Poor Man's Ardent inspired design and build

[Renron]

Man, the Seas W15 is nice, right up until it's not. Agreed , you do get what you pay for. But the $$$ scale is not lineal.
ZA14 $40
W15cy $192
Accuton C79 $400 I had a hard time finding these on the "interwebs" , are they available new? (not that I could afford them) AND a little too delicate for a butterfingers like me.

Because I'm learning, and haven't been flamed yet. Is a 3rd harmonic distortion (of the same amplitude) more or less unfavorable than a 2nd HD ?
It's been said tubes throw 2nd HD and some find it pleasurable.
Thanks for posting those graphs Jon. You constantly go out of your way to help us. Fantastic.
Ron

[BobEllis]

I've been going on the assumption that Jon means https://www.madisoundspeakerstore.co...dome-midrange/ when he says C79 as used in the Wavecor Ardent. I have a sneaky suspicion that C79 was the old number for this part.

Yes, I agree with your assessment Ron. The price/performance curve has a serious knee in it at about $50. I got the impression that the W15 was Zaph's favorite driver and he attempted to create something with a bit better top end performance with the ZA14.

As for favorable distortion, musical instruments often feature primarily even harmonics of the note's fundamental frequency. Square waves are lots of odd harmonics. Even harmonics tend to be less objectionable, which may be why so many love the sound of single ended triodes. Single ended topologies tend to produce mainly 2nd harmonic distortion. The Pass Aleph series has lower than tube distortion but is rich in even harmonics. There are push pull tube amps that push the balance towards odd harmonics. Tubes tend to behave better when clipped than some solid state topologies, which could be why some prefer push pull tubes to push pull solid state.

Honest questions rarely result in flames. Trolls bring out the blowtorches, though.

[5th element]

Pretty much all instruments have harmonics because it's the harmonic structure of the sound they produce that makes them sound the way they do. When we are reproducing sound we want to reproduce these in all of their glory otherwise a flute might end up sounding like a saxophone. To do this accurately we do not want the loudspeaker adding in any extra harmonics of its own. Generally speaking 2nd order is often quoted as being the benign order, with 3rd being far more objectionable. 3rd doesn't create an unpleasant sound though, imo it just makes things sound 'dirty' or less clean than they could be. It's the higher order harmonics that can make your ears bleed.

For a budget version of the Ardent, using the RS225s and the ZA14s makes a lot of sense, the AirCirc, not so much. Is this supposed to be the budget version or not?:E

A tweeter worth considering might be the Scanspeak D2604/833000. This is similar, in more ways, to the AirCirc than it is not. Same wide surround/dome shape, similar looking HD plots, similar-ish looking FR plots along with kinks in the top octave and high sensitivity...$50.

AC FR



833000 FR



AC HD



833000 HD



If you can cross the 833000 over high enough, which you probably can in this design, it should be a pretty good choice. Yet another tweeter, oh joy!

[5th element]

5th Element, any chance you have an education in sonar applications?

Ron

I do not.

[Ray_D]

Another facet approach

I have not been following this thread, so this may be too late. I posted this about five years ago.

http://www.htguide.com/forum/showthread.php?35229-Router-Facets&highlight=Ray_D

Ray

[BobEllis]

Thanks, Ray. Not too late, I still haven't routed the driver recesses much less finished the baffle. I think a router table insert would make a good router base for that technique.

[JonMarsh]

Pretty much all instruments have harmonics because it's the harmonic structure of the sound they produce that makes them sound the way they do. When we are reproducing sound we want to reproduce these in all of their glory otherwise a flute might end up sounding like a saxophone. To do this accurately we do not want the loudspeaker adding in any extra harmonics of its own. Generally speaking 2nd order is often quoted as being the benign order, with 3rd being far more objectionable. 3rd doesn't create an unpleasant sound though, imo it just makes things sound 'dirty' or less clean than they could be. It's the higher order harmonics that can make your ears bleed.

For a budget version of the Ardent, using the RS225s and the ZA14s makes a lot of sense, the AirCirc, not so much. Is this supposed to be the budget version or not?:E

A tweeter worth considering might be the Scanspeak D2604/833000. This is similar, in more ways, to the AirCirc than it is not. Same wide surround/dome shape, similar looking HD plots, similar-ish looking FR plots along with kinks in the top octave and high sensitivity...$50.

AC FR



833000 FR



AC HD



833000 HD



If you can cross the 833000 over high enough, which you probably can in this design, it should be a pretty good choice. Yet another tweeter, oh joy!

Good inputs. I don't have any experience with the 833000 though I have looked at it briefly recently, it came up in another discussion... and while I consider the Air Circ as "budget", now and then I have to be slapped up the side of the head to remind me that most folks wouldn't... thanks for the probie slap, I needed that!




With the transfer function in the Ardent, Zaph's distortion profile looks fine... but...

Zaph's measurements and the factory measurements highlight why I haven't had more interest in this part...




