Playtest: HEAD Sonic Pro/FXP Power
HEAD Sonic Pro/FXP Power is another of Head’s pre-selected “Perfect Match” hybrids. “Perfect Match” is a system developed by Head that allows each player easily to select a hybrid combination based on desired primary and secondary string properties. (See the August 2009 issue of RSI for more information.) This particular combination aims for durability as the primary benefit and power as the secondary benefit.
According to Head, Sonic Pro is made of uniquely refined co-polymer polyester and an extra combination of resins and fibers, offering superior durability and control for extra pop and spin. The 2008 USRSA members’ Choice Awards String Survey ranked Sonic Pro the most durable 17-gauge string. For more about Sonic Pro 17, see our playtest report in the July 2007 RSI magazine.
FXP Power is a multifilament containing a high-tech microfiber core wrapped with “tri-cluster” FiberGEL filaments. According to Head, this combination provides ultimate elasticity unleashing unprecedented power. The 2008 USRSA members’ Choice Awards String Survey ranked FXP Power the fifth best nylon string overall. For more about FXP Power, see our playtest report of the 16-gauge version in the July 2006 RSI magazine.
Head tells us that by using Sonic Pro in the mains, the player gains durability and control, while FXP Power in the crosses adds power to the string bed.
For the Perfect Match program, Sonic Pro 17 and FXP Power 17 are available as half sets in orange/natural only, although Sonic Pro is also available in full sets in black and white. It is priced from $13 ($6.75 for a half-set of Sonic Pro, $6.25 for a half-set of FXP Power). For more information or to order, contact Head at 800-289-7366, or visit head.com.
In the lab
We tested the 17 gauge versions of both Sonic Pro FXP Power. The coils measured 20’ and 20’. The diameters measured 1.23-1.24 mm (Sonic Pro) and 1.24-1.26 mm (FXP Power) before stringing, and 1.20-1.21 mm and 1.21-1.22 mm after stringing. We recorded a stringbed stiffness of 74 RDC units immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16 × 18 pattern) on a constant-pull machine.
After 24 hours (no playing), stringbed stiffness measured 68 RDC units, representing an 8 percent tension loss. Our control string, Prince Synthetic Gut Original Gold 16, measured 78 RDC units immediately after stringing and 71 RDC units after 24 hours, representing a 9 percent tension loss. Sonic Pro 17/FXP Power 17 added 15 grams to the weight of our unstrung frame.
The string was tested for five weeks by 38 USRSA playtesters, with NTRP ratings from 3.5 to 6. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. Average number of hours playtested was 20.2.
As noted by our playtest team, this combination is easy to install, especially because both strings can be installed at the same tension. Our only requirement for this playtest was that the Sonic Pro be installed as the main string.
No playtesters broke his sample during stringing, two reported problems with coil memory, four reported problems tying knots, and one reported friction burn.
On the court
The Perfect Match hybrid impressed our playtest team most with its Spin Potential, giving it a score good enough to be 11th out of the 136 strings that we’ve playtested to date for publication. However, our playtesters also rated Sonic Pro/FXP Power well above average in Durability, Power, Control, Comfort, Tension Retention, and Resistance to Movement. With high scores in each of these seven categories, it’s no surprise that the combination of Sonic Pro and FXP Power also came in with a well-above-average overall score.
Six members of the playtest team broke the sample during play, one each at 1.5, 2, 4.5, 6, 8, and 12 hours.
According to our playtest team, the combination of Head Sonic Pro 17/FXP Power 17 does deliver durability and power. As we noted in the last playtest of one of Head’s Perfect Match hybrids, this program really facilitates experimentation with — and selection of — hybrids that work well together. Once you try one Perfect Match hybrid, it should be no problem figuring out your next move, whether it’s staying with what you’ve got or going for something different.
