Unlinked compression

[MeesParticipant]

Hey all, first post here since recently buying my first A&H console (SQ).

I would like to see the option of being able to unlink L/R in the compressor settings.

I’ve looked in to the current flexibility regarding this way of working and I’ve only found one usable way:

Using two mono groups (one panned left and one panned right, to main) and then duplicating all input channels. One input channel for the left and one input channel duplicate for the right group, and sending more to one or the other for panning.

A simpler way would be to be able to send post fader to groups, a opposed to just routing to a group (which means not having to need two input channels of the same signal). Or just unlink compression in the compressor settings.

Forgive me if I’ve missed an obvious better way of achieving this or if this was already posted (I did find a thread from 2018).

Thanks for reading,

Mees

[Phil DriscollParticipant]

I suspect that the solution will involve some hackery as you’ve described, but I’m very interested to know what your use case is, as I’ve never wanted or needed to do this in my 40 years as a sound engineer. Are you actually really working with two unrelated mono feeds that just happen to be going through the left and right channels?

[Phil DriscollParticipant]

PS I ask because I often want to do something that’s essentially the opposite. Mid session I might deploy a couple of mics on adjacent channels as a stereo pair and want to link their dynamics side chains, otherwise I can’t use compression/limiting without the stereo image flying all over the place.

[MeesParticipant]

I know that some mixers have this functionality built in to their compressors, I believe also some A&H consoles actually.

I learned about the effect a linked compressor has on the stereo image only recently (learned this from Dave Rat). But it’s makes quite a big difference I’ve noticed.
Linked compression tends to create more of a centre focused sound, that more noticeably ducks/compresses.
Unlinked retains a wider stereo image, that’s more ”open” and leaves more of the reverb intact as an example.

Surely there’s more to it, but this is what I’ve learned about it so far.

[Phil DriscollParticipant]

A linked compressor certainly keeps everything in the same place in the stereo image whether it’s compressing or not. Unlinked skews the image when triggered by an off center loud sound. I can imagine that this might be occasionally desired as a special effect, but, at least to me, it smacks of being a mistake in general use. Historically, it is true that stereo compressors built into a desk had a link/unlink button, but, at least in the case of all the ones I came across at the BBC, this was because you might be using them as a stereo bus compressor with the link button switched on, or as a mono compressor in an individual channel, such as a bass guitar. In this case you’d have the link turned off so that it didn’t affect the other compressor, which you might be using in a different mono channel. When we started to get desks with dynamics on all channels, such as the SSL4000E, the bus compressors didn’t have an unlink button, because they were designed to just be used on stereo buses. At least, that’s my distant memory of it!

[MeesParticipant]

Ah interesting! I agree that linked would inherently keep the stereo image intact, however upon testing this the other day I must say I preferred the sound of the unlinked setup. And I don’t think that’s because it added something that wouldn’t naturally be there. I guess maybe because it sounds more like it would without amplification is what I’m thinking? Not sure if that’s true.

In any case I’ll continue to play around with this.

[Phil DriscollParticipant]

Might be a good thing to do blind testing on, and remove your expectations from the equation 🙂 I don’t think I’d be able to convince myself that it wasn’t broken. I can’t see how linking the sidechains could spoil the sound in any way. If there’s no compression going on, the sound will be identical, and if there is, then both sides get quieter at the same time rather than the signal dropping more on the loud side.

[MeesParticipant]

I’m definitely not experienced enough (as a sound engineer) to claim that one is by definition better than the other. I just noticed that I preferred the unlinked over the linked in my tests recently. I also did do a blind test, had it set up that two mute-group buttons switched the groups on and off, switching between a stereo group and mono groups. And then switching whilst having my eyes closed.

I think although technically the stereo image changes, the amount is marginal because the louder side is squashed (if that’s the right term) more and therefor still perceived louder than the other side.

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