Blue Cat Audio MB Dynamix Pack review

Five bands' worth of dynamic control and a multiband mixer

These dynamic effects aren't for the faint hearted.

MusicRadar Verdict

A super-flexible, great-sounding plug-in combo for the more technically inclined.


  • +

    Clever ideas well implemented. Quality multiband processing. MB-7 linking options a nice touch. Cross-band internal sidechaining.


  • -

    Sidechaining can be complex. MB-5 requires careful tweaking. Dynamics section not as powerful as Blue Cat Audio's Dynamics 3 plug-in.

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This package includes two plug-ins: the MB-5 multiband dynamics processor and the MB-7 multiband mixer.

MB-5 is the more powerful of the two, spreading most aspects of Blue Cat's flexible dynamics processor Dynamics 3 across five linkable bands.

The main per-band capabilities (compression, gating, limiting, expansion and waveshaping) are complemented by flexible band crossovers (6dB to 60dB per octave), band-specific peak/RMS response blend, global wet/dry, output limiter and mid/side or stereo modes.

In Blue Cat parlance, there are 'upper band' controls (compression and limiting) and 'lower band' controls (gating and expansion) for each frequency band. You can copy settings between bands, sidechain internally from other bands, and link controls globally in either absolute or relative fashion.

Finally, bands can be soloed, muted and bypassed on an individual basis. Some features can also be accessed from the display, which includes a spectrum analyser and real-time dynamic response curve.

Although much simpler, the MB-7 is the more intriguing processor here, as it applies the multiband concept (up to seven bands) to that of a level mixer. It's simple enough in concept, but factor in band-specific panning, stereo width, mute, bypass and solo, and you've got a powerful mastering and manipulation tool.

For the creatively inclined, you can also link and group band parameters (including reverse link) at plug-in level and even across different instances (so called 'global' groups).

For functional reasons, the plug-in comes in mono, stereo and dual mono versions. Finally, all plug-ins benefit from MIDI CC connectivity.

Making the connection

Many of Blue Cat's plug-ins can send and receive MIDI data in order to facilitate such things as sidechaining, and this function allows the Dynamix Pack to perform multiband sidechaining.

The approach is to use a gain-changing plug-in on your destination track (the MB­7 Mixer), sidechaining it with data created by a dynamics plug-in across your source (the MB­5).

By setting the MB­5 to 100% Dry and using its MIDI output routing, you can generate up to five bands of gain control data, received as MIDI input at the MB­7.

Connecting things up is not only DAW-specific, but also plug-in-format-dependent, and the VST version is your best bet. Blue Cat suggests Logic users can use automation data routed via custom environment objects to get round the AU limitations. We found that getting decent results also required skilful tailoring of settings. So, although powerful, this feature requires patience.

Band on the run

In use, the only real hurdle with MB-5 is understanding that your expander and compressor share the same time response settings (attack, hold, release and RMS average window envelope).

With settings down to 0ms, both expansion and compression can be brutally harsh, but with individual knee shape controls and the peak/RMS blend, the MB-5 can do subtle stuff too.

If we have one real criticism, it's simply that a novice might find themselves moving between those extremes by making only small changes to the controls. For example, the ratio settings can easily be set to 'negative', delivering expansion in the upper curve and upwards compression in the lower curve.

In use, the MB-7 shows itself to be part mastering tool and part creative plug-in, particularly when you combine reverse linking of bands with some automation. But we found it particularly good for controlling the stereo width for specific frequency ranges on a multitude of stereo sources including drum kits, piano, strings and full mixes.

This allowed us to make our sounds more expansive in the mid and high frequencies while retaining low-end cohesion. Equally, if you've time to kill, MB-7 can do a fair job of isolating sounds in mixed sources.

Although Blue Cat's slogan is 'software made by musicians for musicians', these are precise, almost scientific tools in a similar vein to those from Flux or DMG Audio. So, they require time to truly get to grips with. In return, they'll continue to deliver as you explore their depths.

Now listen to our audio demo to hear:

Drums using the MB-7 Mixer with 5 bands - First we solo each band, then add spread to the top 3 bands, one at a time and bypassing to compare. Then we have all 3 top bands together and bypass to compare. Then we quick link the 3 bands and pan them all one way then the other. Next up we solo the lowest band and completely mono it, then do the same to the second lowest band, bypassing to compare each time. Finally we put all bands in together and bypass a number of times to compare.

Bass guitar with MB-5 Dynamics and 3 bands - First we solo the top band and adjust compression to add pop to the sound. Next we solo up the lowest band and add some control to the sub frequencies. Next, we try and smooth out the main body of the bass in the mid band, and rebalance our gain levels slightly. Finally, we link the bands in relative mode and reduce all thresholds to increase compression, and adjust all the gain make ups. Bypass to compare a few times.

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