That 5 dB peak in the output centered at 20 kHz. Now, yeah, it's a soft dome, and there aren't any resonance amplification of distortion products- but that same characteristics is what I tracked down to a big part of what bugged me about a rather pricey SS soft dome, the 6620, which didn't show that kind of behavior in the factory published curves,



but did in my own measurements.



So, maybe I better get out those SB26 small form factor samples SB26STCN and see how the nonlinear looks (they are also a candidate for the revamped Modula NeoD CC), or just go with my old favorite, the D2608-9130. (the Audio Excite data shows decent odd order HD performance, and expects good results if crossed over at 2500 to 3K- bingo.) OTOH, would prefer for this to use a standard 105mm tweeter, so that upgrades are possible.

Feedback welcome, of course.

[BobEllis]

I think standard form factor would be helpful, but will hold off routing my tweeter recesses for now, waiting other feedback. Template routing for upgrades is a possibility but made a bit more difficult with the facets. We'd be counting on good double stick tape from our friends at 3M.

[JonMarsh]

Well, checking online with sites like AudioExcite, the SB26STAC has a significant edge in HD performance- yet it doesn't completely charm me...



I think I'm going to have to get out some RS28a and measure with the current setup- as Ryan pointed out, a lot of these newcomers are just different, and often not as neutral or clean- just newer!

I wish the new Esoteric tweeter was a more continental design with smoother response- that might be interesting.

The metal dome SB26ADC appeals more to me...



But we need a fresh look at the RS28a to see how it compares. On flatness of on axis response, the SB26ADC has the edge, and distortion is pretty fair. Fine for a three way.

[---k---]

If you come to the conclusion that the RS28 is still a contender, and the others are just a newer different flavor but not clearly better then I'll feel much better about the speakers I have, and my upgraditist my be kept at bay a while longer.

[JonMarsh]

what do you 'all think of using a seas 27tdfc in this build? Reason I'm asking is the number of favorable comparisons between the Seas and lesser expensive SS .

Jon, you are too kind, to offer (if it's wanted) a passive sealed design would be right up my alley!
How much of a difference (better?) would you expect with the Wavecor vs. RS225? Not just F3 per say, but, timber tonality?
Just checked prices...........RS225 PE$58 , Solen Wavecor 8.5" on sale @ $170---------------------------RS225 it is! Ha, that was easy for the retired and unemployed. (me)

Sort of hate to ask, but how's the dog? I just got a letter today from my brother in Oregon, he picks up his Springer Spaniel puppy in a few days. (circle of life)
Ron

well, the Vet doctor came to the house on Monday and put the girl dog to sleep- was pretty easy and peaceful for her that way.

Today, GF took the old boy Siberian Husky in for dental work, and in checking him they found a tumor, not so small. they're going a needle biopsy, and will have to decide whether it's worthwhile to operate or if (based on size) it's likely to have spread already. So dental work and that additional work got postponed, until early next week. I'd say there is a good chance will lose him soon, too.

these are both older rescue dogs, and have had a much better life at GF's than their prior existence, but it's still it's hard to see this kind of thing happen. GF feels for older dogs that are hard to get adopted, and usually takes one of those instead of getting a nice younger pup that would last longer, but that many folks would be happy to have.... don't know what will happen yet, this time.

[Steve Manning]

well, the Vet doctor came to the house on Monday and put the girl dog to sleep- was pretty easy and peaceful for her that way.

Today, GF took the old boy Siberian Husky in for dental work, and in checking him they found a tumor, not so small. they're going a needle biopsy, and will have to decide whether it's worthwhile to operate or if (based on size) it's likely to have spread already. So dental work and that additional work got postponed, until early next week. I'd say there is a good chance will lose him soon, too.

these are both older rescue dogs, and have had a much better life at GF's than their prior existence, but it's still it's hard to see this kind of thing happen. GF feels for older dogs that are hard to get adopted, and usually takes one of those instead of getting a nice younger pup that would last longer, but that many folks would be happy to have.... don't know what will happen yet, this time.

Sorry about the dogs Jon ...... we had a similar experience having to put our cat and dog down within 3 days of each other a number of years ago, it certainly is not a fun process. Your GF sounds like my wife,we have a house full of adopted pets and strays (one dog and four cats), I might even be included in the mix somewhere in there as well.

[Renron]

Sorry to hear about your dog(s). You were kind of expecting this though. Doesn't make it any easier.

" GF feels for older dogs that are hard to get adopted, and usually takes one of those instead of getting a nice younger pup that would last longer," I can Identify with you Jon, My wife says the same about me too.

Thank you for the brain work considering the many options available for different drivers.

[Renron]

Just had a thought in regards to of the cost of the drivers for the budget build. If someone chooses to spend more on a driver, would it be better (sound quality wise) to purchase a mid or a tweeter?
I am aware that it is a TOTAL system you hear, but......?
Ron

That was as clear as mud......... Try again.

