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

[technodanvan]

Well, since Tuesday I haven't gotten much done due to work and, a first for me, COVID. Good times. I'm back on my feet and cleaning up the garage today and discovered my stash of EZ-Lok inserts mostly leans towards large sizes (1/4" - 3/8"). Based on Jon's recommendation, I'll order a variety of Rampa inserts to try out. The SKD30 does seem like a rather nice design.

Quick question for the professionals out there: A 10-24 bolt fits perfectly through the PR flange, but doesn't leave much wiggle room for error in placing the inserts. The EZ-Lok inserts would also be awfully close to the edge of the hole, potentially breaking through. Do you all typically go down one size to ensure fitment?

[Steve Manning]

Well, since Tuesday I haven't gotten much done due to work and, a first for me, COVID. Good times. I'm back on my feet and cleaning up the garage today and discovered my stash of EZ-Lok inserts mostly leans towards large sizes (1/4" - 3/8"). Based on Jon's recommendation, I'll order a variety of Rampa inserts to try out. The SKD30 does seem like a rather nice design.

Quick question for the professionals out there: A 10-24 bolt fits perfectly through the PR flange, but doesn't leave much wiggle room for error in placing the inserts. The EZ-Lok inserts would also be awfully close to the edge of the hole, potentially breaking through. Do you all typically go down one size to ensure fitment?

Hey Danny, sorry to here about the Covid! I typically use 8-32 screws/inserts to mount the drivers. Seems to work out well.

[JonMarsh]

Well, since Tuesday I haven't gotten much done due to work and, a first for me, COVID. Good times. I'm back on my feet and cleaning up the garage today and discovered my stash of EZ-Lok inserts mostly leans towards large sizes (1/4" - 3/8"). Based on Jon's recommendation, I'll order a variety of Rampa inserts to try out. The SKD30 does seem like a rather nice design.

Quick question for the professionals out there: A 10-24 bolt fits perfectly through the PR flange, but doesn't leave much wiggle room for error in placing the inserts. The EZ-Lok inserts would also be awfully close to the edge of the hole, potentially breaking through. Do you all typically go down one size to ensure fitment?

Sorry about your COVID surprise- there's been quite a resurgence in many states, and that happened to me August last year when Liubov's older son-in-law thought he had a summer cold that wasn't a cold, and his son caught it too and was quite sick in bed for a week. The son-in-law only experienced what he thought was a summer cold because he and his wife had adopted the Pauling Protocol for cardiac care at my reference, and the high levels of vitamin C boost the immune system. I had a very mild case from them, over in 3 days from when symptoms started. Much milder than what my friends report this summer with their summer colds- but then I do not get summer colds, or any kind of colds, and I've been on the Pauling Protocol about 20 years.



One of the "drawbacks" in my opinion about the EZ-Lok inserts is their relatively large diameter and drill hole. This is specifically why I selected Rampa, especially for the RSS210HF woofers, as they have a relatively narrow mounting flange, and this would result in breakout with an 8-32 insert. I like this guide for working out the issues.

[technodanvan]

Fortunately I've been a bit luckier than my wife, symptoms seem to be dragging on a bit but they are not bad. I can still work...which is probably why they're dragging.

That's a great guide Jon!

[technodanvan]

Minor progress this morning. Rampa inserts came late yesterday. I tested a few out and elected to go with a 1/4" bit for installation (8-32 inserts). Still got a little tearout but nothing too bad. Only did the one PR cutout so far...still not feeling quite right, I think I might have rushed back to work a little too quickly. Will do it piecemeal, which is probably best for my hands since I'm not using a drill to install these.

Found a use for my Chapman master set though, the ratchet makes things a bit easier once the inserts are started.

[Scareurpasenger]

Was the tear out from the drill or the inserts?

[technodanvan]

Inserts. I might be wrong, but I think the threads might be sharper on the EZ-Lok inserts. I'm not sure it'd matter with baltic birch though, that top layer just likes to rise up when threaded into.

It'll all be hidden though, so it won't matter. This particular cutout was also done slightly differently than all the others - I tried a few things before settling on how to do it cleanly, so things weren't going to be quite as flush as they will be on the others. I do like the flange helping to hide the hole on the Rampa inserts.

