X-MTM and X-CS build

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JWCoffman

Re: X-MTM and X-CS build
« Reply #40 on: 6 Apr 2021, 04:47 am »
A lot of progress this weekend as I was able to spend quite a bit of time in the garage.
First off, I redid the acrylic baffles from last weekend.  Compressed air did the trick with keeping the guide bushing clear, but we'll be cleaning acrylic shavings out of the nooks and crannies of the garage for years now as a result.  I also revised the painting order which should work better.  I'm not going to paint the black until just before mounting them on the speakers in order to leave the protective film on longer.  So far everything looks good, but I won't know for sure until the final unveiling.


Rather than try to counterbore the tweeter hole in acrylic as described in Danny's plans, I cut the hole to the full dimension of the tweeter chassis and made some spacers to mount underneath the tweeter out of 9mm birch ply which I then had to plane down to the right thickness with my router in a rudimentary surfacing jig.  I wish I had thought to take a picture, it was...not professional.  However, they ended up being the perfect size.

Once the acrylic and spacers were done I used them as a template to route out the holes in the mdf which the acrylic will be mounted onto.  Once complete, I was able to round off the inside driver holes and even did the tweeter hole even though tt's completely unnecessary.




I then did a dry fit of the drivers and everything seems to fit great.



I cut two wide bases for the MTM's and routed fingerholds into the bottom with a round nose router bit to help with picking them up.  I painted the bottom of those black as along with the tweeter spacers.



I then spent several hours laying out the veneer cuts and cutting the individual panels.



Then came gluing.  I followed Peter's tutorial and got my veneer and Heat Lock glue from Veneer Supplies.  Peter seems to only use one layer of heat lock on each surface, but the instructions say two and I think I read someone else on here saying that made a difference for them.  I tried both methods on the back panels of the speakers and really didn't notice any difference in the ease of getting a good bond.  The only real difference is in the time it takes waiting for the second coat to dry and I can imagine on a surface that is less than ideal a second coat could really help make sure there are no voids.  For the most part the MDF surfaces are in great shape.  On any birch ply surface I may go with two coats depending on how the first coat dries.  If anyone has other experiences with this, please let me know since I still have the highly visible pieces ahead of me.



Mike Lundy's advice to pick up a carbide spiral down cut bit for trimming works very well, though the glue is starting to gum up the bit already.  I'll have to spend some time cleaning it occasionally.

While waiting for the veneer glue to dry, I mounted a piece of 12mm birch ply to the front baffles below where the acrylic will be in order to create a seamless front surface (well, as seamless as I can make it).  Since the acrylic is actually 12mm rather than a true 1/2", birch ply seemed to be the most logical choice to keep the thickness consistent.  Once glued on, I trimmed it to size and put a 1/2" roundover on it.

Finally, I drilled out the tube connector holes in the backs of all three speakers and pulled the leads through the holes.  I wanted to make sure this part was done before the front baffles went on.  I have no idea how I would have done that through a woofer hole.

Next steps:
- I'll need to glue up the front baffles on the MTM's to prep them for the next veneer step which will be the fronts and sides.
- Finish the veneer
- Affix the mounting hardware for the MTM bases and drill a hole to install the plug for the sand chamber in the bottom.
- Start the finish process (danish oil, grain filler, wax free shellac, then perhaps a satin poly depending on how it looks)
- Only when the veneer is on and finished can I trim the outer edges of the acrylic to size, round over the corners, and polish.

Thing I learned/Opportunities for improvement/Screw ups:
- You MUST wait until heat lock glue is completely brown before touching it to the other surface.  If there is any pink left, it acts like contact cement.  I ruined the original bottom piece of the X-CS and damaged the MDF a little in the process.  Lesson learned.
 At least nobody will see it.
- I need a better glue drying setup than my cold garage.  I'll need to carve out some interior space for glue drying next weekend, otherwise it will take far too long.
- All the moving around of the various pieces has damaged a couple MDF corners.  I've repaired them, but it's a hassle not having a space to be completely dedicated to shop work.  I need to completely clear the garage every night so we can bring our cars inside, which greatly increases the chances of something getting dinged.

