Guitar String Gauges: Do They Matter?
Affecting the tone
Generally speaking, the thicker the strings, the tighter and more focused the tone gets. There will also be more tension involved, meaning that the strings have more energy and that they reach their peak frequency quicker. Or, another way to put it – they'll be less floppy. Thicker strings would usually also give a bit more sustain due to containing more energy.
But, of course, this is if we're talking about the same tuning. If you would downtune, then some of those thicker strings might feel the same as regular strings, like .010 gauge for example, in normal tuning. It's not unusual to see guitar players using a bit thicker strings on guitars which are in lower tuning. It is usually recommended to use heavier strings if you're going two, three, or more semitones lower than the E standard.
Then there's also scale length, meaning that those long scale baritone guitars might pair better with heavier sets of strings.
Either way, the longer the scale length and the lighter the gauge, there's more chance that your strings will feel like rubber, making it more difficult to control your playing and tone.
Acoustic or electric
Another thing that should be noted here is that there are so many different factors that influence your tone on an electric guitar these days that the string gauge might not have much of an impact on it. Different pickups, pedals, effects processors, amps, amp modelers – they all shape the tone that it's sometimes difficult to hear any difference in tone if you try out different string gauges. There was a consensus back in the day that thicker strings will make your tone bigger. But then, at the same time, we have Billy Gibbons, who has one hell of a big chunky tone, and yet he uses .007 gauge strings.
If we're talking about acoustic guitars, then thicker strings will definitely have more of an impact on the tone, making you louder, giving you more sustain, and even impacting tone shape more than on electric guitars. But if you're playing through the piezo pickup on your acoustic, then there's probably no need to obsess too much about having thicker strings.
If you're playing completely unplugged and along with wind instruments, then it might be a good idea to get heavier strings for your acoustic.
Of course, there's always the question of playability involved. It's pretty easy to realize that lighter strings will require less effort to play on, especially if there's a lot of bending involved. But of course, some players might find light strings too difficult to play with as they might press them too hard on the fretboard and make them slightly sharp, ultimately sounding horrible in the process.
You'll most often see those virtuoso technical players relying on lighter strings, which is not unusual as they allow them to do all that stuff with less effort.
While we're mostly used to standard sets of different thickness – like .009, .010, .011, and so on – there are also various mixed or completely custom sets these days. It's not unusual to see lead players using lighter E, B, and G strings from a .008 set, while the bottom three are from a thicker set, like .010 or even a .011. Back in the day, it was difficult for many players to get those lighter strings and some have even resorted to using banjo strings, like Chuck Berry. Some were even forced to accommodate to certain sets of strings since there were no other options in cities or regions they lived in. Whereas today, it's pretty easy to get almost any desired string gauge for a decent price.
It's up to you
At the end of the day, the decision comes down to you – the guitar player. Depending on various factors, some might prefer thicker strings to lighter ones and would feel more at home with bending .012s compared to .008s. It's also not rare to see some guitar greats setting different sets of strings for different guitars, even if they're in the same tuning. At the same time, you'll also see guitarists using very light strings and having huge tone, including Black Sabbath's Tony Iommi who has been playing .008 gauge strings for the most of his career.