Design Opinion or Criticism?

[fredygump]

I'm a bit stuck...I guess I'm waiting for some kind of inspiration. I'm torn between doing a sculpted baffle (gloss black) with radius corners, or making the perfect pillar with black laquered wood grain-- the speaker would have square corners and a grill that is flush with the cabinet sides.


Two versions of the scuplted baffle.

What do you think?

 

[kouiky]

I like the righthand version.

There must be people still doing speaker woodwork and piano finishes where you are, or else you ate skilled in the art. I’ve searched for 2 years+ for someone to do a finish and not even a piano shop would get off their seat to make a normal person’s months salary in one job.

 

[fredygump]

I’ve searched for 2 years+ for someone to do a finish and not even a piano shop would get off their seat to make a normal person’s months salary in one job.

Have you tried an autobody shop? I'd look for one that does custom paint, classics restoration, etc, not insurance work. If you have the prep work done and just need it sprayed, it shouldn't cost much. I had a guy spray some molds (for fiberglass parts) for $200 awhile back.

My parents were in the piano business and refinishing business, and I learned that it is challenging to get a smooth gloss finish over wood grain using traditional materials like laquer. Not worth it!

But it is much easier with modern 2k polyurethane/ acrylic finishes that are used in the automotive industry. I would even use a 2k clear over wood grain, although I'd probably have to coat it 2x, and sand inbetween coats to get a smooth finish.

 

[kouiky]

I don’t want to derail your thread, but yes that is the path I’m on now.

I’m taking them to a woodworker tomorrow for a prep estimate, and later an automotive shop will finish them. It’s even hard to find custom automotive shops that paint worth a damn up here in Canada. They don’t want to flat sand between coats. Think orange peel on a six-figure car going to SEMA - that’s what I saw when I interviewed them. I originally wanted polyester for its hardness, flat as glass appearance and piano professionals don’t usually settle for less than excellence. Cost didn’t matter much.

About your speaker:
Is it a progressive concept at this stage and have you chosen drivers, etc?

 

[Randy Bassinga]

Primer from a can, wet sanding with 600, black acrylic from a can, wet sanding with 1000, epoxy with brush, wet sanding with 1000 and remove eggshell totally and check with water splash. (water break free). clear acrylic from a can, many coats, wet sanding with 1000 + 2000, auto cutting compound, wax and buff

Car paint shops fill cans

 

[kouiky]

Thank you both. I’m concerned to attempt it, but the results can be great. Automotive primer or something else for use on veneer/wood?

I’ve had this video saved for a long time, although he used a spray gun and catalyst with the primer.

How to Get An Amazing Piano Gloss Finish

 

[jan.didden]

Note that the better rounded the corners are, the better the sound reproduction. Sharp corners cause secondary waves that mess up the soundstage.
The larger the rounding radius the better for the sound.
So there's a bit more to it than just aesthetics (unless that is your prime consideration of course).

Jan

 

[fredygump]

About your speaker:
Is it a progressive concept at this stage and have you chosen drivers, etc?

I currently have 2 prototypes set up in my living room. I thought one "prototype" was going to be the finished speaker when I made it, but a couple design details don't sit right with me. Because I only had one built, I felt I still have an opportunity to change it. The one I built is most similar to the speaker on the right, but the issues are fixed in the drawing.

The practical differences: the one on the left has a 1/2" thick plate that covers the speaker flanges, and that plate has a radius to reduce reflections. The speakers are front mounted onto the baffle, and then this plate sits over the top of the drivers using different mounting holes.

The speaker on the left also has front mounted drivers, but the cosmetic plate is 1/4" thick and uses the same mounting holes as driver, so the driver would be "sandwiched" between the cabinet and the plate. Making this cosmetic plate is more of an issue than I thought. My first idea was to cut this plate from 1/4" aluminum, but I didn't realize how expensive that would be. A plywood ring would be easy to make, but I'm pretty sure tightening the bolts will crush/ deform it, since the bolts have to be eight enough to secure the drivers. I could make it out of fiberglass or carbon fiber, but I think the same problem would happen.

(I can replace the foam gasket on the drivers with a wood spacer, to prevent the deformation, but then I have more vertical surface to cause reflections. I'm using coaxial drivers that have a high frequency wave guide, so not sure if I need to worry about reflections for measurements. But cosmetically the vertical surface around the driver wouldn't be ideal.)