Caution: verbose, maybe pedantic, and perhaps inane
Just for clarity's sake, the term "relative humidity" is the moisture content adjusted for its temperature. As temps rise, so tood does the air's ability to hold more moisture. So an RH of say 45% in the "cold" will have the same moisture content as an RH of 45% when it's "hot" because the hygrometer that reports "
relative" humidity calculates the
actual humidity and ambient temp together, and then reports the RH, the number we're concerned with. I recall the measurements I took with a sling psychrometer (sp?) which measures actual moisture content, then logged the thermometer, then did the calulation for RH ...
so glad we have cheap meters that do this now
. So the ambient temp really is not a point that is relevant to what I think was the OP's intent ...if I'm reading the OP right.
The health of a given guitar and how it adapts to the env't will clearly vary from maker to maker, but let's say for the sake of argument we're speaking of any decent-quality instrument. Such decent guitars will have a
range of RH that they are tolerant of. Within that
range of health, where it
neither dries and shrinks eventually imploding on itself as evidenced by cracks,
nor swells with moisture as all the faces, particularly the top, bulge like bloated sponges and likewise doesn't produce the tone we were accustomed to hearing before this, within these extremes the guitar is
structurally sound. How it actually "sounds" will vary
within the range, but structurally, it's not gonna crack apart nor turn to gluey mush and fall apart on you. Fact: guitars just don't do this when in said range; they just aren't
that fragile (again, structurally). So keep the guit in the specific RH (within the appropriate range) you prefer its tone in. Me? I prefer the drier side of healthy: 40 to high-40s works for me. But just because the Taylor factory builds them at 47% doesn't mean that I'm going to make that my absolute standard. And not because I think I know better than they do ('cause I don't, duh), but because I have to balance the
reality of my climate with what my desires are for my guitars. I want to keep them out on the wall for immediate access, but I don't want to treat them like they're in some dang ICU constantly monitoring their health. Ahem, I have a real life to live
So that's all I'm saying. There's "reasonable care" (which is substantiated by guitar builders not least of which includes Bob and co. who live with wood and see first-hand what happens to it under differing conditions), then there's various opinions, including my own, which ought to be taken with a multitude of grains of salt. Again, that's all I'm sayin
BTW, food for thought: I've had two laminates in the past get dry and crack because I thought they were "tough laminates" ...wrong! One ought not make the mistake that just because it's a laminate it is "tougher" and doesn't need to be within the proper range of humidity. Wood is wood, as is construction materials and procedures are what they are. Lams are more resilient to RH swings than solid guits, to be sure, but given enoguh time and an RH outside the range, and they
will suffer likewise.
Edward