Ardent Speaker Camp

[Dave Bullet]

Great FR and distortion. I think the most objective comment I can come up with is they look smoother than a baby's bum

[Dean100]

Nice work Jon. Slow work takes time! :T

[Paul W]

Sweet! Bringing them back to Colorado for RMAF?

[JonMarsh]

Well, these may just be mini-monitors next to your projects, Paul, but I don't think I'll be able to take them in carryon! Or checked!

Of course, never say never, we'll have to see how the year goes- my current event horizon is the end of April and the Northern CA DIY meet. I'm not ready to think about next October and another cross country journey- was thinking more of flying this time! ;^) Of course, if I got my butt in gear, I could crate and ship them...

[ColoradoTom]

Well, these may just be mini-monitors next to your projects, Paul, but I don't think I'll be able to take them in carryon! Or checked!

Of course, never say never, we'll have to see how the year goes- my current event horizon is the end of April and the Northern CA DIY meet. I'm not ready to think about next October and another cross country journey- was thinking more of flying this time! ;^) Of course, if I got my butt in gear, I could crate and ship them...

Jon - good work, most impressive. Will the final write-up and building specs be published here or on the Audioworx site?

Tom

[TacoD]

Jon - good work, most impressive. Will the final write-up and building specs be published here or on the Audioworx site?

Tom

Audioworx website, am I missing out .

Great work Jon, does these small accuton mids have enough dynamics?

[JonMarsh]

I'll be preparing a detailed PDF, again, because there is no AudioWorx web site (yet), and it takes less work to do DTP than preparing a web post with the same level of detail. Obviously, there will be a largish ZIP file prepared with all the construction drawing PDF's (sized for superB paper, but you can print on tabloid or legal). Now I'm ready to prepare the Altium schematic and basic BOM with possible modifications.

In answer to your question, Taco, I'd say the "weak" point of this system is the ER18RNX- they're just got so much sweap area and though they were selected for very clean bass and midrange distortion, the Accuton mid and SS tweeter are a tough act to follow. This speaker system was aimed at the 105 dB peak range, and I think the mids have no problems with that- with the Duelund acoustic function, even if a speaker is pushed to 106-108 at 100 Hz, the mids should be OK- higher up, it's a breeze for them. The measured distortion data for the drivers alone confirms this, even when I pushed them somewhat. Obvoiusly, there are benefits to the bigger drivers for larger rooms and if you really think it needful to live at higher SPLs.



Afterall, there's a reason the Isis exists as well as the Indra. Frankly, I think this mid has enough headroom that I could imagine doing a dual 22W SS setup with it on the bottom end. I'm sure Avalon had similar reasoning in developing the Avalon Time, which uses a larger dual woofer setup than the Indra. Then we could lower that distortion floor significantly in the lower end- but of course, at a price. Now, if you guys could take up a collection so that I could retire and work on these full time, just think of all the interesting designs I could crank out- I might even be able to keep up with Paul W! Well, almost!

It all certainly provides me with motivation for the Modula Xtreme build, though I'm still pondering the final tweeter choice- more testing and evaulations to do there. If I can fix the 10 kHz mouth/throat resonance, I'll probably go with the Millenium Excel- otherwise it's the "proven solution" with the D2608/9130.

And yeah, I do have a pair of 22W sitting around- but they're still earmarked for the Nascent/Aducator build. Got new baffles started for the Nascents, unfortunately, also have two weeks of business travel coming up!

[Johnloudb]

Congrats Jon! :T I can say I've really enjoyed seeing this speaker come together and it's great to see that all your work has paid off. Thanks for it!

I'm sure others will get a lot enjoyment from this speaker.

[JonMarsh]

Thanks, John, I'M looking forward to getting some enjoyment from these! And of course, half the enjoyment has been the journey and what I've learned along the way.

[David Meek]

Jon knows I'm a tequila fan. Got a new Austin company to check out:
http://republictequila.com/main.php

Hank, any thoughts yet? Sorry guys, now back OT. . . .

