Why I use Equilibrium's Free Phase mode for mastering filters

If you’ve been following me for a while, you’ve probably noticed that I reach for DMG Audio Equilibrium almost every single time I need to make filtering decisions in mastering.

And there is one feature that completely changed the way I use it: Free Phase mode.

Most EQs force you to choose between minimum phase and linear phase. Equilibrium lets you go way beyond that.

What is Free Phase?

Free Phase gives you control over the phase response instead of locking you into one behaviour. That means you can shape how the EQ affects both the frequency and the timing of the signal.

Free Phase sits between the traditional approaches. Instead of being forced into the compromises of minimum phase or linear phase, you can dial in the phase behaviour to suit the material. This gives you much more flexibility when making mastering moves, especially with filters.

Why I love it for filters

High-pass and low-pass filters don’t just remove frequencies. They also change the phase response around the cutoff.

With Free Phase, I can find the sweet spot where:

• The filter stays incredibly transparent.
• The stereo image feels more natural.
• The low end remains solid and focused.
• The mix keeps its depth instead of becoming flat.

That’s why I almost always prefer it over standard EQs when I’m cleaning up the extreme lows or highs in the master.

Extreme impulse lengths

Something that surprised me: after reading some of Matt Davis’s posts, I started experimenting with extreme Impulse Length settings inside Equilibrium.

Now I almost can’t master without setting it to 262144.

The sound becomes incredibly smooth, detailed and neutral. To my ears it even beats many analog EQs for transparent mastering.

Keep in mind that longer impulse lengths also increase latency and CPU usage, so this isn’t something you’d normally use while tracking or mixing. But for mastering, it’s absolutely worth trying.

Everyone’s taste is different, but if you already own Equilibrium and you’ve never explored Free Phase together with a long Impulse Length, you’re missing one of the plugin’s most powerful features.