Head to head

Kirschbaum Pro Line X 17 (1.25) vs Signum Pro Poly-Plasma 16L

Pro Line X 17 (1.25) leads on 5 of 6 measurements. The widest gap is ball bite, where Poly-Plasma 16L is 24 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.

Measured, side by side

Kirschbaum

Pro Line X 17 (1.25)

Polyester · 17 ga

Signum Pro

Poly-Plasma 16L

Polyester · 16L ga

Stiffness lower = softer, kinder on the arm
21886th pct
22691st pct
Tension loss lower = stays where you strung it
3763rd pct
3966th pct
Energy return higher = livelier, more free power
8735th pct
8734th pct
Spin potential higher = more spin off the string bed
4.851st pct
4.748th pct
Ball bite higher = grabs the ball harder
0.42339th pct
0.46563rd pct
String friction lower = strings slide and snap back
0.08944th pct
0.09861st pct

Bars are percentile against all 791 strings, and the marked side is the one that measures better, which is not always the one you want. A firmer bed is worse for your elbow and better for your control, and no measurement knows which of those you came for.

Which one wins, by problem

Each string's standing on the site's rankings, out of every measured string in the database. This is where a comparison stops being arithmetic and starts being a decision.

Swapping between them: what tension?

Bed stiffness is published at one reference tension, so the only honest conversion is to scale it. These are starting points from 52 lb, not prescriptions. The calculator takes your own tension.

Coming from Pro Line X 17 (1.25) at 52 lb

String Poly-Plasma 16L at 46.4 lb 21.0 kg

Coming from Poly-Plasma 16L at 52 lb

String Pro Line X 17 (1.25) at 59.1 lb 26.8 kg

Hybrid: what if you used both?

Estimated, not measured. No hybrid combination has been tested as a bed. These figures are the two strings' own lab measurements weighted by how much of the bed each one actually is. Treat them as a guide to which way a pairing moves, never as lab data.

Pro Line X 17 (1.25) mains / Poly-Plasma 16L crosses

Stiffness89th pct · 1 measured
Tension loss64th pct · 1 measured
Energy return35th pct · 1 measured
Spin potential49th pct · 1 measured
Ball bite43rd pct · 1 measured
String friction48th pct · 1 measured

Poly-Plasma 16L mains / Pro Line X 17 (1.25) crosses

Stiffness90th pct · 1 measured
Tension loss65th pct · 1 measured
Energy return35th pct · 1 measured
Spin potential49th pct · 1 measured
Ball bite60th pct · 1 measured
String friction57th pct · 1 measured

Open this in the hybrid builder

Which goes dead first?

Estimated from tension loss, which is the only thing the database measures about ageing. This is when the bed stops playing the way you strung it, not when the string breaks.

Pro Line X 17 (1.25)

~21 hours of play

Poly-Plasma 16L

~20 hours of play

Both strings in full

Every published measurement
StringGaugePriceStiff lb/inLoss %Power %SpinBite COFFriction COF
Kirschbaum Pro Line X 17 (1.25) Polyester17find21837874.80.4230.089
Signum Pro Poly-Plasma 16L Polyester16Lfind22639874.70.4650.098

Add a third string Pro Line X 17 (1.25) in full Poly-Plasma 16L in full