Jon, it sounds like you've really got a winner on your hands this time. :T

[TacoD]

I'll be preparing a detailed PDF, again, because there is no AudioWorx web site (yet), and it takes less work to do DTP than preparing a web post with the same level of detail. Obviously, there will be a largish ZIP file prepared with all the construction drawing PDF's (sized for superB paper, but you can print on tabloid or legal). Now I'm ready to prepare the Altium schematic and basic BOM with possible modifications.

In answer to your question, Taco, I'd say the "weak" point of this system is the ER18RNX- they're just got so much sweap area and though they were selected for very clean bass and midrange distortion, the Accuton mid and SS tweeter are a tough act to follow. This speaker system was aimed at the 105 dB peak range, and I think the mids have no problems with that- with the Duelund acoustic function, even if a speaker is pushed to 106-108 at 100 Hz, the mids should be OK- higher up, it's a breeze for them. The measured distortion data for the drivers alone confirms this, even when I pushed them somewhat. Obvoiusly, there are benefits to the bigger drivers for larger rooms and if you really think it needful to live at higher SPLs.



Afterall, there's a reason the Isis exists as well as the Indra. Frankly, I think this mid has enough headroom that I could imagine doing a dual 22W SS setup with it on the bottom end. I'm sure Avalon had similar reasoning in developing the Avalon Time, which uses a larger dual woofer setup than the Indra. Then we could lower that distortion floor significantly in the lower end- but of course, at a price. Now, if you guys could take up a collection so that I could retire and work on these full time, just think of all the interesting designs I could crank out- I might even be able to keep up with Paul W! Well, almost!

It all certainly provides me with motivation for the Modula Xtreme build, though I'm still pondering the final tweeter choice- more testing and evaulations to do there. If I can fix the 10 kHz mouth/throat resonance, I'll probably go with the Millenium Excel- otherwise it's the "proven solution" with the D2608/9130.

And yeah, I do have a pair of 22W sitting around- but they're still earmarked for the Nascent/Aducator build. Got new baffles started for the Nascents, unfortunately, also have two weeks of business travel coming up!

Thanks Jon, the Duelund concept works great as long you are hitting the calculated transfer functions. I can see that a Thiel&Partner is doing fine here. My experience is that most larger 3-way systems (>= 10" for bass duties) using a small mid do sound constrained in the mid band. So I was wondering how your concept was doing.

[JonMarsh]

Well, here I think I'm bass constrained. And I am hitting the transfer function targets pretty well- actually, crossing over to 7's this low is probably not the norm. But look at the distortion curve for the system at 90 dB out (for one speaker). I mean, I get where you're coming from- I wouldn't try to use a single Tangband 1337s as a midrange in this system! And in spite of some earlier thoughts, I don't think I'd do a "Budget" version with the RS100. OTOH, I think the Vifa NE149W would manage OK.

One way to get a handle on this is to use Linkwitz's SPL Excel sheet, though it's setup to compare dipoles and monopoles, and lord only knows Xmax is not the ideal design limit, but it gives a starter sanity check.

Considering the C79, distortion plots, particularly HD3 are a reasonable guide- here's the C79 at 96 dB output:



As you push it harder, the corner frequency where HD3 starts rising (as you go lower) moves up, but you can see here that at 96 dB and 300 Hz, things still look pretty nice compared with a LOT of parts out there.

Now, looking at that in light of our transfer function curve, 96 dB at 300 Hz from the midrange correlates with a nominal flatband output of 102 dB considering the mibass output also- and this from just one speaker, and at pretty low distortion levels. Since I'm using these in a room about 12 X 18 ft, a pair will play at volumes that are probably unhealthy for my ears without being really stressed. That's one of the things one sometimes has to be careful of with really low distortion drivers- you don't realize how loud you may be listening. The first system I built that was really stealthy about that was my X1 SLAM Klones, but it was something of a quantum leap for me in three ways, and between keeping the range for the Eton 7's limited to 150 Hz on the bottom, and using the Focal TC120d tweeters just from 2250 up, they would do things like Michael Hedges at ludicrous volumes, sounding pristine clear, until you realized you were getting some interference from the ringing in your ears.

