Ensemble - 7+ Channels feat. the King Coax and little brother Rex

[technodanvan]

I thought about tackling the high pass filter next, but it's the easiest of them so I decided to defer on it until later. I've been waking up earlier and earlier of late so I decided to work on the crossover for the mid next. It's very three dimensional and I need to make sure it'll fit through the PR holes and around the brace once loaded up.

I also got all the mass loaded vinyl cut and some of the mass loaded foam cut as well. I'm a little behind schedule but should be able to make my end-of-June deadline for the second cab provided I don't get too distracted with other endeavors....like making three tables for a bedroom to match the bed frame I made. Pretty sure the center table (a small TV stand) will have audio capabilities so I might have to document that. It won't be hi-fi given the many constraints on the design, but it'll be a far sight better than the TV speakers themselves.

[technodanvan]

My first attempt with using thermoplastic polyurethane (TPU) filament, which is 'sort of' a very hard rubber alternative. I don't think it will be suitable as gasket material for the input plate (at least not the stuff I tried) but it might work fine for isolating the bolt that will attach the feet to the base. Tolerances were perfect for a 3/8" bolt, and even nailed the 82 degree taper for the particular bolt I was thinking about using.

Of course, this got me thinking about what nut to use on top...and now I'm thinking I want to have new pucks/disks made that are threaded for the top piece.



In other news I think I have finalized the mid crossover layout boards and have moved on to the tweeter. Still need to check spacing to be sure the mid boards will fit though. I have some concerns!

[technodanvan]

Disaster! (almost)

I finished adhering foam on the inner sides of the second cabinet and moved to attach the first 18mm chunk of wood for the rear. No big deal, right? So I started clamping down on it and realized with the second clamp I got turned around somewhere. I was adhering the back to the front of the cabinet! I removed it and slapped the baffle on, centered as best I could by eye, and clamped down. For the first speaker I had an extra set of hands and placed center markers on both pieces to ensure a perfect fit. Hoping this will work out without issues. I think it looks okay...though I'm a bit worried about the amount of glue used since a little came off with the rear and I didn't think to add more in between.

That's what I get for doing this before I had coffee this morning.

[theSven]

Good thing you got it corrected before the glue had dried. Hopefully a nice sand job will get this sorted and then once the cabinet is finished one will never know... Share some photos when you get a chance. Glad to read you're progressing a bit on this this build!

[Steve Manning]

I'd like to say I've only done that once! 🤪

[technodanvan]

Alright, so box is assembled more or less and I finally did the thing I've been dreading a bit - cutting in the back panel. I'll need to get a different router bit to clean up the edges but this should work. Rabbet will be cut once the edges are cleaned up. Haven't decided what material I'll use for the door yet.








First time I have them upright and next to each other. Got plenty of patching and stuff to do yet but we are close to painting. Maybe by the end of the month I can get them dropped off.

[theSven]

Great to see some progress on these cabinets!

[JonMarsh]

Slow work takes time, but you're making some good progress!

[technodanvan]

A little more progress. I wrapped up the opening on the rear, the need a bit of sanding and maybe routing to make them more square, but theey look pretty good. Ended up with a 5/8" deep rabbet for now, though I could go deeper if necessary. All routing was done on a cordless Milwaukee 1/2" router. Cut like butter, and barely used any of the battery. Granted, I used just about the biggest baddest battery they make.

I haven't decided what I'm going to use for the access door though, so I'm open to suggestions? Aluminum is a definite possibility...

Anyway, I'm stuck on the cabinets now - I need the bases back so I can mark and drill out the attachment points on the bottom of the speakers before I round over those edges. Once that's done though, it's just patching and sanding!

In other news, I have a new obsession: AI music. I've made over 50 tracks in a week using Suno. Not sure I'd call them audiophile-worthy, but they're really darn impressive considering the very little time it took to make many of them. The Procrastination Song (https://on.soundcloud.com/qNj11qociO91H4ofmw) might be my favorite, and by far the most applicable to this project given most of the rest are about a video game.

