It’s a useful reset to remember that a synth filter and an EQ filter are the same maths wearing different clothes. On an EQ, resonance screaming at self-oscillation is a mistake. On a synth, it’s half the reason people still chase old Moog and 303 emulations. The parameter’s identical – cutoff, slope, Q – only the intent changes.
→ Glossary: Resonance
From the Studio
Hunting hum by ear
Before you reach for an auto-notch tool, it’s worth learning to find 50 Hz hum by ear – sweep a narrow bell filter with a big cut slowly through the low end and listen for where the hum drops out. It’s a five-minute skill that saves you from notching the wrong frequency and taking a bite out of something that mattered.
→ Community: discuss ground loop and hum fixes on our Music Community boards
From the Studio
Cut narrow, boost wide – until it isn’t
The “cut narrow, boost wide” rule of thumb holds up most of the time, but it’s a starting point, not a law. For example, an exception might be when a piano and lead vocal are fighting in the low mids. The piano sounds warm on its own, but sitting together in the full mix, the vocal lacks clarity. Apply a wide EQ cut of about 2 dB centred at 300 Hz on the piano with a broad Q of around 0.7. Treat the rule as: where you start turning the Q knob, not where you stop.
→ Glossary: Q (Quality Factor)
From the Studio
The HPF you don’t notice is doing its job
The best use of a high-pass filter is usually the one nobody can hear happening. If a listener can point to “the bit where you filtered it,” the slope was probably too steep for the source. On most acoustic sources, I reach for a gentle -6 dB/oct first and only go steeper if there’s a specific problem to solve – mud, rumble, a room mic picking up traffic noise.
→ Forum: share what you’re rolling off and why in the Recording & Production board
From the Studio
The cut-off isn’t where cutting starts
This one trips up a lot of people the first time they hear it properly explained: set your HPF to 80 Hz and the filter is already three decibels down at 80 Hz, not just starting to think about it. Once you know you know. It is so easy to spend a stupid amount of time chasing “missing” low end on a bass track before realising the roll-off began a full octave above the point where you thought it kicked in. Worth remembering next time a cut sounds more aggressive than the number on the dial suggests.
→ Glossary: Cutoff Frequency / Half-Power Point
From the Studio
Too Much Reverb
Less experienced recording engineers and music producers tend to use too much reverb and to use it inappropriately. Using reverb in the wrong way can create very muddy mixes with vocals that lack punch. You have several options to help you avoid these issues.
