Ardent D (aka Kurosawa Jr) Winter Camp

[Evil Twin]

This project has been given a "go ahead" after much discussion with Imperial collaborators...

While I doubt it will prove to be a "technological terror" in the end, it may nonetheless have a certain charm and provide a useful window into musical performances.

It is also part of a planned series of projects to investigate less conventional crossover technologies from both a measured perspective and also by critical listening.



It has reached a certain critical mass due to several factors:



Development of a new cabinet design that is derivative of the original Ardent, not the Wavecor Ardent- this is admittedly part of an effort to engage in "design re-use" and speed the development effort with limited work hours available.






Proof Of Concept explorations have been completed, using actual driver data on similar test baffles, and the potential to reach the desired levels of performance is clearly proven...





Model to sheet construction drawings are nearly complete...






And critical tooling and cabinet materials have arrived...

[Evil Twin]

Working in small spaces...

One of the more difficult phases of material preparation is cutting down the 58" x 22" 1-1/2" maple ply to sizes useful for fabricating specific cabinet parts, such as the front baffles and cabinet base.

This is due to the somewhat unwieldy size and the lack of a truly adequately sized construction area- for the moment, I have to settle for the patio area of Jonmarsh's rented condo. This is quite different from the circumstances under which the Kurosawa cabinets were fabricated.


The SawStop job site Pro saw provides more capability than a typical portable saw, and used in conjunction with a roller feed table, larger work pieces can be accommodated than might be expected...






The SawStop has excellent blade shrouding and dust capture, but this must be combined with an adequate dust extraction system; in this case, a 16 gallon ShopVac will suffice. They are powered on separate electrical circuits, as the combined load could be too much under load for a standard 15A circuit.





With the table in the extended position, a 16" cross cut to reduce the main panel to 42" is straightforward to accomplish, with steady hands.





With the Freud blade I installed, the resulting cuts were impressively smooth... and easy to make, once figuring out how to accomplish in the limited space. Two panels were cut in this manner-




Next steps will be ripping and detail work on the front panel sections and starting the sides and backs from LBL boards.

[Browncoat]

Your work is so detailed and clean. Inspiring.

You must have tolerant neighbors to run a table saw and shop vac on a condo patio! Not sure if you have a track saw, but it changed my life. I have a sliding table saw and still couldn't live without my track saw.

[TEK]

Hmm, I do have some mental challanges in connecting the Kurosawa - that is a design with a lot of elements - to a two elements vented design.
Care to connect the dots?

[Evil Twin]

Hmm, I do have some mental challanges in connecting the Kurosawa - that is a design with a lot of elements - to a two elements vented design.
Care to connect the dots?

The Kurosawa is a three way system using a Duelund derived crossover, built with piano pin block maple ply exclusively.

The Ardent D is an Ardent variant, three way system using a strict Duelund crossover approach, built with piano pin block maple ply and LBL bamboo plus BB ply for some interior components.

The Kurosawa is derivative stylistically of the Tidal Akira, just as is the Vimberg Tonda. The Vimberg Mino is derivative of the Vimberg Tonda.

The Ardent D is derivative stylistically of the Vimberg Mino, but will use only two woofers, and will not (for this build) use Accuton tweeter or midrange units.









Just for reference, the Vimberg Mino sells for $31K per pair, similar to the Avalon Indra, upon which the first generation Ardent was derived. Both of these systems (the Indra and Mino) have cabinets built of MDF.

[mante]

This is going to be fantastic and I can’t wait to see more progress. Sure hope the design is finalized long before heading to Boise.

I gotta say, I sure didn’t expect to see the RS52.....must be something special about it.

[Evil Twin]

This is going to be fantastic and I can’t wait to see more progress. Sure hope the design is finalized long before heading to Boise.

I gotta say, I sure didn’t expect to see the RS52.....must be something special about it.

There is... especially for this application.


I expect to have these constructed in a few months... I would rather under promise and over deliver...

But I have made many design decisions impacting the construction specifically to speed building these - such as using a two layer front panel with 1.5" material, instead of laminating up 1/4" HDF and LBL ply and 3/4" MDF. I expect the front panels to be finished in less than two weeks.

[ergo]

Sawdust in making - that's unexpected with the schedules of the master maker lately but most interesting and great to see. Will be watching with interest.

[dwk]

piano pin block maple ply

Hmmm, hadn't run across this before. Like here? https://www.vandaking.com/s-563-pin-block-maple.html Not much if any cheaper than LBL, but I guess 1.5" panels is an advantage.

I'll be watching your progress with the SawStop with interest. I'm still using a BT3k, and while it's still functioning well it seems that they're getting rarer and rarer, and so I probably need to have a Plan B in place since 'buy another ryobi' is probably no longer a viable support strategy. I need something with a smaller footprint due to space limitations, so the typical hybrid/cabinet saws aren't ideal. Would you see the SawStop jobsite as a reasonable upgrade to a BT3k (or at least a side-grade)?