“High playability for a hybrid. Great feel, control, and power.” 6.0 male all-court player using Wilson K Tour strung at 56.5 pounds CP (Wilson NXT 17)
“This combination works. The control is there from the very first hit. The nylon cross is not only durable, but it adds power and feel.” 4.0 male baseliner with heavy spin using Babolat Pure Drive Roddick strung at 63 pounds LO (Babolat Pro Hurricane Tour 16)
“This is one of the best hybrids I’ve ever tried. No stroke adjustment necessary. Big swings from the baseline come off the string bed with remarkable predictability. Very little shock at impact.” 4.0 male all-court player using Yonex RDS 002 strung at 58 pounds CP (Luxilon Big Banger Alu Power 16L)
“This string has great feel and very high playability.” 3.5 male all-court player using Prince O3 Blue strung at 60 pounds CP (Luxilon Big Banger TIMO/Tecnifibre NRG2 18/17)
“This is a very comfortable and powerful hybrid. Players looking to try poly for the first time are encouraged to start here. This is definitely going to attract a wide audience.” 4.5 male all-court player using Prince EXO3 Rebel (port inserts) strung at 57/59 pounds LO (Polyester/Nylon Multifilament 17/17)
“This is a tendon-friendly control string. It has a crisp response without punishing your arm. It also has great feel, touch, and durability.” 5.0 male serve-and-volley player using Prince EXO3 Graphite (hole inserts) strung at 51 pounds CP (Luxilon Big Banger Alu Power 16L)
“The polyester mains are very easy to install. The playability is there from the first stroke. This blend has a unique mix of control, power, and touch.” 4.0 male all-court player using Head MicroGEL Prestige MP strung at 59 pounds LO (Luxilon Big Banger Alu Power 16L)
“This is a comfortable hybrid with great tension maintenance, feel, and control. Big swings can be executed with confidence. I am considering a switch.” 4.5 male all-court player using Wilson nTour strung at 58 pounds CP (Wilson NXT 16)
“Great spin and power, but without the harsh feel typical of most polyesters. This is one of those rare strings that can be recommended to both big hitters and touch players. My customers will love it.” 3.5 male all-court player using Yonex RQiS 10 strung at 64/62 pounds CP (Pro Supex Big Ace/Tecnifibre X-One Biphase 17/17)
“Even in my stiff frame, this hybrid is very comfortable. The thin mains truly grip the ball. The soft crosses minimize shock and vibration, making for a very pleasing impact. Topspin and slice are deadly. Bite, bite, bite.” 4.0 male all-court player using Head MicroGEL Extreme Pro strung at 56 pounds LO (Luxilon Big Banger Alu Power Fluoro/Prince Synthetic Gut Multifilament 17/17)
“This is an outstanding hybrid. The combination of control and comfort is uncanny.” 6.0 male all-court player using Wilson KSix One (68 Holes) strung at 60 pounds LO (Luxilon Big Banger Alu Power Spin 16L)
“This hybrid lasts a long time. After twenty hours it still looks and plays fresh. The combination of power and control is surprising. Spin is excellent. This manufacturer might be on to something.” 4.0 male serve-and-volley player using Prince O3 Speedport White MP strung at 68 pounds CP (Wilson Sensation/Prince Synthetic Gut w/Duraflex 17/17)
“Installation is a breeze. Touch and feel are slightly lacking, but there is definitely no shortage of pop. String movement is virtually nonexistent. This is a comfortable combo.” 4.0 male all-court player using Boris Becker 11 Special Edition strung at 58 pounds LO (Gamma Zo Tour 16)
“Great feel and control. The mains and crosses are well matched. Power holds up for about 15 hours.” 4.5 male baseliner with moderate spin using Volkl Power Bridge 10 (295g) strung at 58 pounds CP (Gamma Zo Tour 17)
“Noticeable pop on serves. Though power goes down after a few hours, control does not suffer. The color scheme is a winner.” 3.5 male all-court player using Wilson K Blade strung at 55 pounds CP (Polyester/Nylon Multifilament 17/17)
“This is a very comfortable, arm friendly hybrid with above average power. Spin potential is impressive.” 3.5 male baseliner with heavy spin using Prince Tour Diablo MP strung at 58 pounds CP (Luxilon Big Banger Alu Power/Gamma Natural Gut Tour 16L/16)
“This is a very comfortable hybrid.” 4.5 male all-court player using Head i.Extreme MP strung at 53 pounds CP (Prince Synthetic Gut Poly Blend 17/16)
“This is not just a niche string for hard hitters. Touch players will like it too. Perhaps this should be marketed as a crossover hybrid for folks who want to see what all the fuss is about.” 5.0 male all-court player using Head Liquidmetal 4 strung at 58 pounds LO (Luxilon Big Banger Original/Tecnifibre NRG2 16/16)
“Finally, a hybrid for club players.” 4.5 male all-court player using Wilson K Blade strung at 58 pounds LO (Babolat Superfine Play 16)
“This is an arm friendly hybrid with great all-around playability.” 5.0 female serve-and-volley player using Head MicroGEL Extreme strung at 48 pounds CP (Head FXP Power 16)