I also did not use CA glue on any of these six. I don't think it's necessary actually, they're pretty darn snug.

[Steve Manning]

Danny something that helps with the tear is to chamfer the hole after drilling. Doesn't have to be very deep and the flange on the inserts sits nicely below the surface of the wood.

[technodanvan]

Thanks Steve, I was considering that as a possibility.

[technodanvan]

More minor progress, inserts are all done and I think I'm at a stage where gluing must begin. All four sides are warped a bit so I'm hoping gluing in the braces and getting them attached to each other will bring them back to straight. Open to ideas to ensure this will happen...had been considering getting some angle iron or something to force things to be straight while gluing.

Other than this I made a ramp for the front door for my elderly Newfoundland yesterday so he can get in/out a bit easier.

[Scareurpasenger]

Lots of clamps and screws/dominos might do it. You need alignment and some holding power.

this is also why I like using the tongue and groove bits. They align and add a bit of strength because of the surface area.

[technodanvan]

So I thought about your comment for a while and elected to go with screws to keep everything somewhat aligned and, more importantly, pull it all together. I do have a Domino that sees way too little use, but I'm not sure it would help much with my issue right now. My tentative plan here is to use pocket holes/screws for all braces that I think I can reach with a right angle drill once the second side goes on, especially for the top, bottom, and rear of the mid enclosure as these are thicker pieces of wood (~30mm). I'll add wood glue to each hole to keep the screws from shifting later. Wood glue (Titebond III, in this case) will also be used for each joint, of course.



Something that would have been helpful would be to avoid straight butt joints for these areas, but it's too late now unless I wanted to make new braces and rabbets in the sides....which I don't.

Jotting down order of operations here for myself as I'm paranoid I'll forget something until after the glue sets.

1. Locate and drill out pocket holes in all braces top to bottom. Note that two different setups will be needed depending on the thickness of the material (30mm vs 18mm), which means a different length screw may be required for each.
2. Consider locating and drilling out a few pocket screw locations for adhering the baffles as well since they are also a bit out of square. Test to see if a drill could even reach these locations prior to drilling.
3. Locate and place standoffs and inserts for crossover locations. Best guess as to size of crossovers? Big.
4. Locate and drill out/countersink holes for mid enclosure terminals.
5. Consider placement of phenolic plates in key locations. Leaning towards 'none' for this project, but perhaps for the mid enclosure. Remember to leave room for crossover inserts/standoffs and drivers if necessary.
6. Glue braces to one side, be sure to add glue to screw holes.
7. Place denim filling on one side, leave room near drivers to breathe.
8. Glue other side to braces.
9. Add denim filling to other side.

[Scareurpasenger]

Be careful with the pocket holes, they like to pull out of alignment. You need to clamp the really good and then screw them. The Dominos are great at helping with this.

i had 2 sheets of plywood that was bowed. Lots of fun trying to make it usable for projects!

[technodanvan]

Yeah, the plan is to clamp in place without glue and get a few started, then unscrew and glue for real. Always with clamps!

[Steve Manning]

Hey Danny, you could always try the sun and water trick to remove a bit of the warping just prior to glue up. This video shows the process. https://www.youtube.com/watch?v=1VZn0lnuabM

[technodanvan]

Interesting Steve, wonder how well that works with wood that has been laminated the way these sides are. I would think the glue might have something to say about it. Wouldn't hurt to try though, while I still have a little heat.

[Scareurpasenger]

Don’t underestimate the forces of nature! I went the fast and easy route but I also didn’t need the high precision for my clamp storage.

[Steve Manning]

Interesting Steve, wonder how well that works with wood that has been laminated the way these sides are. I would think the glue might have something to say about it. Wouldn't hurt to try though, while I still have a little heat.

You'd be surprised how much the wood will move. I've seen it work on plywood and even straightened out a 6" X 6" timber once.

[technodanvan]

There is glue! Lots of work I'm hoping to get done this weekend, but time is at a premium. We shall see how it goes.

[JonMarsh]

You know what they often say, Danny... Hope is not a strategy!