That's a heck of a crossover. Based on the better image in the other thread I count 14 elements per driver for M and T. The Dueland topology is certainly demanding.

I'm back in the 'maybe' category on the new Ardent designs. My original idea of something inspired by the Sonus Faber Elipsa probably has to be discarded as mock-ups show that they're just too wide for the space. My current "I need something in the living room" setup is Kef R3's on top of woofers in the PE prefab cabinets - the result is ~40"h x9"w and seems to work well. I think another inch or 2 in width will be OK, which puts it squarely in the Ardent footprint.

[Evil Twin]

That is my supplier for the maple ply- I have searched for others with no success. This build is using two 1-1/2" 564D double planks (these can be ripped for all the materials for the front panel and the bases) and one 563 1-1/4" panel which is used for the top plates with some left over.

Yes, this is not a frugal material build, but then some back of the napkin calculations seem to indicate that the extra spent on materials reduces my labor factor substantially, as well as providing a very stiff cabinet construction.

The finished cabinet width for this and the original Ardent is 10-5/8". That seems to fit in your footprint.

This could also be built with Anarchy 708's, but this build is being constructed with AS168 Accutons. The rearward time offset of the woofers is manageable in the crossover, as the posted proof of concepts show, which are actually for the SW223BD03.

Now, going sealed, this could be built with SW223BD, too, with the planned midrange, as there is no large midrange enclosure as is the case with a cone driver.

I also have cone midrange driver tests being readied, but they cannot track or match the time alignment, so a more conventional crossover would be required.

You could say this is a research project follow up to the NeoD CC. And as to the crossover, well, on earth there is a well known saying- "in for a dime, in for a dollar". To work optimally, the midrange driver and tweeter have to track very closely to a specific amplitude and phase response. (this is also true for the woofer, but due to the difference in frequency range and phase relationships in practice it is not quite as demanding for equivalent results.)

At least with this test build we have the opportunity to save quite a bit in BOM costs for the tweeter and midrange. Crossover expense depends on how much the constructor wants to spend, and what matches up well with the rest of the system.

Of course there will be component recommendations...

I, too, have used a BT3K for a long time, and in fact had what I termed a "Frankensaw" for some time which was an amalgamation of the Craftsman saw made by Ryobi and accessories for the BT3K.

I have two models of DeWalt job site saws; the newer large one (DWE7491RS) being a considerable improvement (in storage in the Outer Rim at this time), but the SawStop seems to be in a very different class, as well it should, as it's in quite a different price class. Initial working experience yesterday and today is quite positive.

The provided blade is relatively decent, but I immediately replaced it with a 90T Freud. After cutting 8 consecutive 42" rips in the 1-1/2" maple ply, the blade was barely above room temperature. Of course, I checked the saw setup, too, and have realistic ideas of what this tool can power through.

Still, very satisfactory.

And the manual and setup is truly excellent. Download a PDF of it if you're curious.

[Evil Twin]

The SMJ concept for Duelund three way tower...

Mr. Manning has once more been hard at work...

This time showing a certain Dark lord how inadequate both his CAD and design skills are... truly, Steve is turning out to be a most talented Sith Apprentice!


In this case, what he sent me are renderings for his interpretation of a proposed Ardent D implementation- not something I can argue with, other than that I can't possibly build them here with the tools at my disposal...

These are using the same profile and rib section designs as the previously shown MT with the MW19P-08 and DA25TX00-08. We have discussed the possibility of adjusting some of the driver spacing further...











Perhaps if the performance results from the more conventional test build here prove worthy, this might be the next SMJ offering?

[Bear]

That is my supplier for the maple ply- I have searched for others with no success. This build is using two 1-1/2" 564D double planks (these can be ripped for all the materials for the front panel and the bases) and one 563 1-1/4" panel which is used for the top plates with some left over.

NW Bamboo has 26x96 1.5" LBL for similar pricing. They also cut to ship, so I'll give them a try on a different project once I'm back in SD (traveling for the holidays).

This could also be built with Anarchy 708's, but this build is being constructed with AS168 Accutons. The rearward time offset of the woofers is manageable in the crossover, as the posted proof of concepts show, which are actually for the SW223BD03.

Now, going sealed, this could be built with SW223BD, too, with the planned midrange, as there is no large midrange enclosure as is the case with a cone driver.

Would that hold true for a flat baffle? I'm still thinking along the lines of a large, comparatively shallow center channel as I track your build progress. I still need to get my SDFWA membership purchased and work through the shop safety classes before I can start booking shop time, but this does seem most interesting.

And beautiful work, Steve. The bamboo and black paint go especially well together! That also answers my "flat baffle question, immediately above, though you guys can obviously reserve that version for your own purposes.

