Ardent D (aka Kurosawa Jr) Winter Camp

[Evil Twin]

Viborg

Which flavor of binding posts are you using? I'm sure they are beyond my budget, but I am curious what the Master uses for a proof of concept...

Speaking of the times, Madisound has a notice indicating reduced response times. May we all live in interesting times....

The binding posts for these test cabinets and the design study are Viborg parts, available often on Amazon...





The polyurethane coats for the first cabinet are nearly complete now- soon I will begin the second cabinet. In the meanwhile, planning for the baseplate and platform stands proceeds slowly...

[CraigJ]

Speaking of the times, Madisound has a notice indicating reduced response times. May we all live in interesting times....

About a week ago, our governor issued a “month-long safer at home order that prohibits all "non-essential business" and prohibits "all non-essential travel" in the state during the coronavirus outbreak.” I guess Madisound is considered “non-essential”.....please be safe.

[Bear]

Functioning of the supply chain and delivery systems in this backwater planet under quarantine controls was not a problem I anticipated having to deal with...

However, matters and events have shown more capability than I might have expected... as this image shows.

[ATTACH=CONFIG]30132[/ATTACH]


Deliveries this week include phenolic base boards for crossover assemblies from WoodCraft, Obligatto PP film capacitors from HiFi Collective in the United Kingdom, and crossover inductors and resistors from Parts Express in Ohio.

Additional Accuton AS168 Cell woofers have shipped from Germany, but are "stuck in transit" due to a government mandated shutdown at Solen in Canada.

If you have urgent or pressing need to complete a build during this difficult time, this information could prove useful- guard it from coming into the hands of Rebel dissidents.

Meanwhile, LF test enclosures will be completed shortly for the PuriFi woofers, as well as a Midrange-tweeter module test enclosure that is in progress- finish work on the main cabinets proceeds at a reduced pace due to increased Imperial responsibilities coupled to unexpected financial rewards. A new laboratory setup is nearing completion here also...

Which flavor of binding posts are you using? I'm sure they are beyond my budget, but I am curious what the Master uses for a proof of concept...

Speaking of the times, Madisound has a notice indicating reduced response times. May we all live in interesting times....

[Scottg]

-honestly, the shipping problem sounds EXACTLY like a plot for Star Wars Rebels.. (..and unfortunately I'm sure the plot will "thicken".)

[Evil Twin]

The supply chain still functions in some cases...

Functioning of the supply chain and delivery systems in this backwater planet under quarantine controls was not a problem I anticipated having to deal with...

However, matters and events have shown more capability than I might have expected... as this image shows.




Deliveries this week include phenolic base boards for crossover assemblies from WoodCraft, Obligatto PP film capacitors from HiFi Collective in the United Kingdom, and crossover inductors and resistors from Parts Express in Ohio.

Additional Accuton AS168 Cell woofers have shipped from Germany, but are "stuck in transit" due to a government mandated shutdown at Solen in Canada.

If you have urgent or pressing need to complete a build during this difficult time, this information could prove useful- guard it from coming into the hands of Rebel dissidents.

Meanwhile, LF test enclosures will be completed shortly for the PuriFi woofers, as well as a Midrange-tweeter module test enclosure that is in progress- finish work on the main cabinets proceeds at a reduced pace due to increased Imperial responsibilities coupled to unexpected financial rewards. A new laboratory setup is nearing completion here also...

[Evil Twin]

I have acquired several panels of that, but my order from NW Bamboo came in as natural (supposed to be carbonite). We shall see how to meld them together. The APTITLIG cutting boards from the IKEA Nebula are also a light carbonite at 10 credits per panel.

As the last pictures show, the overall effect is not too displeasing- for a design study, this will be fully satisfactory.

[Bear]

I have acquired several panels of that, but my order from NW Bamboo came in as natural (supposed to be carbonite). We shall see how to meld them together. The APTITLIG cutting boards from the IKEA Nebula are also a light carbonite at 10 credits per panel.

[Evil Twin]

Looks good, your Lordship. Is the LBL of the carbonite variety or merely natural? I like how the Minwax crystals push the edifice towards the dark side.

