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

[technodanvan]

I have mentioned this project several times over the last few years and figured it is about time to start a thread documenting my thought process and maybe holding my hand to the fire a bit, so to speak. The goal is to build a new 7+ channel system, perhaps with Atmos satellites as well, that use some of the better drivers available on the market today but at a price I can swallow. Accuton and Purifi need not apply for this project, though at least the latter would make a compelling case for 'best in class' performance given the use case.

Some of my goals/thought processes:

• Seven channels worth of tower speakers
• Each channel should use a coaxial mid/tweeter and multiple woofers
• Each channel should produce bass well into the 30 Hz range, and hopefully useable bass into the 20s.
• The three front speakers should use the same drivers for consistency across the screen. The mains should be ready for a combination of music and movies and compete well with other contemporary projects.
  • These will use the Seas C18 'King Coax' coaxial speaker driver (3 in hand). While clearly in Accuton/Purifi pricing territory (~$550 each right now) at least we get both a mid and a tweeter for the cost.
  • These will likely employ 6.5" woofers to keep the width of the box relatively narrow
  • These are expected to be large, WWCWW style speakers - center channel as well
  • Given the higher performance bracket, it is expected these will also employ passive radiators. Likely two per side of each speaker (four total) - rear mounting was considered but given the size of the PR (at least 10") that would increase the width of the speaker...making it kind of weird to use only 6.5" drivers.
• The surrounds can use different drivers to save on costs, but should still be considered 'high performance' - just at a somewhat lower cost bracket.
  • These will probably use the Seas MR18REX 'Rex' coaxial speaker driver - seemingly made with many of the same design constraints of the C18 at less than half the current cost (~$240 each). Purchase of all of them has not been made at this time.
  • To keep things similar, they will also use 6.5" drivers to keep the box reasonably narrow.
  • These MAY be large, WWCWW-style speakers...but given their status as surrounds, perhaps they will be a CWW design to keep them a bit less imposing.
  • Porting these speakers will be explored to keep costs down a bit.

Design inspiration comes from KEF (pictures direct from their website):







By the time I'm done with these I may regret passing up on a KEF sale on these speakers...but these will sound better, right? RIGHT???

Anyway, first thing I want to do is get a better feel for all the drivers that will be used. Here's what I have.

• 12x DIY Soundgroup Anarchy 708 6.5" woofers
• 2x Dayton 7" Epique
• 2x Seas MR18REX
• 3x Seas C18 coaxials

Obviously I'm a bit short on woofers and coaxials. The initial plan was to use the Anarchies for all speakers, they're a lowish price and a high performer. Then the Epique 7" came out and it was thought to be a replacement for the front stage, but it turns out maybe those aren't so good, so I went back to the Anarchy plan. Now, it seems DIYSoundgroup has a hard time keeping these in stock, and that has me concerned a bit. I think I'd need the 704 for a CWW and it's been unavailable for forever. They have some 708s in stock but not quite enough to complete a full WWCWW 7 channel situation. That got me looking around at other performers from Dayton (RS line), Wavecor (SW182BD04 in particular) and finally...Misco.



I can't speak on whether Misco's daily stock is better than DIYSoundgroups, but they do have enough on hand right now. This is an XBL^2 driver and is Klippel optimized. Less xmax than the Anarchy and it can't go quite as loud as a result, but still able to exceed 100dB down to 25Hz or so. Pricing is competitive, about $30 more than the Anarchy (at least when buying in quantity), and since there is neodymium in this driver that increase probably makes sense.

Reviews for both the Anarchy and Misco BWX 6502 are below.

https://audioxpress.com/article/test-bench-exodus-audio-w06-017r-anarchy

https://audioxpress.com/article/test-bench-the-bwx-6502-midbass-from-misco-s-bold-north-audio-line

So, first question (of the many, MANY questions I'll have on this project). Has anyone independently measured these two drivers? I'd like to see another review of frequency response and distortion profiles if possible. I'd also be interested in the same for the MR18REX. If not I suppose I'll bite the bullet and place an order soon.

[JonMarsh]

This is my non-technical initial reaction to your build concept




I have some Anarchy's (both the little and big ones) "in stock", but will have to check when I get back how many. Can donate for cost of shipping. I had bought a number for evaluations, but then the switch from Denovo to DIY Sound Group created availability problems.

Note, the main weakness of the Anarchy is nonlinear and limited CMS with excursion.

Which of course leads me to my next comment... (borrowing from the style of Steve Manning) Go large or go home!

