and podcasts is: have a look at your compression and limiting settings, and when in doubt, avoid it entirely. Your listeners will thank you in the long run. I sure will!

Leave a comment

    Add comment