Is it better to spend a few extra dollars (yeah, right, extra) on a mid or a tweeter? Basically purchase the next level up in quality.

[JonMarsh]

Just had a thought in regards to of the cost of the drivers for the budget build. If someone chooses to spend more on a driver, would it be better (sound quality wise) to purchase a mid or a tweeter?
I am aware that it is a TOTAL system you hear, but......?
Ron

That was as clear as mud......... Try again.

Is it better to spend a few extra dollars (yeah, right, extra) on a mid or a tweeter? Basically purchase the next level up in quality.

I think that depends on what is important to you. Everything counts... drivers, cabinet materials, crossover parts.

I'd probably consider upgrading the tweeter first, but it's a tough call versus the midrange. I really consider the C79 to be the heart of this design. I suppose it would also depend on associated gear. I also think many people might be very happy with upgraded woofers first, and the ZA14 and SB26ADC; better bass often grabs people right away, and is not as dependent on source equipment quality to appreciate. The Wavecor woofers are very articulate and powerful. So, who knows? :W

[Renron]

Thank you Jon, errr, Doc. !
I didn't think it would be as easy as I had hoped. It's not.
Kinda like wives and girlfriends, it's a package deal, and what annoyances you can live with. She's not looking is she? Good.

[dar47]

Interesting how that C79 has steadily climbed in price with popularity. :E I think it depends on the quality your going for in the cab, if it's LBL and BB all the way then I would go for the C79, Wavcors and a lower tweet and cheaper xover parts as then you would have an upgrade path. If you bypass the mid there is no going back on the cab. If this is an all MDF affair on the cabs then I would do the RS225's, new mid, tweet and what ever mid is not going to cost you in the xover.

This is going to be interesting comparing cost of the different builds as 3 way xovers and this cab is still an investment.

[kevinm]

Well, checking online with sites like AudioExcite, the SB26STAC has a significant edge in HD performance- yet it doesn't completely charm me...



I think I'm going to have to get out some RS28a and measure with the current setup- as Ryan pointed out, a lot of these newcomers are just different, and often not as neutral or clean- just newer!

I wish the new Esoteric tweeter was a more continental design with smoother response- that might be interesting.

The metal dome SB26ADC appeals more to me...



But we need a fresh look at the RS28a to see how it compares. On flatness of on axis response, the SB26ADC has the edge, and distortion is pretty fair. Fine for a three way.

Hey Jon,

Sorry to side-track here, but as a noob trying to absorb everything here, I have to ask a question here. Would you mind describing what you're seeing in the graph for the SB26ADC that's more attractive than SB26STAC? Is it the smoother bump up top?

[Steve Manning]

Interesting how that C79 has steadily climbed in price with popularity. :E I think it depends on the quality your going for in the cab, if it's LBL and BB all the way then I would go for the C79, Wavcors and a lower tweet and cheaper xover parts as then you would have an upgrade path. If you bypass the mid there is no going back on the cab. If this is an all MDF affair on the cabs then I would do the RS225's, new mid, tweet and what ever mid is not going to cost you in the xover.

This is going to be interesting comparing cost of the different builds as 3 way xovers and this cab is still an investment.

Since I've never done a comparison and am truly curious ........ is there really going to be that much of an acoustical difference that you would be wasting your money with the C79 by using mdf rather LBL or BB?

[Renron]

KevinM,
Good question, I was wondering the same myself. I'll take a dumb luck guess that it's the higher odd order harmonics.

[BobEllis]

My guess is it boils down to a subtlety highly dependent on the rest of your signal chain. There are those like Jon who want the driver firmly attached to the stiffest possible baffle but I have seen others suggest mounting to reduce interaction with the baffle.

[dar47]

I'm not sure if there is a big difference in just the baffle but taken with a solid total cab constructions I would think lower resonance and I would bet a mechanical advantage with stresses on the woofer frame. After switching to solid baffles I wouldn't go back. Most of us start out with MDF because of cost and ease of use but I have found after a few build I end up having spent more time and used more materials to get a nice finish on MDF cabinets. When using MDF I now wrap everything in 1/8" hard board just to have a better finishing surface with more durable edges.

I'm a bang for buck guy so when doing 6 Wavecor Ardents and 8 baffles it was easy to justify the better materials. If I was doing 1 set and trying to save I would glue up poplar on edge and cover with hardboard for the baffle (did this on my CC) and follow the Wavecor MDF and BB laminate cab. Biggest bucks in the Baffle.

Maybe after several builds and not being satisfied with the finish I just thought I needed to step it up a bit. We all have different expectations so it's all good.

[JonMarsh]

My guess is it boils down to a subtlety highly dependent on the rest of your signal chain. There are those like Jon who want the driver firmly attached to the stiffest possible baffle but I have seen others suggest mounting to reduce interaction with the baffle.

It's a free country, and experimentation is the lifeblood of innovation, right?