[JonMarsh]

Good wood working can be a bit messy, eh?

[technodanvan]

My wife happened to help with a bit the other day. I was informed I should invest in a dust collector for next time. Picture incoming...

[Steve Manning]

Looking good Danny. One option for the access plate is to use BB with a carbon fiber veneer on it. This place has many options including colors. https://dragonplate.com/

[technodanvan]

That's interesting, and I'll bookmark for future use. I'm not sure that style would mesh with the other stuff I'm doing for this though. I think it either needs to be aluminum (to match the feet) or painted wood (to match the cabinet)? I'm not sure.

[theSven]

Steve giving me ideas now! I'm thinking it would have been really cool to use that to wrap the ribs for the builds I did. It would really pop with the BB pieces. Cool share on the carbon fiber veneer.

[technodanvan]

First of all, don't tell OSHA about this picture...but it got me a dust collector on the way.



Second of all, my polisher sent me this.

[Steve Manning]

Well 2 obvious questions, is the copper plating on the aluminum and what collector did you order?

[theSven]

Curious about these 2 questions too.

[technodanvan]

That is indeed copper plating on the aluminum, all aluminum parts currently made for this project are undergoing the same process. Unfortunately I have a few more being made since there was a bit of a change to the bases...which is why I'm thinking about the back plate too! They use some kind of clearcoat to keep the copper from oxidizing...really hope it works.

Edit: I'm also considering having bolt heads copper plated...but I'm also thinking that having the bolts chromed (or polished stainless) might be a nice contrast. Thoughts?

As far as the dust collector, I went with the Oneida Mini-Gorilla that was recommended to me a year or two (or more?) ago by a member here.

https://www.oneida-air.com/dust-coll...s/mini-gorilla

[Steve Manning]

Nice ....

[theSven]

Can you share a cad image of the copper bolt heads vs non copper?

[technodanvan]

You know, I haven't tried adding bolts in CAD yet theSven. Probably wouldn't be a bad idea to try. That said, there shouldn't be any visible bolts on the bases, and the back is, at it turn out, on the back, so really the only visible ones would be those holding the drivers in.

[theSven]

You know, I haven't tried adding bolts in CAD yet theSven. Probably wouldn't be a bad idea to try. That said, there shouldn't be any visible bolts on the bases, and the back is, at it turn out, on the back, so really the only visible ones would be those holding the drivers in.

In that case I think the copper would look pretty cool to contrast with the cabinet and the spike mount on the bottom. My vote is yes.

[technodanvan]

I picked up the first batch of copper plated aluminum and I feel like it's a mixed bag. From a distance they all look pretty great, which is all that really matters I suppose, but up close there are some defects. The only ones that really matter are where the clearcoat has been chipped off a little - I need to source something to fix those bits. On the great news front, my 3D printed rubber inserts fit into the feet very well, better than in the 3D printed feet my a long shot.

Today I marked up the bottom of each speaker by resting the plate on a flat surface, then laying down a 1/2" sheet of MDF and setting the speaker box on top of it. This got my offset roughly where it needed to be. I had intended on using a Forstner bit to countersink the bushings that will be between the baseplate and the speaker but, much to my chagrin, I found I didn't have the right size bit (2 3/4"). I couldn't find one from my usual preferred brands (Amana or Famag Bormax) so I ended up ordering a cheapo one. Hope it comes sharp and stays sharp for a dozen shallow cuts. I also don't believe I have used such a large Forstner in a handheld drill before so I need to make some test cuts to be sure I can be reasonably accurate. Worst case, I just don't countersink anything into the speaker and it ends up raised by around a quarter inch.

Also, does anyone know of a jig or something that could be used with a handheld drill and a large Forstner such that I could make repeatable, specific depths of cut? Otherwise I'll just do it by hand.

Pic of the bottom two pieces of a foot. The rubber between each layer is 1/8" thick while the bottom is a bit thicker at 3/16". The through hole on the aluminum parts for this is 1/2" - but the rubber extends through it with a 3/8" hold for the bolt to pass through. This way there is no metal on metal contact, including on the bottom which is crafted such that an 82 degree flat head bolt (such as that pictured) will rest into the rubber. This is not designed for use with a spike or any other foot.



