Introduction

As guitarists, most of us have a fairly good idea of how we want to sound.
Even with all of this in mind, the most tonally savvy among us occasionally fall victim to a bad live sound. What are the reasons for this and how can we get around them?
Maybe there are a few tonal reference riffs you like to crank through your rig at every soundcheck (Unchained works for me!) – and you probably have your intended stage tone dialled in at home or in the rehearsal room already.
1. Tweak your mids

This one is incredibly common. As a guitarist, in most contexts, your instrument most naturally occupies the midrange frequencies – yes, even in extreme metal.
This is admittedly fairly broad – everything from around 3-400Hz to around 5kHz or so can be classed as some sort of midrange in a guitar context.
The middle section of this particular spectrum tends to be known by engineers as ‘mid-mids’, and as a rough guide, they mean everything from around 600Hz to 2-3kHz. The middle dial on your amp generally acts over a fairly wide band of frequencies (its Q factor) and is usually centred around the ‘mid-mids’ part of the spectrum.
A good rule of thumb is Mesa/Boogie’s middle EQ slider, which sits at 750Hz – just high enough to give your guitar sound an emotionally charged vowel content and not so high as to make it honky or harsh. Most rigs won’t include a graphic EQ or even a sweepable midrange (mid frequency) control, but it can still be helpful to visualise this part of the spectrum.
If you’re not numerically inclined, you can forget all of this and remember one thing: your guitar should primarily be occupying a similar set of frequencies to the snare drum.
Ask your drummer to hit his snare drum a couple of times. If you can tweak your midrange so that the guitar seems to sit ‘around’ the sound of that snare drum without burying it, you’ve made your first step towards great live sound.
Don’t worry too much about the vocal at this stage; a good engineer will know exactly how to compress and tweak that so that it sits neatly atop the bed of midrange you’ve just created.
2. Give your tone weight

This means different things depending on the musical context – weight and bottom-end are not always the same thing. When was the last time you heard anyone say, “Wow, what a great guitar sound; it was so bassy”?
When talking about the low-end content of a guitar sound, people tend to use words like ‘fat’, ‘big’, or ‘percussive’. As a rule of thumb, your guitar should sound deep and three-dimensional when playing an open chord, but not ‘bassy’ as such.
Generally, if you can concentrate on designing your rig so that it sounds fuller to start with, you can then dial back the extreme bottom-end so that your tone has a wide and authoritative enough soundstage without impinging too much on the bass guitar’s frequencies or muddying up the notes of an open chord.
Two useful numbers to remember if you’re ever at the controls yourself are 100Hz (this is roughly where your cabinet ‘thonk’ on palm-mutes or powerchords lives), and 300-400Hz (these are variously classed as low-mids or upper bass frequencies, and will fatten your sound).
You can also experiment with sitting your cabinet directly on a wooden floor, a flight case or even a wooden crate, which will couple your cabinet for additional resonance.
If you then find the effect is too much, dial back your bass and/or resonance, or consider carrying a small rug to fine-tune the interaction and reflectivity with differing stage surfaces; the patterned rugs you see on stage with Toto and the like are not necessarily just for visual effect!
As a rule, hollow wooden stages have the greatest potential for enhancing your bottom-end and should be treated with care.
It’s also important to be aware of the effects of a back wall or corner. Here, the potential exists for over-hyping of certain low frequencies due to standing waves – but if you’re aware of this effect, it can be cautiously used to your advantage in certain scenarios.
I once owned a Peavey Classic 30 combo which, placed a few metres from a room’s corner, instantly sounded three or four times bigger than it was. This is an effect to be used extremely judiciously, though – as a rule of thumb, your bottom end needs to be three-dimensional and authoritative yet clear.
Boom is your enemy, so generally you want to keep a safe distance away from corners and back walls.