Official Wavecor Ardent Reference Thread - How we realized the Dream

[BobEllis]

Hi Jon. Nice to see you back again. I hope things are going well for you.

Thanks again for sharing this design. My Ardents put a smile on my face every day.

[JonMarsh]

Makes me happy to hear that, Bob- I know the feeling.

I'm going to try to be around here regularly now- it's just been a bear with all the stuff going on. As is, I'm working today also, finishing a report on a Class D chip and eval board from a Danish company we just bought earlier this year. And my plan for the rest of the summer is a trailer run trip to Idaho every other week to transfer off site storage there.

that happened last weekend, and is scheduled for the upcoming weekend (I'm taking three day weekends for those trips).

[Renron]

Bob, +1

[JonMarsh]

Bob, +1

:welcome:

[Bad_tweeter]

I'm with the other guys. If you have some measuring equipment, driving them in full range three way passive triamp would be possible in principle BUT, the filters and attenuation networks are inextricably linked- this keeps the part counts down and is part of the key to having a very flat impedance curve in the finished design. (just compare the Ardent impedance curve to an Avalon Indra, which is brutal for a tube amp to drive).

The Ardent can be easily driven by a tube (or other high-ish output impedance amplifier) with little modification to the frequency response due to impedance interaction. But I'd say you really want something like a Dyna MkIV or more powerful to start... and some big Conrad Johnson's would be perfect. Or a used sample of one of the larger Sonic Frontiers amps.



[ATTACH=CONFIG]28337[/ATTACH]

I know I'm late to the camp. The fact that it's taken me 5 years to scrimp and save for three used amps and now I can start cutting wood. Then learning this, I thought all parallel
crossovers can be bi-amped or tri-amped? I thought isolating the bands was conducive to runaway ohms, so to speak. Any passing thought are welcome.

[JonMarsh]

They can be, if you retain the passive crossover as designed for each cabinet, and make sure the amplifier gains match.

This might also be an opportunity to use a solid state amp with more control and peak power for the low end, and tubes for the upper range as you wish. Gain matching the amplifiers with level controls will be critical, unless they're all identical. Otherwise, you'll throw off the frequency response.

[Renron]

This might also be an opportunity to use a solid state amp with more control and peak power for the low end

Second that Doc, I've tried several amps (4) and the best one weighs the most. 250W A/B diy amp. More Power !!!! grunt
There are several SS amps that are light weight that are beneficial with a good DAC. But it'll cost ya. I'll let those with more experience name them.
(Marty's voice) "DOC, Where are you?"
Ron

[JonMarsh]

(Marty's voice) "DOC, Where are you?"
Ron

:lol:


On the bottom end of the music spectrum, a good value is a used Aragon amp in good condition. They run forever... I have several.


Right now, WKHanna pointed out a big sale at Audio Advisor for the Cambridge Audio 840W - that's over on this short thread, along with some background info on the 840W, which has a stout power supply and very nice bottom end (actually, very nice everything...)

https://www.htguide.com/forum/showthread.php?44528-no-testing-but

I used one of those as a primary listening amp for years, until I got the Halcro DM68's. But the Halcro's are in storage in Idaho for a couple of years, pending a move there around the end of the year; the Cambridge 840W is my standard driver testing amp amp still (it's still here in CA), and I'm using Cambridge Edge W's for listening here in CA these days- got a good deal on them from a Canadian dealer... the Cambridge's have this XD biasing thing with an offset bias crossover point, and effectively at lower listening levels, they operate in single ended class A. The 840W uses XD, so does the Edge W.



The Edge W's are stereo amps, but they have a feedthrough connector on the balanced inputs, so what with making a phase crossover cable, you can turn the stere amp into a balanced mono block by cross feeding from one channel to the other, and taking the output across the positive terminals.




To revive an old turn of phrase from many years ago, "Wretched Excess", but works wonderfully when the Halcro's are far, far away...

[Renron]

"When the Halcro's are far , far away...... "
ROFLMAO
I've always liked the unique looks of the Aragon 8008. Oldie but a goodie
Thanks Doc.

[JonMarsh]

The really sweet ones are the Palladiums. Heavy class A bias, lower rail voltages, and also balanced mono blocks. I have older set and a post Klipsch set, too. Yeah, I'm a hoarder, so sue me!


Ya gotta have backups for the Zombie Apocalypse ya know! And I have a sort of oddball one, too, an 8008 X3- three channel. That has often been my testing amplifier. But it's a heavy brute- easier to deal with the 840W.

[csmielke]

Another power amp brand to consider if you can find them are the McCormack DNA225 and DNA125. I love my DNA125 and don't think I will ever get rid of it. You guys might need more power than the baby McCormack.
Chris

[kevinlin1013]

Since C90-6-079 has become discontinued(Might be able to order by request?)
Is it possible that a new version of Ardent based on C90-6-724 CELL with modified crossover be developed?

[JonMarsh]

Since C90-6-079 has become discontinued(Might be able to order by request?)
Is it possible that a new version of Ardent based on C90-6-724 CELL with modified crossover be developed?

