Official Wavecor Ardent Reference Thread - How we realized the Dream

[benthe8track]

I'm a little late (two or so years?) to show off the final pictures but we just moved into our new place and have a lot more light.

The new media stand is based off this unit. I used Ikea kitchen cabinets and had 12mm back painted glass cut. Saved quite a bit going the DIY route.

Anyways the pictures!

[BobEllis]

I was thoroughly impressed by the way they sounded just handheld and fed a raw signal without crossover. At low level of course, but both sounded very sweet. Let's see some sawdust pictures, Horio!

[JonMarsh]

Ah, yes, new Accuton midranges and Scanspeak Be Tweeters are something to cherish and enjoy! Just wait until you get to hear them! :B

[Horio]

The driver fairy visited last week and dropped off these beauties!

[Renron]

C3 A and B are a waste of $$$ to use Superior Z in this location, use something less expensive for shunts, Cross Cap or similar price.
Personally, I'd change C6A to a Superior Z to break up the sound monopoly of the Obbligatos. They each add a different flavor the the sauce.
Ron

[Evil Twin]

The group think has some "clarity" in this case... you appear to be well on the way to a successful build, though we won't be convinced until we see sawdust and it's byproducts...

[Horio]

Updated SW223BD02 crossover diagram above (post #206) per everyone's recommendations.

[Renron]

R2 / R4 are mis matched, one of them is going to do almost all the resistance work and the other will be loafing.......... One will get hot(er) than the other.
R's in // should be the same value
Yeah, what Bob said.
Looks like you know your stuff construction wise, I'm looking forward to watching you.
Ron

[BobEllis]

R5 target is 3R9, you can get closer with 5 Mills 20R in parallel at about the same cost as a pair of Mundorfs.

R2 and R4 are 4R7 target - a pair of 10R is closer.

R6 could be drawn as a pair of 1R5s in series unless you know a source for 3R 20W resistors.

[Horio]

SW223BD02 Crossover

Here's version two of the crossover using the Wavecor SW223BD02 woofers with updated resistor values and capacitors. Capacitors in series in the mid-range changed to Obbligato per Jon's recommendation.

[Horio]

Ron,

I'll definitely start a build thread when its finally time to create some sawdust. I've been slowly building a Paulk workbench and crosscut jig which will come in handy for this build. I've also managed to collect a number of nice tools this year as well (festool track saw, dust extractor, and sander). I can source 4'x8' sheets of 3/4" bamboo plywood locally in Seattle at a pretty good price so I may build the entire cabinet out of bamboo ply. I've been wavering back and forth on paint vs veneer. I had been leaning toward a nice painted finish, but after seeing how beautiful your veneer is turning out I am leaning back that way again. I did a raw walnut veneer on my first set of DIY speakers that turned out pretty well. The veneer job on the Ardents is certainly more challenging though.

Realistically I won't get started on the speaker build until early next year, so in the mean time I'll keep stocking supplies and enjoy watching your build along with Bob's finish up. I've been taking careful notes.

[Renron]

Horio,
Awesome, congratulations. Enjoy the sawdust, it's a fun journey and I'm looking forward to your build thread. Have you decided on a finish? Veneer / Bamboo / Paint?
Ron

[Horio]

Well I just pulled the trigger so we'll see how it goes. Once they arrive, I'll have the full set of drivers (already have the BD02's). I need to start making dust soon!

[JonMarsh]

I know some one that has, but I haven't. This European connection thing is looking more and more attractive this year...

[Horio]

Has anyone ever ordered drivers from Falcon Acoustics in the UK? With the Pound being down, you can pick up 2 x Accuton C90-6-079 and 2 x Scan D3004-6640 for about $1300 US shipped. This is roughly a $400 savings over Madisound at the moment.

[Horio]

Thanks Bob, your BOM was very helpful. Studying the original BD01 schematic and the updated one Jon posted above, I think I now understand the changes between the two. I'm going to take a swing at marking up the changes on the full schematic, and maybe I'll post it here for comment and reference.

