"Fundamentals" for a new stand mounted speaker project -what goes around comes around

[Steve Manning]

Dang it, Masha (the Siberian Husky) ate ALL of the candy, all 2 lb of See's mixed nuts and chews! She took that box out to her favorite spot in the back yard and killed it! She was the one with the sugar high on Christmas Eve!

We were just worried to death, because chocolate is poison to dogs, and that much chocolate would kill many dogs her size. She hardly noticed it. Must be the same genes that allow Russians to drink so much Vodka without overly untoward results. Actually, the gal who locally has run a Husky rescue operation for many many years (OK, let's be straight- decades) says they have real tough stomachs and constitutions. But still, there's a straight forward calculation of chocolate per pound of dog, and Masha would have been dead if she were some other breeds. And her son would have been in the dog house for not minding the doors properly.

That's a lot of chocolate ...... I have known of dogs that have pulled a similar trick and then left some rather nasty, smelly, presents in return all over the house 8O Sounds like your pooch has a real strong constitution if it didn't even faze her, which in this case is good.

[csmielke]

Steve and Jon,
Glad to have you two focused on these again - they look really great. I look forward to tracking your progress to completion.
Chris

[csmielke]

Steve and Jon,
Glad to have you two focused on these again - they look really great. I look forward to tracking your progress to completion.
Chris

[sfdoddsy]

There's been movement at my C18 station too.

I've changed the baffles from acrylic to white film faced ply, purely for aesthetic reasons. They fit in better with my modernish decor now.



I've also been experimenting with crossovers. I have been using a cheap generic crossover from eBay, but figured the dudes at Seas might know what they are talking about and so nabbed the crossover for the King4Roy kit from Madisound.

https://www.madisoundspeakerstore.com/index.php?p=product&id=2092

Unfortunately (or fortunately as it turned out) there were issues with the build as I needed it on one board and it came on two so it is going back, but the cheap generic crossover both sounded and measured better in a quick test. I lucked out with it as it crosses in precisely the right spot (2.2k).

However, it is 3rd order and there are issues compared to the LR4 I've tried when going fully active with a MiniDSP, so I will get something made up.

My boundary woofers are also changing, but I'm too embarrassed to admit what I'm going to do given the superb standard of the builds here.

[TEK]

Yes, you guessed it, crossover in the base of the stand. And yes, this is going to be a metric ton of LBL ply... (well, close to it...)


Between these construction concepts and what I'm hearing today, I'm looking forward to early 2016!

What are those side panels going to be made from?
It kind of looks like a ply, and then a metal sheet (3mm thick or so) and finally "something else"...

[Steve Manning]

Hey TEK ..... the plan is the side panels will be painted lbl and your right, the in between is metal, aluminum in this case.

[JonMarsh]

Well, for a while I thought I wouldn't find the time to setup for listening (too many un-done things on my to-do lists) but in the end I decided I needed a little down time, and setting the acoustic demonstrator up in the family room system and running it in mono should be fit into the afternoon schedule.

I ran through everything in the list above, plus a lot of other things, some probably obscure to you guys, like some cuts from the remastered original Ambrosia Album, some Clannad, some additional classical, some Diana Krall, anyway, you can see I got a little carried away. But I didn't just sit like a lump on the couch, most of the time I was up and walking around, checking out the sound in about a 135 degree swath in front of the speaker- including normal listening height and standing, and sitting on the floor. Very satisfactory, quite neutral; yes, the bass was better in some parts of the room than others, but that's just normal room mode stuff.

The interesting thing was GF commented that the system sounded nice and full; did I change something in it? And then I pointed out it was just one speaker playing, the demonstrator, which she hadn't been paying any attention to, as she was in the dining room mostly, and just in the back of the family room. I guess that means they're OK by her. :W

My own impression is that the tweeter is just a bit crispy in an unnatural way compared to the 6640 Be dome, but only a slight amount. Mid to presence range is a trifle darker than the Ardents. Bottom end is quite competitive, at least with the M22 or AHB2's. Vocals were sublimely natural sounding, and overall midrange inner detail was good, most notable playing older recordings I'm quite familiar with, like Acoustic Alchemy, Rite of Strings, Andreas Vollenweider White Winds, etc. Daria was lovely, as was Diana Krall and Gloria Estefana and Sade.

