Parallel Multiband Compression for Mastering

[Holger Lagerfeldt]

How to setup Logic Pro

Follow the instructions to the letter and things will work perfectly.

 

First you need to make sure full plug-in delay compensation is enabled in Logic Pro. If you don't do this you could get phase problems.

 

Logic Pro > Preferences > Audio>General > Plug-in Delay > Compensation > All

 

You need

1 audio track

1 aux channel

1 main output (entitled Output 1-2)

 

Take a look at the screenshot for reference.

 

http://www.popmusic.dk/download/logic/parallel-multiband/parallelpicture.gif

 

How to do it

Place the stereo mix file you are about to master on the audio track.

 

Open a send from the audio channel to Bus 1, and send unity value (0.0 dB). The shortcut for this is Option+clicking on the send knob.

 

This automatically creates a Aux 1 channel with Bus 1 as input, if it isn't already created in your setup.

 

Now apply whatever mastering plug-ins you need such as equalizer and single band compression to your audio track, not the Aux. The audio track is also where you use the I/O plug-in in case you're using hardware. However, do not apply a limiter to the audio track and do not touch the volume fader on this track unless you first set send mode to pre-send instead of the default post-send.

 

If you wish to use a limiter plug-in it should be inserted on Output 1-2 as this is where the processed signal and the parallel signal will meet up, and they need to be processed together.

 

Open the Logic Multipressor (or a Waves Phase Linear Multiband compressor, though Logic's will do just fine) on Aux 1 and load this preset:

http://www.popmusic.dk/download/logic/parallel-multiband/multipressor.zip

 

Place the downloaded preset here:

HD > Users > YourUserName > Library > Application Support > Logic > Plug-In Settings > Multipressor

 

Settings

Threshold

-48 dBFS or lower

 

During this type of compression you need constant gain reduction and you want the compressor to react to very low passages.

 

Ratio: 2:1

The ratio should be fairly low although you can certainly experiment with this parameter for more radical effects.

 

Peak/RMS

0 ms

 

Part of this trick is to violently smack down on transients so you need the compressor to react to peaks.

 

Attack

0 ms

 

Same reason as above.

 

Release

300 ms or above

 

Too short and things will start to pump a bit which isn't what you normally want. So use release times between 300 and up to a few seconds even.

 

Shorter release times = more obvious compression but also more effect (especially in the high frequencies)

 

Longer release times = less obvious compression but also less effect

 

You can set individual release times per band, i.e. longer release times for the sub frequencies and very high frequencies. High frequencies jumping around isn't as much an issue with the Logic Multipressor but more an issue with 5 band compressors like the Waves Linear Phase Multiband where the ultra high frequencies have their own band (11 kHz+).

 

Gain Make-up per band

As a starting point you don't need to touch the individual make-up gains. But if you feel the parallel signal needs to contribute more to a special frequency area this is the place to do it. As you're raising a heavily compressed signal in a specific band it sounds very different to equalizing and is a great alternative solution.

 

Other functions

Do not use autogain or touch the expander. Lookahead isn't necessary for this trick so you can set it for 0 ms (you need to start/stop the song to reset the delay compensation caused by the lookahead if you touch it during playback).

 

Amount of parallel signal

Use the Aux 1 volume fader to choose the amount of parallel multiband compressed signal you want to add to the blend. A normal setting would be about 15-25% of the original signal but always use your ears.

 

How to do fades or change the volume

As mentioned earlier: do not touch the volume fader on the audio track as this will affect the input dynamics of the parallel signal. If you for some reason want to adjust this channel then set send mode to pre-send first.

 

If you wish to do a fade in or out on your master, then do this by automating the volume parameter on the Output 1-2 fader which contains both the original processed signal and the parallel signal.

 

What is parallel compression

Parallel compression is often used during mixing to fatten up tracks, especially drums. It can also be used on vocals to increase fullness and bring up details without the pumping artifacts of regular (downward) compression.

 

Parallel compression is also used during mastering since it - unlike regular compression - can raise low level passages while still retaining more of the original dynamics during loud passages. Just as in mixing parallel compression can help fatten up a master and bring up "buried" details.

 

Parallel compression is not a substitute for normal downward compression but something to use in addition to add fullness and details.

 

Search the internet for more information about what parallel compression is and how it works in details.

 

Parallel Multiband Compression

Parallel multiband compression applies the exact same principles as its single band cousin. However, it sounds a bit different due to the separate bands. Parallel multiband compression also acts a bit like an intelligent loudness enhancer because of the psychoacoustics in how the human brain interprets especially the low and high frequency bands in relation to loudness perception. This trick is not possible in the same way with single band parallel compression, even when used in combination with an equalizer.

Edited July 15, 2010 by lagerfeldt

[jaytranzmit]

Lagerfeldt, is there a reason why you have chosen to output the channel via it's output routing to Bus 1 rather than just using the Aux send amount to Aux 2?