[BobEllis]

Horio, you can take a look at my thread for a BOM. It's missing the 10 uF Clarity MR because I bought it a while back.

In the tweeter circuit in using two 1R5s to make the 3R and a single 3R3. You could use 4 pieces of 3R3 in series/parallel to reduce heating effects.

In the midrange circuit it's a pair of 8R2 in the 4R spot, 2.5% high. The 4R7s are made using 10R, 6% high. You could get closer using a 10 and an 8R2 in parallel but that's on the low side by 4%.

In the woofer circuit Jon had suggested 4 Mills 12W 16R in parallel. The closest available in 15, which results in 4% low. I chose 5 parallel 20R, 2.5% high keeping with Jon's err on the high side philosophy.

Hope this helps

[Horio]

Thanks Jon for updating the crossover for the Wavecor BD02 woofers! When you have time, would it be possible to post a full schematic of the BD02 crossover similar to the first post? I'm going to start working on the crossover BOM for my build and I want to make sure I'm using the correct updated resistors and inductor before I order anything.

Thanks

[JonMarsh]

Update for BD02 woofers

As posted in Bob Ellis's thread:



This is basically the TA5 (test article 5) release with modified resistors (the RIGHT resistors modified the RIGHT way; they interact differently with the network as some of you have discovered)









However, the value for L1/L1011 (as numbered by VituixCAD) is suggested to be changed from 5.6 mH to 5.1 or 5.0; if you already have a 5.6, use as is (just slightly flatter with the different value) OR if you have an LCR meter unwind your inductor to that value. seriously, just how you have them setup in your room will make more difference in the lower midrange than this.. but this would be the optimum for the BD02.

With regards to the tweeter, two points:

• Using the new values, and if you should want to raise or lower the overall trebel level, do it by adjusting the shunt resistor R6/R3051 or better yet, use the voicing filter (or use the Force, Luke!)
• Second, the dip in the response around 4 kHz is due to a cabinet diffraction effect which goes away as you get slightly off axis - it's not something to fix in the crossover, the power response being radiated by the tweeter is quite steady. You'll also see less of this effect with the grilles and recommended felt diffraction contol in place, but these are from bare cabinet measurements.

[BobEllis]

At Jon's recommendation I used these guys http://www.woodworkerssource.com/

[lkaire75]

Thank you all, i will start a thread as soon as i have something to show, i was trying to find lbl here in Mexico, no luck there, so i will have to buy it from plyboo.com send it to Dallas and then wait until the guy who get me my things deliver it to me, normally a week. By the way, can somebody tell me where i can buy baltic birch online?

Thank you, Luis Manuel

[Renron]

Bob,
Don't lay that $hit on me. Jon, you make ready for your company first! Especially Son in law? was it? Enjoy family time it's the greatest gift we can give to each other.
I'm in Zero rush. Bob started before I did, so it's first come..........so to speak. LOL

Luis, Welcome to the Ardent family. If you have any question about anything, post it in a thread you make for your build. We'll all join in the party to help and encourage you if needed. These are not Monkey Coffin speakers which can be built in a weekend, precision early on pays off later. Take your time, enjoy the adventure.
Ron

[TEK]

I was trying to push on Jon oke:

The poor man has way to much on his plate - so I just try to help him get some stuff out of the way so that he has one less thing to think about ;-)
Sorry Jon h:ops:

[BobEllis]

Sorry, I wasn't trying to put pressure on you Jon. Rather pointing out to Louis that you're busy and good things come to those who wait. It looks like Ron is going to be ready before me, so give his version priority if you can get either.

[JonMarsh]

[QUOTE=Alaric;615219]

Link to the Cardas Speaker Set

I find myself in the enviable position of being able to implement this. And leave it that way if I choose. I know what I'm doing tomorrow morning.

I think you'll like it when you get it setup... :W


OK, guys, I promise to make a push this weekend on continuing engineering issues for the Ardents- I'd do it sooner, but we have a lot of out of town visitors from European HQ this week, and that means long days...

