Pricing and availability

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Sweetwater
5.0 (9)
$59.99 $44.99 $15.00 · All time low
Guitar Center
5.0 (8)
$42.39
Amazon
4.7 (2493)
$40.02 New
$35.12 Used (Very Good)
Musician's Friend
4.0 (3)
$44.99 $42.13 $2.86 · All time low

Price History

Based on price data from 4 merchants for "Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings (40-95)". Prices shown reflect NEW condition. Tracking began Apr 2, 2026.

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Description

Discover a new dimension of tone with Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings (40-95). Crafted for bassists who crave the silky feel of traditional flatwounds without sacrificing the dynamic range of roundwounds, these strings are a game-changer. The proprietary blend of iron and cobalt sets the stage for a magnetic attraction that maximizes the response from your pickups, offering an impressive output that’s both punchy and articulate.

With a SuperBright Cobalt ribbon wrap, these strings shine in both sound and appearance. The Cobalt underwraps enhance clarity and output, bringing out the best in your bass lines. Whether you're slapping, picking, or plucking, you'll appreciate the optimal core-to-wrap ratio that delivers a comfortable tension, making fast passages and intricate techniques feel effortless.

These strings are designed to provide a robust low-end with clear definition, a focused midrange, and shimmering highs that don't overwhelm. Plus, they last longer than conventional strings, ensuring you have a reliable set for countless gigs and sessions. Perfect for both fretted and fretless basses, these strings offer a versatile sound palette that can suit any genre.

Key Features:

  • Gauges: .040, .060, .070, .095
  • SuperBright Cobalt ribbon wrap for superior sheen and feel
  • Cobalt underwraps for enhanced clarity and output
  • Proprietary iron and cobalt blend for increased magnetism with pickups
  • Optimal core-to-wrap ratio for comfortable tension and playability
  • High output with beefy lows, defined mids, and crisp highs
  • Longer-lasting than conventional strings

Product specs

Guitar Type Electric Bass
Number of Strings 4
Coated No
Gauges .040, .060, .070, .095
Winding Type Flat Wound
Core Material Hexagonal Steel
Winding Material Iron/Cobalt Alloy
Scale Length Long

FAQs

What are the tonal characteristics of Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings?

These strings provide a smooth, mellow tone typical of flatwounds, enhanced by the cobalt alloy for increased clarity and output. They offer a balanced sound with reduced finger noise, making them suitable for both live performances and studio recordings.

Are Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings suitable for long-scale basses?

Yes, these strings are designed for long-scale basses, ensuring proper tension and intonation across the neck.

How do Ernie Ball Extra Slinky Flatwound strings compare to roundwound strings in terms of feel?

These flatwound strings offer a smoother feel and reduced finger noise compared to roundwound strings, making them ideal for players seeking a more comfortable playing experience with less string squeak.

What is the gauge of the Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings?

The gauge of these strings is .040, .060, .070, .095, providing a light tension that is easier on the fingers and suitable for fast playing styles.

Do Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings require a special setup?

While they generally fit most basses, you may need to adjust your instrument's setup, such as the truss rod or action, to accommodate the lighter tension and ensure optimal playability.

IvanBassist

IvanBassist

Ernie Ball Cobalt Flats | DEMO

Video thumbnail for Ernie Ball Cobalt Flats | DEMO by IvanBassist

Ernie Ball Cobalt Flats | DEMO

IvanBassist

IvanBassist

Video thumbnail for Why I switched to Ernie Ball Slinky Cobalt  Flatwound Bass Strings by Searcy String Works

Why I switched to Ernie Ball Slinky Cobalt Flatwound Bass Strings

Searcy String Works

Searcy String Works

Reviews

PROS

  • Unique blend of bright, articulate tone with flatwound feel

  • Softer tension for comfortable playability

  • Smooth texture enhances playing experience

  • Suitable for various genres, from jazz to rock

  • High midrange content offers distinctive sound

  • Maintains tonal balance across strings

  • Consistent quality without defects

  • Reasonably priced compared to high-end competitors

  • Versatile for both fretted and fretless basses

CONS

  • Occasional rust found on some strings

  • Coated with substance that may leave fingers oily

Owner Insights

We analyzed real musician discussions from forums and Reddit to find what players love, question, and tweak about Ernie Ball Extra Slinky Cobalt Flatwound Bass Strings (40-95).

Comparisons

  • Ernie Ball Cobalt Flats are reported as bright as D’Addario Chromes, with a more mid-focused tone, making them among the most aggressive flatwounds available.

    Source
  • Cobalt Flats are likened to a deader roundwound sound, but remain brighter than most flatwounds, making them a unique choice for those avoiding roundwounds.

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  • Unlike smoother flatwounds like LaBellas, Cobalts offer a more textured feel and are not mirror-smooth.

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User experience

  • Users have noted that the Ernie Ball Cobalt G string may have intonation issues over time, suggesting potential durability concerns.

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  • Owners report that the strings can make the room and hands smell like metal until well broken in.

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  • Once installed properly, these strings can last up to 10 years, improving in sound quality over time.

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Use cases and applications

  • The strings are described as melting-face bright on a par with other aggressive flatwounds, suitable for those seeking an intense flatwound experience.

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  • These strings are preferred by some for aggressive basses like the Stingray to tame brightness while retaining clarity.

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  • Some users prefer Cobalt Flats for their unique slap tone, which avoids the dull thud typical of other flatwounds.

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Setup and maintenance

  • Flats like Ernie Ball Cobalts normally last longer, but one user experienced faster wear, indicating a possible inconsistency in longevity.

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  • Cobalts are initially grabby for flatwounds and come coated with machine oil, requiring a wipe-down with alcohol or WD40 before installation.

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  • Crimp the string a few millimeters past the windings before trimming to prevent the core from slipping and causing a dead string.

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Features and functionality

  • The Cobalt Flats use a cobalt alloy outer wrap, which is more magnetic than steel or nickel, resulting in higher output and brightness.

    Source

Mods and upgrades

  • Users suggest Babicz bridges as an upgrade for basses with vintage-style saddles for improved stability and tone.

    Source

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