DMG's comprehensive multiband dynamics processor adds a whole workshop to your mastering toolkit!

Dave Gamble is not a plug-in developer who does things by halves. In fact, you could say he does things by whole numbers, and large ones at that. Products released under his DMG Audio banner typically sport large numbers of features, large numbers of user-adjustable parameters and large collections of presets. Whatever type of processing is on offer, you can be pretty sure that a DMG implementation of it will cover every conceivable use case, and plenty of use cases you can't conceive of.

The DMG Audio product line already includes comprehensive EQ and broadband dynamics plug-ins, and the latest addition straddles the line where the two meet. Multiplicity is designed to tackle any and every situation where dynamics processing needs to be triggered by, or applied to, just part of the frequency spectrum. To describe it as a multiband compressor would be like calling Amazon's Alexa a music player: Multiplicity can do multiband compression, but it can also perform dynamic equalisation, upwards and downwards expansion, transient shaping, de-essing and much more. (As far as I know it doesn't spy on you or collect data about your shopping habits, either.)

Eight By Three

Multiplicity is available in all the usual native formats for Mac OS and Windows, and is authorised using a downloadable licence key. The basic user interface is businesslike and, considering the amount of power it conceals, relatively unthreatening. The largest area is given over to a graphical display, which overlays a representation of each band's frequency range and activity against an animated spectrogram of the input signal. To the right of this are detailed input and output level meters and a handful of global controls, which include wet/dry mix and automatic gain compensation. The lower part of the interface, meanwhile, displays specific controls for the selected band.

Each instance of Multiplicity can host up to eight processing bands, and these are divided between three stages of processing, labelled Pre, Xover and Post. In essence, you can think of the Xover stage as a more-or-less conventional multiband compressor, with the Pre and Post stages applying dynamic equalisation either side of this. To put it another way, the bands in the Xover section divvy up the entire frequency spectrum for potential processing, while the Pre and Post sections allow you to target individual problem areas and leave the rest of the signal untouched. Thus, for instance, if you wanted to do broadband tonal shaping to make something sound like a digital master from 1995, you'd use Xover bands, whereas Pre or Post bands enable you to target specific problems such as excessive sibilance.

As far as the per-band parameters available go, the only real differences between Xover and dynamic EQ bands concern the filtering. Each Pre and Post band has a full set of EQ parameters including Q (bandwidth factor), slope and filter type, which act independently of other bands. Xover bands, by contrast, are defined by the settings of the crossovers between them, which are established by dragging coloured blobs around in the main graphical display.

Multiplication Tables

So many parameters are available on a per-band basis that although the lower section of the window is generous in size, it still doesn't offer enough room to view them all simultaneously, and some are thus concealed within the optional Sidechain and Advanced tabs. Naturally, each band has all the standard dynamics parameters such as attack and release times, threshold, ratio and a fully variable knee control; but that's not even the half of it.

Each band has a second threshold, which can be offset from the first by adjusting the Deadband control within the Advanced parameters. This is where you'll also find the Ratio Below control, which affects only signal below this second threshold. Both ratio controls offer expansion as well as compression, making it easy to — for instance — apply gain reduction to loud peaks while simultaneously attenuating very quiet signals to control spill or noise, while signals intermediate in level fall into the 'deadband' and are left alone. Ceiling and Floor settings allow you to specify maximum amounts of gain change that are applied above and below the deadband. And, well, that still isn't even the half of it.

DMG's Limitless multiband limiter introduced a two-stage approach to dynamics control, whereby a super-fast lookahead algorithm caught transient peaks and a more conventional process with adjustable attack and release times was used to control dynamic variation on a longer timescale. The same principle has been applied here, separately, to every band. At the central position of the per-band Dyn/Tran control, both transient control and conventional compression/expansion are in full effect. Moving this towards Dyn keeps the latter at full strength but progressively lowers the amount of transient processing applied, and the reverse applies in the other direction. Lookahead is also adjustable per band, and, like the Attack parameter, affects the relationship between the two processing stages.

Please Release Me, Fast Or Slow

You might think we'd be reaching the half of it by now, but not so. For one thing, the Dyn algorithm doesn't just have a single release time control. Instead, there are separate Fast and RMS release times. Which one is applied following any given episode of gain reduction is determined by the crest factor of the peak that triggered gain reduction; the point at which this crest factor triggers fast or RMS release is, natually, configurable. The idea is that compression can be made to sound more natural if recovery from a fast event such as a drum hit is also faster than it might be from, say, a sustained vocal note. In other words, by adjusting these controls you can introduce a very configurable degree of programme-dependence into the release behaviour.

