String comparison
ALU Power vs Firestorm
Luxilon ALU Power against Signum Pro Firestorm: ratings, specs and which one fits your junior.
The short answer
Both are polyester strings. ALU Power leads on control. Firestorm leads on spin and tension hold. They score the same for arm friendliness (2/5). Firestorm costs less per set.
Ratings
Power
Spin
Control
Comfort
Durability
Tension hold
Ratings are on a 1–10 scale. The higher score is in bold when they differ.
Pick ALU Power if…
- You want more control (9 vs 8 out of 10)
- Best for: advanced juniors with full swings
- Best for: players who generate their own power
- Best for: tournament-level competitors
Pick Firestorm if…
- You want more spin (8 vs 7 out of 10)
- You want more tension hold (7 vs 6 out of 10)
- Your player is younger (recommended from age 13 vs 14)
- You want to spend less (from $9 vs $21 a set)
- Best for: powerful baseliners
- Best for: players seeking tour-level performance
- Best for: spin and control seekers
Specs side by side
| Spec | ALU Power | Firestorm |
|---|---|---|
| Type | Polyester | Polyester |
| Construction | Co-polyester monofilament | Round co-polyester monofilament |
| Gauges | 16, 16L | 16, 17, 18 |
| Stiffness | Medium high | Medium high |
| Set price | $21–22 | $9–12 |
| Reel price | $170–200 | $90–110 |
| Arm friendliness | 2/5 · Low | 2/5 · Low |
| Cost to maintain | 3/5 | 5/5 |
| Recommended from | Age 14 | Age 13 |
| Levels | Advanced, Elite | Intermediate, Advanced, Elite |
| Play styles | Baseliner, Big hitter, All court | Baseliner, Big hitter, All court |
| Junior tension | 48-52 lbs for juniors (vs 50-55 for adults). Start low and adjust. | 48-52 lbs for juniors. String at normal poly tensions. |
ALU Power in short
Luxilon ALU Power is the gold standard of co-poly monofilaments with an iconic pro tour pedigree. In addition to being one of the most popular choices on the ATP Tour, this string helped usher in the polyester revolution in tennis. The firm monofilament construction enables players to take huge cuts at the ball without losing control, generating massive stroke speed that produces a dangerous combination of pace and spin. Despite countless attempts to duplicate or improve it, this string remains the gold standard on the professional tour.
Firestorm in short
Signum Pro Firestorm is the ATP tour string that helped propel Matteo Berrettini into the top 10. Available in distinctive Metallic Gold, Firestorm offers the classic German polyester combination of spin, control, and durability that tour players demand. The balanced performance profile makes it suitable for aggressive baseliners who want to swing freely while maintaining placement accuracy.
ALU Power vs Firestorm: quick answers
Which has more spin, ALU Power or Firestorm?
Signum Pro Firestorm, with a spin rating of 8/10 against 7/10.
Which is more arm-friendly for a junior?
They score the same, 2/5. ALU Power is recommended from age 14 and Firestorm from age 13.
Which lasts longer?
They tie on durability (8/10). Tension maintenance: ALU Power 6/10, Firestorm 7/10.
Which is cheaper?
ALU Power costs about $21–22 a set and Firestorm about $9–12, at typical retail.
The short answer and the "pick if" lists are generated from our ratings and junior data only. Data verified 2025-01 (ALU Power) and 2025-01 (Firestorm).