SSL G3 MultiBusComp

Solid State Logic have added some new strings to their G‑series compressor’s bow.

How can you improve upon the classic SSL G‑series bus compressor? Lots of developers have taken it upon themselves to provide answers, adding extra features such as additional ratio settings, side‑chain filtering options and wet/dry mix controls. SSL’s own Bus+ hardware unit takes this trend to its logical extreme in hardware; now, their G3 MultiBusComp plug‑in does the same in software.

The Big G

Available for macOS and Windows in all the usual native formats, and authorised using iLok, G3 MultiBusComp is available to buy outright, through a rent‑to‑own scheme or as part of the SSL Complete subscription package. It incorporates all of the above‑mentioned bonus features and more. But, as the name suggests, it isn’t simply a software recreation of the G‑series bus compressor. It’s actually three G‑series compressors, operating separately on the low, mid and high‑frequency bands.

That is, if you choose to set it up like that. Adjacent bands can be ‘linked’, which is a slightly confusing usage; in practice, ‘linking’ the upper and middle bands, for example, simply disables the upper band and its crossover, leaving you with a two‑band compressor. And the crossovers themselves can be set anywhere from 20Hz to 20kHz, so there’s nothing to stop you having two bass bands and a single mid/high band, or vice versa.

Each band naturally has its own time constant, ratio and threshold settings, as well as make‑up gain. To the original 2:1, 4:1 and 10:1 ratios, this plug‑in adds gentler 1.5:1 and intermediate 3:1 and 5:1 options, and wet/dry mix is a per‑band setting, as is the choice of internal or external side‑chain. Each band also has a button with a headphones icon that lets you audition its filtered side‑chain signal. Additionally, you can introduce variable levels of saturation modelled on the original G‑series compressor circuit, again on a per‑band basis.

Visual feedback is likewise presented separately for each band, with VU‑style gain reduction meters at the top and an animated bargraph at the bottom. The crossover points and thresholds are represented on the latter as vertical and horizontal lines respectively, which can be dragged up and down with the mouse. Cick the View: BANDS icon to the left of this area, and it switches to show the side‑chain EQ page for each band, where your choice of low, high and bell filters can be applied. The frequencies of each are fully variable, and the Q of the bell filter is supposed to be adjustable using the mouse scroll wheel, though I couldn’t make that work using my Apple Magic Mouse.

Throw in global input and output level controls and a global wet/dry mix control, and that’s G3 MultiBusComp in a nutshell. Everything fits nicely into a single window, and apart from the naming of the Link controls, everything should be pretty much self‑evident to anyone who’s used a plug‑in compressor before. Having said that, one facility I did miss is the ability to actually link controls across bands, such that, for example, all of the thresholds could be moved at once.

Powers Of Three

A standard G‑series compressor is a pretty powerful beast. Used wisely, it can add that elusive ‘glue’. Used with a certain amount of abandon, it can inject an otherwise pedestrian mix with real rock & roll energy. And, used unwisely, it can send everything to rack and ruin. G3 MultiBusComp offers many additional ways of achieving all three possible results, and more!

First of all, of course, it can literally act as a standard G‑series compressor. If you link all three bands, what you have is in effect a full‑range implementation of the G‑series design, with extras such as side‑chain filtering and the additional ratio settings. Just for a laugh, I thought I would attempt a null test between G3 MultiBusComp and SSL’s single‑band Bus Compressor 2 plug‑in; I couldn’t quite get them to cancel completely, but they can certainly sound very similar.

If you want a punchy midrange with a controlled, tight low end, that’s easy to configure, without losing the characteristic aggression of the G‑series sound.

Moving on to relatively subtle applications for G3’s multiband processing, one of the main reasons for adding side‑chain EQ to a G‑series bus compressor design is to make it easier to tailor the way the compressor responds to low frequencies. G3 offers significantly more control in this respect, and what I really like is that once you enable the high and low side‑chain filters, they operate independently of the crossovers in the audio path. This means that, for example, you can have compression in the mid band triggered by low frequencies, which could be a neat way of achieving the French house pumping effect; or you could have a narrow mid band triggered by a much broader side‑chain signal, for example to tame a vocal resonance that occurs only on loud notes. If you want a punchy midrange with a controlled, tight low end, meanwhile, that’s easy to configure, without losing the characteristic aggression of the G‑series sound.

Engaging the side‑chain filters for a band effectively uncouples the side‑chain EQ from the crossovers in the audio path, in this case to allow compression in the mid band to be triggered by low‑frequency peaks.

Turn down the threshold or crank up the ratio controls, and G3 MultiBusComp can exert a pretty firm hand on the signal. Such settings are less usable on the mix bus, unless you like rack and ruin, but they can be highly effective on individual sources. One project I was working on had a DI’ed bass guitar that was flabby and lacked definition; a combination of firm control below 200Hz and aggressive push in the midrange sorted it out nicely, and the saturation — which is relatively subtle — added the finishing touch. G3 MultiBusComp is also a great tool for working with vocals: by setting the controls judiciously you can simultaneously tame proximity effect, dial in midrange emphasis and compression for clarity and use the top band as a de‑esser.

Banding Together

By and large, multiband dynamics processors tend to be clean‑sounding devices optimised for problem‑solving and subtle tonal correction. G3 MultiBusComp is perfectly capable of operating in stealth mode if you want it to, but you wouldn’t call it surgical, and there would perhaps be more versatile choices if that’s all you are looking for. Its real strength is to extend the assertive dynamic control we associate with the G‑series bus compressor design into new realms. It’s quite often the case that the desirable artefacts of compression, on the mix bus and elsewhere, are spoiled by unwanted consequences such as a loss of impact in the low end. G3 MultiBusComp makes it easier to implement compression as an effect without the unwanted side‑effects.