Guitar Tone Explained Alnico Vs Ceramic Pickup Magnets

Alnico is an alloy composed primarily of aluminum (Al), nickel (Ni), and cobalt (Co)—hence its name. Some variants also contain copper (Cu), while others (like Alnico 6, 8, and 9) include titanium (Ti). Alnico magnets are classified into grades (1–9) based on composition and manufacturing processes. In electric guitar pickups, Alnico 2, 3, and 5 were among the earliest widely used grades, followed by Alnico 4 and 8. More recently, Alnico 6 and 9 have entered the market.

Each Alnico grade offers distinct magnetic properties and tonal characteristics. A pickup's output power depends on multiple factors, with magnet strength (measured in Gauss) being critical.

Composed of 10% aluminum, 19% nickel, 13% cobalt, and 3% copper (with the remainder being iron), Alnico 2 pickups deliver moderate output, rich midrange, slightly rolled-off highs, and excellent sustain. Initially popular in early humbuckers, Alnico 2 was not used in Fender single-coils until later. Today, it remains a staple for blues/rock rhythm tones due to its warmth and balanced dynamics.

Unique for its cobalt-free composition (12% aluminum, 25% nickel, 3% copper), Alnico 3 has the weakest magnetic strength among Alnico grades but compensates with a distinctive voice. Its mid-low emphasis produces a raspy character with subdued highs and exceptional sustain. High-gain settings yield a fierce growl, while cleaner settings excel in jazz, funk, or reggae. Rare in modern production, Alnico 3 is now primarily found in high-end Gibson Custom Shop models.

Introduced in the 1970s, Alnico 4 (7% aluminum, 14% nickel, 24% cobalt, 3% copper) bridges the gap between Alnico 2 and 5. With higher output, brighter tones, and improved clarity, it handles classic rock, blues, and hard rock effortlessly, offering vintage grit under distortion and bluesy warmth at lower volumes.

The most widely used magnet in pickups, Alnico 5 boasts strong lows and highs, deep mids, and exceptional clarity. Its high magnetic strength slightly reduces sustain but allows versatility across genres—from vintage to modern styles. Commonly found in humbuckers, its ubiquity comes at the cost of distinctiveness.

With 7% aluminum, 15% nickel, 35% cobalt, 4% copper, and 5% titanium, Alnico 8 shares traits with ceramic magnets: high output, piercing highs, and clarity. Ideal for high-gain applications, its dry clean tones respond aggressively to pick attack. Often used in bridge pickups.

Rarely used, Alnico 6 sits between Alnico 5 and 8 in output. It emphasizes lows while retaining mids' hollow quality, producing a darker, modern tone.

Matching Alnico 8's power but with fewer highs and more mids, Alnico 9 blends vintage and modern traits. Its composition mirrors Alnico 8 but differs in manufacturing, making it ideal for pairing with Alnico 4.

Ceramic magnets deliver roughly double the output of Alnico 8, with crushing lows, scooped mids, and aggressive highs. Their icy clean tones thrive under extreme distortion, making them the top choice for metal.

Volume directly impacts tone and output. For example:

• Stratocaster single-coils: Six cylindrical magnets totaling ~1,850 mm³
• Humbuckers: One rectangular magnet (~2,500 mm³)
• P90s: Two magnets (~5,000 mm³ combined)

Seymour Duncan's Invader pickup, with three magnets (including an oversized center magnet), reaches ~7,000 mm³—demonstrating how size scales with output.