Now, I don't think you'd quite get to that turf combining the C79 with a pair of SS 22W, but I think that might be a pretty optimal combination for the Ardent Center channel.

Now, the Modula Xtreme with the big Accuton mids and a pair of 26W on each side, that I think will match the old SLAMs for SPL with low distortion, and with lower coloration.

[cjd]

I would think the Fountek "full range" would be a superb midrange option for a budget variant...

[JonMarsh]

I bet it would be a great driver for a "mini-statement" type of design. Probably the only real shortcoming is the smallish Sd, compared with something like the C79- it's only about 1/3.

[mkc]

Hi Jon,

As far as I know you haven't had the time to do any measurements on the Vifa NE149W?

Best regards,
Mogens

[JonMarsh]

Hi Jon,

As far as I know you haven't had the time to do any measurements on the Vifa NE149W?

Best regards,
Mogens

You're right, I haven't- they came in after the NE180W, in the shipment where they bollixed up the tweeters. Got business travel I'm leaving on for a week this coming weekend, so it will be later in the month before I get to look at them. I'm suspecting/expecting something pretty similar to the NE180W, perhaps a little cleaner cone behavior in the top end? And off axis behavior extending a bit higher.

[Space]

I was just browsing the Magico site and looking at this speaker:

Image not available

Image not available

That sure looks like a Scan Speak 26W. I wonder if the Madisound special a while back on those 12 ohm woofers was a buyout from Magico. It would follow because the 12 ohm impedance works for a trio. They only have that vague image of the overall, but you see there are three of them.

[Face]

Good eye!

[JonMarsh]

Extremely high probability, I'd say... on both accounts.

You know, I didn't used to be a Scanspeak fanboi, but some of their recent products have turned me around... the 26W series is one of those.

[igy137]

Googling for M6 gives some more images, it definitely looks like the 26W.
I was curious about the cabinet size, quickly checked the dimensions 138x87x55 (cm), that's huge, around 500l...

[JonMarsh]

Huge and heavy... just like your wallet needs to be to afford these!

[Space]

The unmistakable Scan Speak feature is seven mounting screws. If you ever happen to try and draft seven equally spaced increments around a circle, you realize why nobody else is "clever" enough to make that design decision--pretty hard to measure 51.428571428571428571428571428571 degrees. But hey, sometimes six is too few and eight is too many, so there you go!

[savage25xtreme]

The unmistakable Scan Speak feature is seven mounting screws. If you ever happen to try and draft seven equally spaced increments around a circle, you realize why nobody else is "clever" enough to make that design decision--pretty hard to measure 51.428571428571428571428571428571 degrees. But hey, sometimes six is too few and eight is too many, so there you go!

you made an engineer laugh this morning :rofl:

[Rolex]

you made an engineer laugh this morning :rofl:

x2

[numberoneoppa]

Does an engineering student count? :P

[JonP]

The unmistakable Scan Speak feature is seven mounting screws. If you ever happen to try and draft seven equally spaced increments around a circle, you realize why nobody else is "clever" enough to make that design decision--pretty hard to measure 51.428571428571428571428571428571 degrees. But hey, sometimes six is too few and eight is too many, so there you go!

Hehehe!!!! Indeed! That IS one HECK of a repeating sequence there!

Of course, just calling it 51.43 would do, but what fun is that?

[Dr.EM]

Been following this project closely but only just joined up to the forum. Really outstanding work! Looks like a great design 8)

The LBL core for the outer front panel has an interesting texture, as seen here in the prepared tweeter opening; it is quite hard and dense, not hard to see why Jim Salk and some others are doing enclosure work with it; but it seems to machine nicely, at least with sharp tools.

I've seen mention of this LBL product in a few threads, but searching for it online turns up nothing for me. Does it go by a different name? Where are you sourcing it from?