I.E., RSS210HF-4. Much better CMS linearity. About 1.5" more diameter (relative to 7" woofer). Much better upper range behavior than the Misco.

Regardless of what choices settle on, good luck and god speed!

[technodanvan]

Thanks Jon! I did consider using the RSS210HF (or other 8" woofers for that matter) for this project, but since I already have two projects using it (The SMJ-40 and the Natalie P Ultra LE) I felt maybe I should explore other products out there to maintain the 'narrowness' of the tower. I'm aiming to keep these around 8.5" wide - with a large chamfer or roundover - and may limit them to ~58" tall so I could try my hand with the pin block material for the baffles (at least on the King Coax version).

I'm glad you're excited about this as I still need to convince you to do the heavy lifting regarding crossover design!

[technodanvan]

By the way, thank you for the offer of the Anarchies - PM or email me what you have sometime and I'll figure out what I could use. I'm still unsure what direction I'm going in but this might push me towards using the Anarchy throughout. If I'm doing Atmos I think I'd want them there as well (an MR18REX + one Anarchy per overhead speaker).

I think I might grab a pair of each of the Miscos in a couple weeks to measure them myself. The one with the phase plug 'might' be better for this application.

[JonMarsh]

Regarding crossover stuff, don’t forget the Minerva- I do have experience working with the C18e.

Another thing to remember is sensitivity matchups when selecting drivers- a 4 driver series/parallel array will have 6 dB higher net efficiency, compared with a single driver. Of course, there’s baffle step to compensate for, but then if you are planning on bafffle step killing excess efficiency compared with the C18e, then enclosure dimensioning will be key. We can coordinate on this, if you can do some basic measurement on a single woofer candidate you choose- QNF at 1’ will usually work well, mimics half plane reasonably closely, then it can be imported into VituixCAD and used for enclosure modeling.

I may have tossed the Anarchiy woofers (558 and 704 and 708, but I think probably not yet- I’ll check after I get back home next week, Unless you already have some of them, starting “fresh and new” might be the best way to go.

If you don’t have means for measurement, then probably you should just plan on sending me one driver after you make your selection, and I can do that. I even think I have one or two fo the Seas Coax around, too.

[Steve Manning]

I actually have a couple of the 554's and looks like 8 of the 708's if needed.

[technodanvan]

Regarding crossover stuff, don’t forget the Minerva- I do have experience working with the C18e.

Another thing to remember is sensitivity matchups when selecting drivers- a 4 driver series/parallel array will have 6 dB higher net efficiency, compared with a single driver. Of course, there’s baffle step to compensate for, but then if you are planning on bafffle step killing excess efficiency compared with the C18e, then enclosure dimensioning will be key. We can coordinate on this, if you can do some basic measurement on a single woofer candidate you choose- QNF at 1’ will usually work well, mimics half plane reasonably closely, then it can be imported into VituixCAD and used for enclosure modeling.

I may have tossed the Anarchiy woofers (558 and 704 and 708, but I think probably not yet- I’ll check after I get back home next week, Unless you already have some of them, starting “fresh and new” might be the best way to go.

If you don’t have means for measurement, then probably you should just plan on sending me one driver after you make your selection, and I can do that. I even think I have one or two fo the Seas Coax around, too.

Thanks Jon, I definitely remember the Minerva, that design is what prompted the desire to look into the C18EN in the first place!

I may actually want the 558/554s as well for Atmos duty...unsure how those will look since I don't have a house for this yet. I do have 12 708s but that might not be enough depending on the final setup. That said, a new contender has emerged from the shadows that may make an 8" variant a requirement...stay tuned.

I actually have a couple of the 554's and looks like 8 of the 708's if needed.

That's great! Sadly you two probably have a more robust supply than DIYSoundgroup...

[technodanvan]

I've been in training all day (virtually) and spent some of the downtime trying to come up with an actual name for this project. Both the overarching series and individual speakers. I'm thinking I'd like to call the series 'Ensemble' with the biggest speaker called 'Crescendo'. Probably not terribly original, but it's what I have for now and I'm not familiar with any other DIY designs using these terms. Thoughts?

That said, a new contender has emerged from the shadows that may make an 8" variant a requirement...stay tuned.

So this didn't work out as well as I hoped. I approached Misco based on reading a rumor elsewhere about an 8" XBL^2 driver. At this stage, all they have done is create a couple prototypes using off-the-shelf parts and the motor off the 6.5". Consequently, they only had paper and poly models available for testing. They were very kind to provide much of the data they had, but alas, when I modeled them both prototypes seemed pretty unhappy in a vented/passive radiator alignment, as I am interested in. I still hope they continue working on it and perhaps make a new motor with longer throw, but for this project it seems a no-go.