The only way to get C90-079 is to find NOS (new old stock) at a reseller. One forum member recently did that, and has started a Wavecor Ardent build.


The cell C90-6-724 is a possibility, but the off axis dispersion is not as wide as the 079, and it has frequency response irregularities which require modifying the driver, as is detailed in the Kurosawa design study.





Both the C90-6-724 and the C168-6-990 have some design issues, IMO. (I have both and have measured both extensively). For the 724, the problem is that the magnetic structure forms a resonant tunnel. This must be damped right at the driver.

There is a brand new version of the C168, the C168-6-890- it's not even up on Accuton's site yet, and most vendors don't have it. This may solve the C168 issues.





For the special 3rd order network configuration of the Wavecor Ardent, I am looking at the possibility of a PuriFi version with PuriFi woofer and 4" woofer used as midrange.




But I'm also inclined to consider the SS 12MU4731 again.

[kevinlin1013]

Jon , thank you very much for your explanation. I am always learning a lot from your posts.

While studying the thread of Ardent and Wavecor-Ardent , I found you are crossing the C90-6-79 with the woofer relatively low in the original ardent and relatively high in the Wavecor-Ardent.I knew that the crossover topology is Duelund transfer in the original ardent and the LR3 in the Wavecor-Ardent but I would like to ask the consideration of the crossover frequency consideration of both speakers. Thank you very much again.

[JonMarsh]

Well, it all depends...

There are a few things that go into this, including woofer differences and fundamentally different crossover approaches. The latter is probably the biggest reason why...

The crossover in the very first Ardent was basically a Duelund. The fundamental design inputs are the center frequency and the aleph coefficient for all the variables. But getting a specific bandwidth for the midrange requires a specific Aleph and roll off characteristic for the other drivers. The ER18 is a paper cone woofer with a good motor considering when it was designed. Though the Duelund LP and HP ultimately devolve to 4th order, the initial roll off is only about 2nd order. So, some care is required for the target response, as you want it to track down to between -12 and -18 dB (my interpretation- tracking forever would be great!)

Now, a problem with this with the C79 and the ER18 is getting the phase tracking to work- due to the fixed offset of the time origin of the drivers. The lower the crossover frequency, the less the phase issue for a fixed delay difference.

A reminder, the target transfer function for the Gen 1 Ardent.





Now, for the Wavecor Ardent, I decided to go with the house brand 3rd order crossover concept, as used in the NatlieP and Modula MT, after the success using it in the Isiris 3 way design study.

A brief recap of "some" of the essentials:

Imagine that we want to create a 3rd order crossover with a passing relationship to a Linkwitz-Riley crossover- that is, -6dB at the crossover point:





Hmmm, at first blush, looks like it's problematical. But that's because virtually all the proposed crossover topologies are designed around the concept of drivers with identical acoustic origins... and how often does that happen in a real world system unless you go to some herculean efforts? (See Ardent D thread for example)

But normally the LF driver has a farther away time origin... pick a driver with the right phase offset at the crossover point.





Just a tiny bit of tweaking can dial in something quite usable...





But, the "gotcha" in all this is that phase offset is related to both the time delay due to design of the two drivers under consideration, and the actual crossover frequency chosen.

So, using this crossover type with the SW223BD02 and the C79 dictated a higher crossover frequency for everything to work out.

Fortunately, the Wavecor has a very stiff cone, a lot of copper in the gap, and extended upper range performance. And this takes workload off the C79, especially in the power range of the lower midrange. All in all, I think it was a good set of choices.

[JonMarsh]

Since C90-6-079 has become discontinued(Might be able to order by request?)
Is it possible that a new version of Ardent based on C90-6-724 CELL with modified crossover be developed?

Something we forgot to mention Kevin is that we did a modified version of the Wavecor Ardent for Renron, using a Scanspeak 4” midrange. They’r discussed in this thread, in passing, and they worked out quite nicely- go look at the frequency response specs for that part. I have all the documentation for it the design, should you be interested and not want to figure it out on your own… but the latter would be a good homework assignment, if you have some measurement gear and use the free design tool VituixCAD!

There’s a picture of Ron’s I took at his home on page 18 of this thread…Ron is an absolute wizard on wood working and finishes, so if you have questions and can get hold of him by posting here or sending a PM, he can definitely point you in the right direction. I’m just a wires and sparks guy, but I can get by without screwing things up too much when it comes to builds.

[JonMarsh]

And speaking of that 4" SS 12MU4731 midrange, don't want to keep you in suspense...

:W





:T

[JBrock]

I'm really interested in building a set of the Wavecor Ardent speakers. As several people have mentioned, the C90-6-079 is a distant memory (and it looks like the SW223BD01 might be hard to find).
Is there another high end version of this build that I could follow? I'm well set up for the box build (tools, CNC, experience), but definitely not set up for developing my own crossover.

Thank you!