[Holger Lagerfeldt]

I've updated the above post so it now is the best and easiest way of doing things, thanks. Edited December 28, 2008 by lagerfeldt

[zeeb]

Hey Lagerfeldt ---

 

thnx loads for this -- will be trying out soon.

 

will report back.

 

Cheers,

 

John

[zosoaudo007]

Even if you try to get around that by using pre send (instead of post send) then you create another problem: you're now parallel processing on the unprocessed signal instead, which isn't what you want.

 

Actually I'm a little confused about what you said. When you say, "you're now parallel processing the unprocessed signal instead". By unprocessed you mean it isn't going through the EQ and compressor you have set up on that audio track, when you send it to a bus via the send?

[djals]

Thanks for sharing your knowledge!

 

Mastering is a skill at which I currently struggle (suck ).

 

I know it won't (at least I think it won't...) get me to the dizzy heights of a professional mastering job, but a high quality demo is what I'm after.

 

A couple of questions regarding limiting:

 

- Adaptive Limiter or Limiter, which one is better?

 

- How hard, in general, should you drive a Limiter?

 

I'm asking in relation to dance music.

[camillo jr]

Lagerfeldt, I don't have L8 installed yet but I'd like to try this with L7's MB compressor. What crossovers frequencies are you using between bands?

[Holger Lagerfeldt]

Even if you try to get around that by using pre send (instead of post send) then you create another problem: you're now parallel processing on the unprocessed signal instead, which isn't what you want.

 

Actually I'm a little confused about what you said. When you say, "you're now parallel processing the unprocessed signal instead". By unprocessed you mean it isn't going through the EQ and compressor you have set up on that audio track, when you send it to a bus via the send?

Exactly. You want to use the processed signal.

Edited September 25, 2008 by lagerfeldt

[Holger Lagerfeldt]

- Adaptive Limiter or Limiter, which one is better?

A trick question: neither. But use the AdLimiter if you have to, better alternatives exist such as the Sonnox Oxford Limiter or Flux Pure Limiter.

 

- How hard, in general, should you drive a Limiter?

As little as possible but as much as necessary. Sorry for the kung fu master response.

 

I very rarely drive more than 3 dB in a mastering limiter, the loudness is achieved by other means.

[Holger Lagerfeldt]

Lagerfeldt, I don't have L8 installed yet but I'd like to try this with L7's MB compressor. What crossovers frequencies are you using between bands?

 

The default settings are quite useful, but I can't really answer your question in relation to the 4 band Multipressor as I use the 5 band Waves Phase Linear Multiband myself.

[zosoaudo007]

Even if you try to get around that by using pre send (instead of post send) then you create another problem: you're now parallel processing on the unprocessed signal instead, which isn't what you want.

 

Actually I'm a little confused about what you said. When you say, "you're now parallel processing the unprocessed signal instead". By unprocessed you mean it isn't going through the EQ and compressor you have set up on that audio track, when you send it to a bus via the send?

Exactly. You want to use the processed signal.

 

I wanted to test this out and I put a reverb on an audio track with a loop, sent it to bus 1, and set the send to pre fader. I then muted the original audio track and through the bus came a reverb processed signal. Made a screen shot of what I did if you want to check it out.

 

So, I'm a little confused about what you mean when you say it doesn't get processed when you send it to a bus via send. Don't mean to be nit-picky but I want to understand fully what you are teaching us.

 

I know that you know your stuff, so I'm hoping you can shed some light on this for me. Otherwise, awesome post man. I really appreciate all the helpful tips.

[Holger Lagerfeldt]

I think you're right and I'm wrong about that because Logic uses pre fader/pan send for the pre send, and not pre processing.

 

I'll correct that in my post, thanks for pointing that out. Just shows that you're alert

 

I think I'll redo the setup part to make it easier and clearer then. Tomorrow...

[djals]

Cheers Lagerfeldt.

 

I know there's no magical zen setting, but its good to know where the boundaries lie (daniel son... )

 

I'll be checking out the suggested limiters.

 

Thanks again!

[Darude]

I think you're right and I'm wrong about that because Logic uses pre fader/pan send for the pre send, and not pre processing.

Yeah, if I've understood correctly, the pre/post setting affects the level/pan, but there sure are times when I hope I could send a track pre processing to a bus (Wouldn't it be cool if you could just choose pre/post process and pre/post fader per each send?). I know i can do this another way, but it would be easier to do it directly via the sends. Especially if you've already set up the channel and have everything sounding good etc, then duplicating the track or creating a whole new work-around gets too "messy".

[Holger Lagerfeldt]

Original post updated.

 

This is now the easiest way of doing things.

[route-electrique]

Thanks, yeah i have to make template from this .