[theSven]

I've been in training all day (virtually) and spent some of the downtime trying to come up with an actual name for this project. Both the overarching series and individual speakers. I'm thinking I'd like to call the series 'Ensemble' with the biggest speaker called 'Crescendo'. Probably not terribly original, but it's what I have for now and I'm not familiar with any other DIY designs using these terms. Thoughts?



So this didn't work out as well as I hoped. I approached Misco based on reading a rumor elsewhere about an 8" XBL^2 driver. At this stage, all they have done is create a couple prototypes using off-the-shelf parts and the motor off the 6.5". Consequently, they only had paper and poly models available for testing. They were very kind to provide much of the data they had, but alas, when I modeled them both prototypes seemed pretty unhappy in a vented/passive radiator alignment, as I am interested in. I still hope they continue working on it and perhaps make a new motor with longer throw, but for this project it seems a no-go.

L/R = Crescendo
Center = Cantata
Surrounds = Etude
Atmos = Accents

This could be a really fun story you are starting and the Ensemble is the perfect name for this musical speaker suite.

[technodanvan]

Those aren't bad ideas Sven! I had been thinking of using Dutch or Latin for several of the names, but it turns out at least Crescendo seems to be Dutch for itself (though I'm not so sure on the pronunciation).

Unsure what names will stick for individual speakers, but I think I will use 'Ensemble' for the suite, as you say!

Regarding the Crescendos (working name for now), I've been playing around with Unibox a bit over the last several days trying to get something I'm happy with. Using the standard parameters for the Misco BWX-6502 and 4 10" passive radiators I get the below. I can also get the same response using a pair of 12" passive radiators, just with a bit more excursion on the PRs (still well within operating range though).




Anyway, compare this to the Anarchy.



Total available volume is unknown right now. Without bracing, drivers, etc it could be around 100L, but I intend on this being a very well braced speaker. Coupled with four woofers, a mid subenclosure, four passive radiators, and crossovers, I figured this could drop to 60L easy. There is not a huge difference in response if this is bumped to 70-75L. The Misco seems capable of going a bit louder when deep (25-40Hz), but the Anarchy, while a tad less efficient, doesn't run out of xmax (and has greater power handling). Between my own stock plus Jon's and Steve's I ought to have enough of the Anarchy's for the project too, whereas I'd have to drop $1,200+ on a dozen of the Miscos for the front stage alone.

I really want to use the BWX-6502 on something, so I'm going to order a pair for testing either way, but I suspect the Anarchy will be the way to go for this project. That's kind of a shame, I wanted availability to be higher. Plus Misco/Bold North is made in the USA, which I do try to support when it makes sense to do so.

[technodanvan]

I just noticed that I didn't have the same power level going to the speakers for the above images so I reran it. If I have 50 watts going to each Anarchy it also runs into excursion problems. It's also more efficient than the BWX-6502.

[technodanvan]

While it's hot outside, I've been busy playing with the VituixCAD enclosure modeling to get familiar with it. I really like that it instantly shows how each parameter changes the response curves, but it doesn't appear to have some of the functionality of Unibox. Using the same parameters in each piece of software results in slightly different results as well, so now I'm not sure what to believe. In the end, I think real-world bass performance between the Anarchy 708 and the BWX-6502 is a mostly a wash; the advantages they each have are small. Realistically they will probably have support below 40Hz anyway (proposed Ensemble name for that 'little' project: Bellows).

Edit: I'm going with the Anarchy. It's cost effective and I have a bunch already. Will start putting everything into CAD soon.

[JonMarsh]

It's too bad the supply for these isn't a bit more consistent.. I like the 558, too. Have a few on hand.

[technodanvan]

Spent a little time in Unibox today trying to find the optimal design for the Anarchy. I think this is the best I can do with PRs, vented might actually be better and easier to achieve than passive radiators. The nice thing about this PR design though is it is nearly volume independent from 50-100L. The more volume I have, I get more of a bass shelf effect and a little deeper extension as a result, so it should be interesting to see how the CAD model works out.

I've been thinking about the KEF design (shown in Post 1 of this thread) and I'm not sure I understand the purpose of the full center brace, at least given the way they did the side braces. I don't think I'll mimic that since it'll take up a lot of volume and complicate the design. I need room for a mid chamber, four passive radiators, and crossovers of an unknown (but probably Jon Marsh-esque) stature. I think the center brace might interfere with all that.

