# Mastering EQ Frequency Chart > A practical reference for what each frequency range actually does and controls, so you're making informed cuts and boosts rather than guessing. [All guides](/blog) # Mastering EQ Frequency Chart Published 21 September 2026, 00:00 UTC · updated 31 August 2026, 13:06 UTC · by Loopin Knowing roughly what each frequency range controls turns EQ decisions from guesswork into informed choices. This isn't a rigid formula — it's a practical starting reference to sweep and confirm by ear. ## Sub and low bass: 20-80 Hz This range carries felt weight more than heard tone — kick fundamental and sub bass live here. Most content below 30 Hz is rumble worth high-passing away; content in the 40–80 Hz range is where a lot of a track's physical impact actually lives. Keep this range mono and be conservative with boosts — it eats headroom fast and translates unpredictably across systems that can't reproduce it well anyway. ## Low mids: 150-500 Hz This is where warmth and body live, but it's also where muddiness and congestion concentrate when a mix is too dense — the most common problem area in mastering, especially for AI-generated or busy arrangements. Small cuts here often do more than any other single move. Too little energy here makes a track feel thin; too much makes it feel muddy or boxy — this range rewards careful, moderate treatment more than any other. ## Midrange: 500 Hz-2 kHz Vocal body, most instrument fundamentals, and a track's overall sense of presence and power live here. This range is heavily perceptually weighted — small mid-frequency changes are often more audible than similarly-sized changes elsewhere. Boxy or honky qualities often trace to a narrow resonance somewhere in this range, findable by sweeping a boost and listening for where things sound most unpleasant. ## Upper mids and presence: 2-6 kHz Vocal clarity, intelligibility, and "forwardness" in a mix live here, but so does harshness and listening fatigue if pushed too hard — this is the most common location for the harshness issue in AI-generated content, and it's the range that makes or breaks how comfortable a track is to listen to at length. Small, careful moves here go a long way — both boosts and cuts in this range are more perceptually impactful than the same dB change elsewhere. ## Air and top end: 6-20 kHz This range adds sparkle, openness, and a sense of "expensive" polish when handled well, but it's also where sibilance sits (roughly 5–8 kHz specifically) and where harshness or brittleness shows up if pushed too aggressively. A gentle boost above 10 kHz can add air without the harshness risk of boosting lower in this range — but only add it if something's genuinely missing, not as an automatic finishing touch on every master. ## Frequently asked questions ### What frequency range is most commonly responsible for muddiness? 150-500 Hz, particularly 250-500 Hz. This is where warmth and body live, but it's also the most common location for congestion in dense or AI-generated mixes -- small cuts here often do more than any other single EQ move. ### What frequency range causes harshness in vocals? Most commonly 2-6 kHz, sometimes called the presence range. It's essential for clarity and intelligibility but is also where harshness and listening fatigue show up if pushed too hard. ### Should I always add a top-end boost when mastering? No, only if something is genuinely missing. A gentle boost above 10 kHz can add air and openness, but it shouldn't be an automatic finishing touch applied to every master regardless of whether it's needed. ## Related reads - [Master your track free](/mastering) - [How to fix a muddy master](/blog/how-to-fix-a-muddy-master) - [How to fix a harsh master](/blog/how-to-fix-a-harsh-master) --- Source: https://onloopin.com/blog/mastering-eq-frequency-chart