When Should I Use Multiband Compression?

Hi i’m new to the forum and waves plug ins and not the youngest member if you get my drift.
So my question is when should i use multi band compression as opposed to more straight forward compressor plug in’s.
In a mix i’m doing just now i have
Vocals
Electric Guitar
Bass Guitar
Drums
Accordion
Keyboard Strings Sound
In order to use multiband compression correctly should i not have to understand the frequencies of all these above instruments or am i over complicating things.
Is it a case of adjust the frequency bands and the compression and just listen to the difference.
Sorry for such a basic question
Gus

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For the most part I believe basic compression does the job. Optical compressors or compressors with low ratios, low thresholds and soft knees for some more transparent level controls, hard knee, higher ratio,VCAs and FETs for more aggressive control and shaping. Generally speaking.

The reason why I consider multibands is to generally solve a problem that can’t be solved with straight forward compression.

For example, maybe a basic compressor might do the job, but you discover it lacks some intelligibility or snappier transients. By using a multiband you can compress the lower frequencies as per normal, but the higher frequencies you can really tailor to help bring out its attack.

Conversely, a recent problem I had was a synth bass sounding about 3dB louder at the start of its 8-bar phrase, than it did at the end. I’m not even sure how that was possible, yet there it is. I tried straight up compression on it, just to bring back some uniformity to its level, but I felt it was being a bit too brutal. So I went for a multiband instead. Well in actual fact I did both, as I still liked the harmonics I was getting from the Fairchild. So I trimmed about 1db or so with the Fairchild and and about another 2dB with the multiband compressor, well at the low end anyway. I decided to take advantage of the multiband and used a middle band to reduce it enough to allow more room for other instruments, without taking too much presence or weight away. I then used an upper band to bring out the articulation and add more definition to the notes. It was a bit of work, but the end result was a better balanced, more articulate bass sound that sat nicely with the other instruments.

There are other occasions it might be useful such as drums stems or other stems of “premixed” instruments for example. So basically the idea is not to unnecessarily complicate issues for yourself unless you need to.

When using a multiband compressor I suggest using it like a regular compressor to begin with and adjust all the controls together if it allows you to. Don’t worry about the band settings just yet, just aimed to get a good overall compressed sound. Once that’s done, then turn towards adjusting the individual bands starting with the one that “needs the most help”. Be sure to always level match it with its unprocessed signal and A/B it regularly to make sure you are doing more good than harm. It’s a very easy thing to over do, so you need to be honest with yourself and not expect “miracles”.

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Hi Simon many thanks for the in depth answer, to be honest its above my knowledge level but the only way to learn is to listen to people who know what they are talking about.
I watched a video about mastering using the waves plug ins and the expert was using i think either the L3 LL Multimaximizer or the L3-LL Ultramaximizer.
This got me thinking that their must be a Waves plugin that lets you see specific frequency ranges of your audio so that novices like me would be able to set the compression band frequency range,instead of not really having a clue.
I have recorded some material that i want to get mixed,the instrument that needs compression is the accordion. The accordion can be a tricky instrument to record,very difficult to get smoothness,this is where the compression comes in, i just dont know what compressor to use and how often to use it,do i try hard compression,or moderate compression and the moderate compression again lol,trial and error i supose
Many Thanks for your reply it is very much appreciated
Gus

I can’t say that I’ve ever recorded an accordion, but I can picture why it might be difficult to process.

The trouble with the compressors that “lets you see specific frequency ranges or your audio” is that it still may not offer you any additional help unless you’ve used them quite bit. It’s only after experience of using analysers that they groove to become more helpful, much like your ears. That said, there are a few very obvious and basic things you could probably pick up relatively straight away.

It may even be, though, that a “dynamic eq” like the F6 may be more useful for your purposes. At least that as a built in visual analyser (RTA version). So even combining that with a softer style of general compression might be the solution you’re looking for.

Hi Simon thanks for the reply.
I think i realised how daft my statement was after i had wrote it.
I have ended up doing a little bit of serial compression to half do the job.
The rest of the job i have been using the Waves MV2,nice and east to understand
but VERY effective.
I came to the conclusion that the accordion requires a pretty fast attack when compressing as there are a lot of transients
and not so fast release times, seems to be working.
To be fair i have been doing a lot of learning, even working out BPM just to see if getting around about
the correct milliseconds helps.
I will have a look at the F6 and see how i get on
Many Thanks
Gus

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Ahhh the MV2. Wished I had of thought of that as a recommendation. That should level out your signal simply and reasonably effectively. Good choice.

Consider F6 as more of a surgical, problem solving tool. It will help you solve problems ordinary eqs can’t. I would have suggested the C4 or C6, as that actually does compress, just not sure that it would give you the visual feedback you were after. Check it out all the same.

Try to keep things as simple as you can, for as long as you can. The trouble when you start introducing tools that help you fix more advanced problems is that its all too easy to make things sound worse with them too. So tools like the F6 and C6 require a bit of experience.

Hi Simon i’ve got a great skill for not explaining things correctly.

As stupid as this sounds i didn’t realise that all of the plugins are visual.
I was just thinking about selective frequencies.
I also ended up using Channel Strip Audio track because it lets me
EQ the lower end frequencies out of the accordion sound and also
allowed me to experiment and learn about how different compression settings
effect the sound.
I have used the C4 and found it very good
I had a look at the C6 and F6 as you mentioned
I could follow parts of Sean Devine and the C6
But i struggled Watching the Video on the F6
Definetly way beyond my knowledge
If i get the plugins relative to my basic knowledge i am sure that
i will get a decent sound.
No point in using a plug in that i dont understand
Many thanks for your feed back
Much appreciated
Gus

Hey Angus, don’t give up on F6 just yet! Start using it as a regular EQ and once you’re familiar with that, you have the added bonus of dynamic EQ when you want it.

