Best Flatwound Bass Strings (our top pick)
Ernie Ball Flatwound Slinky Bass
For the price, the Ernie Ball flatwound bass strings are good value, giving you a longer lifespan - similar to a coated string - and smoother movement with a balanced tone profile.

SUMMARY: A roundup of flatwound bass strings that we've used, tested and researched thoroughly, while also consulting the opinion of multiple enthusiasts and professionals. All of these bass string sets use a flatwound winding design making them smoother feeling, easier to play and longer lasting.
Bass strings don't have a lot of distinct features, especially considering that they're something you feel more than hear. Outside of gauge, coating and where they land on the EQ spectrum, the biggest distinctive feature that bass guitar string buyers should consider is the winding of the string, which is usually one of the following:
- Roundwound
- Halfwound
- Flatwound
While roundwound strings are far more common, flatwound strings - especially for bass sets and heavier gauges - are easier to play because they're smoother. They actually feel flat and cause less friction against your fingers.
Here's a look at the flatwound string design:

Design of a flatwound string winding.
Roundwound strings have more of a curve, which makes them more susceptible to corrosion and gives them a grittier feel on your fingers. In this roundup we'll cover a few flatwound bass strings that we've used and liked.
If you want some other options to consider, be sure to checkout our top guitar strings roundup page.
1. Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings

The Slinky bass strings are on the lighter side and have brighter, more clear tone. They feel noticeably smoother than regular Slinky bass sets and the Cobalt winding adds a unique element that's subtle but still noticeable. Sliding is easy, similar to vertical movement on coated Elixir bass strings.
Through a GarageBand modern stack bass amp model, the clarity was definitely noticeable, though you could still get that thick, rumbling boom that you expect out of clean bass strings.
When we set the amplifier EQ levels to neutral (all at 12 o'clock), the brightness of the tone did come through pretty clearly.
If we wanted a deeper, more bass-like tone, it was easy to dial that in with the amp's bass control or the graphic EQ. Overall, the strings sound great and produce a balanced tone that's moldable to a wide range of styles. They also feel smooth and easy to play, like you would expect from a flatwound or coated string set.
IDEAL FOR: Brighter tone and faster playing
TONE
n/a
LIFESPAN
n/a
PLAYABILITY
n/a
REPUTATION
n/a
THE PROS
THE CONS
2. Thomastik-Infeld JF344 Flatwound Bass Guitar Strings

The "jazz" designation shouldn't restrict the string's style, because these are just fantastic bass strings all around. They play really smooth and have a softer response than the Ernie Ball set, almost like the deep rumble of an upright bass. Going from a roundwound D'Addario set to these, we noticed a considerable bump in tone quality, while also getting a much "bassier" sound out of the high-register notes.
One significant downside to these strings:
They are way more expensive than all flatwound bass string options. Thomastik-Infeld is an Austrian company and certainly a more hands-on operation than Ernie Ball, but it's still hard for us to take the price tag.
At the same time, this set's review section is glowing, to say the least. A lot of verified purchasers say it changed the quality level of their bass entirely.
You get what you pay for.
IDEAL FOR: A high-end choice, deeper rumbling tone, good for recording and performing
TONE
n/a
LIFESPAN
n/a
PLAYABILITY
n/a
REPUTATION
n/a
THE PROS
THE CONS
3. Fender Stainless Flatwound Bass Strings

One issue we have with Fender's promotional material is that there are some listings that say the stainless steel winding gives you longer life. While we haven't used these strings long enough to verify this one way or the other, there's little reason to believe that a steel winding material would be much better or worse than a nickel winding, like we see in most bass string sets.
The two things that will extend string life is coating - like the Elixir strings - and a flatwound string design. Whether it's steel or nickel shouldn't matter.
Fender does seem to experiment more with winding material than other bass string companies with a number of different options, namely:
- Nickel-plated steel
- Phosphor bronze
- Stainless steel
- Roundwound
- Flatwound
- Taperwound
However, these strings - like the rest in this list - are flatwound which means less dirt getting in between the winding and less friction with your finger tips. That alone should extend the life of the string beyond what you'd expect out of a roundwound bass string set.
We found the tone of this set to be good, though not particularly memorable compared to other flatwounds. It's clean and somewhat bright, though seems to be mostly at the mercy of your amp's EQ. With all the knobs at 12 o'clock, the tone sounded pretty much as you would expect, playing through a Fender Jazz bass.
The price point is great, which means we can recommend them as a good value buy.
They won't blow you away, but there aren't any identifiable weak spots either.
IDEAL FOR: An economical choice, good for beginners
TONE
n/a
LIFESPAN
n/a
PLAYABILITY
n/a
REPUTATION
n/a
THE PROS
THE CONS
4. Rotosound SM77 Monel Flatwound Hybrid Bass Strings

