[mas]

Hello all, I recently purchased the AV-3 and OB-5 kits. As a newbie woodworker, I have started on the AV-3 with the OB-5 waiting in the wings. I have the cabinets nearly completed for the next step, but I have a couple of questions before proceeding to the veneering.

I'm curious what folks have done for a speaker grille.

I have some neodymium magnets fromparts express , but their location depends on the grille design.   I was thinking of using the open foam found at http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=LS00904
 I guess I would just glue the magnets into the foam. I'd have to hollow out the foam on the back side to accommodate the flush mount woofers.

The other idea I have is to use a cove moulding to fit on the round-over on each side of the speaker connected  the moulding at the top and bottom with a cross brace, and then wrap the whole deal in grill cloth.

Man, those magents are strong! I'm a little worried repeated on/off might mar the veneer. How deep into the speaker should those go? They are the ones in the current parts express flyer, 3/8" diameter, with a depth of .2"

What size drill should be used for the stock threaded insert? Does the insert just get pushed in, or should I also epoxy it in place?

After I get the inserts and grill  magnets in place, I'm ready for the veneer.  I plan on using raw figured sapele using Titebond pva iron on. My question is how long the glue can sit before beginning the ironing. Do people do the whole speaker at once, or in sections? There are four seperate sections: bottom, back, top, and then front and sides.   I'm worrried about getting glue on the veneer if I have to apply the glue to the substrate after some veneer is in place, so I would prefer to  do it at once.

 My first set of cabinets didn't turn out well. I didn't have appropriate clamping, and my butt joints weren't square. I also learned not to clamp the sides too hard to make up for a not-wide-enough brace. Sure, I was able to glue and clamp, but then the sides were warped! Somehow I had it in my head that a real woodworker doesn't use screws, but I found it works really well to clamp the pieces together without the glue (that stuff is slippery!),  then drill a hole for a screw so the pieces are easily lined up again after the glue is applied.

Oh yeah, I had a couple of oops with the crossover too. I broke off the lead of a capacitor in a vain attempt at a neat layout. Worse was the damage I did to the inductor insulation with a careless moment with the soldering iron. Yup, that plastic melts like butter! Like I said, I'm a newbie, but having lots of fun learning.


After getting replacement parts, I had the speakers set up for a couple of days, and I'm very happy with the sound.  Wonderful transparency and focus.

Thanks to those who have shared their knowledge and experience on this board. Thanks in advance for any responses to my questions.

[Straasha]

I used Danny's grills and front baffles (see my post on front ported AV3).  As for the veneer, I took Al's (RAW Acoustics) advice and used Heat Lock veneer glue from veneersupplies.com.  I consider myself an experienced garage wood worker.  I have been building my own furniture for about 6 years now.  The AV3 was the first time that I have ever veneered so I was a little intimidated.  This stuff made it easy.  Just roll it on, wait about an hour for it to dry, and then iron on.  Worked like a champ. 

One lesson I learned, is that it will bond with just contact (no heat) if you let is sit too long.  I veneered the front and sides of my AV3s from a single sheet.  I started from the front and worked my way to the left side.  When I was ready to do the right side, it had already bonded and had several big wrinkles.  I had to force the veneer apart from the MDF.  That took about 2 hours to do.  I then re-glued it down.  The wrinkles were gone but it left some creases in the veneer were I pulled it apart.  Needless to say I was frustrated with myself.

I used biscuits to secure the top to the sides and to secure the front and back to the main box.  I glued the braces in and tacked them with brad nails in order to hold them in place while the glue dries.  It you don't have a biscuit joiner, and want use screws, there are a couple of things to be concerned about.  Screws installed into the edges of MDF can cause it to split, resulting in a weak or failed joint. You'll need to drill a pilot hole for your screws. Use a drill bit the same diameter as the shank of your screw, and drill your hole slightly deeper than the length of your screw. Secondly, use straight-shanked screws to avoid splitting the material and also to get a better grip in the material. Sheet Metal screws are a decent inexpensive choice for MDF.  Confirmat screws are better but costly. Coarse-threaded drywall screws will also perform well with MDF.
 
MDF fibers will "pull up" when driving screws into the pilot hole causing a "bump" around the shank of the screw. This can make it more difficult to get a tight joint between the panels. If you countersink the pilot holes at both faces of each panel, it creates a cavity that gives the "bump" somewhere to go. This allows for a stronger, better looking joint.  Here is a link with more details:  http://rowecraft.com/blog/2006/01/assembling-mdf.html

[mas]

Thanks for the link. I found with clamping, a pilot hole and countersinking, there were no "bumps". I used a 1/8" pilot hole with #6 - 1 5/8" trim head screw I had laying around. I looked longingly at the power biscuit tools, but passed due to expense. 

I figured out I should use a 5/16" drill for the inserts, and epoxied them in. I ended up putting my magnets 1/8" from the surface. I will figure out the grill later.

I would have used the heat lock, but living in Wisconsin means I wouldn't be able to get it for another month! It sounds like you coated the whole speaker at once rather than in sections.

[Danny Richie]

This might help. See grill cover plans here: http://www.gr-research.com/pdf/grill%20covers.pdf

If you wrap the grill cloth around the back side of the grill frame then it will cover over the magnet in the frame and it will not damage the surface of your speaker.

[mas]

Thanks Danny, just what I was looking for.

[Blaine_M]

All you really need to do to assemble the box is some nails, glue, and some clamps.  It will be rock solid, especially after a layer of veneer is glued down no need to do the biscuits on the box.  I used some smaller trim nails that didn't have much of a head on them. 

[Hank]

I've posted this many times on different forums, but I never use screws or nails.  Screws add not strength to a well-glued joints, but they do add labor hours.  For large cabinets, I do use a few brads to hold some things together while I move them around and add further parts and get the clamps applied.  A pneumatic brad nailer, or one of the new powerful electric models, is very handy.