There is never a more polarizing thread that comes up in bass forums than the one that starts with “what is better?” and ends with “Rounds or Flats?” In this article we’re going to talk about the differences between roundwound and flatwound strings, the pros and cons between the two and then offer up a couple suggestions where either of them would fit the bill nicely.
It’s always interesting: as soon as someone mentions the “flats or rounds” question, you can visualize all of the purists on both sides digging in, getting ready for the impending battle. And while neither is a true “superior” to the other, both have secured a solid place on many musician’s gigging instruments. Let’s explore the similarities and differences.
Flats: Flatwound strings are made by winding a flat, ribbon wire over either a round or hex core. From there, they are then polished to a smooth, sleek finish. This yields a string that has a deep tonal quality that sounds “dead” compared to the zing of roundwound strings. Flatwounds sport a much longer playing life, partly due to the ribbon wire having very little spaces for dirt and oils from your fingers. They also enjoy less finger noise and are very kind on your frets.

One of the big issues people mention with flatwounds is the tension. Because of the flat wire, there is much more mass compared to rounds of a comparable gauge, which can translate into more tension on the neck and a stiffer feeling string under the fingers. The other one is that sound; it’s a love/hate thing. People either love that thump that you get with flats, or absolutely abhor it.
Genres that people tend to use/recommend flats for are funk, R&B, motown and the like, although you can play them in any style you want (just ask Steve Harris).
Rounds: Roundwound strings are made in a similar manner to flatwounds, but use a round wire (most typically nickel or steel, but there are others) over either a round or hex core. This yields a very bright, snappy tone with a lot of harmonic content. Rounds by and large do not last as long as flats; one of the reasons being the spaces in the string that allow for buildup of dirt and oils. Also, they have more finger noise (especially when new) in comparison, as well as a “clack” like sound when hitting the frets.

Roundwounds tend to be very bright and zingy out of the gate, but usually break in after about two-three weeks. From there, they retain their tone until the string is dead. Compared to flatwounds, rounds have less tension on the hands, but due to the construction, can be rough to the touch.
Genres that people use rounds for normally need that aggressive bite and edge, like funk, rock, metal and anything along those lines. Again, you can technically play them in whatever genre you want.
So, which one is BETTER?
This isn’t nearly as simple. For years, I never found a set of flats I liked. I figured that “I’m just a rounds guy,” happy to play my personal set until I can’t anymore. Then, I took a gig (6 weeks! Yowza!) that had me playing electric bass with a string quartet, so I needed something that would fit tonally with the acoustic instruments. I gave flats another shot, and was very happy with the differences. Keeping in mind the tension consideration, I grabbed a set that was lighter in gauge than my usual roundwounds were. With those strung up, I EQ’d the bass to bring out the deeper tone of the flats and went to the gig. The six weeks with flats gave me a better appreciation for flats; what they do and where they’ll fit with my gigging needs.
So for me, the string that is “better” is the one that helps me fit into the gig the best. Most of the time, it’s a set of nickel-iron roundwound strings. But, I now have a bass that has a set of flatwounds on it all the time, for whenever I need it. So let’s hear from you: which side of the fence are you on, or are you one that uses both, depending on the gig?