[JonMarsh]

Laminated Bamboo Lumbar, CJD is also a fan (for more conventional applications, like his home flooring!

Currently I buy 3/4" X 12" cross section boards from the Rockler store in Pleasant Hill; they don't source it through "Rockler corporate" but through a specialty wood wholesaler. The only buy about once a quarter, so I'm often check their status and updating them with my needs- just picked up a couple more boards recently for some of the new upcoming projects.

For "small" pieces, though, I've been turning to a different source - bamboo cutting boards, through online vendors like Amazon, or locals like Target. Bought in quantity online, the price comes down pretty low. (think six packs- literally)



To use for special functions, like a tweeter mounting board with waveguide, or for a whole front panel for a smaller speaker project (like 10" X 16", for example).

[Dr.EM]

Thanks for your response, very helpful!

I can see those boards on Amazon and they are about the right size for the front baffle on a project I'm doing. No issues with wood expansion from these I assume? Do they glue up well? It quite a lot harder/more solid than MDF, potentially hold a screw well too?

[JonMarsh]

Hey, you won't get an objective opinion from me, I'm the LBL fanboi, for certain. This stuff is about 18% harder than Maple, it's a processed wood product, I haven't had any issues with expansion or other behavior so far (Northern CA), and if you use the right pilot hole, screws like black oxide sheet rock screws or square drive screws go in over and over and lock down the way you usually only get with a bolt threaded into aluminum. I used threaded inserts on the ardent, but I don't recommend that now with LBL except for fairly large bolt sizes- say, 10-24 or 1/4-20. The behavior with either threaded inserts or direct screws is MUCH better than MDF.

I've been playing with some more "exotic" materials like phenolic sheet, and I'm glad to find something easy to source and so nice to work with- and very stiff. It's a great "launch platform" in my opinion, and at least deserves to be used in the front panel where, IMO, the stiffest, strongest coupling of the driver to the rest of the cabinet is needed.

Of course, remember, I'm the official HT Guide nutcase, extremism in the defense of sonic resolution, all that sort of stuff. YMMV.

But all my new projects in progress are using LBL, even when it's just a custom front panel for a Dayton cabinet, as in the Modula series. Which are intended to be easy to build, unlike the Ardent. I found some big cutting boards an inch thick that are going into the Modula Xtreme bass cabinet front panels.

[Dr.EM]

That sounds awesome

Sounds like, even if I don't like the raw appearance of it and have to cover it with something, (I might as looking at it i'd probably have one of those light bands showing with my 40.1CM panel section required from the 46CM board) it'd still be worth the extra money over MDF. I'll save on threaded inserts anyhow as I already have the Monacor black hex drive speaker screws.

So the Amazon cutting boards are LBL? I guess that is the only form one can buy bamboo board in anyhow as it's not possible to obtain large unprocessed boards directly sawn from the plant. No expansion worries is what I'm looking for as I originally intended to use real wood for this but was put off by the issues of expansion.

Will probably order some later and let you know how I get on with them! I guess sharp tools (router bits) are important when cutting this tough material so may need to get some more of those too.

Those big inch thick boards sound great! Look forward to seeing you implement them :T

EDIT: Probably irrelevant but the UK boards are a different brand. I assume they are the same material though:

http://www.amazon.co.uk/gp/product/B0007MTP0C/ref=s9_simh_gw_p79_i1?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=center-1&pf_rd_r=1ZX4D97PS7XYATJKV6F9&pf_rd_t=101&pf_rd_p=467198433&pf_rd_i=468294

[numberoneoppa]

Plyboo.com has a great selection of LBL.

[Dr.EM]

I recieved my bamboo cutting boards and have been working with them.

I agree with all the points you made. Much more solid, tools well without making fine dust, holds a wood screw very well and glues up well with normal wood glue. Good stuff, if it were cheaper and more available I don't think MDF would get used very much.

Be careful on rough jigsaw cut edges though, it will give you nasty splinters until you router/sand it!