[technodanvan]

And the vented alignment. I used 2x 3" ports as that's what KEF appeared to use, turned out pretty good with the Anarchy!

[technodanvan]

I spent some of the day working up a CAD model for the Crescendo. The initial look is promising, 58" tall by 21 1/4" deep by 10" wide, with 1 1/4" thick sides and a 3" baffle. The mid woofer chamber constructed of 1 1/4" material, remaining braces 3/4". This is not nearly the final design, I'm just trying to get a feel for where things may go. One known change is in the middle window braces, they need to be cut down to make room for the PRs. Lower chamber would have a removable back and would contain the crossovers.

This model comes out to around 80L.



Edit: Since my wife got a new woofer for us (see the three scrap pile builds thread) I was allowed to get some more woofers as well. A pair of Misco BWX-6502 and a pair of Misco BWX-6501 woofers are officially ordered. I may see if Jon is interested in measuring them to see how they compare to the Klippel measurements taken over a year ago, otherwise I can take a crack at it. I have no intention of using them for this project, but I had an idea for a small 3-way (for the 6502) and a small 2-way (for the 6501). We'll see how that goes.

[technodanvan]

I've been reviewing augerpro's thread on various construction techniques and am considering leveraging that research for this project. Much like the polymer concrete project, the question is do I try it on something small first, or should I just jump in with two feet?

If I did this I 'could' gain volume as the side walls 'could' be thinner. I currently have them set for 1 1/4" throughout because tradition dictates it to be so. I say 'could' because I'm still kind of thinking of using a three layer solution over a two layer one. 1/4 MDF inner, 1/2 baltic birch middle, and 1/2" bamboo on the outside for shaping. My tentative plan would be to construct an inner box of 1/4" MDF (all six sides), adhering a 1/2" baltic birch layer to that with CLD adhesive (again, all six sides), then add the 1/2" bamboo to the exterior (five sides - not the baffle) again with CLD adhesive. I'd then rout out a 1/2" x 1/2" rabbet in each CLD edge joint, and insert a 3/4" x 3/4" piece of wood along that edge and rout it down to size. If I have this visualized correctly, that would mean we would have an inner box floating inside a middle box that is floating inside a bamboo box - and there would be no CLD glue seams showing on the outside. The baffle (still probably 1.5-3" of bamboo or other substance) would likewise be adhered to the middle box with CLD glue, and the 1/2" x 1/2" joint replaced with an appropriate sized piece of wood. Each of the three boxes would be a complete rigid structure. Floating braces would be used inside.

I think this means I could get a good painted finish on these in the end with no seams. I'm afraid an exposed CLD layer would not paint well (even with a basecoat of resin) or leave seams.

As far as cost goes, I'd need a large amount of CLD glue, which is something like $180 for 12 'caulk gun' style tubes. I don't know how far that would go at 1/32" thick, but I'm guessing one order would not be sufficient for two speakers. The 1/4" MDF is apparently $60 at Home Depot...which is the same as 3/4"... but presumably something much more reasonable from a lumberyard. I'd need 1/2" pieces of baltic birch either way, so the only real addition to this would be the bamboo...which could be replaced with MDF or birch as well. If I didn't go with bamboo, it'd be a wash. That said, a fair chunk of the cost of bamboo is the shipping, and if I'm using it for the baffles it probably wouldn't be a huge additional cost to get some 1/2" sheets as well.

It would also take a few more weeks to make, at least at my typical project pace.

Risks...I'm not sure if there really are any. If I crafted a three layer solution I think it would adhere to augerpro's findings.

Oh...passive radiators would be a problem on the sides. I think I'd need 3/4" material to countersink them using brass inserts and very short screws (so as not to penetrate the CLD).

All this said, I kind of wanted to keep construction cost down to keep project costs reasonable for anyone else interested. That was part of my rationale for choosing the Anarchy woofers, every penny matters when your mid/tweeter costs an eye-watering $550. For the price of one coaxial we can just about get all eight Anarchy woofers necessary for a pair of these. I suppose if cost savings is really my goal, a monolithic MDF box should be the order of the day.

Decisions, decisions. Sorry for the rambling!

