another X-static build

kmillsmatsci · « **on:** 22 Jun 2020, 01:59 pm »

I just got started on my X-static build. Its going to be a mid century modern take using stained baltic birch for most of the visible wood work and MDF for internal baffles and the feet. Its a work in progress and I will be making some design decisions as I go. Right now i plan to stain the birch walnut or a dark cherry and leave the laminated edges natural or a lighter stain, think Eams lounge chair. I may do a dark black stain on the side panels.

AlexH · « **Reply #1 on:** 23 Jun 2020, 11:30 am »

Nothing like starting a new build. Have fun and then enjoy the music.

jcsperson · « **Reply #2 on:** 23 Jun 2020, 02:40 pm »

Quote from: kmillsmatsci on 22 Jun 2020, 01:59 pm

I just got started on my X-static build. Its going to be a mid century modern take using stained baltic birch for most of the visible wood work and MDF for internal baffles and the feet. Its a work in progress and I will be making some design decisions as I go. Right now i plan to stain the birch walnut or a dark cherry and leave the laminated edges natural or a lighter stain, think Eams lounge chair. I may do a dark black stain on the side panels.

If you're going to make the side panels black, I'd be inclined to make the edges of the baffle black as well for continuity.

Looking forward to watching this build.

Hobbsmeerkat · « **Reply #3 on:** 23 Jun 2020, 02:47 pm »

Likewise! Its always great seeing how these builds turn out, cuz everyone has a different designs or idea their going for.

Captainhemo · « **Reply #4 on:** 23 Jun 2020, 07:29 pm »

tagging along as well, should look cool when all done

jay

kmillsmatsci · « **Reply #5 on:** 17 Jul 2020, 02:31 pm »

Making some progress....

This was a bigger project than anticipated but my father in law has a bad ass shop and is helping make this an heirloom quality build.

There have been a lot of decisions to make along the way about cutting technique, order of operations etc. due to the drawing package essentially being a design intent rather than instructions. We have three engineering degrees between us so we are not having problems per say, its been fun figuring out how to execute the vision in the drawings.

we are using biscuits for panel alignment during glue up and and considering doing a spline to align the baffles within the side panels.

the 10 degree side panel cut was an open ended question for a while, we ended up making a very careful table saw cut to make a master and then clamping the rest of them to the "mother" panel which then rode a custom table saw fence.

Hobbsmeerkat · « **Reply #6 on:** 17 Jul 2020, 02:57 pm »

These are looking great so far!

hawkeyejw · « **Reply #7 on:** 17 Jul 2020, 03:23 pm »

Looking good! What kind of finish are you planning to do?

kmillsmatsci · « **Reply #8 on:** 19 Jul 2020, 08:34 pm »

We made a bit more progress, We used a 0.25 inch dado blade to cut 0.25 inch depth spline grooves into the side panels and baffle sides and then made 0.5x0.25inch splines (keys?) to support the baffles during glue up. This way we should be able to glue it all up at once except the back panel. I think I'm going to use screws to hold the entire back plate on so I can have relatively easy access for a future no-res and crossover upgrades. It will be cool to get used to the speakers for a while and then hear the upgrade.

And yes, the half baffles mount on the back plate not the front, thats just gravity for you.

As for finish, I am going to do trials on scrap for a dark cherry stain and walnut and see what I like best and then finish it in a satin clear coat. I want to leave the birch sides un-stained if possible to show off the layers like an Eams chair. Most corners will get a 0.75 inch radius to accentuate the edges and the front baffle will get a radius on both edges giving it a full 1.5 inch bull nose profile. The back panel will get a radius of half that to facilitate the screw connection.

I'm leaning hard towards a gray stain such as this for the side panels:
https://www.homedepot.com/p/Varathane-1-qt-Smoke-Gray-Classic-Wood-Interior-Stain-2-Pack-355404/311320198?mtc=Shopping-VF-F_D24-G-D24-Multi-Varathane-NA-Feed-SMART-NA-NA-Paint_Varathan_Classic_INT_Liquids_Smart&cm_mmc=Shopping-VF-F_D24-G-D24-Multi-Varathane-NA-Feed-SMART-NA-NA-Paint_Varathan_Classic_INT_Liquids_Smart-71700000067238961-58700005868074662-92700053689799115&gclid=Cj0KCQjw3s_4BRDPARIsAJsyoLN8hZqhi0yvov9eVwGgCXiZDcCajnvpbAqffu-xjSDscEvIKfP86A8aAp-EEALw_wcB&gclsrc=aw.ds
I'm thinking that will break up all the wood and be reminiscent of the black leather of the chair but show off the grain still, but my wife thinks that's nuts...