[JonMarsh]

You may be in luck, so to speak. The preferred version of the Wavecor woofer was the SW223BD02, 4 ohm part, and Parts Express is showing those coming back in stock around 12-21-2022.


https://www.parts-express.com/Waveco...064?quantity=1

I have a set of 4 NOS on hand, but why not go with new as opposed to new in box old stock?


As to the 12MU/4731T-00, Solen in Canada only has one in stock, but there is an eBay vendor which I've dealt with that has six:



https://www.ebay.com/itm/173950846989


The original D3004/6650 Scanspeak Beryllium dome tweeter is still available, Madisound has stock, of course the price has gone up a bit.



https://www.madisoundspeakerstore.co...eryllium-dome/


If you go with this part, the original high pass crossover for the 6640 should work fine, but I can double check everything for you.

OTOH, if you're annoyed by the idea of a $500 dome tweeter (I am) you might want to consider either the Satori TW29BN-B ($406.50) or an even better value, the TW29B-B with ferrite magnet, $199.


https://www.madisoundspeakerstore.co...-black-flange/



https://www.madisoundspeakerstore.co...errite-magnet/


I have both of those on hand, and can update the crossover for the Wavecor Ardent for either one. That's actually something on our Honey-Do list, (recent update) since the news of availability of the SW223BD02 just came to light.

And we're looking at using the ferrite magnet version in a two way with PuriFi PTT6.5X04 woofers.

Also, note that Renron's build used some SS textile dome tweeters, and if you want to save another $50 or so on the tweeter, the TW29DN-B is $155- I have a new pair of those on hand, too.


https://www.madisoundspeakerstore.co...-dome-tweeter/


And if you really want to have something a bit off the beaten path, I have several new pairs of Peerless DA25TX, and combined with the 12MU4731 things look pretty nice... partly due to the ultrasonic notch filter in the tweeter crossover. That tweeter is now only available in OEM quantities, and would require some modification of the cabinet rebate and cutout, due to it's larger size.

















NOTE! Steve Manning (SMJ) has done complete front panel assemblies for several builds of these, so if you want to simplify your construction effort, you might want to touch base with him with a PM.

[JBrock]

Wow, thank you for the awesome response! It looks like the SW223BD02 is actually available now on PE. Might have to snag those before they disappear again.
I'm glad I'm not the only one thinking that about a $500 dome tweeter. It's been a while since I've built a speaker so a lot of the prices were a bit of a shock to me.
That said, for a build of this caliber, I'm happy to spend the money where it's warranted.
My biggest questions on all those options for tweeters are if any lean towards the 'warmer' end of the spectrum and/or require a less complicated crossover section?

Normally, I'd be reluctant to buy drivers from an eBay seller in Lithuania, but with your recommendation I'd feel comfortable.
Are there any plans to update the build with a different version of the Accuton? Scan makes good stuff, but the Accuton driver is what initially sparked my interest.

Your work and the builds by SMJ (and others) is definitely an inspiration! I may go all baltic birch for the front panel since I have a bunch on hand. And I probably will ping SMJ for CNC/assembly tips.

[JonMarsh]

Here's a hint about tweeters...

I'm looking at reviving the Wavecor Ardent with some updates to address the value proposition. At this point, sticking with parts that we know are available (for now), the tweeter candidate is the SB Acoustics TW29B-B. This is also a Be Dome tweeter, and has a well designed dome (Like the 6640) with essentially no breakup mode to worry about. Earlier this week they were on sale for $200 at Madisound, but now they're back up to $331, which is a bit of a surprise to me. I scored a pair, but for the intended application, (a 6-1/2" two way) they are a bit pricey. They are certainly less than $500, though, and they have double the Xmax of the 6640.






This has probably priced it out of the application I was looking at for them.

[JonMarsh]

The midrange I'm looking at for this update is the Faital Pro 5FE120, originally designed for high output line arrays. Very clean, especially the top end and excellent dispersion (red plot is 45 degrees off axis!)









I've measured and verified it myself, note the slight dip between 300-400Hz is an issue with most of Faital's SPL plots, not with the driver! Looking at this for a CC project, too.

[JonMarsh]

OK, a bit of an update this AM- I have gotten a couple more inquiries about design docs, both cabinet and crossover- and I've reviewed the driver situation and think I have a decent solution, since the D3004/6640 appears to be back in production and in stock at Madisound, and the Satori TW29B-B with ferrite magnet is a good substitute, based on my measurements and the factory data.

I have complete sets of PDF 2D drawings for the original cabinet design for the crossover built into the base- can send those out to anyone who wants them.

I can also now provide an updated BOM for crossover and schematic based an updated (this AM!) design using the Scanspeak midrange and the original tweeter- this is similar to the design done for Renron, but in his case he went for a lower cost cloth dome tweeter, too.







Top end is a bit smoother and lower in level with the grille cloths with felt diffraction control in place.

Measurement data from Ardent cabinets. (which I do not have at this time, a colleague and friend having taken mine off my hand many years ago after hearing them...)

This crossover is based on the BOM developed for the recent builds Steve has done- have detailed component recommendations and sourcing- of course, this is about DIY, and as the Y in DIY, YOU can change what you wish to meet your own needs...