Guitarists change strings when they break. Bass strings almost never break — so bassists change them when they die, and “dead” is a matter of taste that splits the instrument’s whole history in two. Before gauges and brands, settle the one decision that actually defines your sound: the winding.
Flats vs rounds: two different instruments
Roundwound strings — wrapped in ridged round wire — are the modern default: bright, growly, full of harmonics, with sustain for days. Slap, rock, funk fills, and the piano-like modern studio sound all assume rounds. Their cost: finger noise, faster fret wear, and a brightness that fades over weeks.
Flatwound strings are ground smooth. They thump. Notes bloom fast and decay politely, exactly the articulation Motown, soul, reggae, and early rock ran on — and precisely why groove-first players often go flats-and-never-back: note length becomes wonderfully easy to control when the string itself stops arguing. Flats feel stiffer at the same gauge, are kind to frets and fingertips, and famously improve with age; people gig flats older than their cars.
There is no wrong answer, but there is a right question: do you want the bass to sparkle on top of the mix or to be the floor under it? Rounds sparkle. Flats hold the floor.
Gauge and tension, briefly
A standard 4-string set runs roughly .045–.105. Heavier gauges add tension and low-end mass; lighter sets bend easier and speak faster. Change gauge and your bass will need a setup — truss rod and intonation both notice. Drop-D players (our tuner carries drop-D presets) often go a step heavier on the low string so the detuned D stays firm rather than flappy.
Fit: scale length and taper
Strings must match the instrument’s sounding length — a short-scale bass takes short-scale sets, and a 35-inch 5-string wants strings whose low B was actually designed for that length (a floppy B is usually a string problem before it is a bass problem; see the scale-length guide). Through-body stringing needs extra winding length, so check the packet. The double bass is its own universe of gut, steel, and synthetic-core strings at another price class entirely — buy those with advice, not on impulse.
When is a set actually dead?
When it stops doing what YOU bought it for. Rounds are dead when the zing is gone and intonation drifts — weeks to months, depending on hands and gigs. Flats are “dead” on day one by rounds standards and then stay usefully identical for years. A fair test: fret the octave at the twelfth against the open string on each string; when they argue, or when wiping the strings down audibly revives them, it’s time. New set on? Stretch each string, retune with the tuner until it holds, and give it a night of drills to settle in.