Originally Posted by Ramon
It's probably too loose. Some places string racquets so quickly, if you ask for 60 pounds you'll get 45. You can check the tension with RacquetTune if you have an iPhone. The default string factor setting works fine with PPA. I'll bet it's in low 40's or lower.
I strung it at the lowest recommend tension on the head racquet at 52lb.
May be will go up a couple of lbs. Thanks Ramon you definitely know your PPA