Midrange According to Jim and Leo
Let’s turn to a cool bit of free software: Duncan Tone Stack Calculator. (No relation to Seymour D.) It’s for PC only, but Mac users can run it via a Windows shell program such as the $59 Crossover from Codeweavers. It provides visualizations of such common tone controls as those on Fender and Marshall amps, plus that mother of all stoner vee curves, the original Big Muff.
Fig. 2: The tone profile of a typical Marshall amp, with the midrange at 5, 0, and 10.
Fig. 2 shows the frequency curve of a typical Marshall amp with its mid control an noon, fully scooped, and cranked to the max. Lookit! There’s a big-ass scoop at around 800 Hz even when it’s “flat.” Hell, there’s even a scoop when it’s dimed! And when you lower the mids all the way, the distorted discus thrower in Fig. 1 starts to look like an understatement. It’s a wide scoop, too, affecting frequencies from about 100 Hz to 4 kHz — practically the guitar’s entire range.
Fig. 3: The mid cut on a typical blackface-style Fender amp is even more extreme than on a Marshall.
The typical Fender midrange profile in Fig. 3 is centered lower, around 500 Hz. Check out the middle image with its -35 dB cut, which also splashes across the guitar’s entire frequency range. It’s the Marianas Trench of midrange cuts! In fact, if you want to fake an amp sound using a direct-recorded guitar signal, your first needed adjustment is probably a similarly deep and wide EQ cut centered between 500 Hz and 1 kHz, even if you’re aiming for a fat-sounding tone.
Are Scoops for Poops?
So should you avoid scooping mids on your amp? Not necessarily. It depends on the context—duh! Judge with your ears, not the Duncan Tone Stack Calculator. But be mindful that if you nix major mids, it’s not just a bit of EQ nip-and-tuck—you’re disemboweling your tone like it’s a corpse on an autopsy table. Except amp tone controls are machetes, not scalpels.
Fig. 4: Even a humble EQ pedal provides more precise midrange sculpting than most amp EQ knobs.
There’s another way to sculpt midrange upstream from the recording input: using an EQ pedal or similar device. Some of these provide parametric EQ (which means you can specify the bandwidth of the boost or cut). Even a humble Boss GE-7 Graphic Equalizer is surgical compared to amp controls. Here the fixed bandwidth spans about an octave, as opposed to the four octaves or more affected by typical amp midrange pots. (See Fig. 4, with the resulting EQ curve approximated in Logic Pro’s EQ plug-in). Even a maximum -15 dB cut at 800 Hz (roughly the Marshall midrange frequency) is far, far subtler than zeroing an amp’s mid control.The real precision midrange sculpting is likelier to happen within your DAW—and we’ll explore those techniques in an upcoming column. Till then—it depends on the context!