Ernie Ball Cobalt 5-String Regular Slinky Bass Strings 45-130 - Clear

In this review we look at the Ernie Ball Cobalt 5-String Regular Slinky Bass Strings, a set aimed at bassists who want a brighter, more responsive voice without sacrificing low-end weight. The bottom line: these strings are best for players seeking enhanced output and harmonic clarity, particularly if the B string needs to read loud and defined in a mix. The single biggest reason to buy is the alloy - cobalt - which increases magnetic interaction with pickups and yields a clear, punchy tone with improved harmonic response.

Key Features

• Gauges: Set includes.045,.065,.080,.100,.130 for balanced tension across five strings.
• Cobalt alloy: The cobalt formulation provides a stronger magnetic relationship with pickups for increased output and tighter note definition.
• Extended dynamic range: Players get clearer highs and a beefier low end that responds well to attack and touch variation.
• Feel: The strings are described as soft and silky to the touch, which makes bends and expressive playing easier.
• Intonation: Designed to hold precise intonation so notes stay accurate across the fingerboard.

Who It's For

These strings suit session bassists, rock and metal players, and anyone who needs a loud, defined B string and a bright top end that cuts through mixes. The increased magnetic response makes them especially useful with passive and active pickups that can take advantage of stronger string-to-pickup interaction.

Players who prioritize extreme longevity or who frequently gig in corrosive environments should be cautious; some users report premature breakage on heavy-use rigs. If durability under heavy live use is your top priority, consider comparing with other long-life coatings or swapping strings more often.

Pros & Cons

Pros

• Clear, bright tone with a pronounced low-end growl and punch on the B string.
• Enhanced output and harmonic response thanks to the cobalt alloy.
• Soft, silky feel that makes bending and fretting comfortable and helps build callouses.
• Good value for the sound quality delivered.

Cons

• Some customers report limited durability with strings breaking after a couple of weeks under heavy use.

Specifications

Brand	Ernie Ball
String set type	5-String Regular Slinky Bass Strings
Gauges	.045,.065,.080,.100,.130
Material / Alloy	Cobalt alloy
Tone characteristics	Extended dynamic range, crisp highs, increased low end
Part number	2736

Our Verdict

The Ernie Ball Cobalt 5-String Regular Slinky is a strong choice for bassists who want a brighter, punchier sound with a full low end and improved harmonic clarity. They represent good value for players who prioritize tone and feel, though those who need maximum longevity may want to change strings more frequently or test durability in their own setup before committing to large quantities.

Frequently Asked Questions

Are these strings suitable for active pickups?
Yes; the stronger magnetic relationship of cobalt works well with both passive and active pickups and generally increases output and clarity.

What gauges are included in this set?
The set includes.045,.065,.080,.100,.130 gauges for a balanced 5-string tension.

Do they feel different to play than nickel or stainless strings?
Yes; players report a softer, silkier feel and easier bending compared with some nickel or stainless sets, while offering brighter tone and more punch.