That said, I'm a stuck in my ways curmudgeon, and I became that way at a very early age- this type of overbuild baffle construction with thick, stiff front panels is something I worked on in the 70's, and I gave a set of speakers using this in spaces (with baffle facets and all) to a University student that used to work for me at one company, when my new wife at the time said she didn't want big speakers like that in her living room. (note the use of the possessive pronoun... though the living room was paid for exclusively by me... should have been a clue...). Anyway, that guy's name was Charlie Hansen, and he went on to found a little company called Avalon Acoustics, and later one call Ayre Acoustics.

If you look at what Wilson, YG Acoustics, Magico, and Rockport do, though they differ in materials, crossovers, and drivers, the point they are agreed on is massively strong stiff front panels.

As to other material properties, go to Home Depot and get a small piece of MDF and a small piece of red oak or maple (similar in strength and hardness to LBL, though not quite as good...) . Get some Drywall screws, which are the right size for mounting many drivers. Drill some 1/8" pilot holes, then put the screws in and out of the board scrap a few times. Watch how the MDF threaded hole turns to mush compared with the other wood projects. (I'm assuming you can't buy any LBL at your local HD).

Please, PLEASE, do yourself a favor, use two layers of LBL (such as from Woodworker's source, 48" boards to source) for the front panels, two layers of BB ply for the next two layers, and use BB ply for the walls and back. If you must use any MDF, use them for the braces, as it's mostly a matter of compression strength, and it's sort of OK in that mode.

Oh, remember those 2-3" wide small boards I asked you to buy earlier in this post? Try breaking the MDF piece across your knee/thigh. No big deal. Don't try breaking the oak or maple or a similar piece of LBL (say, 2" to 3" wide, 3/4" thick) that way- you'll hurt yourself seriously.

Harangue concluded. :W

[BobEllis]

I'm with you empirically, Jon. Makes sense to avoid yet another resonant system. It makes my wonder why so many subwoofer drivers have their rims wrapped in rubber, though. I guess if you screw them down hard enough the resonance is out of the passband. Although it's a special case, Linkwitz at one time advocated drivers not touching the baffles at all.

I'm not as likely to pull drivers as many times as you, but I have noticed that even the first removal after a year or more of use leaves MDF baffle screw holes fuzzy.

On the topic of thick baffles, are cavity resonances a potential issue when going 3-4" thick? It seems like that cylindrical cavity might have a resonance in the midrange area.

You've got me pretty close to using my "spare" LBL boards for the outer baffle layer on my poor man's build. Waiting on unseasonably warm weather to get outside and start routing, so I have time to make up my mind. Tomorrow is raining/freezing rain at 39°, otherwise we aren't supposed to get into the 30s in the next ten days.

[Steve Manning]

I'm not as likely to pull drivers as many times as you, but I have noticed that even the first removal after a year or more of use leaves MDF baffle screw holes fuzzy.

That's why I use threaded inserts regardless of the type of wood, you can take screws in and out all day long and your good to go ....... Though you guys are right about the mdf not being as rigid or durable in general. I was just wondering if anyone had compared a 3" thick mdf baffle vs a 3" thick LBL or BB and noticed a major difference in sound? Though at what all the components cost for Jon's latest build they would certainly deserve an upgrade in cabinet material if for nothing more than general principle.

[Renron]

Baffle wise, what's the thinking on BB plywood / 1/2"Hardi backer concrete board / BB plywood ? This is dense concrete board, not the crumbly meshed stuff. Opinions?

Jon, What is the logic behind your statement, "the SB26STAC has a significant edge in HD performance- yet it doesn't completely charm me... ". Why not? Pleases explain to the class.
Found this on the P.E. Forum , "The SB26STAC is the newest tweeter offering from SBA. It was designed by the same engineer that designed the Scanspeak Revelator tweeters, and Scan 9700 was target as a design target for this tweeter, but at a much lower price."

Thanks Doc!

Ron

[JonMarsh]

Baffle wise, what's the thinking on BB plywood / 1/2"Hardi backer concrete board / BB plywood ? This is dense concrete board, not the crumbly meshed stuff. Opinions?

Jon, What is the logic behind your statement, "the SB26STAC has a significant edge in HD performance- yet it doesn't completely charm me... ". Why not? Pleases explain to the class.


Ron

I'm familiar with good backer board, have redone some bathroom floors using it, but it's not something I would have thought of for gluing up a speaker baffle... I'd wonder how the coefficient of expansion with temperature would be compared with the woods under consideration?


As to the STAC, it has a nice general slight downward slope in the frequency response, then this bump in the upper octave, which for me produces an unpleasant subjective reaction (no extra "air" for me, thanks...)




Also, the HD2 curve above 5 kHz doesn't "charm" me, either... could be nothing more complex than a soft breakup mode of the dome... but that's also a characteristic soft dome coloration I don't like, and seem to be sensitive to (YMMV, etc, all the usual disclaimers).