“Very easy to install. Very comfortable.” 4.5 male all-court player using Prince O3 Speedport Black Team (port inserts) strung at 65 pounds LO (Prince Premier LT 17)
“The crosses move a little more than average. The feel is firm yet comfortable. Spin potential is excellent. This is recommended to folks who want the control advantages of polyester in a more comfortable package.” 4.0 male baseliner with heavy spin using Fischer M Pro No. One strung at 58 pounds LO (Luxilon Big Banger Alu Power 16L)
“The feel is stiff. The playability is higher than anticipated, given the polyester mains.” 3.5 female all-court player using Wilson K Blade strung at 57 pounds CP (Wilson Reaction 17)
“This is an extremely comfortable combo. The playability, control, and power are excellent. The only downside is the lack of durability. Big hitters might consider a thicker gauge cross.” 4.5 male all-court player using Head MicroGEL Prestige Pro MP strung at 56 pounds CP (Polyester/Nylon Monofilament 16/17)
“This is solid feeling string. Very little string movement.” 5.0 male all-court player using Wilson nPro Surge strung at 50 pounds CP (Polyester 16)
“Very powerful and responsive from the baseline. Spin is outstanding. Lower tensions are advised.” 4.0 male all-court player using Wilson nTour strung at 52 pounds CP (Signum Pro Poly Plasma 17)
“Nothing exceptional to note. I prefer strings with higher levels of comfort and control.” 4.5 male baseliner with moderate spin using Prince OZone Seven strung at 60 pounds LO (Babolat Conquest 16)
“Very easy to string. The impact is very comfortable. Great control and playability. Cross strings broke a little too soon.” 4.5 male all-court player using Wilson K Tour strung at 50 pounds CP (Luxilon Big Banger Alu Power 16L)
“Impressive resistance to movement. High marks for tension maintenance. Unfortunately, this hybrid does not grip the ball. It is also a little too springy. Higher tensions might counter this.” 4.5 male all-court player using Wilson Kobra Tour strung at 61 pounds CP (Wilson Hollow Core 16)
“Great playability and control, but the crosses lack durability.” 5.5 male all-court player using Prince Triple Threat Warrior MP strung at 51/48 pounds LO (Pro Supex Blue Gear 17)
“This string is recommended to ball bashers in search of more control. Big cuts seldom fly long. After a few heavy hitting sessions, the responsiveness goes down. String movement increases markedly at the five hour mark. The crosses snap shortly thereafter.” 5.0 male all-court player using Yonex RDS 002 Tour strung at 55 pounds CP (Tecnifibre X-One Biphase 17)
“Power and comfort are not lacking in this hybrid. The crosses tend to fray, especially if you hit with heavy spin. This leads to premature breakage.” 5.0 male all-court player using Prince Thunder Ultralite Titanium OS strung at 52 pounds LO (Luxilon Big Banger Original Rough 16)
“Playability, bite, and comfort are above average, but durability is a concern.” 4.5 male baseliner with heavy spin using Dunlop Aerogel 3 Hundred strung at 57 pounds CP (Tecnifibre Red Code 18)
“Plays great for the first few sessions. Eventually, the responsiveness goes down and control suffers.” 4.0 male serve-and-volley player using Prince O3 Speedport Black (port inserts) strung at 63 pounds LO (Wilson NXT 16)
“Too stiff. Not enough power.” 4.0 male all-court player using Volkl V1 Classic strung at 57 pounds CP (Wilson Super Spin 16)
“Not enough energy return. The multifilament cross lacks durability.” 5.5 male baseliner with heavy spin using Volkl Tour 10 MP strung at 55/58 pounds CP (Luxilon Big Banger Alu Power Rough/Wilson K Gut 16L/16)
“This is a low powered string which makes a deep ‘thud’ upon impact. Too much effort is required to get the ball deep.” 4.0 female all-court player using Head MicroGEL Extreme strung at 61 pounds CP (Head Sonic Pro 16)
“The feel is lacking. The string bed goes from too stiff to too springy with nothing in between.” 5.0 male all-court player using Wilson K Tour strung at 66 pounds CP (Prince Poly EXP/Head Synthetic Gut PPS 18/17)
(Strings normally used by testers are indicated in parentheses.)
| EASE OF STRINGING
(compared to other strings)
|Number of testers who said it was:|
|about as easy||18|
|not quite as easy||3|
|not nearly as easy||0|
| OVERALL PLAYABILITY
(compared to string played most often)
|Number of testers who said it was:|
|about as playable||11|
|not quite as playable||18|
|not nearly as playable||3|
| OVERALL DURABILITY
(compared to other strings of similar gauge)
|Number of testers who said it was:|
|about as durable||15|
|not quite as durable||6|
|not nearly as durable||1|
|From 1 to 5 (best)|
|Spin Potential (11th overall)||3.6|
|Resistance to Movement||3.8|
TI magazine search
TI magazine articles
- String Playtest: Head Gravity
- Our Serve: Our Guiding Lights
- Industry news
- ‘Coach Youth Tennis’ Hits A Winner with Providers
- Pioneers in Tennis: The Wit and Warmth of Vic Braden
- Person of the Year: Bahram Akradi
- Private Facility of the Year: Army Navy Country Club
- Stringer of the Year: David Yamane
- Builder of the Year: Trans Texas Tennis
- Sales Rep of the Year: Allan Iverson