Peter J

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Re: X-MTM and X-CS build
« Reply #41 on: 6 Apr 2021, 04:57 pm »
JW, I love that you're innovating and thinking ahead on processes. That you take the time and effort to understand the whys is refreshing. This often seems lacking in many projects I see, not just in the speaker building world. 

To clarify a couple of things. Concerning Heat Lock and two coats vs. one; I don't think there's a pat answer here, nor do the instructions state it's mandatory. The variables are many. Substrate porosity and/or  flatness. Application method, project size are a couple more. A simple test on one's specific project is probably prudent.
I'm a firm believer that the "more is better" way of thinking is just not true much of the time. More is just more, and may be better or worse depending on situation. I guess I embrace a minimalist approach that says "just enough is plenty".

Spiral cutters in general offer an advantage in many cases. Never has this been more evident than to me than with CNC. They shear rather than chop like conventional cutters and in many cases direct chips out of the cut.  I try to keep bearing out of glue by dropping router base.  I also use this frequently which seems to make getting the goo off easier.

https://www.practicalprods.com/onlinecatalog/bostik-bearing-lubricant/

On wiring after the fact. I've used a fish tape designed for electricians, but have improvised with all manner of things.

https://www.greenlee.com/us/en/product-overview-reel-x-fish-tapes?utm_campaign=_fishing+reel_intent_q3+21_ecdc_fishing_us&utm_medium=_2021+reel+x&utm_source=google&utm_content=google+text+ad


JWCoffman

Re: X-MTM and X-CS build
« Reply #42 on: 6 Apr 2021, 05:53 pm »
Ah, fish tape!  I should have thought of that since I've spent far too many hours trying to run cable through walls.  That said, it was remarkably easy with the front baffle still off.

Good thoughts re: Heat Lock.  My gut was pretty much saying the same thing: substrate conditions will largely determine the need.  My concern with two layers is not just drying time but also overall veneer thickness and how noticeable that glue layer+paper might be, but I'm probably overthinking that.

I should also mention that the glue build up on my trim bit is on the cutting surface itself, not the bearing.  I've got the bearing riding ~1/2" below the veneer surface which keeps it's path pretty clean.  I'll invest in some lubricant, however, since I definitely want to protect the sizable investment I've made in router bits over the course of this project.

Thanks for your feedback and for all your contributions to the community.  It makes it much easier for us newbs to jump in and give it a try.

jonsk2514

Re: X-MTM and X-CS build
« Reply #43 on: 6 Apr 2021, 06:55 pm »
These are going to be very interesting speakers...  :thumb:

A cleaner you can try for the spiral cutter is automotive brake parts spray cleaner.  I wet a paper towel or cloth towel with it and then wipe off things like what you are dealing with.  Be careful wiping the cutter that you don’t cut yourself.  Also, if you spray it on the cutter, keep it away from the bearing as it will strip the grease out of the bearing.  This stuff is oil free, so it won’t mess up your wood if it happens to get on them.

JWCoffman

Re: X-MTM and X-CS build
« Reply #44 on: 13 Apr 2021, 01:57 pm »
The finish is in sight.  Pun intended!

Dad jokes aside.  This past weekend started with gluing the front baffles on the MTM's.



The dowel holes I drilled a few weeks ago made this step super easy and I think pretty darn strong as well.

Then the rest of the weekend was spent getting veneer on.  I took over the TV room as a veneering station to keep the drying time down.  Even then, it pretty much took the entire weekend to apply glue, let it dry, iron on, and trim each piece.  The MTM front and sides went on in one piece and took an hour each just to iron it on.  I was probably going slower than necessary, but even then I came across a few spots that needed to be reheated for full adhesion.  Once again, Peter's video proved invaluable as I wouldn't have thought to use a flat file to finish the edges, but it worked great.  Sandpaper would have worked as well, but would have been less accurate and the glue would have meant going through a few sheets versus just brushing off the file and getting back to it.

