Josef,
I have built a pair of Seas Thor speakers (
www.seas.no) and I am currently building 3 Odin-MK3 and 2 Froy-MK3 speakers for a surround sound system. Here's my advice: 1) lose the metal frame. No matter what you do it will cause warping. I have built metal frames with wood backing for art pieces. When the temp rises, the frame warps. 2) Bloodwood (aka Satine wood) is very stable.
http://tropix.cirad.fr/index_gb.htm has the data sheet on this species under African woods. I used Bubinga veneer with a Pommelle pattern and solid 1/2" x 1/2" Bubinga edging on my Thor speakers and have had no expansion problems over the last 5 years. Compare the specs of Satine wood against Bubinga. They are very similar. 3) MDF is your best substrate for speaker building. It is plenty dense. Machines like butter and is perfectly flat which is great for veneering. 4) How you build your box determines how you veneer. If you veneer the panels first, then you must use a backing veneer (can be anything -- beech, poplar, etc.) on the opposing face to avoid warping as the glue dries. If you build the box first, there is no need for a backing veneer. However, you are limited in the types of veneer you can apply (more on this below). Unprocessed veneer requires a lot of clamping pressure. This is why you can only use it on flat panels before assembly. Because of glue squeeze out the panels should be oversized and cut down to size. Raw veneer may also need to be flattened and requires some acquired skill and special tools to work with (
http://www.joewoodworker.com/veneering/welcome.htm ,
http://www.schurchwoodwork.com/tools/index.html ,
http://www.veneersystems.com). A good source for raw veneer is
http://www.wood-veneers.com/ . This has a long learning curve filled with frustration until you master it. So if it seems overwhelming, just go to "manufactured" veneer. It has a backing (paper, resin, another wood) to make it flat and stable. It comes in pre-spliced sheets up to 4'x8'). Some are prefinished.
http://www.treefrogveneer.com/ is one such source. Their sister company, Chemetal,
http://www.treefrogveneer.com/chemetal.htm sells metal veneers. This may be a better alternative to achieve the same look as your metal frame. For trimming metal veneers, use a spiral cut bit
http://www.amanatool.com/invectra/. 5) Glue: with manufactured veneer you can use spray adhesive. I avoid it like the plague with raw veneer because it leaves a rubber glue line and shrinks (joint creep between seams). However, if you use manufactured veneer you can have one full size piece per side and then there is no joint (except at the edge). After gluing a side, wait a few days for the glue to dry, then trim it with the router. Joint creep at the edges will be reduced. In your case, your veneer is 1/4" thick so this may not be an issue (as it would be 1/28" thick veneer). Yellow glue with clamping is good too. Cover all sides with paper for the squeeze out. Use two 3/4" pieces of MDF as cawls (clamping platens) on each side of the speaker (veneer side/opposing side). Gorrilla Grip polyurethane glue is great but required a lot of clamping pressure. Spread a very thin layer with a 4" plaster spreader on just the box. You must position and clamp your veneer withing 10-15 min so be ready to go. If you go the thin raw veneer route, you will find yourself dealing with time sensitive catalyzed glues and vacuum bag presses.
My last bit of advice is to test everything before you try it on your speakers.
So this is my brain dump at this late hour. I hope it helps.
Steve