The Advanced pop-out also contains a control called Shape, which runs from Lin[ear] at one extreme to Log[arithmic] at the other. The shape in question is that of the attack and release curves, and determines whether gain change during the attack and release phases is scaled linearly, on a dB basis, or somewhere in between. The stereo behaviour of each band is also very freely configurable. Gain change can be applied either on an M-S or an L-R basis, and can be applied equally to both channels, or weighted progressively towards one using a control analogous to the Dyn/Tran parameter described above.

Oh, and of course, where there's a dynamics processor, there's a side-chain; and, naturally, side-chains in Multiplicity can be sculpted to within an inch of their lives. The side-chain source can be either the full-bandwidth input signal, an external source, or the filtered signal feeding the selected band; Xover bands can also select each other's filtered signals as side-chain sources, and whichever source you choose, a further three-band EQ lets you shape it to your satisfaction. Side-chain detection can be set to M-S or L-R independently of the setting used for gain reduction, and again, can be weighted towards one channel or the other; the two channels can also be progressively unlinked.

With individual bands offering so many different parameters, DMG have sensibly included two separate preset systems: one for the plug-in as a whole, and one that saves settings on a per-band basis. These mini-presets are accessed from the contextual menu that appears when you hover the mouse over a blob on the main display. They don't store or recall frequency or slope settings, so you can configure the bands to target the frequencies you want to address, and then cycle through band presets to find one that does what you were hoping to do! (There is, inevitably, a vast range of setup options for configuring Multiplicity; one I'd like to see that isn't yet available is the option to specify default presets for newly created bands.)

"Any limitations on what you can achieve with Multiplicity are not to do with its capabilities, but with the user's ability to harness them."

Multiband On The Run

When you have a product that's this comprehensive, some of the questions you'd usually ask of review gear become irrelevant. Any limitations on what you can achieve with Multiplicity are not to do with its capabilities, but with the user's ability to harness them. From that point of view, it's interesting to compare Multiplicity with my longstanding favourite multiband dynamics processor, FabFilter's Pro‑MB.

Both functionally and in the broad outline of their user interfaces, the two have a lot in common, but there's a clear difference of emphasis. Whereas Multiplicity exposes lots of basic parameters for user control, FabFilter streamline things by providing fewer, higher-level controls. For example, Pro‑MB offers only a single attack and release slider per band, which aren't even calibrated in milliseconds. However, they seem to incorporate a degree of programme-dependence that allows them to adapt to the material in a very effective and forgiving way. This default programme-dependent behaviour works very well most of the time, and when it does, it saves you the effort that would be involved in setting up something similar in Multiplicity. However, when it doesn't, you'll search in vain for the controls to configure it differently.

Likewise, when you create a new processing band in Pro‑MB, it's created with default settings that actually do something right off the bat — and it's surprising how often those default settings provide exactly the right amount of dynamic control with little or no user adjustment. Newly created Multiplicity bands, by contrast, default to a 1:1 ratio and a 0dB threshold, meaning that no gain reduction will take place until you adjust them. All this means that Pro‑MB is sufficiently intuitive and immediate to be valuable in mixing contexts, where you need to quickly throw something on a track and move on; by contrast, Multiplicity is much more of a mastering-specific tool.

It takes a while to get a theoretical handle on how the various Dyn/Tran settings and release time parameters work, and even then, you still need to build up a sense of how they affect the sound in practice before you can really get the best from this plug-in. There's a large set of well-designed presets to help you along this journey, but the goal can seem distant at times; and until you've generated your own set of per-band presets, the number of parameters on offer means configuring Multiplicity from scratch can be painstaking. The flip side of this is that there are many things that Multiplicity can do that Pro‑MB and other multiband tools I know of simply can't. For instance, there's no Pro‑MB equivalent to Xover mode, nor any way to create very narrow bands to notch out specific frequencies, nor any dedicated transient control; nor can a single Pro‑MB band act both as a conventional compressor and an upward expander. Multiplicity takes some learning, but once learned, it'll never prove inadequate to a task!

Sonically, Multiplicity is not intended as a 'character' processor, but one that can perform necessary dynamic control as transparently as possible, and it always sounded impeccably clean to my ears. It will be of most interest to those who value pristine sound quality over simplicity, and flexibility over immediacy. To those who are willing to put in some work and fully understand what all those controls do, this has the potential to be both an immensely versatile processor for shaping the tonality of a mix, and a uniquely powerful toolkit for solving frequency-specific dynamics issues in the most invisible way possible.