The Rotosound strings have the same boutique feel as the Thomastik-Infeld sets, yet are much cheaper. We don't like the tone as much because it's not as thick and rumbling, leaning instead into the chime-friendly, harmonic bass sound. Highs are really high and a great fit for slap bass, though not as ideal for achieving a more modern bass EQ.
It reminded us a lot more of a tone like Les Claypool or even Flea from the Red Hot Chili Peppers. It's a string that you hear more than you feel.
Still, that's what some people want out of their strings.
If that's your context, the tone is extremely crisp and satisfying while still delivering the smooth feel and quicker movement that's typical of the flatwound string design.
IDEAL FOR: Crisp, brighter tone
TONE
n/a
LIFESPAN
n/a
PLAYABILITY
n/a
REPUTATION
n/a
THE PROS
THE CONS
How We Chose the Best Flatwound Bass Strings
Our review and rating structure relies on my own personal experience as well as other bass players and guitarists that I consult with.
Moreover, we also look to community consensus as well as actually testing the flatwound bass strings that were most often used and purchased on the open market.
In most cases, we use Amazon.com to determine which products are the most current, relevant, and popular.
Broadly, we can also look at a number of well-known quality indicators.
These would apply to all bass strings, not just flatwound and include the following:
- String Gauge: The size of the string, usually given for each one in a pack
- Bright EQ: Bass strings that respond better to the mid and treble end of the EQ spectrum
- Low EQ: Bass strings that respond better to the low end of the EQ spectrum
What do bass players need from a good set of strings?
- Balanced Tone: Bass strings, flatwound or otherwise, should sound good on both low and high EQs. Depending on style, you might want your string to lean more towards the low-end of the frequency spectrum, especially for more modern rock playing styles, or the high-end for more artistic, melody-focused bass playing.
- Playability: Flatwound bass strings are prized largely because they feel smoother and are easier to play. This is especially important concerning bass strings since they are so much larger.
- Lifespan: All strings corrode and wear out over time, but coated and flatwound strings tend to last a lot longer than average because it's harder for dirt to get into the middle of the wound material.
Other Important Considerations
Bass strings are a simpler purchase. As we've mentioned, most sets are harder to distinguish from a tone perspective. Instead, you're dealing primarily with brand loyalty and a lot of subjective preferences. However, there are some additional things to consider, regardless of which bass string set you end up with.
How long do flatwound bass strings last? How often do they need to be changed?
The lifespan of flatwound bass strings is similar to that of the Elixir coated bass string, which is somewhere around 10 to 12 months, depending on how picky you are and how much you play. We've seen flatwound bass strings last a long time, so if this is a concern for you, it should definitely make the flatwound option more appealing.
They last longer because the design makes it harder for dirt to get into the winding and build up. All of this depends, of course, on a number of variables, primarily the amount of time you spend playing.
What are some signs that my bass guitar strings need changed?
One of the most obvious signs your bass strings are past their prime is that they'll leave a corrosion and weird smell on your finger tips.
You'll notice a visible corrosion, staining and reduction in tone quality at approximately the same point in the string's life cycle. You might also have less resonance and less body to the string's sound.
As previously mentioned, this is going to be much less frequent with a flatwound bass string design.
Conclusion & Questions
These are flatwound bass string sets that we know and have first or second hand experience with.
We recommend them based on that trust, which is not to say that there aren't other good options available. This is just what we would (and do) recommend to people who ask us in a face-to-face conversion, "Which flatwound bass strings have worked for you?"
If you have questions about them or even about bass strings we haven't mentioned in this list, feel free to leave those in the comments section below.
Reference
- Fender University, How to String a Bass Guitar, Video
- ErnieBall.com, Company String Page, Manufacturer Website
Related Articles
Written by Jasmine Wong on Bass and Roundups
Written by Bobby on Bass and Comparisons

Been using D’addario Flats forever ( surprised you didn’t mention them as they make more strings than anyone) but just recently changed Fender since they are less expensive and made by D’addario.
what do you think about Olympia FLS 4B-45100 bass guitar strings
I honestly haven’t heard of them. Looks like some kind of a boutique brand?
Thanks all the info on flatwounds. The Rotosound 77 mellow out after broken in and lose that bright edge. For my ears, that’s when the real magic in sound happens. I have thrm on a fretless Fender j, and I’ve had then on a P bass.
GHS Precision Flats 45 -105 are worth a try. Well balanced, full, and rich sound. Long lasting too. Easy on the picket book.
Thanks for sharing, Ryan.
*Humid climate, not warm.
Stainless steel strings are considered to last much longer than nickel strings because stainless steel does not corrode as readily as nickel. That said, when considering the lifetime of a string, corrosion is not a huge factor unless you live in very warm climate, because it would take years for properly stored strings to corrode much. At least, in my experience– I don’t live in a particularly dry place but my nickel strings do not corrode.
*Humid, I meant, not warm.
When I decided to put a set of flats on my Pbass the first ones I tried were the DR’s. I hated them. The E strung was just a thump with no definition. So off they came and I started looking for a set in the .045-.100 range figuring the the lighter gauge would have more balance and definition. I found a set of fenders in this range and they made all the difference. The notes on the E string were clearer with more definition. I liked it so much I started looking for a set of rounds in the same range to put on my Alembic bass. Made a big difference there too. Combined with a 15” speaker the lighter gauge still moves plenty of air so as not to miss the heavier .105 E string.
Thanks for sharing, Pete. Personally, I would have started with the Ernie Balls. Glad you got it worked out though.
Fender, D’Addario, and the Ernie Ball Group series flats are all pretty similar to each other. Not exactly the same, but close. They’re nice if you get them in a light or medium-light gauge.
The Slinky Flatwound are a bit brighter than those, but not as smooth.
I have and generally use DR Legends and I like ’em but might give the Ernie Ball a try since I use their Cobalts on some of my other basses.
Good call. Thanks for sharing, Cole.