Earlier this year I bought a Martin D-28 Authentic 1931 with high hopes of an amazing sound. It came with Martin SP strings and I was deeply dissapointed with its sound. I changed the strings for the much heralded Martin Authentic strings. Again, very dissapointing. A friend had tried and recommended these Fenders, so I bought a couple of sets and fitted them......WOW! What a difference. They have transformed this guitar. Describing the sound of an acoustic guitar is like trying to describe wine, but the sound of this D-28 is now strong, rich with overtones, shimmering and crystaline. I play single notes and just listen to the sound hanging in the air as it slowly dies away. I simply cannot stop playing this guitar, the sound is so good. AND I believe these strings have substantially contributed to this turnaround. I am soon to fit a set to another old Martin. I will keep you all informed.
Interestingly these are made in the USA, not Mexico as most other brands seem to be. How relevant this is I cant say, just an observation!