[technodanvan]

More progress, but no glue today. Maybe later. Terminal cut outs for the coax enclosure have been made, as have crossover boards and standoffs for them. Still have two sets of standoffs to drill out once I make a decision on the placement of the third panel (should I need it). Double sided carpenter's tape worked great here - I'm leaving them stuck on to ensure they match when I drill out the wood and install inserts later. Need to hit Ace and grab some bolts and washers for this as well.

[JonMarsh]

Slow work takes time...

[technodanvan]

I completed the crossover boards and standoffs, just need to add the inserts for the other speaker at some point. I'm moving forward with speaker #1 though as it is the priority. Coax enclosure is currently being glued to the one side right now. Should be able to knock out a few more braces later today. I'm running low on appropriate clamps so I'm a bit limited - four of my eight 24" parallel clamps are being used to control movement of the baffles right now, and the other parallel clamps I have are 50" long and a bit unwieldy for small jobs.

Regarding the inserts - I was a bit nervous about placing these in such small boards, so I made several attempts in a scrap piece to get them right. As usual, Steve was correct. I ended up using a totally inappropriate bit to widen the top of each hole and it prevented the ply from separating.

[technodanvan]

Oh, I also ended up removing the pocket screws from the bottom piece. While that certainly helped keep things clamped up really well I discovered a problem: I need to place large inserts for the aluminum bases I ordered, and I won't know exactly where those will go until I have the bases and can position them accordingly. I didn't want to risk a screw being in one of those locations so I decided to pull them all.

[technodanvan]

Received the final quote for the CNC parts, much better than the first ballpark I received though does not include anodization or finishing of any kind. I'll have to get that done locally. That's fine. This will be done at a CNC shop in Iowa - my mother is the accountant for a small-ish CNC firm there and got me in touch with her boss. No shipping since I'll be going there anyway in a few weeks time!

[technodanvan]

Things are accelerating a bit now that I have the crossover mounts figured out. That took me a bit to reconcile.

I ordered a bunch of foam and vinyl from Parts Express yesterday, should be here Thursday. I was wanting to use the denim I already have but its thickness is prohibitive for the side walls due to the placement of the crossovers - it would just intrude too much. Sonic Barrier has been acceptable in the past so I'll use that for the sides then the denim for the rear (and maybe the coax enclosure).

[Scareurpasenger]

Besides, denim insulation is rare now and you should hoard it! All joking aside, it was discontinued in the 2” thickness and the others are more difficult to locate now.

I may need to purchase some Havlock wool batts. Price is decent but the denim was a great value.

[technodanvan]

I just checked prices from Jon's source on Amazon and they are steadily increasing on the 2". It's becoming less cost effective for sure. I have a whole box still that takes up room in my garage...I'd kind of like it to be used!

[technodanvan]

Sonic Barrier was delivered yesterday so I installed it last night and this morning. I used both the 3/4" PSA foam and, what I think is a relatively new product, their vinyl damping sheets. Individually they were relatively inexpensive, but I calculated I'd need four large sheets of vinyl and eight sheets of foam so it added up pretty fast. Just waiting for my wife to wake up so I can staple it down to ensure it doesn't move over time, then I should be ready to adhere the other side to this assembly (hopefully this morning).

This weekend the plan is to get the back pieces laminated together then glued to the main assembly as well. Once that's done I can wrap up the stuffing of the cabinet and get wires placed. On that note: JonMarsh, what would be the best wiring for the Anarchies for testing? These are the 708 model. I'm guessing it's the below, but I guess I don't really know if it matters since the impedance should be the same regardless. Unless you think doing a 3.5 way is better maybe?

Proposed wiring of Anarchies: Top/Bottom drivers connected in parallel, inside top/inside bottom drivers connected in parallel, then the two pairs of two connected in series.





Edit: Success! Though I was a bit short on clamps again...I would have used the 50" parallels but on that table on those speakers they would impact my garage door. So we made do.

[technodanvan]

CNC guy sent me a pic today. The raw materials have arrived!

[technodanvan]

And new happenings. I decided to install the binding posts now, then apply foam around them to ensure correct fitment. I ended up using Viborg posts as they're really reasonably priced and seem nicer than Daytons. Why I'm using them on the internals is beyond me, but whatever.