This variety is the carbonite version from woodworkers source, though I find it is not as dark as some other versions in the past...

https://www.woodworkerssource.com/ba...ized-dark.html

[Bear]

Looks good, your Lordship. Is the LBL of the carbonite variety or merely natural? I like how the Minwax crystals push the edifice towards the dark side.

[Evil Twin]

The opposite of computer model rendering...

Your impatience is not nearly as great as mine...


Imperial matters will dominate the rest of the weekend, but these two photographs not taken with one of your primitive smart phones show a more accurate picture of the promise...





The drivers are not properly mounted, merely placed in the corresponding cut out hole, and the full hardware for the woofer mount is not present... but this should convey some aspects reasonably well...

[theSven]

It looks gorgeous. Looking forward to seeing the crossover and all the speakers mounted.

[Evil Twin]

Well it's bin a while since I have posted, I have to remark your A game cabinet has grown to an A+. Although I will continue my admiration of my Wavecor's I look forward to your comparison of this new verses old. The new Nat P's is a build I would be interested in and look forward to that fine work.

As a note I have went through 2 years of weekly vertigo but am now in remission with my Meniere's disease and only have 5% hearing in the left ear. Was contemplating passing along all my gear but glad I didn't as even with 1 good ear low distortion sound is great! Glad to see your back with a vengeance Master.

I am very pleased to hear that there is some good news in your case as well as a clearly positive attitude- in these trying times, that can be a critical factor for all matters large and small...

I appreciate the kind words and will endeavor to make this follow up worthy of your respect in all ways... I am also very pleased that you are still able to enjoy music- this is something I have thought about myself, (what the future may hold) being more acquainted with issues related to mortality and personal limitations, due to events befalling others in my life as well as the larger world around us...


Meanwhile, the work progresses...

[dar47]

Well it's bin a while since I have posted, I have to remark your A game cabinet has grown to an A+. Although I will continue my admiration of my Wavecor's I look forward to your comparison of this new verses old. The new Nat P's is a build I would be interested in and look forward to that fine work.

As a note I have went through 2 years of weekly vertigo but am now in remission with my Meniere's disease and only have 5% hearing in the left ear. Was contemplating passing along all my gear but glad I didn't as even with 1 good ear low distortion sound is great! Glad to see your back with a vengeance Master.

[Evil Twin]

I have been curious to get an early impression of how the wipe on polyurethane will work with this build-

So after finishing the second cabinet mechanicals to the same stage as the first one above, I indulged myself slightly... by applying a fast test coat of Minwax wipe on polyurethane.







While it must be remembered that the primary point of a design study is utility, it is useful if the esthetic results are not an eyesore...





The initial results indicate some promise, with a very simple application process... the key to productivity in a design study.

[ergo]

Very nice progress! This one promises to become a very good looker also from visual shape and balance point of view. With the wall thickness and the materials in use it must be a close to "rock solid" indeed.

[Evil Twin]

More progress has been made, to the point that one cabinet is nearing completion...

Certain trim operations and the PR mounting holes have been completed, along with a fine sand with 120 and 240 grit Arabnet disks...





After completing a base trim operation and sanding to 120 grit, the PR mounting holes bracketing the back center brace must be prepared.





The cut depth is to the full capability of the router on the edges near the cabinets side wall, but is restricted in the center so that the disk is still supported by a small amount of the BB ply material- then this is cut with a saber saw, and the overall hole must be cleaned up with a follower bit.




A test fit confirms the required 1mm clearance was implemented correctly...





After sanding to 240 grit surface, the cabinet was placed back on it's mobile work base to return to interior storage and the next steps in detail work (installing threaded inserts, etc.)





Regrettably, the pictures do not convey the solidity and surface polish that the construction now possesses....

Nor the remarkable strength and solidity due to the construction materials that were chosen.

Satisfactory... very satisfactory.

[Bear]

If one is careful with the machining, especially roundovers, and one likes the look of the bamboo, it can be surprisingly cost-effective compared to MDF+Veneer. And one gets to stay away from MDF.

[Evil Twin]

Some progress is being made...

In a project like this, there is much detail work- at times, the hardest problem to solve is finding the time for this work when Imperial matters keep intruding...