While the SB26ADC isn't perfect either, it comes closer to being a 9800 on a budget with some extra Xmax, something I'd say I can live with. I also think is sounds cleaner on the swept sine chirps that Fuzzmeasure uses for measurement. (Not MLS, but does do convolution to an MLS type signal for gating) (works like Praxis in this regards).








It's a free country, and all, and if you're on a really tight budget, well, I think the ADC version costs about $10 more. But I would go for it.

I should redo the distortion on the ADC sometime, too, because I think the variation with frequency could be due to the driver or baffle not quite being tightened down enough.

The STAC seems to have the edge in LF distortion, and would be better as a two way, but as we're crossing over at 3 kHz, it's sort of moot point. Like I say, I should make another baffle and retest the ADC sometime soon.

[Renron]

Doc,
Thank you very much for the explanation for your preference between these tweeters. I learn something every time I read one of your posts. I'm sure I'm not alone, and I'm not blowing smoke up your Lab coat, when I say how much i appreciate you taking the time to teach.

In Marty's best voice; "Damn it Doc!".
After reading your reasons for choosing LBL baffle and the expense that alone will occur, I can easily see mission creep in the driver selection too. Excellence is seldom inexpensive.
(I'm trying to build a better sounding speaker than my re-designed Seas Thor) knew it wouldn't be cheap.
Thanks Doc.

[JonMarsh]

you're very welcome, Marty, uh, er... Renron!

[Renron]

Bump with a question, ... or two.
Thinking about purchasing some drivers with gift cards the Kids gave me at Christmas. I really like the looks and performance of the Dayton Rs225 (price too !), Probably go with those. 8 Ohm version, correct? Stretching the budget as the build starts to form in my mind. Mission Creep! Thanks a lot Doc!

5th Element,
in a different thread you suggested the SB Acoustics SB17MFC35-8 for a mid driver, also the Satori MW16P-8 I believe.
I'm starting to look at the other drivers which may not be exactly in the realm of "Poor Man". If this is inappropriate in this thread (Bob) I'll take these types of questions elsewhere. Let me know. Don't want to step on toes.
With respect to performance, is the SB17MFC35 any better than Zaph's ZA14W08? Price is close enough.
Without going "Full Monty" on the drivers ie:Accuton C79, would the Satori MW16P be a noticeable upgrade sound quality wise from the other two mids? How about the MW13P? It's smaller diameter of 5" rather than 6". Easier to CtC with a tweeter.
I'm planning on using the ScanSpeak D3004/6600 AirCirc tweeter on Jon's recommendation list. (not quite Poor Man friendly)
Thanks for the advise, I'm learning a lot from just reading.
Damn that Satori is a sexy driver. Whoa.
Ron

[JonMarsh]

Not the 8 ohm version. 4 ohm version- different T/S parameters, a bit more like the Wavecors (which are 4 ohm, too), then you wire them in series.

The SB17MFC35 is a bit on the large size to use as a midrange; the dispersion usually falls off a bit for that size in the 3 kHz and above area (though they show it hanging in pretty well)- I don't have any distortion data or anything else for it- i'm sure it could be made to work, but I don't see an advantage for it- it does cost more, and the ZA14 has an excellent motor. OTOH, I could imagine someone using it as a midrange with a tweeter that was happy down to 2000 or so, something in a bit bigger cabinet (*you need to consider the rear enclosure volume, which will get a bit cramped unless enlarged for the 6-1/2" driver. The impedance data suggests the upper range distortion should be low, given the low inductive rise.


Me, I'm not all that fond of paper or plastic cone drivers. There is a lot of engineering going into them to try to gradually decouple the break up mode and make it more of a soft landing, but it often results in mechanical resonances in some part of the working bandpass, which show up on the impedance curve and which I find audible on pink noise. That used to be how I selected drivers in the 70's, listening to them versus high end headphones with pink noise, and looking at the RTA response on an analyzer I had back then.

This is the measured impedance curve of that Satori.... which shows the bobbles in the impedance curve which results from mechanical resonance.



Two samples of the Satori measured at AudioExcite.

A lot of folks like these, and YMMV, it's a free country and all, but the whole concept behind what I was doing in the 70's and which Avalon did at it's introduction was finding drivers without these issues in the pass band. The ZA14 is quite clean up until it's breakup mode at ~8.5 kHz.

IF you have the resources for measurement of the drivers in the cabinet, I can help design a crossover for whatever drivers you select, but if you plan to follow the Ardent form factor, a 6-1/2" woofer won't really fit as a midrange with the existing design.