[Steve Manning]

Thanks Bear .... this is more for you guys and showing you different options for cabinets for the same internals. If any of it floats your boat and you need some fabrication assistance, give us a yell, we can help you out. By the way, the SMJ concept would use cabinet grade mdf for the walls considerably reducing the cost of material, unless of course you want it all bamboo. :P

[Evil Twin]

NW Bamboo has 26x96 1.5" LBL for similar pricing. They also cut to ship, so I'll give them a try on a different project once I'm back in SD (traveling for the holidays).

This is useful information which will bear investigation in the near future.

[Bear]

Thanks Bear .... this is more for you guys and showing you different options for cabinets for the same internals. If any of it floats your boat and you need some fabrication assistance, give us a yell, we can help you out. By the way, the SMJ concept would use cabinet grade mdf for the walls considerably reducing the cost of material, unless of course you want it all bamboo. :P

Thanks! I'm still stuck with needing a smaller footprint (California real estate prices and room sizes; no more Texas-sized rooms for me). Tall is okay, to a point. Having found the SDFWA shop, I think that I can manage the fabrication that I need without having my own shop. I do have lots of questions, though, regarding material breakdown and glue-up time. My guess is that I'll need to do glue-up at home, but that is usually not a noisy process. The odd swear word notwithstanding.

Since I'm sitting on 4xSW223BD02 and 4xSW223BD03, I look at your rendering and wonder if a single SW223 firing to the rear might be interesting/useful to compensate for baffle step and/or to implement the ever mythical cardioid bass (2xSW223BD02 in front and a single SW223BD03 in parallel in the rear; quasi 3.5 way...). This obviously changes the rib structure, among so, so many other other things.

Because I am starting with the idea of sub-optimal placement and going downhill from there, the cardioid bass concept has thrown a wrench into my plans. I'm starting to eyeball a variant of the Dutch & Dutch 8c as being more suitable to my needs. All of that is for a different thread and a different day, though.

For now, I'm just along for the ride to learn more from Team Sith.

[dwk]

NW Bamboo has 26x96 1.5" LBL for similar pricing. They also cut to ship, so I'll give them a try on a different project once I'm back in SD (traveling for the holidays).

Hmmm, you could get two full bamboo 3" baffles out of one piece of that. I'd been looking at this as a cheap bamboo option: https://www.ikea.com/us/en/p/tolken-...mboo-20371269/ . The dimensions result in a lot of waste though - you can only get a single layer unless you go with a much narrower baffle than the existing Ardent design, so as long as the NW Bamboo shipping costs aren't outrageous it may be a good solution for the 'final, production' version. I'm assuming I'll need to build at least one rough version first before dropping $$$ on finish-grade materials. Fortunately, I am coming out of a kitchen renovation where I installed plywood countertops to hold us over until the granite was installed, so I have a couple sheets worth of 'decent' ply to start with (big box grade, but the best they had).

And beautiful work, Steve. The bamboo and black paint go especially well together! That also answers my "flat baffle question, immediately above, though you guys can obviously reserve that version for your own purposes.

Yes, very interesting. This suggests there might be slanted and flat baffle versions of the xover. This design is kind of a hybrid - retains some of the possibilities I liked from my Ellipsa idea, but in a more compact footprint. Food for thought, for sure.

[dwk]

I have two models of DeWalt job site saws; the newer large one (DWE7491RS) being a considerable improvement (in storage in the Outer Rim at this time), but the SawStop seems to be in a very different class, as well it should, as it's in quite a different price class. Initial working experience yesterday and today is quite positive.

The provided blade is relatively decent, but I immediately replaced it with a 90T Freud. After cutting 8 consecutive 42" rips in the 1-1/2" maple ply, the blade was barely above room temperature. Of course, I checked the saw setup, too, and have realistic ideas of what this tool can power through.

Still, very satisfactory.

And the manual and setup is truly excellent. Download a PDF of it if you're curious.

After a bit of research, more research is definitely needed. A quick perusal online indicates that the SawStop seems to be based on this Ridgid unit: https://www.ridgid.com/us/en/heavy-d...saw-with-stand , but whereas the SawStop seems to be favorably reviewed, the Ridgid is much less so. Expectation bias, or does SawStop make some improvements to the base unit in addition to adding the brake? I'd definitely like to go with something more like this https://www.homedepot.com/p/RIDGID-1...4512/202500206 (particularly since I just got a 220V circuit run as a concession in the kitchen reno),but I'm not sure I can give up the storage in the base of my BT3k cabinet (that's where my Dewalt SCMS lives) .....