And once you understand dynamic EQ, then you can sidechain to it and use F6 to carve frequency space out in a dense mix, to make room for a guitar solo or make the vocals stand out better, etc. It’s possible to do this subtlely enough that the listener doesn’t notice, but it can add clarity to the sidechained material.

As far as multiband compression and when to use it — imagine wanting the bass frequencies and high hats to have the dynamic range they currenly have, but you want to squish the mid range frequencies to make it fuller and stand out more. That’s a perfect example. It lets you compress sections of audio separately so that you don’t mess up the dynamic range unnecessarily. It also ensures those other frequency ranges aren’t triggering the compressor unnecessarily. (Your midrange compression will ignore the bass hits and high hat hits & cymbals, if configured correctly.)

Or maybe you do want to compress the whole signal but you want a different amount of compression in each… Maybe a different ratio, different attack/release.

Using a multiband compressor requires that the user can identify frequencies and also hear compression. By definition it’s an advanced process, because picking that out by ear can be hard for some people if they don’t know what to listen for.

There are some YouTube videos “how to hear compression” that will help.

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Dynamic eqs and multiband compressors are definitely an acquired skill. You’ll get it wrong more often than you’ll get it right at first. Here are a few things I learned along the way…

At first treat your multiband compressor like a regular compressor. Don’t worry about the crossovers and adjust all the bands at the same time until you have a decent sound. On the C6 you can adjust settings globally with the controls on the left side.

Most audio can do with a few cuts to some frequencies, I find that its roughly these areas that make a good choice to park your crossovers. It should sound a little bit better when you have the right frequencies.

Leave the multiband for a while and come back to it when you have more pieces in play and it starts becoming noticeable that you need to do more work.

When you start to look towards the individual bands attacks of 3-5ms is a good place to start with low frequencies and attacks of 1-3ms are good for highs. Meanwhile 30-50ms is a good release time for the lows while around 15-30 is a good start for highs.

When using a dynamic eq, its often best to use it like a regular eq at first. Focus on the frequency Q and gain controls at first. Set up a decent sounding eq “curve” at first, and come back to it later to refine it some more.

If you want to brighten something without making it sound harsh use a quick attack on the highs (below 3ms) and a pretty quick release (like 15-30ms). If sounds too hard reduce the release if it doesnt sound bright enough increase it. if you get to about 50ms you might want to consider increasing the Range instead.

Likewise if you want more base but without the boom, do a similar thing, quick attack and quick release. But for bass were now talking about 5 or 7ms and below for attack and 20 - 40ms for release. None of these time are exact though, but it should put you in the right ballpark.

When it comes to cuts consider using times like the above. If it starts sounding to thing or hollowed out then reduce your release, if its too dense, lengthen it.

Hope you find this helpful.

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Hi Simon,
Thanks for giving us complete information.

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Hi Simon,i cant thank you enough for your very detailed and educational post.

I have saved your post and setting as it will be a fantastic starting place.

I have just watched again Brad Divens explaining the F6,i actually understood more this time

as I am getting a handle on Sidechaining
As I have mentioned to Sam in another post I think that really getting a good knowledge on how frequency ranges effect effect different instruments,vocals and drums is a knowledge that is essential.

If I dont have an indepth understanding of frequency ranges how can I set eq’s and multiband compression setting’s properly.

I find the attack and release times interesting as I am very much a BPM guy,especially for reverb and delay’s if you can get a close approximation on the milliseconds by the beat it is taking away a lot of the guess work.
I think as you have mentioned just start by doing the basics and take it from there.

Once again many thanks for your invaluable information

Best Regards

Gus

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Hi Sam many thanks for your encouragement.

As you mentioned frequencies,i know that I need to

understand frequencies of different instruments,vocals and drums.
There is lots of information on the internet but I cant help wondering that

if the human ear picks up a certain reaction to different frequency ranges

Then does that frequency not have the same effect on any instrument that

crosses its path so to for example

320 – 640 Hz (5th Octave) Midrange power, adds depth and body
This example is from one of many eq tutorials that I have looked at

So if a piano played this frequency and a violin played this frequency

would this frequency range have the same effect on both instruments.
First of all I need get the basics right.

Figure out how the different frequencies ranges effect the sound of different instruments.

I think understanding frequency ranges is going to be a real step forward
Im getting a little bit better with compression settings and even been experimenting with a noise gate on a pipe band snare drum that is quite an interesting learning curve.
Once again many thanks for your encouragement and im sure I will have loads more of daft question

Best Regards

Gus

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Totally agree with you Peggy
Thanks
Gus

I generally end up trying MBC if using an EQ to try and solve a frequency problem results in too drastic of a cut in that range and I lose more than I gain in overall fidelity. Thinking of the MBC as a subtle way to soften the impact of a problem frequency range without “sucking the life out of it” is a good way to start down the MBC road. Once I got the hang of how MBC contributes to a mix I found more sophisticated, or exotic, ways to use it but its not yet my go to compression tool. I do use the LimMB on the master track for almost every mix but that’s what it’s for and probably a bit off topic.

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To sum it up the underlying point is to keep it as simple as possible for as long as possible.

Hope the information serves you well. :wink:

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Thanks Gus :slightly_smiling_face:

Thanks Simon i will do my best
Gus

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Many thanks im listening to lots of good avice
Gus