[Alaric]

[QUOTE=Renron;612449]Link to the Cardas Speaker Set

I find myself in the enviable position of being able to implement this. And leave it that way if I choose. I know what I'm doing tomorrow morning.

[TEK]

Welcome Louis :-)
Hope you will have a great time building these.
Please create a build thread for you build when you start. Thats a great way to collect information for your self, share experience with others as well as getting input on issues that you might run into during the build process.

And keep in mind that everyone here is doing this for the fun off it - so any dependency on others are dependent on a whole bunch of factors outside of your control.
That said, there are a bunch of people here and in reality you are likely to get better support than with almost any paid service :-)
And we love builds threads with a bunch of pictures :-)

[lkaire75]

Thank you Bob, i´ll begin building the cabinets, for sure these are not easy ones.

[BobEllis]

Welcome to the club Luis. 5.6 mH is correct, Jon has been too busy to update the schematic. The sw223bd02 is 2 dB less sensitive and will need crossover adjustments. Again, its something on Jon's to do list but he hasn't had a chance yet. There are at least two of us building these with the 02 woofers. If you're going to join us, I'd suggest holding off on ordering crossover parts until Jon is able to work it into his schedule. The cabinets will take quite a while to build and finish in a manner appropriate for this design.

[lkaire75]

Hello, I´m new to the forum, just want to say thank you to Jon Marsh and all who contribute to this fantastic loudspeaker design.

I will begin shopping for parts very soon, just want to make two questions: 1) In the crossover schematic for the woofer reads 5.6mh dcr 0.2, but the No.Part 266-916 correspond to 3.5mh dcr 0.2 inductor, just want to know which one is correct, 2) The wavecor sw223bd02 works with these crossover?.

Thank you, Luis Manuel

[JonMarsh]

Yes, but it's very "ear friendly". :W :B

[Renron]

Link to the Cardas Speaker Set-up PDF.

http://www.cardas.com/roomsetup.pdf

I'll have to try this layout when the wife unit isn't home. It's not WAF friendly. As Jon knows....
Ron

[JonMarsh]

Hey, you haven't bothered me at all! Don't Worry! I just wanted to be sure you understood the physical basis for my statements.

I've emptied out part of the message box, should be room now.

No worries from my side, I'm sorry if I came across at all angry or anything - i'm not- I'm more amused by your friends statements than anything else...

Still, I'd like to send you the Cardas Speaker setup PDF, if you're interested in reading it. I know most of the guys can't follow that kind of guideline for setup, but you ought to do it at least once as just an experiment, so you have some "hands on experience" with the difference it makes.

[flamethrower1]

Jon, your message box is full.
Hey Jon,
Man I did not mean to piss you off, really sorry if I came across the wrong way.
I never meant to start a personal attack on yourself or your professional abilities.
All that happened was he requested the link to the website and then started making a big deal of the graph.
I personally could care what he is seeing or not seeing because I understand what you said about the measurements not being optimal.
Maybe I should have requested it in email with a better explanation.

I sincerely apologise if I have offended you in any way.

Greg

[flamethrower1]

Thanks Jon, what I am going to do is just forward this to him and hopefully that will satisfy his concerns.
Like I said earlier, I am not personally concerned myself.
Just looking forward to the day I have them ready to light up

[JonMarsh]

OK, since your friend is an engineer, here's the math....

(BTW, what loudspeaker company does he work for? I'm assuming with the statements he's making he as actual experience designing and testing loudspeakers, including in a home environment?)

(One more BTW, back around 2007 our former moderator and I did a count up of the number of speaker builds I've done since starting in this activity, of course, that includes times when I was actually working for two different pro audio companies and doing this at times as part of my living- at that time, we counted 55 different system designs I've done. Since then I've done a few more, including the Modula MT XE and the other ones lower on that list, and a few I've never published on the board) This doesn't make me any kind of expert, but it does mean I've been down this road quite a few times, and have some skills in the art...