[Bear]

Hmmm, you could get two full bamboo 3" baffles out of one piece of that. I'd been looking at this as a cheap bamboo option: https://www.ikea.com/us/en/p/tolken-...mboo-20371269/ . The dimensions result in a lot of waste though - you can only get a single layer unless you go with a much narrower baffle than the existing Ardent design, so as long as the NW Bamboo shipping costs aren't outrageous it may be a good solution for the 'final, production' version. I'm assuming I'll need to build at least one rough version first before dropping $$$ on finish-grade materials. Fortunately, I am coming out of a kitchen renovation where I installed plywood countertops to hold us over until the granite was installed, so I have a couple sheets worth of 'decent' ply to start with (big box grade, but the best they had).

If they posted a weight, you could have a reasonably accurate guess of how solid they were. I did a build last Christmas for a simple TM bookshelf for my brother in law, and I used cutting boards from IKEA as the cheap source of LBL. They turned out well, but the material had a lot of voids that I had to deal with. Your mileage will vary....

I also found out that my Sears BT3100 clone table saw blade was Not Square. That was Not Fun, and prompted me to hit a holiday sale on a Makita track saw.

As a further aside, since I'm on-call but not busy right now: one of the things that caught me by surprise about bamboo was the sculpted feel of the finished product. It felt almost like stone in my hand, rather than wood. If I can be careful with construction, I'll go with just finishing the cabinets directly, rather than veneering.

[Steve Manning]

Thanks! I'm still stuck with needing a smaller footprint (California real estate prices and room sizes; no more Texas-sized rooms for me). Tall is okay, to a point. Having found the SDFWA shop, I think that I can manage the fabrication that I need without having my own shop. I do have lots of questions, though, regarding material breakdown and glue-up time. My guess is that I'll need to do glue-up at home, but that is usually not a noisy process. The odd swear word notwithstanding.

Since I'm sitting on 4xSW223BD02 and 4xSW223BD03, I look at your rendering and wonder if a single SW223 firing to the rear might be interesting/useful to compensate for baffle step and/or to implement the ever mythical cardioid bass (2xSW223BD02 in front and a single SW223BD03 in parallel in the rear; quasi 3.5 way...). This obviously changes the rib structure, among so, so many other other things.

Because I am starting with the idea of sub-optimal placement and going downhill from there, the cardioid bass concept has thrown a wrench into my plans. I'm starting to eyeball a variant of the Dutch & Dutch 8c as being more suitable to my needs. All of that is for a different thread and a different day, though.

For now, I'm just along for the ride to learn more from Team Sith.

So you know, with the SMJ TTC style there is no gluing required, unless your making the parts yourself from scratch.

[Evil Twin]

There is a project started inspired by the Dutch & Dutch 8C, but scaled up somewhat (8" midrange, 10" woofers, 1" ultra low distortion compression drivers and high performance constant directivity horn/waveguides) that has been put somewhat on hold due to the need to focus on completing the Ardent D investigation...

It won't fulfill a 10" maximum width requirement, though...

It might scale down with the right components, and there is a concept in mind, but not in the next few months. For the initial version, we were targeting "Ludicrous Mode" as regards sensitivity... that aspect would have to be scaled back, but then Wavecor woofers could be feasible. Say, with 6ND430 midrange and SST1 waveguide coupled with a Peerless DFM-2544 driver... The 2544 requires relatively little massaging and has a fairly benign impedance curve, and a low Q breakup above 20kHz.

Of course, it is not a solution to consider unless you really do want midrange and high frequency distortion at the -80 dB level...

[Bear]

There is a project started inspired by the Dutch & Dutch 8C, but scaled up somewhat (8" midrange, 10" woofers, 1" ultra low distortion compression drivers and high performance constant directivity horn/waveguides) that has been put somewhat on hold due to the need to focus on completing the Ardent D investigation...

It won't fulfill a 10" maximum width requirement, though...

It might scale down with the right components, and there is a concept in mind, but not in the next few months. For the initial version, we were targeting "Ludicrous Mode" as regards sensitivity... that aspect would have to be scaled back, but then Wavecor woofers could be feasible. Say, with 6ND430 midrange and SST1 waveguide coupled with a Peerless DFM-2544 driver... The 2544 requires relatively little massaging and has a fairly benign impedance curve, and a low Q breakup above 20kHz.

Of course, it is not a solution to consider unless you really do want midrange and high frequency distortion at the -80 dB level...

The SST1 waveguide is a bit "more" than I'm looking for. I have waveguides, courtesy of Brandon's efforts, for both SS6600 and SB26ADC that should match something between a 15cm - 18cm normal cone profile woofer. The Satori woofers tend to be quite a bit deeper for the frame size, so those aren't as good of a match for what I've got in the parts bin. I'm still playing around, but the MW19P-8 perhaps paired with the Bliesma T34A seems to currently catch my fancy. The SW223s would be deployed for subwoofer duty, naturally.

I can always be persuaded to head over to the dark side, of course.

[Scottg]

There is a project started inspired by the Dutch & Dutch 8C, but scaled up somewhat (8" midrange, 10" woofers, 1" ultra low distortion compression drivers and high performance constant directivity horn/waveguides) that has been put somewhat on hold due to the need to focus on completing the Ardent D investigation...