[Renron]

Thank you Jon,
I really like the design of the Ardent cabinet, I will follow that form factor. RS225 4 Ohm wired in series, check. Don't forget the LBL baffles. I"m paying attention.
"This is the measured impedance curve of that Satori.... which shows the bobbles in the impedance curve which results from mechanical resonance." Wow, what a fantastic clue to look for in the charts. I learned something new! I'd be happy with the ZA14w08, just looking for other ideas. Can't hurt anything but the wallet. other suggestions?
Why your aversion to paper cones? ScanSpeak paper sounds very nice, the ones I've heard at Burning Amp shows.
I have just purchased some measurement equipment, as of now, not a clue how to use it. At 5th Elements advise I've downloaded Arta software.
Help with an eventual XO is extremely kind, if you need help with anything I live near Sacramento and have a big pickup. LOL.
Ron

[JonMarsh]

My aversion to paper is based on the design goals and compromises- SS paper cone drivers have similar issues in the 1 kHz area. This is not to say you can't make a nice sounding speaker with them, and the motor for a two way is very good- but if we're looking at a three way, and on a budget, then some care is required adhering to principles. I used to work with Scanspeak kevlar and paper woofers in the 80s', but abandoned them for these issues and switched to Eton. That too, was a bit of a compromise, as the basic motor is better in the Scanspeak, but the cone was free of spurious resonances in the Etons. (honeycomb kevlar/nomex construction). Eton makes some very good motors these days, but mostly only sells them in OEM products, such as they make for Avalon.

[Renron]

Thread hog

Jon, Thank you for explaining your reasoning. I appreciate you taking the time out of your overly busy schedule called life. :T

Bob, I apologize for being such a thread hog lately. My brain got started on which drivers to buy and one thing led to another, down the "mission creep" one way alley.

I would appreciate opinions about this driver combination for a version of the Ardent.
2) Dayton RS225 4 Ohm in series
1) ScanSpeak 12MU/4731T-00 4 Ohm mid (the 4 Ohm FR is flatter than the 8 Ohm)
1) ScanSpeak D3004/6600 AirCirc Tweeter 4 Ohm

The financial manager has decided that it may be possible to extend my credit limit for higher end drivers than originally proposed. (I begged the wife, and promised to take her to S.F. soon. Amtrak makes getting there easy peasy.)

As I understand it (or don't), each driver presents itself through the XO uniquely to the Amp, so Impedance is per driver and where crossed, not all drivers summed. Is that right?

My reasons for choosing these drivers are the flatness of the FR and the behavior of the 2nd and 3rd harmonics.
Jon, I looked at the impedance plot too. Thanks for that tip!

Not cheap drivers by a long shot, I know, and maybe a bit dyslexic to use the Dayton RS225 with the premium SS, but playing down low maybe the $$$ difference between the Dayton and Wavecor will help buy the SS 12MU/4731 Mids.
I have metal cone drivers now, Seas W18EX-001 and Seas T25CF-002 Millennium Tweeter (soft dome) in a modified (larger) Thor cabinet. They are almost too clean sounding, if that is even possible. Some of the old recordings from the '70s just aren't worth listening to, even though I enjoy the music. Is this common?
I've heard speakers built with SS drivers that sound excellent. I'm hoping to build something a few steps up from the Thor's.
Being able to compare the two side by side would be fantastic.

Thanks to any and all for your opinions.
Ron

[BobEllis]

No worries, Ron. I've been MIA moving in with my girlfriend and doing an indoor cycling challenge. http://www.trainerroad.com/tour-of-s...015/bobe102330 The videos make it almost fun and it's a fundraiser for the www.davisphinneyfoundation.org which I like for its focus on helping those with Parkinson's live better lives. A cure would be nice, but in the meantime...

Mission creep is inevitable, isn't it? By June you'll be justifying Be tweeters... I think that you've got priorities straight. Although I'm a bass head (built my first sub in 1984) I think that with a sub you'll be fine with the RS225s. That mid was Jon's choice "if you don't use the C79". Just drop the Wavecors in after the trip to SF.

Don't expect that the chosen drivers will be any easier on your less than great recordings. From what I've seen on the web it sounds like Thor was not one of Joe D's best designs. Someday even Jon may make a clunker. 8O Here's hoping that the issues you're hearing are related to not controlling the huge woofer breakup just outside the pass band well enough more than the quality of those old CDs. Looking at the W18's breakup, it's either a <1.5 KHz Cauer filter two way or a three way driver to me. I think you'll find a proper 3 way more satisfying, anyway - you'll have nearly twice the Sd to move air and a proper midrange.

I've got a W15CY/T25CF system now that is pretty darned good, just lacking in the bass department (especially in the new larger living room). So why am I spending so much on these new systems? Mission creep. Although I enjoy this hobby, I'm hoping to build a reference speaker that will hold me for quite a while. It will be fun to see how well the RS225/ZA14/6600 does against the full boogie effort.

You are almost correct in your impedance assumption. The drivers are in parallel to an extent in the crossover region. There will be an impedance dip, but high enough in frequency that the net impedance should be OK for a reasonably robust amp.

[JonMarsh]

These are reasonable choices- the 4 ohm mid may require a bit more robust amplifier. Can you get measurement data?