I made a couple mistakes that only I would notice and know about.  Mostly in trying to get the grain patterns on the tops to line up with the sides.  The X-CS is the one that I wish I had back as one side looks great...


While the other side I inadvertently applied upside down.


At least the seam in the veneer lined up like I planned, so the overall finish still looks pretty good.  On the tops of the MTM's I didn't quite allow for the fact that I was giving myself a lot of wiggle room to line up the veneer pattern on the front and sides, so when it came to putting the top on I didn't actually have enough material to fully line up the seams.  It's pretty close and still looks good, but a lesson learned there.
Here are the speakers ready for finish.




Yesterday morning I got two coats of Danish Oil (Dark Walnut) and this is what they look like now.



After getting the second coat on, I realized I didn't want to go any further.  I had grand plans for some grain filler and shellac, but both my wife and I think they are perfect as is.  I'm now almost afraid to do any more, but I really feel I need to get a protective coat on, so my thought is to do a couple coats of wipe on satin poly after the danish oil has cured a couple more days (it's still pretty cold in the garage, so drying time is an issue).  I'm open to other suggestions, however.

Next steps:
- Trim the acrylic to size, roundover the edges and polish (the last scary step ahead of me)
- Finish the finish
- Install the bases
- Install the acrylic
- Basically, finish everything

I'm teleworking most of this week so I should have some time in the shop around meetings to get a lot of this done.  My goal is to be done by the end of next weekend.

Thing I learned/Opportunities for Improvement/Screw ups:
- Biggest mistake was mentioned above
- These things are really getting heavy now.  I'm 6'2" 220lbs and pretty strong, but I'm now really having to plan out how I move them around carefully, mostly so I don't damage them.  I still have the bases, acrylic, drivers, and some sand to add, so there's quite a few pounds of additional weight still coming.
- Don't overthink good veneer.  This walnut is gorgeous and has some great patterns that I think I highlighted pretty well.  Danish oil/tung oil are magical when it comes to highlighting good wood, so just let it do it's thing and get out of the way.

Tyson

Re: X-MTM and X-CS build
« Reply #45 on: 13 Apr 2021, 02:50 pm »
Those look amazing, nice work so far!  I can tell that this build you are a lot more confident than in the last build.

Also, I think for other people that are new builders, there's real value in the methodical, step by step approach you illustrate in your threads.

Hobbsmeerkat

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Re: X-MTM and X-CS build
« Reply #46 on: 13 Apr 2021, 03:24 pm »
That's some absolutely stunning veneer!
Really excited to see these all finished!  :thumb:

jonsk2514

Re: X-MTM and X-CS build
« Reply #47 on: 13 Apr 2021, 04:42 pm »
Beautiful!  :thumb:

Your MTMs are going to be heavier than mine, so I sympathize with your concern about having a way to hold on to them while moving them around.  You need something like a dog harness with the handle on it...

JWCoffman

Re: X-MTM and X-CS build
« Reply #48 on: 14 Apr 2021, 02:39 am »
Those look amazing, nice work so far!  I can tell that this build you are a lot more confident than in the last build.

Also, I think for other people that are new builders, there's real value in the methodical, step by step approach you illustrate in your threads.
Thanks, I'm really getting stoked about them now and the drying time with Danish oil is killing me as I know the finish line is close.  I did these mostly concurrently, but there's definitely a sense of making mistakes on one that you can make better for the other.  You are correct that I'm feeling much more confident about things now.
I got through the toughest part of the acrylic today, which went very well.  I'll wait until the final unveiling to share these last few steps.  At this point it's really just some paint, glue, and polyurethane to get the cabinets done.  All the cutting and milling is over.
Almost there.