Pic of the setup I had for locating the holes. Would have been preferable to do this before the copper plating, but the boxes just weren't far enough along at that time and I didn't trust myself to measure them all accurately without the plate available. Note the orientation of the plate in the photo is reversed from how it will actually be installed. Don't mind the drill, I ended up using a 3/8" brad point drill bit and lightly tapped it into place to mark the location of each hole.



This is the bushing that will be used. The stud side will screw into the bottom of the speaker into a stainless still wood insert. However we have a slight issue. The stud is long enough such that with the countersink for the bushing the hole for the insert would need to go completely through the bottom, meaning we'd have a potential air leak unless the bases are installed (a la Tekton). While they certainly will be installed for any use case I can dream up, I still don't like that idea. I'll probably cut off the bolt and clean up the threads with a die, then use a drill press guide with a stop for my handheld drill to ensure I don't penetrate the bottom.

The other side is threaded for a 3/8" bolt, which will go through the bottom of the base. I need to put a little thought into how that's going to work as I did not think to have it countersunk when being manufactured. I might also use an acorn nut and threaded rod to do this, unless I can find a 'pretty' bolt head. Yeah, yeah it's on the bottom, but details matter!




Finally, I put together a CAD model for the back plate. I'm awaiting new binding posts to finalize those measurements and send it to a CNC shop. I'm printing a test one right now on the 3D printer to ensure external tolerances are good to go. I could also potentially use it for marking each of 24 holes that will need an insert. Any thoughts on waiting to install the inserts until after the painter finishes up with each box? I'm split on whether it would matter. I don't 'think' it should.

A short poem about our recently deceased Newfoundland (Winston) will be etched into the plate. He was large, black, and loud, much like these speakers will be. They will be a monument to him.

[Steve Manning]

Hey Danny ..... sucks that there are imperfection on the plating ..... will they not fix the issues?

I'm liking the poem for your dog. 👍

Also you could try one of these, https://www.rockler.com/rockler-portable-drill-guideit has a depth stop and is on sale!

As for the inserts, I'd put them in before finish. Any issues you have installing them trying to fix things will be a royal bitch after the finish is on, GMTC.

[technodanvan]

Thanks Steve! My wife put that poem together over the last couple of days. I'm a fan!

Regarding the defects - it's not nearly as bad as pictured as there is a ton of shop dust on the parts that needs to be washed off. I haven't gotten around to that yet to see the full damage. There are two things I need to ask about when I call: (1) what to do about the holes in the finish and (2) what's the deal with these little black 'scrapes' in the finish? They are only in a couple of parts as far as I can tell but depending on their orientation in the final product they may be visible.

The drill guide is a no-go for large Forstner bits, unfortunately. I'm kind of leaning toward not countersinking the bushings at all for fear of ruining something. Also, one of the speakers has a not-so-flat bottom during a mistake made a while back so I'm not sure how well that would drill.

I'm with you on the inserts, I'll install them before painting. Hoping to get all this done in the next two weeks + patching and sanding so I can get these out of my garage for a while.

[Steve Manning]

I believe that guide will handle up to 2 7/8" diameter bits

[technodanvan]

Interesting, well I ordered one so we shall see. Doesn't look big enough to me but that is what they say...

[technodanvan]

Well you might see why I had doubts the Rocker drill press jig would fit a large Forstner as it is derived from my experience with the Woodpeckers press. A quick visual comparison.



As you can see, there is a bit of a size difference between the two! The Rockler feels nice, though I do wonder what additional cost would come from having a metal bottom plate in place of the current plastic. I typically use the Woodpeckers press with a 12v cordless Milwaukee, but for this job...the big boy was needed.



Honestly the whole experience was...disappointing. Nothing against the drill or the press, but against the 2 3/4" bits I acquired. One Rockler branded, the other some no-name one with decent reviews on Amazon. I just can't find this size in a 'premium' brand. And that's a bummer, because I only got two holes drilled in half an hour and the drill was so hot that I had to stop. The Rockler is the better bit but boy does it start and finish SLOW.