But complaining does not solve problems, or build speakers.

Operations such as basic side wall clean up and sanding are easily completed...






The only real "trick" involved here, since no veneering is planned, is that enough material must be removed so that the surface seepage of epoxy into portions of the wood is completely removed...






Specialty tools are advised for operations such as leveling the sidewalls to the rear panel...






The results prove most satisfactory...





Whether the matching of LBL and Maple ply will be esthetically acceptable is a judgement call, but it is deemed adequate for a rarely seen part of what is essentially a design study, not a finished product.






For only two hours of work, the results are acceptable...

[JonMarsh]

Agreed, that looks fantastic. You've really got your cabinet making skills dialed in, 'cause those went pretty fast. Any other Ardent cabinets nearby for a side-by-side comparision?

No, as my Wavecor Ardents have been owned by a colleague at work for several years now- this is where Ergo heard them, in fact. It was necessary to find a new home for them when the family room needed to be converted to more of a home care area due to the pancreatic cancer- the stereo had to go.

However, I should be able to prepare some simple profile drawings from the original CAD files to illustrate the differences, once some time can be freed up on the weekends.

[Evil Twin]

I'm going to wager a guess of 125. I wonder what prize the winner gets:roflmao:

You are far closer to the current value, without base, crossovers, or drivers, but you are a bit on the high side.

[chrisn]

The enclosure looks great. Looking forward to see what components are gonna be used from all your testing. How much does that enclosure weigh, >50 lbs?

I'm going to wager a guess of 125. I wonder what prize the winner gets:roflmao:

[Browncoat]

Agreed, that looks fantastic. You've really got your cabinet making skills dialed in, 'cause those went pretty fast. Any other Ardent cabinets nearby for a side-by-side comparision?

[theSven]

The enclosure looks great. Looking forward to see what components are gonna be used from all your testing. How much does that enclosure weigh, >50 lbs?

[ergo]

Looking good and nicely angular indeed.

[Evil Twin]

Hints at what is to follow

I find this interesting to ponder...





This is the smallest Ardent style project as regards external physical dimensions, but the weight per enclosed volume seems to set a new benchmark.


There are many additional steps before they will produce music, but it is most satisfying to see this stage realized at last.

As expected, managing some dimensions with regards to the visual character of the design is tricky- looking at this picture, you will most likely think that the upper facet bevels are longer than the lower, because of what the driver arrangement does to the eye/brain interface, as well as perspective- but the lower facet bevels are 2" longer.

[Evil Twin]

Thank you for the link to investigate. My current plan was to use measurement and acoustics functionality in my Audio Precision analyzer, but this looks interesting, depending on price and configuration.

Interesting that you need to download a MatLAB runtime for running their software under Windows.

Also, it seems that they provide a reasonable amount of introductory information about the IM distortion analysis, which seems to be a separate add on, but it is quite unclear from the online material how to actually order or trial it, unlike the other products. There is a strong focus on system equalization and time delay correction as needed for live sound and car audio...

But as I have a "spare" LG 17" laptop, the trial version or individual versions seem like something worth investigating.

[Scottg]

I plan as a starting point to do tests with a two frequency IM setup like HiFi compass has posted- the combination of 30Hz and 255Hz can be very revealing for larger drivers, as well as integer multiples of this frequency set for smaller drivers to examine their linearity.

-while not Mac software:

http://aplaudio.com/conc2/products/tda-im/

[Evil Twin]

In the meantime...

This thread has languished for some time, not due to lack of activity, but due to priorities- continuing construction activities. It will be updated in detail showing the phases of efforts for those interested.


For those who enjoy a fast glance at an advanced stage of construction, this picture may be interesting...





Setup and the work steps leading to this will be posted soon in an organized fashion...

[Zvu]

Your feedback is welcome and seems to hit on key points... dull versus shouty can also be an indication of variation in axial response versus power response - lacking in power response off axis, but clearly showing a coloration if the level is boosted to compensate...

My thoughts exactly at the time. Then i did measurements 0-90 degrees and averaged them. This was the result:



Averaged:



That's when i started to look at other directions to search what may be the problem. I even wrote something about it here:

https://www.htguide.com/forum/showthread.php?44139-Some-measurements-of-Kef-R300-drivers&p=631866&viewfull=1#post631866

I should take R300's back for a revision. I've found some midwoofers that could work in smallish volume in the meantime.