[xandresen]

I currently have them set for 1 1/4" throughout because tradition dictates it to be so. I say 'could' because I'm still kind of thinking of using a three layer solution over a two layer one. 1/4 MDF inner, 1/2 baltic birch middle, and 1/2" bamboo on the outside for shaping. My tentative plan would be to construct an inner box of 1/4" MDF (all six sides), adhering a 1/2" baltic birch layer to that with CLD adhesive (again, all six sides), then add the 1/2" bamboo to the exterior (five sides - not the baffle) again with CLD adhesive. I'd then rout out a 1/2" x 1/2" rabbet in each CLD edge joint, and insert a 3/4" x 3/4" piece of wood along that edge and rout it down to size. If I have this visualized correctly, that would mean we would have an inner box floating inside a middle box that is floating inside a bamboo box - and there would be no CLD glue seams showing on the outside. The baffle (still probably 1.5-3" of bamboo or other substance) would likewise be adhered to the middle box with CLD glue, and the 1/2" x 1/2" joint replaced with an appropriate sized piece of wood. Each of the three boxes would be a complete rigid structure. Floating braces would be used inside.

Danny,

As someone who has made a working CLD cabinet of my own design, let me offer some feedback on your thinking/planning.

1. I start making a box from 1/2" MDF (could be BB). 1/4" is so bendy/flimsy that I can't imagine getting a straight, square box.

2. there is no such thing as "CLD glue"
On DIY audio's CLD thread, Dr. Geddes has said endlessly that it is the filler mixed into the polyurethane that makes it visco-elastic (gives it serious damping in a CLD). Yet, over and over, on the very next page of the thread, people are right back to talking about using something out of a tube.

3. my experiments say that MDF and BB are too soft to benefit at all from a CLD construction using the damping sheets that are designed to damp sheet metal in cars.

4. as you are planning, you do not glue the edges of the two layers (wood for us) together. they need to bend independently to stretch the visco-elastic layer.

My most important thought is that you should make test panels of any CLD construction you are considering. Compare them for damping to the same sandwich without the visco-elastic layer. I screwed each test panel to a rectangular frame of pine, made from 1x4", so I could tap the panel in a repeatable way.
I did this and it proved many of my ideas did not work (at least with the materials I could buy).

I still have a set of partially constructed cabinets where I used Green Glue without testing.
My best use for these cabinets is as workbench supports in the basement...

If you want to see my approach, which uses ceramic tile for the inner layer, search HTG.
Here is the link, hope linking works

https://www.htguide.com/forum/forum/mission-possible-diy/41345-constrained-layer-cabinet-walls-bathroom-tile-as-constraining-layer?42597-Constrained-layer-cabinet-walls-(bathroom-tile-as-constraining-layer)=

[technodanvan]

Thank you for your response! I just checked out your thread and some adjoining links. I should really be better about doing a search within the forum to see what others have done!

First, in response to your comments:
1. I have been thinking about this as well, especially when I'm considering use in a large floorstanding speaker. I think I have successfully created a (mostly) square 1/4" MDF box for my other project, but that is much more manageable in size.

2. I apologize, I used shorthand here and I shouldn't have. I should have stated this is a viscoelastic layer I'm talking about (Weicon Flex 310 M, is the proposed material right now). I also should have differentiated it from a constraining layer.

3. This is interesting, and I'd like to test it in a quantifiable way! See below.

Tile is an interesting choice. Ceramics can of course provide great stiffness in addition to decent mass for the volume they take up. Also interesting that the Green Glue is that bad - is it really only for use with drywall? Good stuff, I'll definitely consider tile.

I'm thinking of setting up a quantifiable way to test various materials, kind of like Brandon did. My project with the polymer concrete already had me thinking about this, but testing various forms of CLD could be interesting. How large were the panels you used? I would think we'd want something that was rectangular so we could get more than one mode. I was thinking of using a fairly large panel so the resonance would be pronounced, something like 1x1.5 feet or so.

All this has me thinking I should not do this on these large floorstanders. Maybe using these methods on the Kairos or Auricle builds would be a better proof of concept. Or another set of boxes for the Keramiskas so I have a direct comparison.

[xandresen]

Construction adhesive thoughts
I looked at the manufacture's website for the Weicon Flex 310 M. Looks like a construction adhesive.
My experience with urethane and acrylic construction adhesives is that they are not supposed to flow - just like the website photo of applying 310M to a wall shows.
I have never been able to figure a way I could apply a 1/32 or 1/16" uniform layer of these materials to a large panel. (my floor standers are about 34" tall)

Then there is the challenge of joining the panel with adhesive applied to another without introducing large trapped areas of air - maybe vacuum bag?
I never tried it, but a possibly is making the constraining layer from perforated metal to allow trapped air to escape?

Also it will take weeks for the adhesive far from the panel edges to cure (by giving off or absorbing moisture). not a deal breaker but makes testing very lengthy.
A two-part adhesive would cure in a few hours.

