Cabinet w/Hardwood front baffle

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Caninet w/Hardwood front baffle

Hey guys, i tried googling this but didnt come up with much info. Might be my use of search terms but hopefully someone here can help me out.

My question is to do with using a piece of hardwood for the front of the speaker cabinet where the drivers are mounted. Its purely for looks, and im wanting to use hardwood over veneer for the front as its going to be round edges. Veneer over corners always looked rather off to me since you dont see the difference for the grain being cut into. Small potatoes i know but its something that will bug me every time i look at it lol.

Now i know theres issues with hardwood cracking from expansion and such with moisture. I've seen a couple threads mentioning it on here also.
So whats the solution exactly to making this work? I've seen some pics of hardwood boards being hollowed out on the inside and left alone where it will bond the the cabinet edges. Is there a laminet process being used here to fill it in, ect? Any info and links addressing this would be very much appreciated.
 
Re: Caninet w/Hardwood front baffle

caz said:

Now i know theres issues with hardwood cracking from expansion and such with moisture. I've seen a couple threads mentioning it on here also.
So whats the solution exactly to making this work? I've seen some pics of hardwood boards being hollowed out on the inside and left alone where it will bond the the cabinet edges. Is there a laminet process being used here to fill it in, ect? Any info and links addressing this would be very much appreciated.

Jim Salk puts hardwood edges on the cabinet, undercuts his hardwood baffles to match, and attaches the baffle with flexible construction adhesive:

Technique:

http://www.avsforum.com/avs-vb/archive/index.php/t-170942-p-6.html

Example:

http://www.salksound.com/speakers_veracity_ht3.shtml
 
Zaph describes a method he uses to attach MDF baffles that would actually work with solid wood also. Know that a 9" wide baffle is going to contract and expand 1/8"-1/4" from summer to winter and back to summer. This movement is only across grain and not along grain. A baffle pinned at the 4 corners with bolts in over size holes will allow the baffle to move without cracking. The nut will stay still and the bolt will move with the baffle swaying in the oversize hole as the baffle moves on the weatherstripping.

If you keep them in an air conditioned area, they may never expand/contract.
 
A little thought and you will come up with a solution

Most hardwoods have a shrinkage and expansion ratio of around 8 to 12%. So to make math easy take a board 10 inches wide and multiply it by the worst case of 12% so 10 * 0.012 = .12" or about 1/8th of an inch shrinkage and expansion. So summer when you make it the board will be 10 inches winter it will shrink to about 9 7/8 inches. You need a joint that will survive this ratio of movement.

The easiest way is to pin the corners as said and set it on a bed of elastic compound. There are a couple that come to mind. Silicone is easy. Galzing tape is another one. These things are elastic enough that there will always be a seal to the box. How to hide it is usually done with a little undercut so that there is a small crack all around baffle box junction.

Mark
 
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