Anyway, MathCAD is a fine little tool for doing this, though it was a better one in some earlier incarnations that allowed you to make a few tricks in defining functions- this was developed back in the 90's, and I still keep an old early version of MathCAD for Windows just for the freedom it allowed in recursive functions.








Bottom line, for different sets of boundary distance, you can enter a function that describes the low frequency alignment of the speaker (such as a 2nd order sealed box, Q as defined; 0.707 for Butterworth) and combine that response with the net boundary reinforcement. Hey, I didn't invent this math, go read up on the papers by Roy Allison.




For prettier graphing, the data was output to PRN files, and plotted in Excel...

Let's look at some examples from the M8a design paper (long in the tooth, from 2004, but still some nuggets in there).

LF driver plus cabinet transfer function is the magenta curve- then we show the boundary curve (green) and the combined curve (blue)

Two positions- first not at all ideal, with close to the same distances for all three boundary spacing; the second with two dimensions similar (common) and one different:





Next, we show a more ideally spaced boundary location set for both a ported example, and in the same location a critically damped sealed box example, (mind you, this is just modeling boundary reinforcement issues- room dimensional modes are another can of worms)




Last, reversing the blue and green colors, here is a notional analysis for the Isiris, big brother to the Ardent.




Now, if you don't space out those boundary distances just so, you have the reinforcement modes stack up, creating both peaks and dips. That was highlighted in the M8a design article.

[JonMarsh]

Jon, I was wondering if help me out.
I have an acquaintance (who is an engineer) whom I mentioned to that I was going to build a set of these to.
Sent him the link for this forum and after he looked at the frequency sweep graph, he is trying to convince me that I need to change the crossover for the Wavecores.
He is all hung up on the fluctuations in the 50Hz region.
I told him to read your explanation about the measurement not being taken in optimal placement and his comment was that it should not matter.
Can you give me some ammo to putt this to rest?

Thanks, Greg

What Bob posted after yours hit all the key points. These were setup and measured in the back of the room- the crossover has no effect whatsoever below 200 Hz, but the room acoustics sure do. Normally I setup in the back of the family room where my GF won't bug me about them being in the way of her watching her PBS period piece type shows- she has an erratic watching schedule, not usually using cable, but streaming them from her iPad. But this makes the LF stuff less than idea. Same thing went on with the Minerva, but I got a little bit nicer spot.

Regarding optimum setup, PM me your email and I'll send you the Cardas guide to speaker setup. I can also put up the math for how a woofer interacts with the three nearest boundaries, and how that can gang aft aglay, as the Scotts would say... and why the golden mean ratio spacing works.

As to what the SW223BD0X drivers look like close up without room stuff, here's an on axis example-



And here's off axis with a PR, measured way off to the side, so the breakup mode isn't very prominent, but the PR contribution is more evident:




The nominal crossover points for the Ardent are illustrated in the LspCAD simulation:




(about 650Hz and 3 kHz)

And I can show you other in room measurements taken during development which don't have the dip at 50 Hz because they have a peak!




The surest way to eliminate those kinds of issues are to build the speaker into a wall or the junction of wall and ceiling, and design it for that location- haven't seen that go over very big with the ladies.

Or, add a rear firing woofer and some DSP and convert the radiation pattern from an OMNI at low frequencies to a cardiod. this is also a good argument for more placement flexility to use a wall boundary loaded sub, and crossover around 50-60 Hz.


Last, here's a measurement of the Isiris in the same room after I'd disrupted the couch and speaker positions and set things up as "right" as I could prior to a visit by my friend from Munich (the one with the Savoy's now)




GF won't let me leave the family room setup that way, unfortunately... :W

[flamethrower1]

Yeah, I am FULLY confident in what Jon does and would never second guess him.
Just received the mids today, nice looking drivers.
Cant wait to be able to listen to them.

Thanks, Greg

[BobEllis]

Greg, your engineer friend needs to read up on measuring speakers. The long window absolutely affects measured response of low frequencies. I'm guessing non optimal measurement setup means Jon didn't clear the room and there are plenty of early reflections sneaking into the measurement window causing the response irregularities. Usually the low end is measured with close mike placement and that measurement merged with a far field measurement. That may be what he's used to seeing.