JWCoffman

Re: X-MTM and X-CS build
« Reply #49 on: 14 Apr 2021, 02:43 am »
Beautiful!  :thumb:

Your MTMs are going to be heavier than mine, so I sympathize with your concern about having a way to hold on to them while moving them around.  You need something like a dog harness with the handle on it...
LOL.  I was actually thinking of something like these as a solution (not really)

https://www.amazon.com/Shoulder-Dolly-Moving-Straps-Efficiently/dp/B00022749Q/ref=asc_df_B00022749Q/?tag=hyprod-20&linkCode=df0&hvadid=167124268234&hvpos=&hvnetw=g&hvrand=12756616443786069786&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9033292&hvtargid=pla-312952868090&psc=1

JWCoffman

Re: X-MTM and X-CS build
« Reply #50 on: 14 Apr 2021, 02:48 am »
That's some absolutely stunning veneer!
Really excited to see these all finished!  :thumb:
Right?
I paid the premium for "architectural grade" veneer from Veneer Supplies thinking I was just being a sucker for the upsell, but this stuff is fantastic.  I LOVE walnut to begin with, but this stuff outclasses anything else we have in our house.

mflaming

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Re: X-MTM and X-CS build
« Reply #51 on: 14 Apr 2021, 01:47 pm »
Wishing I'd gone with walnut on my project now! I'm using architectural grade white oak from veneer supplies - it is also great quality, but not as pretty as walnut.

On my SLS project, I plan to attach a small solid wood block on the back of the cabinet 8-1/2 in down from the top to provide a finger hold to make moving a little easier. Screwed into the internal bracing, it should be strong enough. It'll be 3/4 by 3/4 by 4 in or so. I think I can contour it to make it look nice.

JWCoffman

Re: X-MTM and X-CS build
« Reply #52 on: 15 Apr 2021, 02:48 pm »
Wishing I'd gone with walnut on my project now! I'm using architectural grade white oak from veneer supplies - it is also great quality, but not as pretty as walnut.

On my SLS project, I plan to attach a small solid wood block on the back of the cabinet 8-1/2 in down from the top to provide a finger hold to make moving a little easier. Screwed into the internal bracing, it should be strong enough. It'll be 3/4 by 3/4 by 4 in or so. I think I can contour it to make it look nice.
I was thinking of something like that on the back myself and was considering handhold like they install on pro PA gear.  After starting to build the boxes I realized how big these were going to be and thought that wouldn't be sufficient as there wouldn't be an obvious place to hold it on the front.  I figured a handhold on the front of the base and using one of the ports would provide a good grip.  Of course, that means getting low to pick up a relatively large, top heavy speaker, so that may not be the best plan either.  We'll see.  I think it will be best to plan on these being a 2-person move getting them down into the TV room.

JWCoffman

Re: X-MTM and X-CS build
« Reply #53 on: 16 Apr 2021, 05:07 pm »
Much progrees and many pictures incoming.

Since my last post I put 3 coats of wipe on satin polyurethane to protect the cabinets more.  I didn't really document that part since it's pretty boring, it did add a touch more sheen to the cabinets than the Danish oil which brought out the grain a little more.  I briefly considered knocking the sheen back with some 00 steel wool, but thought better of it.

Here's a photo of the various layers making up the front baffle (mdf, BGB ply, and veneer).  I like how well bonded the veneer looked around the bend.



Between poly applications, I finished trimming, milling and polishing the acrylic.  Up until this point I left the acrylic oversized by about 1/8" so I could trim it down to size once the veneer was on and largely finished.  This actually happened before the first coat of poly, and I used some painters tape to protect the finish from the router bearing.  I then ran it through a 1/2" roundover on my router table to get the edge shape.  Next came 320 wet/dry on a sanding block to remove the tooling marks then 600 wet/dry in hand to knock down the 320 grit.



Finally, some compound on the buffing wheel brought it to a shine.  I did find that once I painted the backs of the acrylic black, I noticed a few spots I had missed, so these took a couple rounds to get right.


