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FabFilter Pro-Q 2

Superb EQ Plug-in Delivers Pristine Sound, Eminent Flexibility

When FabFilter unleashed its Pro-Q plug-in in 2010, it quickly became my go-to equalizer for mixing, mastering and post-production sessions. With the release of Pro-Q 2, the euphonic and versatile plug-in has become even more musical and powerful. Pro-Q 2 is available in AAX Native, Audio Units, VST, VST3, AudioSuite and RTAS formats (with both 64- and 32-bit frameworks, except for the 32-bit-only RTAS). I reviewed the AU plug-in using Digital Performer Version 8.06 and an 8-core Mac Pro running OS X 10.9.5.

Old & New

Like its predecessor, Pro-Q 2 offers up to 24 bands of analog-modeled equalization and mono, dual-mono, stereo and mid-side operation. Both linear-phase and zero-latency (minimum-phase) filters are offered, their parametric control sets (frequency, gain, Q, channel assignment and so on) displayed for only one selected filter at a time in the uncluttered GUI (see Fig. 1). A real-time spectrum analyzer transparently overlays the plug-in’s interactive EQ (x-y) display. Multiple-undo/redo functions, A and B workspaces, preset management and online documentation are included.

Pro-Q 2’s new processing engine uses CPU resources more than twice as efficiently as its predecessor. Newly added Natural Phase filters more closely match the phase response of analog EQ than Pro-Q 2’s other filter types, without producing noticeable pre-ringing artifacts or incurring long latency. The plug-in’s linear-phase mode has reportedly also been improved, offering better magnitude response and avoiding artifacts when using any of its lower-resolution options (which incur lower latency). You can change the frequency, gain or Q in linear-phase mode without incurring zipper effects—a plus for automating EQ changes while mixing or mastering.

The updated plug-in offers steeper filter slopes for all filter shapes, including bell and shelf: up to 96 dB/octave. (Eight other slope selections are available.) Tilt-shelf and bandpass filters have been added to the pre-existing arsenal of bell, HPF, LPF, notch and low- and high-shelving filters; the tilt-shelf boosts on one side of the selected frequency while cutting on the other. A Gain-Q interaction function, when activated, progressively narrows a bell filter’s Q as you boost the filter’s gain—much the same way as some analog mixing boards work.

A new EQ Match mode changes the spectral balance of the plug-in’s input signal to match that of signal routed to its external sidechain input. Normally, both signals are analyzed at once, but controls let you analyze each in turn so that, for example, you can conform the input signal’s spectra during a chorus to the sidechain signal’s spectra during a verse. The spectrum analyzer can be made to show the sidechain signal’s spectrum in lieu of or together with spectra pre- and post-EQ for the audio path’s signal.

In Piano Display mode, Pro-Q 2 shows the musical note—including any +/- offset in cents—corresponding to each band’s center or corner frequency: for example, “441.83 Hz A4 +07.” In this mode, Pro-Q 2 replaces the frequency titling traditionally used along its x-axis with the 88 keys of a virtual keyboard (the frequency grid remains). For each filter you add in the x-y display, a colored dot is placed on the key that corresponds to the filter’s center or corner frequency. Click a key’s dot to quantize its associated EQ node to the frequency of the corresponding musical note. Drag the dot to another key to quantize the node to a different musical note. Alternatively, double-click either a band’s node or its frequency knob and type in a musical note value (such as D#2) to quantize the band’s frequency.

Activating Pro-Q 2’s Auto Gain mode applies make-up gain to compensate for gain changes caused by equalization. Drag the new Gain Scale slider to proportionally scale—from 0 to 200 percent—the boost and cut amounts of all active bell and shelving filters. You can also flip the phase of the plug-in’s output signal.

The new Spectrum Grab function removes the guesswork in identifying and neutralizing offending peaks in frequency response: Click on a peak displayed by the spectrum analyzer to create a bell-curve filter centered at that frequency, then mouse-drag the amplitude lower.

