FabFilter Pro-MB Help
Once one or more bands are selected in the multiband display, controls for the selected bands will appear at the bottom of the display. The band controls will be positioned below the currently selected bands. Note that the arrow at the top of the container has a glow that matches the color of the band it is controlling right now. A subtle yellow glow indicates that you are controlling multiple bands simultaneously.
The Attack knob sets the speed with which gain reduction sets in. Fast attack times are needed when you want to react on transients as fast as possible, for example to achieve limiting (Compress mode) or gating (Expand mode). The Attack knob shows a percentage value from 0% to 100%, because actual attack times are very program dependent, and even depend on the placement of the band in the frequency spectrum.
The Release knob sets the speed at which the compressor/expander recovers from gain reduction. Higher release values will result in more subtle leveling. Like Attack, the Release knob shows a percentage value from 0% to 100%, because actual release times are very program dependent, and even depend on the placement of the band in the frequency spectrum.
The Ratio slider adjusts the amount of compression or expansion that is applied, scaling the dynamic effect of the band on the input signal. For example, when applying compression with a ratio setting of 4:1, three of every four dB above the threshold will be attenuated. In comparison, the Range knob limits the final amount of compression or expansion rather than scaling it.
FabFilter Pro-MB can apply any kind of dynamics processing per band, using the Dynamics Mode buttons in combination with the Range knob. When the Dynamics Mode is set to Compress, use either a negative or positive range to apply downward (normal) or upward compression. The same applies to Expand mode. Here are diagrams to visualize the four different combinations:
Using Compress mode in combination with a negative Range will result in normal, downward compression. The dynamic range of the signal is reduced by attenuating peaks that exceed the specified threshold level.
Using Compress mode in combination with a positive gain does the opposite of normal compression: instead of reducing peaks above the threshold, it adds gain as soon as the level drops below the threshold. So this reduces the dynamic range from the noise floor up instead of from the peaks down. Upward compression can be very useful to add loudness and body, while leaving the transients untouched. Also, when used with extreme range, ratio and release values, you can achieve creative pumping effects.
When using Expand mode in combination with a negative range, the signal will be attenuated as soon as it drops below the threshold, increasing the perceived dynamics of the signal around the threshold. This is the most common type of expansion and with higher ratio and range values, it's often called gating.
Expand mode in combination with a positive range will again do the opposite of normal expansion: instead of attenuating the signal when it drops below the threshold, it will add gain as soon as the signal exceeds the threshold, emphasizing the peaks in the audio. So this increases the dynamic range from the threshold up instead of from the threshold down. Upward expansion is a great way to enhance transients. For example, you can easily increase the impact of a snare in a drum loop using upward expansion.
If you hold down the Alt key while dragging a band's Output Level knob, the Output Pan ring will simultaneously be adjusted in such a way, that make-up gain is applied according to the current Stereo Link Mid-only or Side-Only processing amount. For example, when using 100% mid-only processing, holding the Alt key while dragging the band's Output Level to +6 dB, will also set the panning to "-6 dB Side". This ensures the side signal stays unchanged, only adding make-up gain to the mid signal.
Next: Expert band controls