How to EQ a guitar amp
Set the gain first, then start with bass, middle and treble at 5 and move one control at a time. Cut the band that bothers you before boosting the one you want, because boosting raises the overall volume and tricks you into thinking the tone improved when it only got louder.
Guitar amp EQ is subtractive work. The amp is already making every frequency it is going to make, and the tone controls only decide which ones survive.
Set the gain before you touch the EQ
Gain and EQ are not independent. The distortion stage generates harmonics from whatever reaches it, so changing the gain changes the frequency content the tone stack is then working on. EQ dialled in at a low gain setting falls apart when the gain goes up.
Get the amount of dirt right first, playing the part you actually intend to play. A chord voicing that sounds tight at low gain can turn to mush at high gain, and that is a gain problem no amount of EQ will fix.
Start flat, then cut before you boost
Put bass, middle and treble at 5 and listen before you change anything. Most amps are voiced to sound reasonable there, and it gives you a reference to move away from.
When something bothers you, find it and cut it rather than boosting its neighbours. Cutting keeps the overall level roughly where it was, so you hear the change in tone rather than a change in loudness. Boosting does the opposite: it raises the volume, and louder reliably sounds better for the first few seconds.
One control at a time, and move it far enough to hear it. Small simultaneous nudges to three knobs tell you nothing about which knob did what.
What each band is actually doing
Bass controls the weight and the body. Too much and the low strings smear together, especially under distortion, because the distortion stage multiplies the low frequencies into everything else. High-gain rhythm tones almost always want less bass than feels right in a quiet room.
Middle is where the guitar lives. It carries note definition and it is the range that decides whether a part is audible with a band playing. Cutting it makes a guitar sound heavier on its own and disappear completely in a mix.
Treble sets the attack and the string noise. It is also the first control to turn harsh, and how harsh depends on volume: a treble setting that is bright at bedroom level can be painful at stage level.
Presence sits above treble and works on the power section rather than the preamp, which is why it behaves differently from the other three. See the guide on what each amp control does for the detail.
EQ at the volume you will actually play at
Human hearing is not flat, and it is less flat at low volume. Bass and treble both fall away as level drops, which is why a tone dialled in quietly sounds thin and shrill when it is turned up, and a tone dialled in loud sounds dull and boomy in a bedroom.
If you rehearse loud and practise quiet, you need two settings. This is not a failure of the amp.
Where the general method runs out
Everything above gets you a good sound. It does not get you a specific sound, because the same target lands at different knob positions on different amps: the tone stacks are voiced differently, they sit at different points in the circuit, and a 5 on one amp is not a 5 on another.
That translation is what Tonelify does. Name the amp you own and the tone you are chasing, and it returns the positions for that amp's actual controls rather than a generic curve.
Common questions
Should guitar amp EQ be set flat?
Flat is a starting point, not a destination. Set bass, middle and treble to 5, listen, then cut whatever bothers you. Most amps are voiced to sound usable at 5, which makes it a useful reference, but no amp is designed to be left there.
Do you set gain or EQ first on a guitar amp?
Gain first. The distortion stage generates harmonics from whatever reaches it, so changing the gain changes the frequency content that the tone controls then act on. EQ set at low gain will not hold up once the gain is raised.
Why does my amp sound different at high volume?
Human hearing is less sensitive to bass and treble at low volume, so a tone dialled in quietly sounds thin and harsh when it is turned up. On valve amps the power section also compresses as it is pushed, which changes the response on top of that. Dial in at the volume you will actually play at.
Settings for your own amp
This guide covers what is true of every rig. For a specific song on a specific amp, Tonelify reads the documented chain behind the recording and returns gain, bass, middle, treble and presence values for the controls your amp actually has. Free for 7 days, no charge until the trial ends.
Keep reading
- What every knob on a guitar amp doesGain sets distortion, volume sets level, master sets power-section drive, presence works above treble. What each guitar amp control does and which ones interact.
- What does scooping the mids mean?Scooped mids means cutting the midrange and boosting bass and treble. Why it sounds enormous on its own, why it disappears with a band, and where it is genuinely correct.
- Why your amp doesn't sound like the recordRecords are layered, compressed, mic'd and mastered. What of a recorded guitar tone is reachable on your own amp, what is not, and where the remaining distance comes from.