Jump to content

Side Chaining Possibilities & Bussing questions.


Recommended Posts

:idea: 1.)The recent version of Logic pro X is not responding to my side chain compression effect.

I set up compression on vox with bus 1 input for the side chain and then have a separate drum track routed to bus 1 with vol up to 0.0

Anyone walk me through the process?what am I missing?


2) What are some other cool possibilities with side chaining. Can you sidechain eq? Reverb?any cool things you guys stumbled upon?


3) When I bus a track to a bus. is the original track still routed to master? (Or do I manually have to disconnect it from the master to have it routed just through the bus to master?)

Link to comment
Share on other sites


Track A = destination (track you want to be externally side-chain compressed)

Track B = source track (track you want to be the source of the side-chain compression)


1) Insert a compressor on Track A

2) In the upper right corner of the compressor, choose Track B (which could be a bus number) as the source

3) Usually you want to remove auto gain in the compressor and set make up gain to 0, so you have a 1:1 signal being ducked.


In Logic Pro you can only have an audio track, audio input or bus as the side-chain source. If you want to use a software instrument channel as the source you need to route that track through a bus first. Then side-chain to that bus.


Unless you've fiddled with other settings the compressor you will now have some kind of external side-chain compression when you lower the threshold. For a noticeable ducking effect you probably want to remove soft knee (set it to hard), use a fairly high ratio, a fast attack and fast to medium release. The different compressor styles such as Platinum, VCA, FET, etc. all behave differently and will affect the type and speed of ducking. The Platinum style is the most transparent, but also has a slower non-linear release.



Typical uses of external side-chaining include


· Ducking music to a voice over/speak as an alternative to volume automation

· Ducking a bass to the kick to make space in the low end or for rhythmical purposes

· Ducking a synth or pad to the kick for creative purposes

· Ducking any instrument or group of instruments to the vocal or a solo instrument to make space in the mix

· Ducking a delay (or reverb) to the vocal, so mainly the tails between sentences or words are audible

· Ducking a dynamic EQ (e.g. FabFilter Pro-MB) to fix something or make space

· Gating backing vocals in time with the lead vocal (a lazy but fairly effective way of tightening up dubs)

· Gating a live played bass in time with the kick drum to tighten up the bass attack

· Gating a reverb in time with a snare or other instrument (think 80s rock songs) for creative purposes


The FabFilter Pro-C2 does a better job and is more flexible than the stock Logic compressor for more advanced and cleaner ducking. The variable lookahead alone is important in getting good ducking. Tip: In the C-2 you must both choose the external side-chain input in the upper right corner as well as select "external" as the side-chain input in the lower part of the plug-in or you will not get external side-chain compression.



You can route a track to a bus or you can send a certain amount of signal from a track. If you route the track then no signal goes directly to the master bus from that channel - it must pass through the bus & an aux first. When you send, the original signal still goes to the master bus, unaltered. You route by changing the output of the channel strip to a bus. You send by using the send knob on a channel strip. Routing is generally used for summing tracks on an aux. Sending is generally used to send to wet effects (e.g. reverb & delay) or parallel processing.

Link to comment
Share on other sites

The Logic Pro compressor automatically has the external side-chain on whenever you choose an external input.


In FabFilter Pro C-2 you need to activate the external input in the dropdown side-chain panel as well, as I mentioned above.


Also be aware that in the C-2 you need to have the side-chain dropdown menu open (showing) for it to be active. Close the panel and the external side-chain or filtering is deactivated!


Semantics: the correct use of side-chain here would be "external side-chain" since the compressor is always listening to the (internal) side-chain.

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...