The other challenge for your friend would be to propose something to flatten response. Remembering passive crossovers only cut, you'd have to lower everything else to compensate for the dip if it exists. Parts to flatten a peak at 40 Hz would be huge and expensive.

[flamethrower1]

Jon, I was wondering if help me out.
I have an acquaintance (who is an engineer) whom I mentioned to that I was going to build a set of these to.
Sent him the link for this forum and after he looked at the frequency sweep graph, he is trying to convince me that I need to change the crossover for the Wavecores.
He is all hung up on the fluctuations in the 50Hz region.
I told him to read your explanation about the measurement not being taken in optimal placement and his comment was that it should not matter.
Can you give me some ammo to putt this to rest?

Thanks, Greg

[BobEllis]

Sounds like a busy weekend, Jon. Thanks for doing the update, but don't push yourself too hard.

[JonMarsh]

Got a new smaller lighter amplifier to try out for speaker testing- hope I don't regret spending $200 for a Behringer A500- regardless of what some of the trumped up specs say, it's basically a 100W/ch at 8 ohms, 150/ch at 4 ohms amplifier. Which is fine for speaker testing, especially when just using one channel at a time. Will bench it first, make sure there aren't any issues.

One way or another the inductor part number on the woofer will get updated this weekend...

And I did get some new test inductors and caps- so this will be an experiment this weekend, to get the AP setup running on acoustic tests, do some detail studies, and see if what models in VituixCAD is happening in the real world (I figure if it isn't, it's more likely issues with my models and measurements, but we'll see how that goes.

And the knock down cabs for the test enclosures for the AS190-4-252 arrived yesterday, too, but that belongs in a different thread...

[Renron]

Very happy to hear things went well yesterday, it's not always the case.
I talked the wife unit into seeing a Chiropractor last week because her legs were going numb after standing or sewing for a few hours. He gave her the "Once Over" and the next day I think she hated me, sore everywhere. Several days later she thanked me and is going back for another "Whack" at it next week, some times it takes a while to feel better after you feel worse.
No problem with dips into the 4-5 Ohm region for me, I've got a Honey Badger Amp that is happy to drive 2 Ohm loads. I do understand that others may, may want to use more common amps / receivers to drive these. Take you time, enjoy some (what should be) down time.
Tequila seems to be a good pain med as I recall . If needed.
Thanks Jon.

Different note; I am trying out some UV cure polyester grain filler soon. Should be interesting. I'll post pictures in my "Budget" thread.
Oh, almost forgot. I bought some 50W hollow core ceramic wire wound resistors and will test the inductance today, also in the budget thread.
Ron

[JonMarsh]

Things went well yesterday, I feel better today than the day following the procedure in Germany, and no pain killers, either.

I have test parts already on order, so it's my intent to give more feedback on this ASAP, maybe by next weekend. Good that you have an inductance meter of some sort around- that makes things more reliable.

Note that in some subsequent re-evaluation for the base design I've gone as low as 4 mH on that inductor, LF impedance dips a little more (but not below 4 ohms- around 5 ohms). I may play with that some more today, since I'm officially off work also (other than a conference call with my boss...)

One thing that occurred to me, since you're in CA, and in Northern CA, might be an onsite measure and if needed tweak. I want to be sure we get this right... Let me know what you think.

[Renron]

Thanks Jon,
It's apparent how much you LOVE this audio hobby / obsession. Thank you for your continuing work on my project, I thought you were done! The perfectionist in you is appreciated. I've purchased and built all the woofer and Tweeter components. I have about 1/2 of the Midrange parts needed, just waiting on a few $$$ to buy the rest of the Jantzen Superior Zs for the XO. I have an EL Cheapo Inductance meter that is surprisingly accurate, easy enough to unwind and measure mH as needed. Easier than adding mH. LOL. But I've done that too............

Take it easy and don't push yourself much. Enjoy the "Fruits" of your previous labors.

Ron