[JonMarsh]

I recieved my bamboo cutting boards and have been working with them.

I agree with all the points you made. Much more solid, tools well without making fine dust, holds a wood screw very well and glues up well with normal wood glue. Good stuff, if it were cheaper and more available I don't think MDF would get used very much.

Be careful on rough jigsaw cut edges though, it will give you nasty splinters until you router/sand it!

No argument there- you need sharp tools and fine cutting bits- I use Bosch finish grade jig saw blades, but you konw, I think I've done all my work on LBL with either multi-tooth carbide table saw blades or router bits (jasper jig is your friend for circle cutting), or on occation template follower bits with phenolic templates.

I'm going to be diving in to a big stack of LBL boards next week when combined "Ardent Speaker Camp" and "Modula Xtreme Speaker Camp" go into session. Only the latter working with new boards and front/rear panels plus some construction pieces, such as tweeter mounts for waveguides or sub-cabinet fixtures.

[Renovator]

I'm going to be diving in to a big stack of LBL boards next week when combined "Ardent Speaker Camp" and "Modula Xtreme Speaker Camp" go into session. Only the latter working with new boards and front/rear panels plus some construction pieces, such as tweeter mounts for waveguides or sub-cabinet fixtures.

opcorn:

Waiting with much interest.

Have been reading as many of the threads as i can keep up with since I found the site. Have to say I am amazed at the quality of information and workmanship that I have seen in my short time here. Inspiring stuff.

The technical expertise available is pretty impressive too.
;x(

[JonMarsh]

Welcome to HT Guide, Renovator- there's lots of great contributors here, and tons of potentially useful reference threads, too. Hope you enjoy your stay!

Two days till Ardent Speaker Camp 2010 starts...

[JonMarsh]

That sounds awesome

Sounds like, even if I don't like the raw appearance of it and have to cover it with something, (I might as looking at it i'd probably have one of those light bands showing with my 40.1CM panel section required from the 46CM board) it'd still be worth the extra money over MDF. I'll save on threaded inserts anyhow as I already have the Monacor black hex drive speaker screws.

So the Amazon cutting boards are LBL? I guess that is the only form one can buy bamboo board in anyhow as it's not possible to obtain large unprocessed boards directly sawn from the plant. No expansion worries is what I'm looking for as I originally intended to use real wood for this but was put off by the issues of expansion.

Will probably order some later and let you know how I get on with them! I guess sharp tools (router bits) are important when cutting this tough material so may need to get some more of those too.

Those big inch thick boards sound great! Look forward to seeing you implement them :T

EDIT: Probably irrelevant but the UK boards are a different brand. I assume they are the same material though:

http://www.amazon.co.uk/gp/product/B...pf_rd_i=468294

Same stuff, as far as I can see. There's several brands doing this in high volume over here on our side of the pond.

[Dean100]

Two days till Ardent Speaker Camp 2010 starts...

Looking forward to seeing the results of Speaker Camp. Enjoy your time off and keep up the incredible work. :T

[JonMarsh]

Status update and Crossover schematic

Been so busy I've didn't get around to finishing drawing up the crossover schematic for those that might be interested and posting it-




I'll be putting together a BOM with general component selection guidelines during the upcoming week.


A few notes are on the schematic, but a few more may be in order.

The LCR network in the midrange, C17/L14/R23 came about from the listening campaign described earlier; it takes care of a bit of a bump in the 2 kHz region of the C79. Blue is "before" and violet is "after". This follows the Duelund transfer target better.



Some have asked about the "fugly" diffraction pad- what does it really do?

This plot probably shows the why's and wherefores better than any arm waving, at least as regards on axis.



Diffraction induced effects are also not usually uniform with regards to the measurement axis... so a "pet" theory of mine (which doesn't mean it isn't wrong) is that if you clean up the diffraction related stuff, if the drivers are operated in the right band and the crossover is solid, you should have pretty consistent behavior at least out to +/- 30 degrees or more (considering the limits of driver dispersion as you approach the top of the pass band).