Definitely at a point where we need to have the final cabinet configuration before any further tuning.

[TEK]

Jon, my good man! You must be the only one that might get a listening session to sound like a decent workout session :conveyer: :rf

[JonMarsh]

That's how you get multiple benefits out of one activity! :W :B

[Hank]

WOWZERS! And that stand concept - outta the box for sure.

[JonMarsh]

WOWZERS! And that stand concept - outta the box for sure.

yup- Steve should take a bow for his second pass on the stand design. Mind you, we have to run a bit of cabling up the center of the stand, so there are some good design reasons, too.


Good news from Steve today, too, as the LBL ply has arrived at our vendor.





Now, this is one of the weirder posts I've ever made, as regards methodology- I'm posting from Edge on Windows 10 running in a virtual machine on a MacBook Pro I just bought off of eBay and upgraded to handle running test interface and data acquisition from an Audio Precision as well as more LspCAD work.

Anyway, maybe 2016 will be the GE year- "Progress is our most important product". Gonna involved some jumping through hoops I think!

[sdl2112]

Good new! 1200lbs of LBL is a lot. How many speakers do y'all plan on building?

[JonMarsh]

Think Translam construction.

One pair, with a pair of stands, as visualized above. These will use as much or a bit more than I used to build the Isiris three ways. Translam is not an efficient way to use wood, but it allows most of the hard work to be done with CNC milling, and gives more freedom in cabinet design.



Now, I'm sure some will say this is kind of crazy, but keep in mind the target design is the TAD Compact Evolution One, which is basically a 6-1/2" woofer ported with a 5" concentric midrange tweeter driver, (that costs $28K per pair) so we're going for bear using the 8-3/4" long throw SW223BD02 Wavecor woofer with Scanspeak 10" PR, plus the 7" Seas C18EN001. So, for a variety of reasons related to some of the target usage of this particular pair (CLASS D amplifier evaluations, including within my day job), going a bit further for the investment on this seems justified, in a certain light.

We talked about using BB ply, but the problem we see over and over again with that kind of ply is delamination of the material in Translam enclosures. Additionally, the woods it is made of just aren't nearly as hard and strong as LBL. That doesn't preclude someone else from trying BB ply or even specialty high strength MDF; but that is up to the constructor.

So, yeah, for DIY, this is sort of a "Magico" class effort, IMO. A bit over the top, I'm sure some will think. But the use of CNC facilitates some extra bang for the buck, in my opinion. It's interesting to note, what I would say is my generation calls this DIY, but Millenials call this Maker movement. The latter is characterized by more effort to use technologies more advanced than a table saw, whether it is CNC cutting or 3D printing- I have 30-ish quasi-relatives and relatives involved in what is known as the "Maker scene". It's an interesting contrast in approach.

But you know what they say, if some's good, more is better, and too much is just enough! :B

[Steve Manning]

Have to look into what can be made from the dropout's ...... when I did my Modula project I was able to make the stand columns from the cabinet dropout's. Not in this case, but something will pop up.

[sdl2112]

Cool :T That's what's neat about DIY. You are only limited by your imagination...umm and the depth of your pockets. I have some not so rational decisions in my build as well but when finished, sitting back listetening to them they will sound all that much better :B

[TEK]

Shit, just realized LBL stood for Laminated Bamboo Lumber... I don't think I have ever seen a translam using bamboo. Have you? Or are this actually new ground and your speaker build will be the one that proves (or disproves) that translam out of bamboo is a good idea?

[Steve Manning]

I have seen one other, though rather small in size, more or less computer monitor size. So this could be new ground for a speaker this size, though it was not part of the design criteria.

[dar47]

Going to be fun and Steve pick up ever piece and put it away, you find use for it!. Ben said to me a while ago dad what did you do with that extra ply and I said what extra, haha.

