Anarchists Build Log

[4thtry]

I put together a spreadsheet showing how much the VituixCAD curve slopes change when I flip from partial to full spin data. When setting up your target curves for Listening Window and In-Room Response, this should give you a good idea as to how much you need to compensate. No compensation for the Listening Window target curve and about 0.14dB/oct compensation for the In-Room Response target curve.

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Regarding your other questions, I'll give these a try as best I can. Not sure about 9ms gate in ARTA before export, will have to skip that question. Regarding the merger tool in VituixCAD, I do everything without minimum phase. I adjust the delay value manually to align NF phase with the FF phase curve. "With 2 channel data, Z offset is not needed and should be cleared to zero?" In VituixCAD, Z offset is generally zero'd out, but only for flat, non-stepped baffles. The X & Y values are still used for simulation in VituixCAD. The x,y,z values that you have entered above appear correct.

[4thtry]

I tried to edit my post to correct a typo, but then the spreadsheet disappeared. Here it is again:

[wogg]

Interesting analysis Bill! I hadn't really considered how the lack of 360 degree data would effect the power response target. I have a stack of parts with some adjacent values to play with when I get to the real life prototyping phase. For now I've pivoted to finish.

Here's the right side baffle, at this point I was ready to do one more layer of red dye to get it deeper before doing the poly seal.



Pro tip: glue residue on boards is invisible until you start staining, use a solvent on the bare boards first! I hear lacquer thinner will show you where the glue is, as will a black light for some types of glue.

I think there may have been a piece of tape on this board at some point, the lack of penetration is in a slightly rectangular area. This was not visible at all until the ebony stain was applied.



There's not a lot of good methods to fix this after the fact, blending will be difficult. On some cabinet maker forums someone mentioned using sandpaper dipped in the stain to work it out, adding stain while sanding through the glue residue. So in an effort to avoid sanding the whole baffle down for a complete re-do, I gave it a shot.



I gave it a couple applications, let it soak a good while...



Well crap, that made it worse.

Now I'm back to sanding this baffle down to clear that area and re-apply an even finish. I figure I'll do both baffles so the end result is consistent. Taking a lot more time than planned, but on the upside the last time I did this add finish / remove finish / refinish and repeat business it resulted in a depth that was pretty cool.

[PWR RYD]

I've never considered any measurement further than 60 degs off axis worth taking or worrying about. Thanks Bill for confirming that.

[PWR RYD]

Sorry wogg for continuing the off topic. And sorry for your finishing woes. I'm sure they'll sound and look great when you're done.

[wogg]

Actually not a huge deal. After sanding down with 220 grit the look is even and quite cool in a kind of vintage weathered way.



Not enough red left though, so another hit of RIT.



After drying and rubbing down these may be ready to seal. I'll check them out tomorrow and see how I feel about the color.

[tomzarbo]

Looking good! This makes me wonder why I hardly ever use oak, it looks pretty nice.

[4thtry]

Nice fix. The problem area appears to be completely gone.

[6thplanet]

That's looking sweet!

[PWR RYD]

They look great!

[unclejunebug]

Looking great! Bummer about that adhesive spot but it looks like you fixed it up nicely. I had even considered using RIT dye on wood. Interesting idea!

[wogg]

Baffles are all set, definitely have some weathered rustic style.



Now the MDF needs finished. The weather is cooperating a bit so I was able to sand the back sides flush, my inset wasn't perfect so the lip to the rear panel had +-1mm or so that needed straightened out. So I bolted them on with the weather strip seal in place to settle them in for a while then removed the bolts and belt sanded them around the edges to bring everything to flush.


I was going to use white Duratex only because I have plenty on hand, but black would just look better with these baffles. The white would have been good with a bamboo or other light wood baffle, but the dark red will lend itself better. Now I have to make another order... not enough black on hand to cover everything.

Pondering Duratex vs. ExoHyde... Is the Exo worth saving $5 on a quart???

[Steve Lee]

No - stick with your original coating material.
Start a new project with the ExoHyde.

YMMV.

[wogg]

This post had pictures yesterday. :(

[wogg]

Just added the pictures back to the post... I'm pondering how to make progress on the stands before getting out the rollers for the Duratex. The weather continues to get better in central OH, should be able to make some sawdust outside soon if other obligations don't get in the way.

[wogg]

Final prep for the bottom of the cabinets before they're paintable. I installed three 1/4-20 insert nuts for bolts to the stands. Here's the stand top pieces that need a little cut down, sanding and boring for the 2" dowel in front, the 1" steel pipes in the back, and 5.5" centered holes to clear the outside of the port. I'll do a 45 degree chamfer around the outside edge and the port clearance hole as well.



At the junction between stand and cabinet, right where those 1" steel pipes are we'll have the hidden banana jacks. These will serve as the connection point from stand to cabinet with the wire running down the pipe and into routes leading to the back edge of the stand bottom where the main connection terminals will be.

I was just going to do a 3/4 or 1" hole straight through and glue a metal piece behind to mount the jacks, but they landed right in the edge of the internal 1x2 lip for the back side. Needed a new plan.



Turns out the jacks fit right in a 1/4" washer with a 3/4" outside diameter. A 1/4" deep bore with a Forstner bit, and a 1/2" hole to the inside will let me drop and glue the jacks in there.



Holes ready, and here's how the jacks fit.



That'll do! The jacks are straight holes to the inside, but with the stands mounted and banana plugs providing the signal it shouldn't affect the woofer at all.