Anyway, it seems I'll be breaking up this process over the next several days.

[Steve Manning]

Hey Danny .... I hear Fisch Wave Cutter forstner bits are very nice. Not cheap, but razor sharp. I know your using a 2 3/4" bit though most of the big Fisch bits are metric. You might have to see what size is in that ball park. I've seen up to 70mm which is a tad over.

[Scareurpasenger]

The alternative is making a router template. I know it isn’t as easy to locate the center with but it would do the job.

[technodanvan]

This is good stuff, thanks gents. For some reason using a router did not occur to me...something to consider.

[technodanvan]

Damper countersinks for one speaker done. I was hoping the dampers would be a little more aligned along the stud than they are, but ultimately the first one is good to go. There is about a 1/4" gap between the cab and the plate when all is said and done.

Edit: I should point out the bolts on the bottom use stainless washers with a neoprene washer adhered to them. Though this would be the best way to avoid further scratches to the finish.

Edit again: I think I might try to make or source some thin neoprene washers to put on either side of the damper.

[Scareurpasenger]

Looking great! The investment into the cnc work looks to have paid off.

[technodanvan]

Given the cost of all that and the relative overall quality, I imagine the cost of consistent, perfect bases for boutique speakers play a fairly substantial role in the final price to consumer. If and when I do the other speakers in this series I will probably use the CNC service again but will skip the plating procedure...except maybe for the center channel. MAYBE.

[technodanvan]

I wrapped up the final of the 12 countersinks this morning...more and more muscle was required with that bit, but it got the job done. I just didn't feel comfortable putting a router up that high (at face level), though that would have made a much cleaner cut and I could have done all 12 in a row.

Today the foot toppers arrived from the CNC artist, so I had to stack them up to get a feel for how the feet will look in the end. I'm missing one rubber washer still as I haven't made printing them a priority (it's missing from the top position), but here is how it'll basically look. Just image the middle puck being swapped out for a corner of the large plate the speaker will rest on. 16 oz. can of local beer for comparison.

The toppers are threaded for a 3/8-16 bolt that runs all the way through the stack. Gotta send them out this week to get finished in copper.

[technodanvan]

I did some stuff. Here are some pictures.

3/4" roundover on the front and back vertical sides. Used a cordless Milwaukee router for it, cut like butter in one pass. Employed a 5 Ah battery for everything shown here, still 3/4 bars. I had printed a back plate to test fitment so I used that when routing near that opening so I didn't need an expanded baseplate on the router. I contemplated going bigger on the front but decided I didn't like the safety implications so left it at 3/4".

Top and bottom edges were given a 1/2" roundover.






This brace was in the way of the mid crossover here and had to go, so I got out the finest of woodworking tool and took care of it.








The only sawdust that remains is from sanding, patching, and more sanding. Put in a request with the painter so I'm hoping I can drop off this week.

[technodanvan]

The binding posts I ordered came in - supposedly Mundorf, with Mundorf pricing, but they came without any original manufacturing packaging or anything and have no branding on them. Is that normal?

Anyway, they're nice enough so I'll use them either way. Modded the CAD drawings to accommodate their dimensions and printed the bottom half of the plate to test fitment. Perfect!

[Scareurpasenger]

The finish from your printer looks amazing! My Bambu x1 may need a tune up. Any tricks to share?

[technodanvan]

Thanks! Best advice I can give is to slow it down, I no longer use the standard speeds and choose 'quality' modes whenever it makes sense. Sometimes the time added is significant but I think it's worth it. Granted, for rapid prototyping like this I suppose I could have sped it up.

Edit: The camera was also a bit generous in this case.