-when you start into that: getting the directivity right on the midrange is largely due to the distance from the internal rear cabinet wall relative to the driver's magnet (with of course the standard aperiodic venting on both sides of the cabinet on opposite sides of the driver). It took Keyser a while to get this correct relative to the baffle. Basically you want the baffle about as small (narrow) as possible relative to the driver you are using with a small cabinet section (volume) and interior rear wall that's very close to the driver's magnet. For the best possible result: get a driver that's VERY efficient while having only modest Qe (..around .5), otherwise distortion starts getting bad if you push it much lower than 300 Hz. BTW, I've always felt that resistance designs like this (..midrange) lacked depth (ultimately). There is of course another method other than resistance for a similar directive result.

[Evil Twin]

Small work breaks from the Imperial tasks

Stage 1 of the front panel routing is complete for both panels now... time and light are running out this late in the day.










Tomorrow the through holes for the forward portion of the front panels.

And yes, with the addition of a non-skid pad, the saw table with the riving knife and blade cranked down (hardly "Cranking"- one turn) makes a stable work table.

[Evil Twin]

-when you start into that: getting the directivity right on the midrange is largely due to the distance from the internal rear cabinet wall relative to the driver's magnet (with of course the standard aperiodic venting on both sides of the cabinet on opposite sides of the driver). It took Keyser a while to get this correct relative to the baffle. Basically you want the baffle about as small (narrow) as possible relative to the driver you are using with a small cabinet section (volume) and interior rear wall that's very close to the driver's magnet. For the best possible result: get a driver that's VERY efficient while having only modest Qe (..around .5), otherwise distortion starts getting bad if you push it much lower than 300 Hz. BTW, I've always felt that resistance designs like this (..midrange) lacked depth (ultimately). There is of course another method other than resistance for a similar directive result.

Thank you for sharing your knowledge in this area; it matches my intuition based on the design and construction of the Dutch&Dutch 8C, and the 10" drivers I have been looking at for the midrange duties
fall into that range of performance, with 95-96 dB sensitivity for 8 Ohm drivers with a Qes of about 0.45.

[Bear]

-when you start into that: getting the directivity right on the midrange is largely due to the distance from the internal rear cabinet wall relative to the driver's magnet (with of course the standard aperiodic venting on both sides of the cabinet on opposite sides of the driver). It took Keyser a while to get this correct relative to the baffle. Basically you want the baffle about as small (narrow) as possible relative to the driver you are using with a small cabinet section (volume) and interior rear wall that's very close to the driver's magnet. For the best possible result: get a driver that's VERY efficient while having only modest Qe (..around .5), otherwise distortion starts getting bad if you push it much lower than 300 Hz. BTW, I've always felt that resistance designs like this (..midrange) lacked depth (ultimately). There is of course another method other than resistance for a similar directive result.

That starts to sound a lot like the Grimm LS1 -- except for the narrow baffle thing. That's definitely the opposite of the Grimm. I'd love to have a layman-friendly (Noob friendly?) write-up on executing a resistance midrange if someone can point me to it.

[Scottg]

There really isn't a good write-up on this. ops:

The best thread I've seen is MBK's "Adventures in Cardioid" here:

https://www.diyaudio.com/forums/multi-way/142691-adventures-cardioid.html

-you really get to see the alterations in various constructions and effects IF you look very closely at each of his posts. Post #8 shows a real cardioid response, and tends to highlight some of the problems. What you don't really see is that overall the proximity of rear wall (reflection) to driver is critical, instead you just see a "muffler" that does just that. (..though he also explores some longer open-rear pipes as well.) Post #16 & 17 explores putting that "muffler" on different sized baffles that are circular. Post #18 shows what the muffler plus rectangular baffle is like. Note: as you move even a rectangular baffle closer to the size of the driver, the negative consequences are reduced, so for midrange-only use IF the "box" is rectangular then "go small" relative to the driver's size.

Here is Keyser's initial DIY effort (that later produced the Dutch & Dutch 8C):

https://www.diyaudio.com/forums/multi-way/192737-2-waveguide-cardioid.html

It's a very nice design, but it's not cardioid. Compare to MBK's efforts and to the 8C (fig. 3):

https://www.stereophile.com/content/dutch-dutch-8c-active-loudspeaker-system-measurements

-expanded on through Soundstage's anechoic room measurement:

https://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=2073:nrc-measurements-dutch-dutch-8c-loudspeakers&catid=77:loudspeaker-measurements&Itemid=153

..sorry for "muddying" the thread. ops: (..blame it on rebel scum.) :P

[Evil Twin]

A wide range of information sharing is always welcome... your contributions are recognized for the value and information they bring.

However, do not expect this equanimity from me at all times... it is not as if I am a moderator or something...

