Spks. wood veneer is drying out.

use pure lemon oil & rub in 2 coats every couple of months,it will bring back 99% of the lustre that they used to have.

The veneer on your speakers very likely has a factory-applied "varnish" top coat that could be catalyzed conversion type. Even if it is a lesser quality top coat you will not effectively be able to penetrate it with oils. Go to a quality hardware store and inquire about the MinWax line of finishing and wood maintenance products and you may find a good solution. Also purchase a can of Guardsman furniture polish for regular maintenance. Stay away from the stuff sold at the big box hardware stores like Homer Fornsby. And do not ever use Murphy's wax products. Both of these really dry out the wood. If your wood is generally exposed (meaning you do not see a finished top coat) try working a more out of sight area using linseed oil. I sell cabinetry so I am not faking it here. You are welcome to email me if you care to discuss further.
John

Thank-you for all your responses. I believe Snell used the "natural approach" and applied only oils. I do not believe a sealing finish was applied. I appreciate all your advice and will consider all your fine advice.

Bill, Just curious, what leads you to believe the veneer is drying out? What are the symptoms?

I've owned 3 different pairs of speakers that used the natural approach. All of them benefited from the use of oil in conditioning the wood. The signs I saw were dry areas in the finish. Less luster in certain areas and places where the grain of the wood didn't have that almost luminescent quality. After using Scotts lemon oil the luster has returned. I use it atleast once a month to wipe down the speakers. Whether Jayboard agrees with me or not, I know this stuff worked wonders on my speakers.

Good luck Bill