Test panels
My test panels were 8x10.5", which was based on an available tile size. Remember in my approach the cabinet shelf braces attach to the outer box walls, as usual. I just added CLD damping to the wall sections between the shelf braces.
I later added a few cross braces inside the box between the layers of tile - the box within a box idea you mentioned. no idea if it helped.

MAX+
As an alternate to thin bathroom ceramic, you could go for a HTG double hernia-master cabinet with slate or ceramic flooring tiles. Who needs epoxy when you can use solid stone and a diamond tile cutting blade to cut it.


Green glue
has a consistency sort of like a thick, tacky Vasoline Jelly. It never hardens - it's not supposed to.
And believe me no one is going to succeed in spreading that stuff out into a uniform thin layer.
I used the squiggle method they recommend for drywall - 3/16"(?) diameter bead in a random squiggle pattern across one panel's surface, press the two panels together. easy to do but what a disaster.
supports for a tool bench is all those cabinets are good for.


Interesting CLD materials, new to me since I did my CLD

https://www.polytechinc.com/products/vibration-damping

https://www.pyroteknc.com/products/decidamp/decidamp-dc30/#

A YouTube site claims this next material can be used for the visco-elastic layer in CLD.
I am not sure this is true but bought some to test. never got around to it. could send it to you.
they sell a paint-like adhesive to go with it, which I also have.

https://www.schluter.com/schluter-us/en_US/Membranes/Waterproofing-%28KERDI%29/Schluter%C2%AE-KERDI-BAND/p/KERDI_BAND?facets=false

[JonMarsh]

Decidamp DC30 looks interesting, but 10kg is a bit of a commitment!

[technodanvan]

You've got me thinking about this some more, I appreciate your experience and suggestions. Brandon brought up air pockets being a concern as well, and curing is a concern, but I still want to try the box-within-a-box approach. I'll have to think about that. Probably not as big a deal for smallish speakers.

I'm interested in your MAX+ approach. Tell me more!

And thank you for the links, it's nice we have several options out there to try.

[Steve Manning]

Danny if your worried about bubbles, one of these will help. The epoxy table community has this stuff down!

[technodanvan]

I saw someone using one of those on Youtube Steve! Looks pretty cool, but I'm really starting to run out of room for new toys.

[xandresen]

I'm interested in your MAX+ approach. Tell me more!

I assume we both have our tongues firmly in our cheeks here.

However if you search for "floor tile saw"
at Home Depot and other stores, you will find water-cooled diamond-blade table saws for cutting stone and ceramic floor tiles. At all sorts of prices.

From my experience working stone sculpture, don't expect the saw to cut fast.

Also you will find slate, marble, ceramic and probably other types of floor tiles. Sizes can be big: 18x18", 12x24", etc., 5/16" or 3/8" thick.

So a determined person could use these dense, heavy tiles either as an outside finish layer (polishing sawn edges would take quite some time) or as a hidden inner layer.

------------------------------
I took the Kerdi fabric I mentioned above and made a MDF sandwich test panel to test for CLD damping, versus my other test panels.
The original poster (on DIY, not YouTube as I said earlier) allowed a week for the Zinsser BondZ primer to dry so I will do that.
The primer acts as the "glue" and somehow the mixture of the primer and Kerdi cloth is supposed to provide damping...
He used a BB/MDF sandwich and didn't provide any details so I am curious how well it works.

[technodanvan]

I'm not sure I'd trust any adhesive to hold that long term given the weight....but I like where your head is at! Interesting project you have going on there, definitely let us know how that works out.

In other news, the King Coax has new competition for the throne. My understanding is this offering from Satori will be priced similarly.

https://sbacoustics.com/product/7%c2...t19cp-8-paper/



Not that I'll be switching now, but I'm glad to see other high end coaxials on the market besides Seas.

[technodanvan]

Looks like the Satori is available, and at a much more competitive price. If it competes or beats the King Coax it'd be hard to pass this one up.

https://www.madisoundspeakerstore.com/coaxial/satori-mt19cp-8-coaxial-with-papyrus-cone-8-ohm/

For comparison, the King Coax:


From my untrained eye it appears the midrange on the Satori may be easier to deal with, the tweeter goes lower and might be ever so slightly flatter as well.

[theSven]

Some day I hope to get my eyes trained to interpret these graphs!