[Bear]

There really isn't a good write-up on this. ops:

The best thread I've seen is MBK's "Adventures in Cardioid" here:

https://www.diyaudio.com/forums/multi-way/142691-adventures-cardioid.html

-you really get to see the alterations in various constructions and effects IF you look very closely at each of his posts. Post #8 shows a real cardioid response, and tends to highlight some of the problems. What you don't really see is that overall the proximity of rear wall (reflection) to driver is critical, instead you just see a "muffler" that does just that. (..though he also explores some longer open-rear pipes as well.) Post #16 & 17 explores putting that "muffler" on different sized baffles that are circular. Post #18 shows what the muffler plus rectangular baffle is like. Note: as you move even a rectangular baffle closer to the size of the driver, the negative consequences are reduced, so for midrange-only use IF the "box" is rectangular then "go small" relative to the driver's size.

Here is Keyser's initial DIY effort (that later produced the Dutch & Dutch 8C):

https://www.diyaudio.com/forums/multi-way/192737-2-waveguide-cardioid.html

It's a very nice design, but it's not cardioid. Compare to MBK's efforts and to the 8C (fig. 3):

https://www.stereophile.com/content/dutch-dutch-8c-active-loudspeaker-system-measurements

-expanded on through Soundstage's anechoic room measurement:

https://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=2073:nrc-measurements-dutch-dutch-8c-loudspeakers&catid=77:loudspeaker-measurements&Itemid=153

..sorry for "muddying" the thread. ops: (..blame it on rebel scum.) :P

Very much appreciated.And in keeping with the thread: arigato. I shall refrain from making the thread resemble Rashomon any more than I have already.

[Evil Twin]

If you review the original Ardent Summer Camp thread, you may see at times relatively wide ranging discussion.

This can be useful because of additional associations and logical connections made-

Do not refrain from expressing yourself unnecessarily - I shall assure that there is not unnecessary censure of discussions by otherwise well meaning individuals. You know who you are...

[Bear]

Back on topic: the main complaint against the D25 is the size of the faceplate and the implied CTC. With a Duelund (Fc=1600, aleph=2.7) target, I peg the Fc for the mid/tweeter at 3.7kHz at-6dB down. In terms of distance, this equates to ~9.4cm (depending upon how hot/cold your room is) -- which is less than what is possible for the two units butted together. With the original Ardent(s), this seems like less of an issue since one just backs up the listening point/integration point). With Duelund, does the same hold?

[Evil Twin]

With Duelund, does the same hold?

This is why I am terming this a research project... investigating the resulting in room performance will be key.

You probably have little idea how many tweeters were purchased and evaluated earlier this year in the search for a preferred tweeter moving forward...


TW29DN

TW29BN

T34A-6

T34B-6

SB29BAC

SB26CDC

DA25TX00-08

Also on hand for comparison are the 7140 and 6640.

This is not including a number of high performing compression drivers and associated waveguides/horns.

Priorities included flatness of on axis response, flatness of off axis response, HD3, HD2 (a weak point for Scanspeak, for example)

Some applications, such as some contemplated high efficiency designs, may only be possible with the Bliesma designs, but in most cases 90-92dB is more than adequate sensitivity.

At first I was looking for a $300 to $500 tweeter that could solidly beat the DA25... then I was looking for one that would merely match it, any issues about form factor aside.


Some products have a desirable form factor, such as the SB29BNC-C000, the Illuminator D3004/6040 or 6040-10. But key characteristics were not up to expectations.


Another tweeter that I find measures quite well, from TL, is of course no longer in production.


After evaluations and design of a simple MT system, the achievable results seem to justify making a certain leap of faith, in building a larger scale demonstrator.






Will I come to regret that? Time will tell...

[Bear]

This is why I am terming this a research project... investigating the resulting in room performance will be key.

You probably have little idea how many tweeters were purchased and evaluated earlier this year in the search for a preferred tweeter moving forward...

This year, My Lord? Absolutely not. I'm but a poor street rat from Corellia, not one who is wise and skilled in The Force. However, my SS 6600s in inventory were once profiled by Your Most Malignant Majesty a long, long time ago...

Working from the top down, starting with the treble unit.
[..]

D3004-660000 "Air Circ"



D3004/660000 Air Circ Axis Curves



D3004/660000 Air Circ NF 4"



D3004/660000 Air Circ Distortion at 92 dB output



Strengths and weaknesses seem to be as individual and characteristic as their designers and companies. But two possible winners do emerge- the 27TBFCG for those of a sensible inclination or limited means; the D3004/662001 for those with deep pockets and demanding tastes.

One has attempted to follow such events as best as one can over the years.

After evaluations and design of a simple MT system, the achievable results seem to justify making a certain leap of faith, in building a larger scale demonstrator.



Will I come to regret that? Time will tell...

