Action
It’s a word long bandied about in guitar circles, but what does ‘action’ actually mean?
Starting out as a guitar player, this writer quickly became aware of the term ‘action’. More experienced guitar-playing friends would blithely declare that one guitar had ‘great action’ while another one had ‘poor action’. Or even more broadly, that Gibsons had better action than Fenders. It didn’t make much sense at the time –and decades later it still doesn’t. Back then, ‘great action’ invariably meant low-set strings, which was associated with easy playability. But optimum string height and playability are really down to player preference. String benders often like a guitar that feels slinky and facilitates finger vibrato, while others prefer a bit of resistance and fight.
Two guitars with identical string-height settings can still be very different, with one feeling loose and freed up while the other is stiffer. Action and playability are interrelated, but neither can be assessed simply by measuring the gaps between strings and the top of the 12th fret. It really involves a combination of different factors that contribute to the overall feel and tone and allow you to play to the best of your ability.
Clearly, we all have different playing styles and use our guitars for different applications. You wouldn’t expect your acoustic to play like a Les Paul any more than you’d expect a 1960s-style Strat to play like an Ibanez JEM. Taking a holistic overview, then, we think that action is really about general playability, rather than simply string height, and the terms can be used interchangeably. So let’s identify the areas where tweaks can be made, discuss some of the structural issues that limit scope for adjustment, and consider some alternative setup ideas.
Light Relief
There are three main areas that can be adjusted to change string height: the bridge, nut slots and neck relief. Although plenty of us might feel inclined to head straight to the bridge, the starting point should actually be neck relief.
If you visualise the arc of a vibrating string, the displacement is greatest halfway along the length and it’s lowest near the bridge and nut. To ring cleanly, the string needs sufficient space to prevent contact with the frets –and that’s why the truss rod is usually slackened to allow the neck a very slight up-bow under string tension. If the neck is flat or it’s pulled into a back-bow due to excessive truss rod tension, the strings will buzz and rattle when they’re adjusted for a medium or low action.
Agap of around 0.02 inches is fairly typical, but you can judge it by using your eyes, ears or feeler gauges. If the strings seem low and are buzzing around the lower frets, the neck probab