Keithh · « **Reply #9 on:** 20 Jul 2020, 05:56 am »

Quote

Most corners will get a 0.75 inch radius to accentuate the edges and the front baffle will get a radius on both edges giving it a full 1.5 inch bull nose profile

Remember the surface mount drivers have a frame that is 7-1/4" in diameter. If you are using the standard 8-1/2"
wide baffle, the flat area between the 3/4" corners will be 7" so the edge of each driver will hang out 1/8" over the radius.

kmillsmatsci · « **Reply #10 on:** 20 Jul 2020, 01:06 pm »

Good catch! I'll check it out and adjust if needed

kmillsmatsci · « **Reply #11 on:** 25 Jul 2020, 12:43 am »

Thanks Keithh, you were right, there was going to be a small overlap. Thank you, not sure we would have test fit it. We switched everything to 3/8 inch rounds except for the back side of the open baffle which remained 3/4".

We also worked on the intersection of the rear open baffle board, the top plate and the front panel. its a complex situation when you throw in rounded corners. I forgot to take a picture but we decided to terminate the round on the top plate about an inch before it enters the joint which solves what would have been an intersection of three boards, a 10 degree bevel and two different radius corners, scary.

kmillsmatsci · « **Reply #12 on:** 29 Jul 2020, 05:51 pm »

We made some more progress last night by doing final assembly and cutting critical parts to actual, as-built dimensions. The hardest part was cutting the 10 degree bevel into the open baffle back plate. Since we did all the routing before this it no longer had any true edges to help keep things square. We also spent a good chunk of time figuring out just how much to cut off and then translate that dimension to the visible face on the table saw. The second one was super fast once we figured out what the heck we were doing. We used hand planes to true up the joints after getting super close with the table saw and used a spoke shave to blend some high spots.

Our only mistake so far was accidentally reversing a bevel direction on the top plate. we were able to flip the board and hide the mistake within the box volume. It's part of the joint where the side plates, front plate,top plate and baffle backer plate all join up so its already a crazy strong joint so I'm not going to lose any sleep about it.

Hobbsmeerkat · « **Reply #13 on:** 29 Jul 2020, 05:59 pm »

Damn! Im impressed by the work you've done already! I cant wait to see how these turn out!

hawkeyejw · « **Reply #14 on:** 29 Jul 2020, 07:47 pm »

Looking good!

Carlos74 · « **Reply #15 on:** 29 Jul 2020, 07:56 pm »

Those are looking great!! Fabulous idea with the removable back for easy access to place no-rez and upgraded crossover.

Enjoy the build!!!

kmillsmatsci · « **Reply #16 on:** 2 Aug 2020, 12:42 pm »

Home stretch! We glued up one box on Friday and may do some more today. I did some fine sanding with an RO disc sander up to 220 grit and it made a huge difference in the Baltic Birch figure, I may not stain it and just clear coat it at this rate. Also, I made the decision not to round over the top of the side plates and back plate, this gives it a crisp edge all the way around the top of the box in contrast of with every other edge. Also the 10 degree bevel in the back plate makes it look like a really intentional aesthetic.

We did not glue in the baffles or the back plate for the open baffle section, it made more sense to break it up. We used hide glue rather than standard wood glues due to the extended working times. Even with the two of us the extra time was handy (think Lucy in the chocolate factory, even with a lot of pre-practice and dry fit up and staging of clamps). There are a significant number of biscuits that all needed to be glued and assembled which was complicated but assured perfect alignment during clamping. I was skeptical when my father in law insisted on it but it paid off and I think it will be stronger too.

Question: whats the best way to wire the MTM section and get it into the main box? I don't see a lot of pictures and we are considering running a channel between the two open baffle plates. Getting the wires to the channel poses aesthetic problems too. Please point me to pictures of clean jobs!

Peter J · « **Reply #17 on:** 2 Aug 2020, 02:55 pm »

Nice! I'm guessing your FIL appropriated the apron, but maybe not.

I can't point you towards photos, but some have run wiring through dado between the open baffle parts. As I recall, the cleanest used a channel around driver hole and a centered slot. Could also run up side and an intersect driver opening. Both may be possible still if you haven't glued back piece on.

Fussy to wire that way, but a really clean look.

You could also run wire externally in flex loom and some clamps to keep it crisp and clean.

I'm not a fan the look of stained Baltic Birch and if I wanted color it a bit, would use dye tone coats using between clear coats. This assumes spray capability. To my eye, most stains tend to obscure the muted grain of birch and look blotchy. It's a lot like maple in that regard. Gel stain mitigates that to some extent.

AlexH · « **Reply #18 on:** 2 Aug 2020, 07:39 pm »

I did what Peter suggested. I cut slots around the driver hole. I then drilled between each driver hole into the slots. To bring the wires from the lower box the the upper woofer I drilled a hole at an angle from the bottom of the lower upper driver hole into the lowere box cavity. I believe I got this idea from Jay or Mike. It was kind of a PIA but made for very clean looking install. Its hard to get a picture of but here they are.

kmillsmatsci · « **Reply #19 on:** 3 Aug 2020, 02:34 pm »

Thanks guys!
And that apron is all him!