I also got the bases and bottom of the MTM's ready for final assembly.  The hole in the middle will be where I fill the sand cavity and will be plugged with a removable marine plug.





After the back of the acrylic was painted in flat black and the final coat of poly had dried, I did a dry fit of the acrylic.  Everything looked good.




My original plan of gluing the acrylic was to use black E6000.  Since I had added veneer to the cabinets, that meant I also had to add space between the acrylic and the mdf so it would sit either flush or just a little proud of the veneer below it.  I ended up having to add two thicknesses of veneer as a spacer since the acrylic was just slightly thinner than the 12mm BB ply.  My plan was to tape the edges of the acrylic and veneer really well and essentially use the glue as a visual seam between the two materials.  It didn't end up working out that way.
The glue step was a little stressful as I found my tube of E6000 had gone bad and was extremely difficult to work with on the X-CS.  I had to redo my plans and ended up using clear E6000 (that's all they had at the local box store) with black silicone sealant to seal the gap.  I think this worked out to be the best solution anyway as the silicone is much easier to work with in a tight seam like I had.  I wish I had gotten photos of that part, but things were moving pretty fast and I didn't think of it.

Finally, after a long night of soldering, drilling, burning my fingers, etc.  They are home.

















The effect of the acrylic is hard to describe.  I had not anticipated how much it would act as a magnifying glass on the copper paint beneath, though it seems obvious now.  So as you move horizontally past the speaker, it changes shape and color.  From the side the copper dominates the acrylic and exactly matches the lighter tones of the walnut.  This was not planned, but was a very happy accident.  The black becomes apparent as you move to the front.  It's kind of insane.

There is a lot more to do in the room to make a more permanent platform for the center channel, give more room to the left channel and dial things in more.  This is not to mention getting some front wall treatment.
Overall, very pleased with the outcome.

I'm not really going to do a screw ups on this post as I just want to focus on the things that went well.  I'll have plenty of time to think about the many small imperfections.
Thanks for reading, supporting, advising, and helping make this a very fun learning process.

Jason

PS: Still burning them in, but the top end clarity and extension are the first things that jump out after about an hour of listening.

Hobbsmeerkat

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Re: X-MTM and X-CS build
« Reply #54 on: 16 Apr 2021, 06:04 pm »
Wow!  :o

Those turned out absolutely gorgeous!  :thumb:

Im sure they sound as good as they look! (If not better)

hawkeyejw

Re: X-MTM and X-CS build
« Reply #55 on: 16 Apr 2021, 06:10 pm »
Woo boy those are some beauties. Love the unique approach you took, they look super custom and I'm sure they sound as great as they look.

jonsk2514

Re: X-MTM and X-CS build
« Reply #56 on: 16 Apr 2021, 07:15 pm »
Much progrees and many pictures incoming.

....

I'm not really going to do a screw ups on this post as I just want to focus on the things that went well.  I'll have plenty of time to think about the many small imperfections.


Really - mistakes on those?  I am sure that even the Mona Lisa has a flaw somewhere and that da Vinci won’t say where it is. 

Original and Beautiful - nuff said...  :thumb:

Tyson

Re: X-MTM and X-CS build
« Reply #57 on: 16 Apr 2021, 07:18 pm »
Speakers look amazing, a quantum leap up in quality with your 2nd build!   Your living space is very cool too.

mkrawcz

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Re: X-MTM and X-CS build
« Reply #58 on: 16 Apr 2021, 10:40 pm »
Those look awesome.

JWCoffman

Re: X-MTM and X-CS build
« Reply #59 on: 16 Apr 2021, 11:55 pm »
Speakers look amazing, a quantum leap up in quality with your 2nd build!   Your living space is very cool too.
Thanks, I appreciate that.  One thing to clarify is that these are my first build.  You may have me confused with someone else or it took me so long to do it that you thought it was two different builds, which would be entirely understandable.  It was a lot to take on for a first timer, but the risks turned out to be well worth it.