I'm definitely intrigued. One wonders whether such efforts might unfreeze out of carbonite ideas along these lines, as well, given the limited volume required from the SW223 droids from planet Wave in the Cor worlds...

https://www.htguide.com/forum/showthread.php?41692-Proposal-for-a-compact-three-way

Such old ponderings from Your Majesty have had a lasting influence on my own limited investigations. I've been particularly intrigued by the idea of both traditional CC layouts and side-firing woofers as a way to break the packaging issues of a compact three-way. Finding a set of drivers that can work within quarter-wave boundaries as an alternative for proper phase alignment executed in the crossover has been a challenge, especially when SPL is taken into account. All this helps drive my interest in the latest experiment coming out of Sienar...

[Evil Twin]

the 66000 air circ is a very good tweeter for it's price- the main critiques would be the typical soft dome resonance which manifests as a bump in the response between 14 kHz and 22 kHz, with the addition typical issues of off axis response - in fact, the most similar recently measured tweeter to it is the Satori TW29DN, which has similar overall characteristics. Where both do not perform as optimally as mighty be desired is in the off axis response. 30 degree response is deteriorating significantly...

TW29DN


Note the difference in smoothing (1/48th octave vs. 1/12 octave), and that this measurement, like my measurements of the DA25TX00-08 were made on small cabinet baffles, not on large IB type test baffles.

Compare the spread between the 1st and 3 traveling of this measurement and that of the complete system measurement with the DA25 above, which only has a notch filter for the 28kHz tweeter peak, not any EQ for the base tweeter response.

I believe the shallow dome design and very flat tweeter faceplate are key factors in this behavior. In that regard, it is like the Transducer Lab tweeters. The off axis dispersion was immediately noticed during my first listening tests with the DA25. Steve Manning picked up on this also, when he assembled the Satori MT and gave it a listen.






The air circ 66000 is still a very high value tweeter from ScanSpeak, and it most cases can be dropped in place of the 6640.

[Bear]

Compare the spread between the 1st and 3 traveling of this measurement and that of the complete system measurement with the DA25 above, which only has a notch filter for the 28kHz tweeter peak, not any EQ for the base tweeter response.

I believe the shallow dome design and very flat tweeter faceplate are key factors in this behavior. In that regard, it is like the Transducer Lab tweeters. The off axis dispersion was immediately noticed during my first listening tests with the DA25. Steve Manning picked up on this also, when he assembled the Satori MT and gave it a listen.



[ATTACH=CONFIG]29887[/ATTACH]

Since the 80 - 100uF capacitor that one typically needs for an AirCirc Zobel costs as much as the DA25, I'm not hung up on using them. I merely brought it up to point out that I am familiar with many of Your Magnificent Sithness' investigations over the years. I did, however, pick up the last 4 elliptical waveguides from a group buy at DIY Audio for the AirCirc and Ring Radiator units. My hope is that it helps significantly with the off-axis behavior. Brandon's measurements made it "worth a flyer" to have as an option. This is especially true since the form factor is common to the ScanSpeak line and the SBA line, and they should match well with a number of mainstream 17cm/18cm woofers.

I'd really like to get my hands on a pair of Bliesma T25s, though, whenever they come out...

[Evil Twin]

I'd really like to get my hands on a pair of Bliesma T25s, though, whenever they come out...

Many people are thinking the same thing...

[Bear]

It might scale down with the right components, and there is a concept in mind, but not in the next few months. For the initial version, we were targeting "Ludicrous Mode" as regards sensitivity... that aspect would have to be scaled back, but then Wavecor woofers could be feasible. Say, with 6ND430 midrange and SST1 waveguide coupled with a Peerless DFM-2544 driver... The 2544 requires relatively little massaging and has a fairly benign impedance curve, and a low Q breakup above 20kHz.

Of course, it is not a solution to consider unless you really do want midrange and high frequency distortion at the -80 dB level...

Picking this back up. The SST1 still looks quite a bit bigger of a form factor than I would want (it's loosely 10"x8", while the waveguides that I have on-hand top-out at ~4x6), but the ME20 that Vance used in the review might be doable (~6x6). That starts to be a fair bit of cabinet volume, though. The '2544 + ME20 has fairly high HD2 in Vance's measurements, but HD3 is quite low.

For the 6ND430, how would you use it? It looks great in Unibox at ~6L with an 80Hz tune, but that port resonance is a factor to watch. It also looks like a great low-end roll-off for a midrange in a sealed box, but that's an awfully low Qts as a starting point.

[Evil Twin]

Interesting transfer function on Accuton Cell woofers

One thing I am looking forward to is testing the AS168 soon, in the individual test cabinet prepared.

