Collision highlighting only picks a suspect
In Pro-Q 4’s Instance List, one track can become the collision reference while possible overlaps with other Pro-Q instances are shown around it. The red glow in the main analyzer asks the same question. A line in FabFilter’s own manual matters here: collision detection is an indication, not exact science. Bass and piano can share 200 Hz perfectly well when their attacks, note lengths, and stereo positions differ. The reverse is also true. A vocal consonant and a guitar pick can mask each other at the same instant even when the averaged graphs do not overlap dramatically.
The first move after seeing red should therefore not be creating a band. Loop the busiest four bars shared by the two parts and change the reference one track at a time. Looking at the kick from the bass and the bass from the kick can change the decision about which one must speak in front. Then try lowering the competing track by 1 dB, or briefly change its pan, octave, or note length. If that small arrangement experiment resolves the relationship, EQ is unnecessary or can be much shallower. Collision highlighting is closer to a map for the order of listening than a mark for the site of surgery.
Move the problem moment, not the whole band
A static EQ cut stays active throughout the song. If a thin verse vocal is fine but the chorus becomes hard around 3 kHz, a permanent cut drains life first from the quietest lines. Pro-Q 4’s Spectral Dynamics does not move the gain of the entire band together like conventional dynamic EQ. It reacts to specific frequencies inside the chosen band when they cross the threshold. That distinction becomes useful when the broad presence should remain but a narrow component jumps out only on a certain syllable or pick attack.
Start deliberately modest. Loop the rough passage, make a reasonably broad bell, limit the dynamic range to roughly 1–2 dB, and trade it against bypass. Before asking whether the consonant hurts less, ask whether the word has moved backward. Raising Spectral Density makes the affected regions narrower and more selective, but a display with more dots removed is not the same thing as natural sound. FabFilter also specifies that spectral bands use linear-phase processing, with latency determined by processing resolution. Instead of placing them by habit on a low-latency recording path, enable only the bands that earn their place during editing and mixing.
A good tool needs a stopping rule
The Instance List is valuable because it lets you compare EQs scattered across a session from one screen. It can also make every track look ready for a cleanup pass. Set the song’s priority first. Write one sentence: is the kick’s weight the reference, the bass pitch, or the language of the vocal? Collision removal without a reference often carves matching holes into different tracks. The result can be clean, small, and flat.
BGC uses three stopping rules. First, match output level before and after the move so the louder version is not mistaken for the clearer one. Second, any band made in solo must be auditioned at half its gain in the full mix. If a 3 dB cut looked right, ask whether 1.5 dB already separates the roles. Third, pass both the densest and the sparsest section. If clarity gained in the chorus erases expression in the verse, turn a static cut into dynamic or spectral processing—or delete it. Pro-Q 4 is good at shortening comparison time, not making the decision for you. The final approval comes from whether every part can finish its sentence at low monitor level, not from the graph.