Cabinets: We have table saws, a jointer, smaller router, glue and plenty of clamps. What else might we need? I perhaps might be able to make that "outer front baffle plate" out of aluminum, as I have a CNC milling machine in my machine shop. While I know I can make it look VERY cool because I can radius the edges and anodize it any color, would there be any sonic good and bad about doing it?
Your tools would be plenty to do the job.
An aluminum front baffle plate would look very cool, but there would be no sonic differences between it and MDF. For a while Jim Salk had anodized aluminum front baffle plates for the early versions of the SongTower RT (the ribbon tweet version). They sold out a long time ago and he uses MDF now. He says there was no difference in their sound.
Finishes: I can get a 4'x8' sheet of 3/4" MDF with cherry veneer for $76. Would this be easier than attempting veneer for the first time? If we attempt veneer, what thickness would be advised if we were to try wrapping around 1/2" radiused corners of the front baffle? If I use the cherry veneer MDF, we'd have to stick with square corners.
MDF with cherry veneer at that price sounds too good to pass up. If you like the look of that veneered MDF, I would go for it.
The first time I applied veneer (to much smaller cabinets) I found it difficult, and didn't like my results. It took me some practice before I got comfortable doing it. I've tried the contact cement method and the wood glue method. I much prefer the wood glue method. (Dilute wood glue with 1 part water & 1 part wood glue. Paint the MDF surfaces with 2 coats of wood glue, allowing each coat to dry. Apply the veneer, and use an electric iron to heat and melt the glue. Use a protective cloth between the iron and the veneer, and keep that iron moving all the time. Practice this on scrap wood before doing the real thing!!)
Some people apply veneer last after the cabinet is assembled, and others veneer the panels (while slightly oversized) before trimming and assembly. Think about it some, and take your pick. If I were doing it, I would veneer the MDF panels before assembly. Jim Salk says he has a "cold press". It's a large heavy plastic vacuum bag and an expensive vacuum pump. I've never seen one in use.
I've never tried wrapping veneer over rounded edges. I'm not sure a ½" round over would work without cracking the veneer. In the Salk speakers like the SongTower or the HT-2TL, all the veneered edges are on squared corners. The black painted MDF panel, that outer front panel, has the rounded over edges.
Any got photos of finished speakers they can post? I know Photobucket has turned to a giant moneysucker and they aren't getting my money either. I downloaded the documents kindly posted here, but didn't see and photos of finished product. How do the response plots of thee compare to something like the Salk Veracity HT-2L?
For photos see this link
https://forums.audioholics.com/forums/threads/looking-for-proven-diy-that-is-better-than-klipsch-r-28f.110015/#post-1226125. You can look at photos of the Salk HT-2TL and copy it's look as much as you care to. The cabinets are the same dimensions.
The ER18 MTM's response compares closely to the HT-2TL. The crossover designer was the same person. The major sound quality difference is the Seas ER18 mid woofers produce a somewhat less detailed sound than the much more expensive Seas W18 magnesium alloy woofers of the HT-2TL.