[JonMarsh]

Mostly looks pretty good, except for the tweeter dip at 9 kHz on axis and quite evident 30 degrees off axis. It's hard to make a driver cone into a good waveguide. it would be difficult to "fix" that in a crossover. Oddly, the 60 degree off axis curve for the tweeter doesn't look bad. Of course, no hints with what's going on with the break up mode, as the graph cuts off at 20k.

[JonMarsh]

But in all fairness, if you want to see what "funky" looks like, go check out the Seas C16N001/F coax. Would give a crossover designer nightmares. I don't know why they release a driver in that state.

[theSven]

I wish I could add a laugh emoji to your comment. Maybe they want to see how many people realize this and don't buy the driver...

[duvixan]

Here's a dark horse

https://en.toutlehautparleur.com/coaxial-speaker-sica-6-5c1-5cp-8-8-ohm-6-5-inch.html

[JonMarsh]

Looks pretty good, and from one of my favorite vendors in Europe!



And Hard core, measured on a box (no overall dimensions given though) and with an AP- been a while since I"ve done speaker measurements with mine, maybe I should go back and review that possibility again... I don't recall it having some of the windowing options I use to get "de-noised" measurements.

But the price is right, and the driver doesn't look hard to work with, based on this data.

Thanks for the link!

[technodanvan]

Been a bit since I've posted much...doing 100+ articles kinda wore me out! My Bold North drivers just arrived, both the BWX-6501 and BWX-6502. I picture them here with an Anarchy 708 for comparison. Something I did not notice when originally looking at these is they're a bit smaller. Small enough that pairing with the larger frame of the C18EN coax might look odd. The Anarchy is also smaller than the C18EN...but only by 3mm. Anyway, I'm good with my decision on the Ensemble Crescendo, but am excited to try these in something else. I'm hoping a 2-way with the 6501 and a small 3-way with the 6502 is possible.

[JonMarsh]

Nice looking parts, Danny!

[technodanvan]

Attending Iowa DIY has stirred my motivation a bit for these - I want to have them completed in time for Iowa DIY 2024.

This weekend I need to clean up the garage and get ready for some sawdust.

[theSven]

Attending Iowa DIY has stirred my motivation a bit for these - I want to have them completed in time for Iowa DIY 2024.

This weekend I need to clean up the garage and get ready for some sawdust.

Hopefully the weather is getting cooler out there and you will have a good 4 to 6 months to work on this project.

[technodanvan]

Looks like the weather might turn come this Sunday, so I want to be ready!

[technodanvan]

I dusted off the CAD files I started a few months ago and found them incomplete, so I started working on them this morning. I'd like to figure out the base and crossover sections before cutting, but I think the rest of it getting there. Each pair of Anarchies would be in a 30L compartment with a pair of passive radiators. The coax would have a nice deep compartment to itself, plenty of room to pack stuffing in there to absorb much of the backwave. I have a lot of unused space at the bottom, presumably where the crossover will go. Not shown is some sort of brace or two within the mid compartment.

[theSven]

I dusted off the CAD files I started a few months ago and found them incomplete, so I started working on them this morning. I'd like to figure out the base and crossover sections before cutting, but I think the rest of it getting there. Each pair of Anarchies would be in a 30L compartment with a pair of passive radiators. The coax would have a nice deep compartment to itself, plenty of room to pack stuffing in there to absorb much of the backwave. I have a lot of unused space at the bottom, presumably where the crossover will go. Not shown is some sort of brace or two within the mid compartment.

The design is coming along nicely! Keep up the work to progress 😀

[technodanvan]

I needed to drive our old Subaru yesterday before I could smog it (dead battery, again) so decided I would head to my favorite place in Las Vegas - Woodworker's Emporium. Sadly, I was met with some kind of auto parts store instead. Apparently the physical location closed during COVID at some point, so I headed home wondering about when the last time I was there.

When I got home, my sadness turned into a bit of joy as I started searching for any other local woodworking shops - we now have a Woodcraft in Vegas! I have no idea when it went in, the building definitely looks like it has been there a while, but I'm glad I have a place to go to browse and make poor decisions.

[theSven]

I needed to drive our old Subaru yesterday before I could smog it (dead battery, again) so decided I would head to my favorite place in Las Vegas - Woodworker's Emporium. Sadly, I was met with some kind of auto parts store instead. Apparently the physical location closed during COVID at some point, so I headed home wondering about when the last time I was there.

When I got home, my sadness turned into a bit of joy as I started searching for any other local woodworking shops - we now have a Woodcraft in Vegas! I have no idea when it went in, the building definitely looks like it has been there a while, but I'm glad I have a place to go to browse and make poor decisions.