[Steve Manning]

Here's an idea for you, not so much as go out and buy it, rather, the concept. https://www.curvomatic.com/

I made these out of layers of 3/16" hardboard. There very strong with very little spring back during the glue up process. Getting the profile you need shouldn't be to crazy to do. Use your CNC to cut ribs, top and bottom and away you go.




If you have a band saw, you could laminate some wood together and cut the profile on the saw.

[Bear]

My personal thought is semi-translam. A sequence of ribs to define the structure, a solid front baffle (and possibly back - not sure yet), but the curved sections created by laminating up something like 1/8" hardboard onto rebates in the translam ribs. This makes it pretty natural to reproduce the horizontal divisions, and reduces the veneering work to a bunch of small panels which is less intimidating. No idea how to handle the sides, though.....

I have a small cnc (a 6040) which can just barely handle the translam ribs for this, and that is indeed my intended direction - I wouldn't ask it to handle the volume of a pure translam build, but ~12 per cabinet seems viable.

To my simple mind, the point of the translam would be to avoid the issues for side adornment. If you are looking for side pieces (cheeks??), then a traditional build using kerf cuts may be the easier route. Steve's process, but with ~6" rib sections would most closely match the SF original. I could see the piano black ribs, white spacers and bamboo baffle/end caps being attractive here.

[dwk]

My personal thought is semi-translam. A sequence of ribs to define the structure, a solid front baffle (and possibly back - not sure yet), but the curved sections created by laminating up something like 1/8" hardboard onto rebates in the translam ribs. This makes it pretty natural to reproduce the horizontal divisions, and reduces the veneering work to a bunch of small panels which is less intimidating. No idea how to handle the sides, though.....

I have a small cnc (a 6040) which can just barely handle the translam ribs for this, and that is indeed my intended direction - I wouldn't ask it to handle the volume of a pure translam build, but ~12 per cabinet seems viable.

[Evil Twin]

It would work very well as a translam model. We'll just ignore the amount of waste that it would take...

Not particularly concerned with "sustainable" manufacturing I imagine...

Truly, you are strong in the Dark Side!

[Bear]

I've always thought this would be a cool build to try.

It would work very well as a translam model. We'll just ignore the amount of waste that it would take...

[Steve Manning]

To be clear- in this case the wider baffle is purely an aesthetic consideration. My design target is the SF Elipsa.



This may make some of my questions/investigations a bit more sensible - will they fit in the space? how much woofer volume can I squeeze out of this form factor? Is there any detrimental impact on imaging from the wide baffle? etc. Thus the effort to create a test mule using relatively modest cost drivers to investigate (which will effectively be Troels Poor Man's Strad http://www.troelsgravesen.dk/PMS.htm)



Well, maybe I have my thread title for this effort :-)

I've always thought this would be a cool build to try.

[Evil Twin]

I plan as a starting point to do tests with a two frequency IM setup like HiFi compass has posted- the combination of 30Hz and 255Hz can be very revealing for larger drivers, as well as integer multiples of this frequency set for smaller drivers to examine their linearity.

This is why the interface electronics for the test setup have been updated, and in order to accommodate Thunderbolt 3 and USB-C, the laptop needed a refresh to a 2018 MacBook Pro also.

[dwk]

The Strad is definitely impressive, but I actually prefer the design of the Elipsa - I think the single woofer looks more balanced. The opposite of the Avalon style designs - I think they look much better as dual-woofer designs that single woofer.

But both are definitely very pretty, though. The obvious potential flaw in my grand plan is that my woodworking skills may not be anywhere near good enough to do justice to the concept.