The spectrum analyzer has been updated to offer gain-range settings up to 120 dB, horizontal zooming, a freeze (peak-hold) function and adjustable tilt settings. Higher tilt settings give more weight to (display relatively higher amplitudes for) frequencies above 1 kHz than below. You can select among four different GUI sizes or full-screen mode. (The VST3 plug-in’s GUI can be made any size by dragging the edge of its window.)

Although Pro-Q 2 offers virtually unlimited internal headroom and will never clip, its new output level meters are useful to alert you to possible clipping downstream from the plug-in. The meters include peak-level readouts and can be hidden.

In Use: Post-Production

Whether used on music or dialog tracks, Pro-Q 2’s new Natural Phase filters sounded outstanding—very subtly more analog-like than the plug-in’s also excellent Zero Latency filters.

I found Pro-Q 2’s steeper filter slopes to be extremely useful when using highpass filtering on dialog tracks. On a track terribly marred by rumble in one particular spot, I automated the bypass for an HPF and dialed in a 96dB/octave slope. The super-steep slope allowed me to move the filter’s corner frequency much higher than usual without audibly thinning the talent’s timbre, completely eliminating the rumble.

I also liked the new Auto Gain function. One videographer I work with likes to ride fader levels on dialog tracks before sending them to me for noise reduction, equalization and so on (an ass-backward approach, I know). Auto Gain provided me a shortcut to preserving her preferred balances.

EQ Match mode worked beautifully when given a relatively simple task: making the timbre of an unprocessed dialog track match that of a copy of the same track that had been EQ’d to taste. In this application, EQ Match made the two track copies sound identical. Matching the track’s timbre to that of a totally different dialog track, on the other hand, yielded a sound that was noticeably phase-y—no doubt due to the extremely steep slopes the process rendered on a few midrange filters implementing high amounts of boost or cut (see Fig. 1).

Thankfully, lowering the Gain Scale slider to roughly 60-percent all but eliminated the phase artifacts. Lowering the Q for a few of the steepest filters smoothed the sound further. Bottom line: I could get a bit smoother and warmer sound by EQ’ing manually from scratch, but with a little bit of follow-up tweaking EQ Match sounded very good. Unfortunately, there’s currently no way to save EQ Match’s analyzed spectra as presets for later recall. (FabFilter plans this capability for a future update.) Presets would allow EQ matching across multiple projects and greatly speed use on lengthy programs with high track counts.

The spectrum analyzer’s lowest tilt setting more readily revealed excess energy in the upper-bass and lower-midrange bands—a common problem with dialog tracks. Spectrum Grab, spectrum freezing, full-screen mode and horizontal zooming all worked beautifully. All that said, I usually get better results equalizing by ear than when relying on a spectrum analyzer (unless I’m tuning a control room to mitigate room modes). Everyone has their own work methods, though, and you may find these tools to be very helpful. As was the case with other FabFilter plug-ins I’ve reviewed, I encountered no bugs.

Better Than Ever

Pro-Q 2 is one of the finest plug-ins I’ve had the pleasure to use. The sound quality is superb. Its bountiful selection of filters, wide-ranging controls, and dual-mono and mid-side processing meet any static equalization challenge in mixing, mastering and post-production applications with grace and surgical precision. What’s more, Pro-Q 2 is reasonably priced. Two thumbs up—way up!

Michael Cooper is a recording, mix, mastering and post-production engineer and contributing editor for Mix magazine. You can hear some of Michael’s mixes at

Try This

When using a steep highpass filter to roll off bass response, use Pro-Q 2’s Zero Latency mode for transparent results. A linear-phase filter (from any manufacturer) could cause audible pre-ringing, most often perceived as a softening of transients.

Product Summary

COMPANY: FabFilter


PRICE: $199 (discounted upgrade pricing available)

PROS: Superb sound quality. Extremely flexible. Feature-rich. EQ Match works very well with minor follow-up adjustments. Excellent GUI. No apparent bugs. Good price for value.

CONS: Can’t save EQ Match’s analyzed spectra as presets