wood likes to be dry. It's moisture that causes a problem. You will get lots of recommendations, mostly from people who are not wood workers.
I wouldn't apply anything.
I wouldn't apply anything.
S7horton is both right and wrong. First and foremost avoid large changes in ambient humidity. Too wet is usually the case, but too dry can be just as bad. When the moisture content falls below 6-7% the cellulose bonds within the wood become very brittle and can crack (could affect the sound in something that relies on box reverberation). As for applying something, a lot depends upon the finish type and none of them will add moisture nor will anything keep the speakers from losing moisture in order to reach stasis with the environment. With that said, it is hard to go wrong with a good paste wax such as Johnson's (not auto wax) to protect the finish. Ultimately, you should consider adding moisture if it is really that dry. FWIW, an air washer (filter) such as a Venta should work great for you.
Disclaimer: I am a cabinet maker
Lemon oil works for me,S7horton has 1/2 of it right also.Extreme dryness will cause cracks depending on many variables,thickness,type,temps,changes,finish etc. etc......common MDF with a veneer[common in speakers]could use a little TLC.1.5" solid wood[unusual for speakers]won't be cracking much if at all,figure what you have,google wood finishes,then go to the yellow pages under furniture,make some calls,listen and learn,then go and score 1 or 2 products and try out.Wood is so interesting you can't go wrong investing a couple of hours and 15-20$.Need to know what you have first,good luck,now get to work....
The simple fact is moisture content should not be falling enough to notice any change if the product was sealed correctly in the first place.
In addition, it takes an extremely dry place to get below 6-7% moisture content in wood.
Lemon oil is useless unless you feel the need to lube up your speakers.
Isn't Las Vegas in the desert? Would that not be considered "extremely dry" ? I use a Venta here in Michigan during the winter as my boiler severely dries out my home, and the winter air does not contain enough moisture to help. Many older furniture factories have steam misters to help add moisture carefully.
As for "sealing" to prevent transmigration of moisture- doesn't work and never will. Furniture making would be 10x easier if that were the case. Sealing only slows down the process- a lot, I admit - but nature seeks equilibrium. Lemon oil on the other hand, is mainly solvent with a little oil- a nice penetrating "cleaner" offering little protection. Wax will not keep moisture in/out, but clogs the micro pores/cracks a bit and ads a slippery protective coating. Both beneficial for longevity of any piece of fine woodwork. You might try asking a known skilled furniture maker in the vegas area, they will know. For the record, wax won't hurt anything. If you don't like it, lemon oil will probably take it right off ;).
Oh BTW, FWIW I've seen veneer over mdf crack due to severe dryness. Higher quality items will have a layer or two of "cross banding" (veneer with grain rotated 90 degrees) seldom seen in audio products. Really though, if your home is very dry you might look into some form of humidification. Your sinuses will thank you as well.
Humidification is the best answer per 4est. I would bet that your speakers are not the only wooden furniture in your home. The expansion/contraction of wood is one of the greatest forces known to man. Maintain humidity to "normal" levels and your speakers, furniture, skin and sinuses will thank you. A simple Google search on "house humidification" will produce years of reading material on the subject. Good luck!
Wood does not like to be dry ! Wood needs a good balance in its environment between not being too dry or being too high in humidity . Wood does need room to expand and contract within the moisture and temperature extremes of the environment it is placed . Therefore, the goal is to place it in an environment that sees little to no change in extremes of temperature and humidity . A controlled environment is the only thing that will keep wood as stable as it was the day it is placed in its new environment . There is good reason why when working with wood you never just bring it home and use it immediately . Good practice is to always allow the wood to sit a few days to allow the wood to acclimate to its new environment . This goes from installing pre finished wood floors to using unfinished solid woods or applying veneers when cabinet building or even installing trim . When a product is manufactured it is made within a controlled environment of both tempurture and moisture . That being the case after it is purchased if placed in homes that are too dry it shrinks and cracks, tight fitting joints are now loose and open and wood will twist and warp. If too moist it swells and finish will deteriorate from expanding beyond its plyable minute limitations to do so and will exert pressure causing bowing and warping of the wood. No, wood does not like to be dry or moist , we need it to be stable to work with and last . Maintain the environment first . Finishes contrary to peoples beleifs do less controlling of moisture than they do for beautification and protection of the surface itself from use . Veneers are affected quicker due to the fact they are usually applied to either MDF or in better designs HDF . These man made products are inherintly more stable and less affected to moisture and temprature extremes making the veneer more likely to fault being the weakest link unless properly applied and maintained . Lemon oil on solid wood cabinets contrary to the previous statements is not a waste of time . Using a high quality furniture cleaner such as Circa 1850 will clean the surface of dirt leaving a fresh new looking finish . Then applying lemon oil to polish the finish to the desired lustre . It does so by replacing some of the oils in the original finish that have dried up . Thus rejuvinating the finish which protects the wood surface . High quality furniture waxes do the same . They treat the surface finish not the wood and only act as a protection from use and will impede moisture loss or gain very marginally and only when situated in an evironment with minimal extreme swings . Air conditionings primary goal to control temperature is to remove excess moisture over the 35 percent mark and a humidifier is to put it back in from the effects of drying from heating . This is not just for comfort of the people in it but also the stability of the materials the home is made from . Expansion and contraction are negated by controling the variables we can control , tempurature and humidity . Perhaps thats why we are seeing materials like carbon fibre and corian to mention a couple that are more inert and stable being less effected by moisture and temperature extremes and when coupled with good sound engineering create a dead cabinet free of the negative effects of resonance the designer wants removed. An area with only 6 to 7 percent moisture used as a home would require everyone in it to have a bucket tied around their neck to catch the nose bleeds and vat of moisturizer to swim in to stop from turning into lizards .. 35 years of woodworking and raised by a woodworker with 60 years plus .