You have turned the volume up and the voice is still hard to follow. It sounds thick, boomy, a bit like the speaker is talking through a duvet. Adding more volume at this point makes the problem louder rather than smaller.

What you have is a balance problem. Some frequency ranges are crowding out the ones that carry intelligibility, and an equalizer is the tool that separates them.

What each band is doing

A six band equalizer covering roughly 60Hz, 150Hz, 400Hz, 1kHz, 3.5kHz and 10kHz maps onto speech quite neatly:

  • 60Hz. Sub bass. Room rumble, traffic outside, air conditioning, desk bumps. Speech contains almost nothing useful down here.
  • 150Hz. Body and warmth in a voice. Too much and it turns boomy.
  • 400Hz. The mud zone. When audio feels thick and congested, this is usually the culprit.
  • 1kHz. Core presence. Where a voice sits in the mix.
  • 3.5kHz. Consonant clarity. Cutting this makes speech mumble, boosting it makes words distinct.
  • 10kHz. Air and sparkle. Also where hiss lives.

Cut before you boost

The instinct is to boost whatever seems missing. The better habit is to cut whatever is in the way. Cutting reduces total level, which leaves headroom and avoids pushing anything into distortion. Boosting stacks energy on top of a signal that may already be close to its limit.

If speech is unclear, taking away what is masking it beats adding more of what you want to hear.

A starting point for muddy speech

This handles the majority of thick sounding podcast and lecture audio:

  1. Pull 60Hz down by 4 to 6dB. Removes rumble you were never meant to hear.
  2. Pull 400Hz down by 3 to 5dB. This is the change most people notice immediately.
  3. Lift 3.5kHz by 2 to 3dB. Consonants sharpen and words separate.
  4. Leave 1kHz alone unless something still feels off.

Adjust one band at a time and listen for a few seconds between changes. Moving three sliders at once tells you nothing about which one helped.

Hiss is a different problem

Constant background hiss sits high, so pulling 10kHz down reduces it. The catch is that it takes clarity with it, since consonants live nearby. A modest cut is worth trying, but heavy handed high cuts trade one problem for another. Persistent broadband noise is better handled by noise reduction than by an equalizer.

Presets versus manual

Sound mode presets are shaped for music, where the goal is character rather than intelligibility. A bass preset on a podcast will make an already muddy voice worse. For speech, either use a vocal oriented preset or set the bands yourself using the steps above. It takes about thirty seconds and the result is specific to what you are listening to.

Order matters

Fix the balance first, then set the level. An equalized voice is clearer at a lower volume than an unequalized one was at maximum, which usually means you need less boost than you thought. If you do still need significant gain afterwards, the guide to going past 100 percent volume covers doing that without introducing distortion.