I've gone through several sets of strings with the LJ Pro I purchased last December at Gruhns Guitars in Nashville.
As I stated in a previous post, Laurence Juber uses his Signature GHS True Medium strings. The LJ Martin, ironically, came strung with their Lifespan lights. It sounded great, but I did notice the 1st string lacked proper umph and body.
Swapping out to a set of True Mediums starting last January resulted in a guitar just as playable but now with more body and the 1st string sounding balanced.
But now I've done it. This last string change changed something in my guitar's neck. It might be temporary. Wood is elastic and very subject to humidity and temp. My last set was over two months old. They still sounded great, but lacked some of the resonance. And at just $6 per set from Sweetwater (free shipping too!) I decided to restring with another set of True Mediums. But as I tuned this up with the new strings and began to play there was an annoying fret buzz at the 5th fret for the first time and several strings lacked full resonance and sweetness.
The last two changes the result was immediate bliss and the thought of why didn't I do this sooner. But not this time! After tuning up, and playing/returning a couple times something was out of whack.
Barring at the fifth fret, now the 3rd and 4th strings has a distinct and annoying buzz even playing softly. And the 6th string sounded dead and half volume. I can't remember a string change ever affecting any guitar--electric or acoustic--in all my years of playing.
Can some guitars be sensitive to how you change strings?
I Googled "string changing and fret buzz" and found the age old discussion over whether to change your strings all at once or one at a time. Personally, I've done both and have never given it a second thought or had it make one iota of difference---until perhaps now! The Martin guide that came with the guitar implies changing them all at once, not one at a time. And that's how I had previous changed the strings on it twice before with no ill effects.
But this time I had the TV going and it was something I wanted to watch and so, distracted, I did half-and-half. None of that should have had much impact one way or another--except that my guitar had spent 4 days at a beach condo. It never went outside and it was air conditioned but perhaps the humidity and temps were quite different than my home.
UPDATE: after two days with the new strings there is still the new buzz at the fifth fret and the one is still subdued on the 6th string. Switched out the strings for a new set of True Mediums--doing them all at once like the previous 3 or 4 times. Same result. Obviously something in the neck has shifted.
UPDATE: GOOD NEWS! a local luthier who does work for a number of famous guitarists as well made a very slight adjustment and literally a piece of paper shim under the bridge. Presto! It's back. Just as playable and no abnormal buzz. Tone is back to it's original too. He said the neck indeed was razor straight so he put a very slight relief in it .032 of an inch. Indeed, the neck must have rocked back on the string change and, being new, simply didn't return to it's original position. By the way, he usually changes ALL strings at one time.