Signum Pro Poly Plasma String Review

Signum Pro Poly Plasma 17 (1.23) String

Video Review



Signum Pro Poly Plasma String Scores
Power 33
Spin 65
Comfort 58
Control 85
Feel 80
Playability Duration 78
Durability 92
Overall 76


  • Control
  • Durability
  • Feel
  • Good price-to-value ratio


  • Too firm and underpowered for "non-poly" players


Poly Plasma is the flagship co-poly of Signum Pro, a German string manufacturer becoming known for producing high quality polys. According to our playtest team, Poly Plasma performed more like a reliable workhorse than a fancy race car. It had the kind of predictable and controlled response that inspires confidence on full swings, but unlike similar control strings, it never felt overly stiff or anemic outside the sweetspot. What it did lack, at least for one playtester, was the kind of juicy power found in the newer, more elastic co-polys (think Tourna Big Hitter Black 7 or Volkl Cyclone Tour). It also didn't deliver the lethal bite and huge spin potential of a Solinco Tour Bite or Kirschbaum Black Shark, but it still performed well enough for hitting effective spin. Ultimately, for the player who wants an affordable co-poly with exceptional control and decent comfort, Poly Plasma is worth a serious look.

Power - Score: 33 | Control - Score: 85

Neither too dead nor too lively, Poly Plasma delivered a moderate power level that was ideal for the long, fast strokes of our playtesters, hence the respectable control score. Chris appreciated the response across different tensions, saying, "I found this string to offer a pretty solid level of power and control. It was middle of the road when it came to power for a poly. I liked the overall response, and I felt connected to the ball, so I could judge the level of power very well. The string played with good control at my usual tension of 55 lbs, and I felt dialed in. When I dropped the tension to 53 lbs or lower the string really opened up. Whereas some polys remain pretty stiff and dead even at low tensions, this string offered a much deeper ball pocket and a much more powerful feel, even when I dropped the tension to just 53 lbs."

Andy found excellent control early in the playtest, saying, "This string offers a low-to-medium power level with above average control. For the first couple weeks of the playtest I felt in total control of the ball as it left the strings. The response was predictable, with enough pop for it to not feel 'dead.' After the strings were in my racquet for a couple of weeks they lost tension and began to play livelier. The power improved, but I lost a bit of control."

Spin - Score: 65

Our playtesters rendered somewhat divergent opinions on the spin potential of Poly Plasma. For Andy, who prefers the sharp teeth of his shaped polys, this round string didn't provide enough grip. He said, "Compared to other polyester strings, I didn't feel like spin potential was one of Poly Plasma's strong points. It didn't grab the ball exceptionally well, and the ball seemed to just slide off the strings at impact. This resulted in a lot of control but only a moderate amount of spin. I really had to make an effort to get my ball to kick or stick to the court."

Chris wasn't "blown away" by the spin either, but he had slightly better results than Andy. He said, "Again, the best way to describe the string's performance is, in a word, solid. I was not overly impressed by the level of spin I was generating, but I wasn't disappointed either. I found the level of spin to be very predictable with this string. I was able to attack the ball with pace while going for an aggressive target, and I was confident I'd get enough spin to still be consistent. I also felt like I had decent feel for the amount of spin I was getting, which helped me control the depth on shots like drop shots and lobs (usually hit in that exact order)."

Comfort - Score: 58

Although Poly Plasma is made from firm polyester, our team didn't encounter any discomfort. Chris said, "Not surprisingly, the stiffness level felt pretty middle of the road. I would call this string medium-firm. It is far from the softest of poly-based strings, but it does feel nice and soft once the tension is lowered. At my regular tension of 55 lbs the string felt a little firmer than Volkl Cyclone, but it was far from overly stiff. I didn't have any comfort issues while testing this string and found it to be plenty forgiving even on shots hit outside of the sweetspot."

"The softer, more dampened feel made this string fairly comfortable for a co-poly," said Andy, who also found this string to be sufficiently forgiving for a firm string. "It's in the soft/dead category, so it's ideal for players who like to slug the ball but don't want a jarring feel. This isn't a 'miracle poly' that's softer than some multifilaments, but it's certainly a comfortable option for players already familiar with polyester strings."

Feel - Score: 80

According to Andy, big hitters looking for a softer playing control string should be right at home with Poly Plasma. He said, "The strings feel soft, dead and dampened at impact. Once again, it's ideal for players who like generating their own pace but want a comfortable string that doesn't have a crisp feel."

Chris said, "I liked the feel of this string. It had a medium-firm response that was not at all harsh or brassy. It was just slightly firmer than an average co-poly for me, and I liked how that crisp response had me feeling connected to the ball. I had good touch with this string. I was able to find my targets on delicate drop shots, touch volleys and when looking to roll a lob over a net rusher. "

Playability Duration - Score: 78

Poly Plasma performed quite well over time for our team despite the typical tension loss that afflicts all strings, especially polys. Chris was satisfied with the playability, saying, "I managed to get my requisite two weeks of hitting on Poly Plasma without finding a major drop off in performance. As the string bedded in it became a tad livelier, but not enough for me to lose control. Comfort remained good, and the string never became buzzy or harsh feeling. Even when I strung the string at a lower tension to enjoy a more powerful response the tension never felt like it dropped too low, and I was impressed that the response remained predictable for the duration for the test."

Playability also remained high for Andy, who said, "Tension maintenance was good for about two weeks, and then it started to drop noticeably. However, I didn't mind the boost in power from the loss in tension, so I found the playability to last, and maybe even improve, as the playtest wore on."

Overall - Score: 76

What type or player would you recommend this to?

Andy - "Poly Plasma is a string for players who are already familiar with polyester strings. It's ideal for players with long, fast strokes who like to generate much of their own power."

Chris - "A player looking for an affordable co-poly that hits all the performance variables at a good level will get a lot out of this string. If you are looking for a solid playing co-poly with consistent power, control, spin and feel, then this one is well worth a try."


Andy - "It has a comfortable, dampened feel for a poly, with excellent precision and feel."

Chris - "I liked the predictable feel of Poly Plasma. It was decently comfortable, and the control was very solid."


Andy - "Poly Plasma was a little too low-powered for my liking, and it doesn't bite the ball as much as I like."

Chris - "Nothing for me to really dislike here, but also nothing that really jumped out as impressive, either."

Comparing the string to others they've tried, our testers said:

Andy - "Poly Plasma would be in the same camp as Polyfibre TCS or Yonex Poly Tour Pro. All three strings have a soft, dampened and dead feel at impact and are relatively low-powered."

Chris - "Poly Plasma was a pretty middle of the road co-poly for me. It played a tad firmer than Boris Becker Bomber and felt pretty similar to Luxilon Adrenaline."


(Scores are determined by averaging individual play test scores)

Andy's Scores
Power 2.5 Durability 9
Spin 6
Comfort 5
Control 9
Feel 8
Playability Duration 7.5
Overall 7.5
Chris' Scores
Power 4 Durability 9.4
Spin 7
Comfort 6.5
Control 8
Feel 8
Playability Duration 8
Overall 7.7

Playtester String Setups

Playtest Racquet: Wilson Blade 98 18x20
Playtest Tension: 53 lbs
Typical String: Luxilon Alu Power Spin 16L

Playtest Racquet: Volkl 8 Super G 300
Playtest Tension: 53 & 55 lbs
Typical String: Volkl Cyclone 16

Review date: July 2014. If you found this review interesting or have further questions or comments please contact us.

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