String comparison
X-One Biphase vs NXT
Tecnifibre X-One Biphase against Wilson NXT: ratings, specs and which one fits your junior.
The short answer
Both are multifilament strings. X-One Biphase leads on power, comfort and tension hold. They score the same for arm friendliness (5/5).
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 X-One Biphase if…
- You want more power (9 vs 8 out of 10)
- You want more comfort (10 vs 9 out of 10)
- You want more tension hold (7 vs 6 out of 10)
- Best for: players wanting natural gut feel without gut price
- Best for: those with arm issues or tennis elbow
- Best for: flat hitters with slow to medium swing speeds
Pick NXT if…
- Best for: players with arm issues or tennis elbow
- Best for: young juniors needing comfort
- Best for: players with slow to moderate swing speeds
Specs side by side
| Spec | X-One Biphase | NXT |
|---|---|---|
| Type | Multifilament | Multifilament |
| Construction | High Heat Capacity (H2C) fibers with Biphasic trimerization process and polyurethane immersion | 1,600 fibers with polyurethane resin coating |
| Gauges | 16, 17, 18 | 15L, 16, 17 |
| Stiffness | Low | Low |
| Set price | $18–22 | $18–20 |
| Reel price | $200–250 | $180–220 |
| Arm friendliness | 5/5 · Excellent | 5/5 · Excellent |
| Cost to maintain | 3/5 | 3/5 |
| Recommended from | Age 8 | Age 8 |
| Levels | Beginner, Intermediate, Advanced | Beginner, Intermediate, Advanced |
| Play styles | All court, Serve and volley, Touch player | All court, Serve and volley, Touch player |
| Junior tension | 52-56 lbs for juniors. Holds tension well for a multifilament. | 52-56 lbs for juniors. Multifilament is very forgiving. |
X-One Biphase in short
X-One Biphase is Tecnifibre's premium multifilament that combines their best technologies into a single string. The patented Biphasic process with visible marks extends string life by 20% while the H2C fibers allow extreme temperature treatment during manufacturing. Multifilament fibers are immersed in polyurethane for shock absorption and optimum comfort. Many users say "I've never tried natural gut, but X-One Biphase is what I imagine it would feel like." Easily one of the more powerful multifilaments available with cloud-like comfort even at higher tensions.
NXT in short
Wilson NXT is the most popular multifilament string on the market. The incredible feel and outstanding comfort comes from its construction of 1,600 fibers that create a cushioned response. The polyurethane resin coating seals the delicate fibers and enhances durability while softening the feel. NXT offers a 10% increased sweet spot over traditional synthetic gut and 74% less vibration. Players with slow to moderate swing speeds will benefit from the power of NXT. Tennis elbow sufferers looking for a softer, more comfortable string should give NXT a try.
X-One Biphase vs NXT: quick answers
Which has more spin, X-One Biphase or NXT?
They tie on our spin rating (5/10 each).
Which is more arm-friendly for a junior?
They score the same, 5/5. X-One Biphase is recommended from age 8 and NXT from age 8.
Which lasts longer?
They tie on durability (5/10). Tension maintenance: X-One Biphase 7/10, NXT 6/10.
Which is cheaper?
X-One Biphase costs about $18–22 a set and NXT about $18–20, at typical retail.
The short answer and the "pick if" lists are generated from our ratings and junior data only. Data verified 2025-01 (X-One Biphase) and 2025-01 (NXT).