There is actually a pair of Elipsa for sale 'locally', but for some reason the wife is balking. https://tmraudio.com/speakers/floors...ecial-edition/

Getting back to the driver discussion, I'm very interested in seeing the IMD testing progress. I've always thought that the 32-tone AP multitone IMD test is pretty much the best 'one picture summary' for the preformance of an electronic component, and I'm intrigued by the idea of applying something similar to speakers. The Purifi certainly seems poised to do well on the test

If I go with the Elipsa style design I think there's a pretty good chance that the SDX-10 will prove to be the best fit - it models very nicely in 40l (as long as you have a bit of power), which is the volume Troels managed in his PMS. I'm not sure whether it'll reach high enough for a Dueland, but it does seem to stay pretty flat up past 1kHz according to the datasheet. Still, very interested to see what the measurements say vs the WO24 and other candidates.

[Evil Twin]

It is rumored that they take 4 weeks just to cure the lacquer finish...

[Bear]

SF knows how to finish a cabinet. I keep coming back to the Strad's/Ellipsa for inspiration.

[JonMarsh]

Maybe you should look at these Sonus Faber Stradivari, too?

Have been very popular with some folks, seems right up the same alley esthetically...

[dwk]

You are making clear progress, and if anything we have done has been a catalyst of sort, all for the better.

The bare DA25TX has wider and more uniform dispersion than typical of a lot of "direct tweeters", and I say this after buying and testing many tweeters in 2019... this was quite noticeable in testing the finished crossover design for the first SMJ MT, so I would suggest thinking about the tradeoffs- the SB15BAC has reasonable output capability, so reinforcing it's low end with a wider baffle is probably not really necessary- or useful.

To be clear- in this case the wider baffle is purely an aesthetic consideration. My design target is the SF Elipsa.



This may make some of my questions/investigations a bit more sensible - will they fit in the space? how much woofer volume can I squeeze out of this form factor? Is there any detrimental impact on imaging from the wide baffle? etc. Thus the effort to create a test mule using relatively modest cost drivers to investigate (which will effectively be Troels Poor Man's Strad http://www.troelsgravesen.dk/PMS.htm)

But this is DIY, and if wandering in the wilderness suits your whims, why not?

Well, maybe I have my thread title for this effort :-)

[dwk]

Kef R300 is also a bit dull sounding. I don't think it is a product of dispersion though. [...]

I might be wrong about the cause of dullness though, but this is my opinion based on living with those loudspeakers (in factory variant and modified) for over a year.

Very interesting. The R3s are my desktop speakers (I have a big desk), and in that role I find them terrific - not dull at all. Moving them into the main room with RSS210 woofers was where it was apparent, particularly when casually listening around the space (living room /kitchen/dining room). Hence my initial thought that dispersion may be a bit narrow.i'll have to see if I can find some more time to do some more listening/comparison at some point.

[Evil Twin]

Thank you for the links- I will review this evening... I have having my 3rd Monday for the week, and the schedule for tomorrow appears very similar...

[ergo]

It seems you are planning something more advanced with IMD measurements. Would be interesting to hear more

Klippel has also some interesting new approaches like
3D Intermodulation Distortion Measurement
and the prior multitone method
Multi-tone Distortion Measurement
Getting the 'current into speaker' spectrum should be doable also with the tools I have, but I'm yet to get around to attempting that. The data it produces looks interesting though.

[Evil Twin]

Your feedback is welcome and seems to hit on key points... dull versus shouty can also be an indication of variation in axial response versus power response - lacking in power response off axis, but clearly showing a coloration if the level is boosted to compensate.


Other thoughts which floated to the surface last night-

The proposed RS225 + SB15NBAC + DA25TX should be a very high value combination- note the RS225 was used in a floor standing predecessor to the Ardent. Like many of the other RS series drivers, it works best in a large enclosure, too. As posted in the last 12 months, the WO24 has some very strong performance characteristics, but it is even more desirous of what I believe is termed "monkey coffins" in the colloquial slang of this sector.

Also, I have a developing plan to study the comparative performance of high BL Flux linearity drivers against other more "popular" types, especially with intermodulation tests, and I believe some components, such as the SDX10 previously mentioned and in my own plans for a special system, may outperform otherwise popular choices like the RSS265 variants. Only hard data will tell the real story, though.

This is why a similar IM spectra comparison is now also planned between the SB15NBAC/CAC and the Anarchy 554/558. Their frame diameters are conveniently equivalent, so test conditions will be quite well controlled. Both are actually 6" drivers.