After I was done with all the foam I had to take a look at baffle fitment - it looked really good! Everything seems to line up well. Pic below gets an idea of the size, these are about a half inch shorter than my wife as they stand, they'll be a few inches taller when all said and done.



And then I adhered the rear 'baffle' to the speaker. I thought about it a while and decided doing it in this order would be best.

[Steve Manning]

Some nice progress Danny .... looking good!

[technodanvan]

Thanks Steve, we're getting some place for sure. Denim has been attached to the inside rear and holes drilled for a few wires out the back. I can reach pretty much any part of the speaker through the PR holes so that is advantageous. I wanted to adhere the baffle last night but felt I was rushing things, so did it over lunch today with help from my wife. I think they're pretty centered...I hope.


That's all I had for today, until I saw some pretties.

[Steve Manning]

Is that a local place doing your aluminum work Danny?

[technodanvan]

This place is in Iowa - my mother is an accountant for machining company there. Now that I think about it, I don't even know the name of the company, I've just been talking with the guy in charge. He seems very reasonable and open to all kinds of work. They do not do finishing work though, so I'll be doing that locally.

[technodanvan]

It's looking like a speaker! I'm waiting on a very large flush trim router bit to clean up the edges of the baffle, but I'm getting close to ready. I already have one of these and used it on the rear...but boy did it not seem happy doing it. Feels pretty dull, and these are inexpensive bits from Yonico, so I purchased several of them for the next cutting phases on this and the other speaker (when it's ready). Not sure these are worth trying to sharpen. These feature a 3/4" diameter, 2 1/2" cutting length bit.



Like I said, we're looking like a speaker now! Once the baffle edges are cleaned up I can finish sanding, just 60 grit right now as I clean up tooling marks and such - I might not go much finer as this may give a better surface for the painter in a few months. The bottom is pretty messed up but I have an idea there that might make installation of the bases easier anyway, so it won't matter. I'll be putting a roundover on the vertical edges of the baffle for testing but may wait on determining an appropriate finish for the other edges until later. I really wish I had a bit somewhere between the 3/4" roundover and 1 3/8" roundover...that's a big difference and I'm not sure either of them are appropriate for this speaker.

[technodanvan]

Aluminum work is all done as of tonight.

[JonMarsh]

Shiny!

[JonMarsh]

Besides, denim insulation is rare now and you should hoard it! All joking aside, it was discontinued in the 2” thickness and the others are more difficult to locate now.

I may need to purchase some Havlock wool batts. Price is decent but the denim was a great value.

Dang! All this vintage stuff that works great disappearing or degrading- I probable shouldn't mention I have two boxes of this stuff from AST... selective use will be the key, I think.

[Scareurpasenger]

I ended up purchasing some Havlock wool insulation since the only dampening material I have is 1/2”. 200sqft should last me a while…

I do plan on using it for acoustical panels though with a fabric that is approved for use.

[technodanvan]

There were some bumps and hiccups, but she's ready for a road trip. There is something weird about the coax, one bolt was always tight, and it was always the same hole. Ended up snapping the head off a screw - just manually this time, I'm not using power tools on that driver. I'm wondering if that one hole is just off filter a bit but I really don't know. Already had to extract and replace one Rampa insert because it was so tight, and now I'll almost certainly have to do another one. I decided to leave it as is for the time being. The other five bolts worked perfectly, as did all the bolts for the Anarchies.

[theSven]

This is turning out very nice! I really like the aluminum base that you designed, and I could see myself really loving that aluminum in blue...

Sounds like those threaded inserts are hit and miss with, that must be a pain to remove and re-install when they aren't working properly.

Looking forward to get a trip out to Vegas to come hear these in the future!

[Steve Manning]

There were some bumps and hiccups, but she's ready for a road trip. There is something weird about the coax, one bolt was always tight, and it was always the same hole. Ended up snapping the head off a screw - just manually this time, I'm not using power tools on that driver. I'm wondering if that one hole is just off filter a bit but I really don't know. Already had to extract and replace one Rampa insert because it was so tight, and now I'll almost certainly have to do another one. I decided to leave it as is for the time being. The other five bolts worked perfectly, as did all the bolts for the Anarchies.