That's good this post had a happy ending... I live in between 2 Woodcraft, but they are both a good 30 minute plus drive depending on traffic. That is definitely a great store to make poor decisions. However 6 months after the decision I'm usually still happy with what I did 🤣.

[JonMarsh]

Yeah, it's very sad when a good wood store closes (like the Woodcraft in San Ramon, CA, back around 2018), and a joy when you discover a new one locally. I got used to ordering online, but often it feels a lot better to just hold things in your hand and ponder.

Here, the Woodcraft in Boise is literally in the location of an old supermarket, and I have heard it is the largest one in the country, and does more dollar volume than any other Woodcraft.

[technodanvan]

Wood delivery day! I'm excited to turn some of this into sawdust. Not all of it will go towards the Crescendo, plenty is earmarked for other endeavors. I'm hoping to get this all rough cut over the next week or so, and make a few piles for all my upcoming projects.

[JonMarsh]

Ah... the smell of BB ply in the springtime! Makes one's musings turn to thoughts of table saws and routers!

[technodanvan]

Over the last few days I have broken everything down into expected dimensions + 0.25"-0.5" with a track saw. I kept them large because I need to laminate all sides first, then I'll trim to exact dimensions later on the table saw. I also cut extra pieces for internal bracing and whatnot, so I should be able to keep the track saw in storage now. Previously I would use the saw on the floor because I didn't have a table, which was hard on my back. I still did that for the first cut on 4x8 sheets of MDF (they're just too big), but I now have an old kitchen table in the garage for breaking down 5x5 Baltic Birch and further breaking down of the MDF. I like my track saw a lot more now!

In any case, I believe I have the necessary wood for the Crescendos and the SMJ-40PE.

Final decision for the Crescendos is BB all around, including 18mm+12mm sides.

Track saw setup.



All wood cut down to rough size.



Gluing first of six required laminations.

[technodanvan]

Further work on the bracing this morning. Could make the center piece solid or the window braces solid. Leaning toward the latter. Also working on the base, I'm considering making it solid steel, either polished stainless or chrome. Current projections have it (the base alone) weighing around 50 lbs. at 1" thick...might reduce down to 3/4", or whatever the steel guy says is available. No matter what it'll be overkill, but I wanted something that would shift the overall center of gravity down. It needs to be a bit deeper though, I don't care for the overhang that I initially tried as shown below. Deep enough the base would create a slight lip on the front and back would, I think, look better and have slightly better stability.

I also tried an X-like shape but I didn't really care for it. Another option would be a T-shape, with only one foot at the rear....but I'm having a hard time believing that would be particularly stable unless the front feet were spread wider.

[theSven]

Further work on the bracing this morning. Could make the center piece solid or the window braces solid. Leaning toward the latter. Also working on the base, I'm considering making it solid steel, either polished stainless or chrome. Current projections have it (the base alone) weighing around 50 lbs. at 1" thick...might reduce down to 3/4", or whatever the steel guy says is available. No matter what it'll be overkill, but I wanted something that would shift the overall center of gravity down. It needs to be a bit deeper though, I don't care for the overhang that I initially tried as shown below. Deep enough the base would create a slight lip on the front and back would, I think, look better and have slightly better stability.

I also tried an X-like shape but I didn't really care for it. Another option would be a T-shape, with only one foot at the rear....but I'm having a hard time believing that would be particularly stable unless the front feet were spread wider.

What about an oval shape? I think that would be pretty cool with the design.

[technodanvan]

Oval is basically what we used on the Ardents so I was inclined to do something different. That said, the above image is remarkably similar to the wood (cherry) feet I have on my existing living room speakers, so maybe that isn't a great criteria to use.

[theSven]

Oval is basically what we used on the Ardents so I was inclined to do something different. That said, the above image is remarkably similar to the wood (cherry) feet I have on my existing living room speakers, so maybe that isn't a great criteria to use.

Important detail I missed. What about your Initials a D for the left and for the right the first letter of your last name. Otherwise there is always a circle, Y, hexagon, or diamond.

[technodanvan]

Now that's interesting, I hadn't considered doing something asymmetrical. I'm normally one for symmetry so I don't know that I'd try that particular idea, but maybe I could integrate my initials elsewhere.

By the way, has anyone seen speaker feet - they'd need to be fairly large - that features a spinning ring on the outside (or top) that could be rotated, and with each rotation a spike would descend from the inside of the foot? I was thinking this could be a fairly elegant option that one could use to have both a nice rubber isolator and a spike in the same package, to be used based on preference or floor covering.