So, this is the response measured at 30 degrees off the horizontal axis.



Not perfection, but certainly something I can live with.

For reference, set the Wayback machine to October in Denver, when first fired up based on just LspCAD calculations, and when they were running the D3004/6620 tweeters on top.



One of the things I also want to mention is how much I'm enjoying these with what I would call "non audiophile recordings", but just well made ones of typical performers- two in particular I've been listening to the last week,



Harbor Lights, Bruce Hornsby


Acoustic Extravaganza, KT Tunstall


Originally Acoustic Extravaganz wasn't released by the record label, and was only available on her personal web site as a CD/DVD combo; the DVD detailed the recording, which done in just a few days. You know how I love that explicit content... that's why I always try to be so explicit in my design notes and construction details. That is what they're talking about, isn't it? :W

[---k---]

Although I consider KT Tunstall "chic music", I really enjoyed her first album. I also have her second, but consider the first better. I'll have to pick this one up. Thanks fo rhte heads up, I didn't know about it. Saved.

Harbor Lights is $6.99 from Amazon. With free Prime shipping, Done!

[SoundOfNothing]

Jon I don't see components numbered "C17/L14/R23" in the schematic for the mids, am I missing something? Did you mean 13/16/10?

[JonMarsh]

Jon I don't see components numbered "C17/L14/R23" in the schematic for the mids, am I missing something? Did you mean 13/16/10?

Nope! But I am! Thanks for the catch- will correct and update! That's what comes from having too many things on different pieces of paper when you try to create the "master plan".

Updated evening of 3-25-2010.

Ryan, you can probably preview the cuts on Amazon if you want- it's an interesting album, more of an R&B feel on some cuts, definitely more of a "risk" taken then her first and most recent pop efforts. Probably why the label wasn't supporting it initially.

[Jonasz]

38 components per speaker! :E That's what is called a "perfectionist" crossover I assume? :P

[JonMarsh]

Other than three parts, it's what just get's the job done...

38 components per speaker! :E That's what is called a "perfectionist" crossover I assume? :P

Alas, it's what get's the job done. Of course, I suspect you're counting paralleled resistors- though you may not be counting paralleled caps.

You could leave some parts out, but every time you do, things get a bit more problematic... like some of Tony Gee's crossovers.

For example, leave off the woofer low frequency zobel, and the interaction of the main LF inductor and the driver impedance shifts gives a nice bump in the upper bass- might be preferred by some that like their bottom end a bit zaftig.



The SS tweeter has a significant impedance rise which if left "untreated" will put a bump in the bottom end below 1 kHz- with the Duelund concept, we must match the transfer function well down to -20 dB or better-

Similarly, the C79 has impedance swings that can't be ignored either for crossover operation.



Steen's crossovers I've heard would make this one look like a piffle...

But if you want to build the "basic" version, as opposed to the "perfectionist"
version, then one can remove L10, C14, and R10, as their only purpose is to kill a bump in the impedance curve that occurs between the midrange driver and tweeter, which may interact with amplifiers with higher output impedance (vacuum tube or no feedback solid state designs), causing a bump in the presence region (that's how it models).

So, there are some options.... but those parts are so relatively small and inexpensive in the overall scheme of things, I didn't see the need to point that out. :B

[lbstyling]

hello jon,
ive been reading and reading.......and reading, and im very impressed to say the least!
i have been seaching for another design to build for years now and i have to say that im interested.
the problem is that im advised by many that its important to have as few components in the signal path as i can get away with. there are lots and lots of them in this design- i know there is little theory to support the sq loss of doing this - but still im uneasy with the idea of all those caps on the signal path.
i have tried to get to the bottom of this idea but i just cant. -its suported by the fact that many of the speakers i have realy been impressed by were 1st order, with the aim of as few components as possible.-can anyone offer some enlightenment on this?
im kinda between tony gee's soup sandwich and this atm.

ps- just awsome cabinet work!