Hey Danny, Jon and I were having a conversation the other day on this. I'm finding some drivers need to have their mounting holes re-drilled. I'm finding that if the holes are on the small side or just partial blocked and if the inserts are not perfectly installed and since they are done by hand they usually off a smidge, it doesn't take much to cross thread those inserts.

As an FYI, I run a screw into every insert to make sure the threads are clear before I call it good and send the parts out.

I need to look into how to get those inserts installed perfectly perpendicular.

[technodanvan]

I don't think it was the inserts or the location they were placed, so I'm thinking your first comment regarding drilling out a mounting hole may be most appropriate in this situation.It wasn't far off so I think it's fixable, one way or another!

Edit: For smallish parts I've used a drill press to install inserts, just by turning it manually while applying pressure to the lever. Perfectly perpendicular every time! That's a bit unwieldy for large baffles though.

[Scareurpasenger]

The Rampas are much easier to thread straight. They have the initial section that is unthreaded to help align vs the ezlok which tilt easily. I also found that running the drill in reverse sets the base of the Rampa when the hole is just a tad small. From there they almost self align.

For aligning ezlok I use a longer bolt with two nuts tightened to each other. This gets chucked into a portable drill press from rockler. The ezlok is threaded onto the bolt till it stops to the nuts. This keeps it straight as it is threaded into the hole by turning the chuck by hand. Once enough depth is established, I move to the ezlok bit.

[Steve Manning]

The Rampas are much easier to thread straight. They have the initial section that is unthreaded to help align vs the ezlok which tilt easily. I also found that running the drill in reverse sets the base of the Rampa when the hole is just a tad small. From there they almost self align.

For aligning ezlok I use a longer bolt with two nuts tightened to each other. This gets chucked into a portable drill press from rockler. The ezlok is threaded onto the bolt till it stops to the nuts. This keeps it straight as it is threaded into the hole by turning the chuck by hand. Once enough depth is established, I move to the ezlok bit.

Glad to here that works ..... I was looking at the Rockler portable drill press last night. I was thinking one could add a large acrylic base plate for installing inserts in baffles to span over the driver cutouts.

[Scareurpasenger]

That would make it easier. A longer 24” or greater would be able to span the larger drivers. For really deep installations a longer threaded rod could be used.

[technodanvan]

The first of the Ensemble lineup hit the road yesterday and arrived at a familiar setting today for some nice discussion and measurements. You might recognize a few of the background elements!

[theSven]

That's awesome, and yes I do recognize some of the elements there... I hope you have some great measurement experience to share.

[Hdale85]

That looks sweet!

[JonMarsh]

It was a quite interesting day yesterday, and we enjoyed hosting Danny for the measurement experience! Of course, we had to enlist Jon Hancock & Sons Moving and Storage team to get this monster into the living room... no sons available to help (there aren't any!)



Danny was at least slightly impressed with my collection of hand carts and moving dollies...



Danny re-loaded the PR's into the cabinet (PR holes make a very good carrying and maneuvering control handles) and it was off to the races!




First thing was some impedance testing- results for the "King Coax" midrange and tweeter are shown below.




The bobbles at around 500-600 Hz and 2kHz raised some questions in my mind, but it seems the 2kHz one is the only one manifest in the SPL response, and it's effect is relatively minor.







As is common in many Coax drivers, the tweeter seems to have a very small rear chamber, and a relatively high Fs- this requires some care in the HF filter network and determining the best crossover frequency.

Next up will be Fuzzmeasure testing, and fortunately, with something a little more sophisticated and analytical than Seas's own technique and data sheets, (put it in a box, measure in the box at 1/2 meter; baffle step, diffraction issues, and what not be damned) you can see the driver's real potential.

[JonMarsh]

One other note... if you haven't picked up on it, though the form factor looks very different, to a considerable degree this is a blood relative to the Minerva project, sort of like a gangly young nephew, and I expect any crossover proposals I prepare for Danny to have a "family resemblance", due to the use of an evolved C18 coax driver (and my, they are certainly pricey these days!