I get what you're saying about the clean and transparent drivers making older recordings a problem. I've found there are two solutions-

1. Use a down tilt voicing which closer approximates the typical monitor response used on many of those recordings- this de-emphasizes the upper range distortion you may be noticing, with digital sources. Several speaker manufacturers do this.
2. Substantially update your DAC. Best lower midrange DAC I've found in this case is the NAD M51. Next step up would be an Auralic Vega. Beyond that, well, I use a TotalDAC-D1 Dual, and I'm sure your financial manager would have very strong words for you if anything like that was brought up.

[Renron]

Thanks guys for the support and reinforcement of my changing goals. "I didn't change my mind, I "evolved" my expectations".

The original "Thor's" that were designed by Joseph D'appolito were a compromise on cabinet size, which crippled them as a TL. They were re-designed by Dave (Planet 10) Canada and (ScottMoose) from England. ScottMoose has a background in aquatic audio engineering (sonar) and has the same style of writing as 5th Element, Hence why I asked about 5th's educational background. I built the resized cabinet and added curved sides after I modeled water ripple action to simulate audio waves inside the cabinet. The redesigned speakers work well, but it's time for another build.
Jon, you had mentioned that you'd like to see a version with curved sides. So would I. When I actually start my build, I'll start another thread and not pollute this one any further than I already have.
I've got some honey-do's to complete first and a built in hutch w/drawers I've been putting off for a while now.
Amp wise, I've built a Pass F5 that is scary good, but only ~50 watts@4 Ohms. I've got the parts for a Honey Badger Amp waiting to be built too, ~200 Watts @ 4 Ohms.
DAC I've got a Denon DVD1600 w/ BurrBrown parts and an Oppo BDP-83, I've built a "HotRod" DCB1 preamp that is very clean and silent with a little gain if needed, rather than strictly a buffer as designed by Papa.

On a personal note, I went to the dentist last week and he informed me that I needed an "Implant" (not the wife type) . ops: Oral Surgeon the next day pulled the tooth and ground out a spot in my skull, placed a titanium threaded insert (just like the kind we use in MDF) added some Cadaver bone and skin graft, then told me to come back in 3 months. Meantime I sound like Sylvester the Cat and whistle a little bit when I say "S" words. :T Unbelievable as it may sound there was only very minor pain and 1 Advil took care of it the same day as the operation. Now when I "Toot" in presence of my wife, I tell her I "had a procedure", our standing joke after her heart surgery last year.
Getting older, hopefully wiser, has it's downside as well as it's upside. Part of life's plan I suppose.
Jon, how's your Girlfriend doing with loss of her dog(s)?
Ramblin' out.
Ron

[benthe8track]

Thanks guys for the support and reinforcement of my changing goals. "I didn't change my mind, I "evolved" my expectations".

The original "Thor's" that were designed by Joseph D'appolito were a compromise on cabinet size, which crippled them as a TL. They were re-designed by Dave (Planet 10) Canada and (ScottMoose) from England. ScottMoose has a background in aquatic audio engineering (sonar) and has the same style of writing as 5th Element, Hence why I asked about 5th's educational background. I built the resized cabinet and added curved sides after I modeled water ripple action to simulate audio waves inside the cabinet. The redesigned speakers work well, but it's time for another build.
Jon, you had mentioned that you'd like to see a version with curved sides. So would I. When I actually start my build, I'll start another thread and not pollute this one any further than I already have.

I followed that evolution of the Thor thread very closely back when you built yours. They were actually going to be my expensive last speaker project for a long time but then my dad talked me into the Ardents.

[JonMarsh]

Thanks guys for the support and reinforcement of my changing goals. "I didn't change my mind, I "evolved" my expectations".

The original "Thor's" that were designed by Joseph D'appolito were a compromise on cabinet size, which crippled them as a TL. They were re-designed by Dave (Planet 10) Canada and (ScottMoose) from England. ScottMoose has a background in aquatic audio engineering (sonar) and has the same style of writing as 5th Element, Hence why I asked about 5th's educational background. I built the resized cabinet and added curved sides after I modeled water ripple action to simulate audio waves inside the cabinet. The redesigned speakers work well, but it's time for another build.
Jon, you had mentioned that you'd like to see a version with curved sides. So would I. When I actually start my build, I'll start another thread and not pollute this one any further than I already have.
I've got some honey-do's to complete first and a built in hutch w/drawers I've been putting off for a while now.
Amp wise, I've built a Pass F5 that is scary good, but only ~50 watts@4 Ohms. I've got the parts for a Honey Badger Amp waiting to be built too, ~200 Watts @ 4 Ohms.
DAC I've got a Denon DVD1600 w/ BurrBrown parts and an Oppo BDP-83, I've built a "HotRod" DCB1 preamp that is very clean and silent with a little gain if needed, rather than strictly a buffer as designed by Papa.

