Tom here is the trimming trick I used, After you have the first piece of veneer attached to the speaker flip the speaker over so the veneer is face down on your work bench, be very carefull, you will need a piece of wood on top of your work bench so you wont cut it up with the utility knife. I used a big piece of mdf that I had laying around,its like a piece of plywood but nice and flat . Now the tuff part making sure you keep enough veneer for sanding and not to much so you dont have to sand for a solid hour.Here is a trick I used, I took a piece of my scrap veneer that is 1/42 of an inch thick and layed it against the speaker on top of the veneer were I was going to make my cut with the utility knife, this will keep you away a good 1/42 of an inch away with little sanding left to do.Trick is new blade in utility knife, go very slow with very little pressure should take 3 or 4 passes to cut the veneer mabe more when doing it against the grain of the veneer. Be very carfull near the end of the veneer you dont want to rip it and mess it up. Once you got the venner timmed turn speaker over and take 100 grit or 150 grit sand paper on a block sander and sand it flush to the speaker, be very carfull neer the ends of the veneer if that sandpapper catches it wrong you will rip a chunk off not good. Use the sanding block like the utility knife very little pressure and take your time. I spent hours sanding down the edges of these speakrs so I wouldnt have any tear outs. Also take your finger and press down on the veneer at the ends of the veneer when you are sanding them with the block sander this will give the veneer more support while sanding that area and help avoid tear outs. Hope this helps.