I expect the results will be similarly thought provoking as the AS190, and the large baffle measurements I have seen on HiFi Compass for the AS190 and AS168 confirm my suspicions, that the intrinsic response of the AS drivers behaves (for what ever reason) as if there is baffle step compensation built in. This may be a natural and accidental by product of the long VC and hemispherical aluminum dome radiator- or some other factor may be at play. One sees the possibility of this potentially easing the work load in the crossover, if the cabinet choice is made in a complimentary manner.


This is various AS190 responses measured in a sealed PE 28L cabinet, at different distances, ranging from 20cm to two meters, and including a polar set. These were all done with long gates and little smoothing in room- not really a special setup, more a quick exploration of characteristics. The intent was to develop a feel for the behavior between 100Hz and 1kHz.












For an 8" class diaphragm driver, the consistency of off axis response is fairly uncommon, in my experience.

[ergo]

If I remember correct then one of the Vance Dickason's books referred to a woofer from old times that had dual voice coil and by driving the other through coil one could achieve similar... but having this 'in built' into driver sound even more interesting indeed.

[Evil Twin]

Like inverse baffle step built in

If I remember correct then one of the Vance Dickason's books referred to a woofer from old times that had dual voice coil and by driving the other through coil one could achieve similar... but having this 'in built' into driver sound even more interesting indeed.

HiFi Compass measurements show the half plane response behavior of the AS190 here...



A nearly ideal 4dB baffle step correction for the right enclosure width- one like the 28L PE cabinet.

His measurements of the AS168 are similar in the area between 100Hz and 1kHz.

[Evil Twin]

Front panels being assembled.

The 2nd of the front panel core assemblies comprised of the two 1.5" maple ply panels is glued up and drying...




Materials for the inner front panel and the laminated sections for the side side panels and rear panel have shipped.

As I have often observed, slow work takes time...

On the other hand, a front panel comprised of only 3 layers total is much faster to fabricate and assemble than one of 7 layers...






Some might call this "cheating" by using high priced materials more convenient to fabricate with, but as a Danish acquaintance of mine several times remarked, if you're not cheating, you're not trying hard enough...

[JimS]

Hey ET, hope all's well!

I've been occasionally following the Ardent threads and this one might actually convince me to pull the trigger on a new build...

- getting tired of rebooting crossovers
- have a line on a planer 3 and probably shouldn't run it through the LIO-8 on principle
- just realized it's been ~10 years since my last significant build 8O
- craigj appears to be onboard from the other thread, so will be just like old times :evil:
- getting tired jon's builds so might as well try one of yours :W
- started pricing out the TM driver cost and this build makes really good financial sense, oh wait, nevermind...

now, if only someone could help build a nice cabinet within a few hours of DC...

what a fortuitous confluence of extreme meteorological phenomena :storm:

SUBSCRIBED

[JimS]

...and now off to listen to 2112 which kicked off this whole love of music thing many years ago...RIP Neal

[Evil Twin]

...and now off to listen to 2112 which kicked off this whole love of music thing many years ago...RIP Neal

Yes, that is a shame...

[Evil Twin]

Hey ET, hope all's well!

I've been occasionally following the Ardent threads and this one might actually convince me to pull the trigger on a new build...

- getting tired of rebooting crossovers
- have a line on a planer 3 and probably shouldn't run it through the LIO-8 on principle
- just realized it's been ~10 years since my last significant build 8O
- craigj appears to be onboard from the other thread, so will be just like old times :evil:
- getting tired jon's builds so might as well try one of yours :W
- started pricing out the TM driver cost and this build makes really good financial sense, oh wait, nevermind...

now, if only someone could help build a nice cabinet within a few hours of DC...

what a fortuitous confluence of extreme meteorological phenomena :storm:

SUBSCRIBED

How far is Suffolk VA from DC? (a rhetorical question- my Force Intuition tells me less than 3hr 15 minutes)

[Evil Twin]

Hey ET, hope all's well!

I've been occasionally following the Ardent threads and this one might actually convince me to pull the trigger on a new build...

- getting tired of rebooting crossovers
- have a line on a planer 3 and probably shouldn't run it through the LIO-8 on principle
- just realized it's been ~10 years since my last significant build 8O
- craigj appears to be onboard from the other thread, so will be just like old times :evil:
- getting tired jon's builds so might as well try one of yours :W
- started pricing out the TM driver cost and this build makes really good financial sense, oh wait, nevermind...

now, if only someone could help build a nice cabinet within a few hours of DC...

what a fortuitous confluence of extreme meteorological phenomena :storm:

SUBSCRIBED

Yes, just like getting the old band back together again...

The driver cost can be variable- this appears to be feasible to do with the Anarchy's (based on what appears to be a successful POC crossover design using Wavecor driver data, including driver Z axis offset delay), though the first full dress build will be with the AS168. There will be an acoustical test build for dual Anarchy's, for which the cabinets are already nearly complete.

I would look for ways to further motivate the Seinar droids I had working on this, but they all quit and joined the rebel scum.