[JonMarsh]

Shit, just realized LBL stood for Laminated Bamboo Lumber... I don't think I have ever seen a translam using bamboo. Have you? Or are this actually new ground and your speaker build will be the one that proves (or disproves) that translam out of bamboo is a good idea?

I haven't seen a big one, but then big is relative- technically we're just trying to make an oversized stand mounted bookshelf with a little extra cojones.

[5th element]

Those are going to be really impressive once they are done and very solid.

You'll probably have one of the most capable and technically proficient stand mount loudspeakers on the planet when you're done. Not that I don't like SEAS own but the intrinsic limitations of the hypex gear worries me for absolute fidelity.

[DS-21]

the intrinsic limitations of the hypex gear worries me for absolute fidelity.

????

[csmielke]

Jon & Steve,
I did some modeling of the SW223BD02 and 26W/0-00 combination just for grins and it looks good. In 22L I came up with an F3 in the 24hz range with a nice roll off. Only thing that could be better is a little higher efficiency 81.57db SPL 1W/M and do the impedance peaks need to be addressed? Great performance in such a small enclosure. Really looking forward to the completed project - you two are really raising the bar on what's possible.
Chris

[JonMarsh]

Those are going to be really impressive once they are done and very solid.

You'll probably have one of the most capable and technically proficient stand mount loudspeakers on the planet when you're done. Not that I don't like SEAS own but the intrinsic limitations of the hypex gear worries me for absolute fidelity.

Yeah, it wasn't a great choice using the Hypex plate amp based on UcD technology. UcD can be improved, as the AURALiC Merak's show, but I don't know that I'd want to go with the stock plate amps. (OTOH, they seem fine for my GF's sub setup- just questioning that for full range).

Also, I don't think the Seas passive crossover design for the mid to tweeter extracts the best performance for that combo. But I'd have to build and test it to be sure-

As is often said, it's about the trade-offs. Such as the benefits of eliminating passive components in the path for a full electronic designs, say, versus the limitations of the mini-DSP DACs. (A question brought up in a recent PM exchange)

[5th element]

????

The hypex plate amps are great for what they are but you can improve upon the quality of the clocking and the DACs. Whether or not this will be audible, or rather make a considerable difference towards the end result is most likely debatable, but for my main systems I like going for the best (relatively easily obtainable) objectively performing hardware.

[TEK]

The hypex plate amps are great for what they are but you can improve upon the quality of the clocking and the DACs. Whether or not this will be audible, or rather make a considerable difference towards the end result is most likely debatable, but for my main systems I like going for the best (relatively easily obtainable) objectively performing hardware.

But where comes the plate amp in regarding the topics beeing discussed here? I might have overlooked something, but I just dont see where a plate amp fits into the discussion.

[JonMarsh]

But where comes the plate amp in regarding the topics beeing discussed here? I might have overlooked something, but I just dont see where a plate amp fits into the discussion.

Matt is referring to the Seas Kit with the C18EN001, which uses an LROY 10" Seas on the bottom end, sealed, and uses a Hypex plate amp for the power and the low to mid crossover. This kit is available now at Madisound in the USA, with an enclosure option, too, I believe.

[JonMarsh]

Earlier in this thread I discussed the King ROY project from Seas in some detail:

You know, the KingRO4Y "King Roy" project did give me some pause for thought when initially contemplating a coaxial driver project with the C18EN001. Of course, since I'm not marketing kits or selling plans, in one sense it didn't matter at all. But, it would be logical to say, "Build or buy?" - could I bring anything to the party that would make a bespoke design worth the time and effort? Here's the main points that convinced me to go ahead...