On a personal note, I went to the dentist last week and he informed me that I needed an "Implant" (not the wife type) . ops: Oral Surgeon the next day pulled the tooth and ground out a spot in my skull, placed a titanium threaded insert (just like the kind we use in MDF) added some Cadaver bone and skin graft, then told me to come back in 3 months. Meantime I sound like Sylvester the Cat and whistle a little bit when I say "S" words. :T Unbelievable as it may sound there was only very minor pain and 1 Advil took care of it the same day as the operation. Now when I "Toot" in presence of my wife, I tell her I "had a procedure", our standing joke after her heart surgery last year.
Getting older, hopefully wiser, has it's downside as well as it's upside. Part of life's plan I suppose.
Jon, how's your Girlfriend doing with loss of her dog(s)?
Ramblin' out.
Ron

The Thors were a very nice project for their time- looks like you did a very nice job with these! :T

Speaking of aging, I actually feel like I have a bionic girl friend, as due to her excess of athletic activities at younger ages, she's now already had joint implants for both hips... I figure that's sort of cheating, but I can hardly blame her- made a big difference in her mobility and gait.

The second doggie is still hanging in there- his slow growing cancer isn't a problem yet for his functionality, as old as he is, it's hard to predict what will catch up with him first- he also has a heart condition, with abnormally slow heartbeat. She misses the girl dog, who was especially sweet- but life goes on.

[JonMarsh]

Interesting how that C79 has steadily climbed in price with popularity. :E I think it depends on the quality your going for in the cab, if it's LBL and BB all the way then I would go for the C79, Wavcors and a lower tweet and cheaper xover parts as then you would have an upgrade path. If you bypass the mid there is no going back on the cab. If this is an all MDF affair on the cabs then I would do the RS225's, new mid, tweet and what ever mid is not going to cost you in the xover.

This is going to be interesting comparing cost of the different builds as 3 way xovers and this cab is still an investment.

I'm totally with you on this idea... the next drop back in expense would be using the RS225's, but still keeping the C79. The cab build is a big investment, and any three way crossover trends that way, too.

[Renron]

Benthe8track, Thanks, just having you follow along is a great complement. The voicing on the Thor's is still thin on the bottom end, but Alison Krauss can bring real emotions.

Jon, my apologies, I do NOT have a separate DAC, just the ones built into the DVD players. Yes, the financial manager would indeed have strong words for me. And a shotgun!
Thanks for the complements on my version of the Thor's, coming from you that means more than you know. (humble)
One of my pheasant hunting buddies had both his hips replaced a few years back, walking in plowed muddy fields is hard on body parts. You would never know from the way he traverses those fields today. With any luck we won't need parts replaced, fingers crossed. Glad she is doing well too.
Edit: Forgot to thank you for the recommendation of the Porter Cable 390 Sander, Whoa. Almost makes sanding pleasurable. Almost.
Very little hand vibration, takes material off quickly and leaves a swirl-less finish. Just finished some cherry corbels, Bravo! Why was it discontinued???

I ordered some of my drivers today, Solen in Canada is having a sale on ScanSpeak 12MU/4731T00 $100 off the pair of mids, so I jumped on that deal.
Also, Ordered the ScanSpeak D3004/6600 AirCirc Tweeter 4 Ohm. Even with shipping, boarder patrol tax, income tax, revenue tax, import tax, cross-pollination tax, I came out way ahead due to the USD$ - Can$ exchange rate. :dancenana:

Ron

[shootinnutz]

Would it effect the cabinet if I used 3" of bb on the baffle?

[---k---]

Would it effect the cabinet if I used 3" of bb on the baffle?

Arguable.

Jon used the materials he did because he thinks the benefits justify the additional cost, as he's discussed several places. But, I can guarantee you that if you post this question on three other forums, you'll get a much larger response that at 3" thick it doesn't matter what material you use than you will of people supporting the Bamboo LBL Jon used. I can also guarantee you'll have people arguing that 3" of anything is overkill. I've found people who preach using steel angle bracing and concrete walls as well as people preaching braced 1/2" ply. And on the internet they, they all sound like experts.

To each their own. ... I think this is where years and years of speaker building comes in handy. After all those years, you realize what is and isn't important to you as an individual. Some people find the stiff overkill box as their nirvanna, others open baffle speakers, others folded horns. Some people like the woodworking aspect and build complicated boxes just to challenge/improve those skills. Others find themselves to be better rough carpenters than finish carpenters and gladly accepts any slight knock on the potential sound quality impact just to get the project done (I include myself in the latter). Your truth is out there, but you got to build to find it.

Wow.... how's that for an answer!

[shootinnutz]

The cabinetmaker was asking the question why lbl and not just bb. For me, using lbl was a no brainer.I just didn't think I could give the cabinetmaker a good enough explanation on why it is being used.

[Renron]

Ug,
Solen Canada has the Wavecor drivers on sale..............I bought 4..........so much for "Poor Man's Ardent". Now I am a poor man, but with excellent drivers for the Ardent!
SS 3004/6600 Tweeters
SS 12MU/4731 Mids
Wavecor SW223BD01

8 week wait for shipping because they only had 3 on hand. I'm in no rush.
Only the Tweeters weren't on sale, fate saw my refund check and decided to give it to Solen.