[technodanvan]

Dropped off the speakers this morning, same place I did the subs a few years back. We talked a while about finishes and while I had initially wanted a satin black look I decided gloss black might be better for long term durability. They'll shoot them with a few coats of resin to seal everything up, sand, prime, sand, paint, and shine for $750 apiece. It'll be done in a week or two. I say this just so others have a ballpark if they're looking for a similar service. Surprisingly, I think this is a bit less than the subwoofers were, I was bracing myself for double that price.

I gotta dig out the Keramiskas and get them painted sometime too. Maybe after Iowa.

[technodanvan]

Wife is out of town for a couple of days so I'm trying to start and finish the baseline test crossovers while she's out. Don't tell her what I'm using the kitchen island for!

[Steve Manning]

With that fancy new printer of yours, you should have some nice looking crossovers Danny! I can also see why PE doesn't have parts in stock, you have them all!

[technodanvan]

Well I didn't get as much done as I had wanted, but all boards were glued together, all components attached to the boards, and some have been wired up. Pretty much no soldering yet.

[technodanvan]

Bases are complete, here’s a shot next to my existing mains. They’re pretty beefy.

[theSven]

Looks really good! The finish from the photo on the base turned out really nice.

[technodanvan]

Thanks! I might have the clearcoat stripped and reapplied sometime soon, but no time right now. IOWA IS COMING.

[technodanvan]

Working on interior wires today. Painting still not complete...getting a little worried about that. I know they sprayed resin a week ago, hoping it's just down to polishing now. Still though, I need at least a full day to drill out the backplate mounting holes, screw in ~50 inserts, assemble everything and test them for functionality! I'm also a little paranoid that I messed up a crossover somewhere and they just won't sound good at all. Anxiety sucks.

I ordered some stuffing as well. This is a PR design of course, but I wanted to experiment with a little stuffing depending on the specific tuning we end up with - at least in the lower cabinet, and maybe throughout.

Anyway, this is just the first two for the input terminal to the low pass crossover. You probably can't read it, but these are for the low pass crossover. Will get the other input cables done-ish today (I won't cut to length for the mid/high until I have the cabinets back). Plan is to have them all directly connected to the input terminals instead of using jumpers between boards. Might start the output cables today too.

Nothing fancy, just 12ga copper wire.




Oh, I also printed some PLA backplates in the event the aluminum ones aren't ready in time. I have to say, I'm really annoyed with Mundorf. These posts are keyed and installed exactly the same way. I know it's a small thing, but to me, these should all clamp down in the same direction. I don't even care what direction that is necessarily, but the fact that they do not is troublesome on such a pricey product. Not sure I'll go this direction in the future.

[JonMarsh]

Now, that sounds to me like a perfectionist talking, for certain! And also, there is a certain familiarity...

[Steve Manning]

Nice .... they should do the trick.

[JonMarsh]

So, is this a race down to the wire, if you're taking these to Iowa? Making steady progress, I see...

[technodanvan]

Iowa is the plan. I depart on the 14th...if everything falls into place.

[JonMarsh]

I certainly hope that works out for you- you've put a lot of effort into this!

[technodanvan]

Thanks Jon, couldn't have done it without the help from both yourself and Mr. Manning!

[theSven]

I hope to see another thread with photos and write up of the Iowa DIY show. I'm overseas during that week and will not be able to attend. Go figure this year has been really bad with getting to events I want to be at vs events I'm told to be at. Something to iron out next year.

You got this, to finish it up and get to the show.

[technodanvan]

That is the plan of course. Maybe I'll even take a notebook with me this time.

[technodanvan]

Today is the day of days! More to come...

[technodanvan]

So as expected, not everything was perfect today and I've got a fairly major problem to solve. However, one speaker is wired up and making music well enough that I'm confident the crossovers are probably working as expected. Problem is...one of them is too tall, and interferes with installing the passive radiators. Heck, the other two are tight as well and I need to make sure they won't short anything out. But I think I have a plan for tomorrow to fix this. In any event, a few photos.

[Steve Manning]

Looks like they did a nice job on the finish Danny👍👍

[theSven]

The paint looks great on these cabinets. I hope you get them wired up this weekend to post some completed pics! Wonderful to see this project grow from ideas to completed.