• The passive crossover for the midrange to tweeter in the King Roy is a rather non-optimal design, IMO. It doesn't do a good job supperssing the upper break ujp mode of the midrange (hardly surprising- bog standard 3rd order electrical); 25 dB versus 40 dB+ attenuation (my past experience with metal cone drivers from any source indicates this is very important)
• The Hypex plate amp is well designed, BUT, we're running everything through a DSP and DAC, and the UcD grade class D amps; which are not bad, but they're not nCore amps, and the DAC output stage is a question mark in my mind- it's not an M51 or AURALiC Vega or Metric Halo ULN-8, much less a TotalDAC-D1.
• The per speaker price is about $1500, if you include their pre built cabinet, which looks pretty nice, for a rather conventional style and proportioned box. (me, I hate conventionally proportioned (as from the 70's or 80's) speaker cabinets).
• Speaking of that cabinet, it's a bit on the small side, 16.7 L, and requires a fair bit of EQ but delivers at about 30 Hz at -3 dB using that EQ and a fair bit of power. Contrast that to the Wavecor + Scanspeak design, no EQ, -3dB at about 22-23 Hz, and a very well behaved upper end response on the woofer. Hmmm.
• The King Roy design is extensible, using two SEAS SL26R PR's and extending the subwoofer cabinet volume by 50cm in length, with re-calcluation of the DSP filters. Then, alternatively, there's the Model 2 tower which is planned; SDX10 woofer(s), not sure about the cosmetic design yet. Probably just a taller version of the Model One.
• Also, there are several DSP presets, and some nice optionis provided standard for the King Roy. That's both a plus and a minus, in my book. For middle range expectations, it's pretty nice.
• So, I figure with the cabinets and other materials required, we're looking at a BOM per pair for the King Roy of about $3K USD, closer to $3500 to $4K for the tower version.
• That leaves some wiggle room for the Model One with SW223BD02, and a floor stander using, let's say, dual SDX10's in series for each cabinet, with 2 PR's. That would be an interesting shoot out, depending on associated source electronics.
• Per cabinet BOM for the Model One is running $472 + $123.40 + ~$390 (cross over), and that doesn't include any power amps, unlike the King Roy. So I would say the King Roy has a nice value proposition, EXCEPT that the crossover is less ideal than I would prefer, and there's no flexibility about amplification and DAC/DSP in the signal path. One could do a King Roy using a ULN-8 and whatever power amps you want, but that would be pretty pricey. Might be worth it, though.
• OTOH< compared with a TAD Compact Evolution One, either of these solutions is a stone cold bargain. Will either approach the listening gestalt of the Compact Evolution One? That's rather another question, but I think the Model One has a better chance. I.E., let's take some of that $24K price of the Compact Evolution One and spend it on DAC, and amplifier, and preamp.

[TEK]

Are you and steve/jon building the same speakers? One (or two?) pairs in usa and one pair in Tallin?
Could you share a bit about your cnc setup? Is it a private setup, or dontounrun a woodshoop?
Also, where do you source the bamboo from?

[Steve Manning]

Are you and steve/jon building the same speakers? One (or two?) pairs in usa and one pair in Tallin?
Could you share a bit about your cnc setup? Is it a private setup, or dontounrun a woodshoop?
Also, where do you source the bamboo from?

Hey TEK, as far as things here state side, we're building two pairs of the Minerva Monitors, Jon can tell you more on the Tallin side of things, I believe Ergo had been following this thread and once Jon posted pictures of what we had planned, he wanted to build them.

The CNC stuff is being done in my neck of the woods in Virginia at a local lumber yard. The guy that owns the place has two machines, one that will cut 4' X 4' and his new machine does 5' X 10', we are doing this on the larger machine. It could be done on the smaller machine but would take considerably longer and potential require more lumber and that all costs money. This machine is new and unfortunately the factory installed some parts made from the wrong material which has prevented the vacuum table from working, which has caused some delays (weeks) in getting parts cut. The machine is supposed to be fixed as of yesterday and I'm hopping sawdust will fly this week.

I'll make notes on things like feeds and speeds once we get underway and of course post some pictures.

I sourced the bamboo from a company north of here in Maryland and had it shipped directly to the lumber yard. Not only do I not have a truck, but the thought of moving ~1300 lbs of lbl a couple of times, did not have too much appeal. 8O

Steve

[JonMarsh]

Not only do I not have a truck, but the thought of moving ~1300 lbs of lbl a couple of times, did not have too much appeal.

Boy, that's putting it mildly.... :B