A New Adventure

[JonMarsh]

as Willy the Shake said in one of his plays, "There's many a slip twixt the cup and the lip"

And wow, does November 2019 ever seem like a long time ago...

But I like the way this is evolving.

[Steve Manning]

Thanks guys. Yeah that bamboo gives a ton of options for staining or not. Would be an interesting trick to get just the center strip without bleed over into the surrounding area though.

[Bear]

That would be fun to play with some tints on the center racing stripe. Take it a bit darker than it is already to pop the contrast. Great work, as always.

[theSven]

The profile looks awesome! It all flows nicely and the bamboo is stunning.

[Steve Manning]

Ardent D prep work

While getting some parts ready for an Ardent D build, it gave me the opportunity to fit up the recently cut curved test baffle. No spacers and rough edges, but you get the idea of where the design is going.

[JonMarsh]

As Dr. Jeno Tihanji, the inventor of Siemens SIPMOS would say (and did say about many things), slow work takes time...

But, imagine trying to get the same result manually...


There are many reasons that YG Acoustics and Magico speakers are as pricey as they are; this is one of them.

[Steve Manning]

Bamboo version looks superb. I would keep that with some transparent finish for sure and would like the look of it for sure.

Steve,out of curiosity - how long did it take for one of such bamboo panels on the CNC. You get such a good finish out of machine, so it should mean very small step size and thus quite a long machining time ?

Thanks Ergo ..... I was hoping to be able to use this as an actual part, but timing did not work out and I needed to determine how well the process would work with bamboo. I'll probably sand it and throw some finish it to show customers.

Time wise for this is ~75 minutes actual machine run time. I have a few tweaks I need to do that might shave a few minutes off. Of course you have time involved in tool changes and all that as well. The biggest chunk of that time goes to creating the curve which is an even split between the roughing and finishing passes at ~30 minutes each. Step over on the finishing pass is 0.040".

Now this is for a 20" tall baffle ..... an Ardent size, which is on the way, will be considerably longer.

Steve

[ergo]

Bamboo version looks superb. I would keep that with some transparent finish for sure and would like the look of it for sure.

Steve,out of curiosity - how long did it take for one of such bamboo panels on the CNC. You get such a good finish out of machine, so it should mean very small step size and thus quite a long machining time ?

[Evil Twin]

There is much effort that goes into the ability to fabricate this relatively simple looking artifact....

[theSven]

They look really good and I like the way the grains look too. Would look really great with a few coats of the emtech clear!

[Steve Manning]

Next Step .....

Continuing with curved baffle tests. Parameters had to be adjusted some from the earlier mdf test ..... bamboo is a tad harder. :W



By the way, the baffle has not been sanded yet .... not 320 grit smooth, but very nice none the less.



Next to the mdf version.

[Norm]

Oh so very fine.

Steve is further advancing his already considerable skills in 3D modeling, G code creation, bits selection, and fixtures.

[Evil Twin]

Just to let folks know, early tests on an actually 3D sculpted baffle looks rather promising. This has been on my list of things to figure out and was prompted by on going work into center channel designs by Jon.

Here are some pictures from the test run. This is essentially the same size baffle as what's on the Calliope MT.

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[ATTACH=CONFIG]30433[/ATTACH]

Ah, yes, I see that Steve had raised the quality of his photo realistic renders by a quantum order, no doubt now using AR to superposition them within his own domicile...

I similarly previewed an Apple XDR display in my personal computing environment using the same technique before making that commitment...

Either that, or he actually has overcome some vexing programming and fixturing issue to actually fabricate the baffle displayed in this point...

[Steve Manning]

That looks great! I like that look and think the Ardent D’s with a baffle like that would look irresistible for me. Would this also make assembling easier?

Thanks Sven .... mounting of the baffle would be similar, though there should be no hole drilling like you had in the Calliope's. Since this style baffle would also sit on the front of the ribs rather than in a pocket as it were, it should also be easier to line up. Your also looking at reducing diffraction issues as well .... not sure if that will be audible or not?

[theSven]

That looks great! I like that look and think the Ardent D’s with a baffle like that would look irresistible for me. Would this also make assembling easier?

[Steve Manning]

New Baffle Option

Just to let folks know, early tests on an actually 3D sculpted baffle looks rather promising. This has been on my list of things to figure out and was prompted by on going work into center channel designs by Jon.

Here are some pictures from the test run. This is essentially the same size baffle as what's on the Calliope MT.

[theSven]

Great work on the site! The build photos of the minervas was really cool seeing that process. That cabinet is a solid tank! The stands are some stylish eye candy too.

[Bear]

Thanks Ergo ..... fixed it. Seems no mater how many times you go through it, you always miss something.

Never mind. It just took a long time to load on my end.

[Steve Manning]

Congrats on getting the website up. I hope with all the "sit at home" policies around the globe it will help drum up some new business as people have more time to dream and browse the web.

***

Just a tiny typo that I noticed - on a page

http://www.smjaudio.com/speakers-1#/speakers

the image description is "Modular MTM" while I believe the original name is "Modula MTM"

https://www.htguide.com/forum/showth...uction-Details

Thanks Ergo ..... fixed it. Seems no mater how many times you go through it, you always miss something.

[ergo]

Congrats on getting the website up. I hope with all the "sit at home" policies around the globe it will help drum up some new business as people have more time to dream and browse the web.

***

Just a tiny typo that I noticed - on a page

http://www.smjaudio.com/speakers-1#/speakers

the image description is "Modular MTM" while I believe the original name is "Modula MTM"

https://www.htguide.com/forum/showthread.php?11321-Modula-MTM-1-Design-and-Construction-Details

[Steve Manning]

Website ....

Well that long overdue website I mentioned a while back is finally up ........ http://www.smjaudio.com/

[Steve Manning]

Thank you Sven .... very kind of you to say.

[theSven]

i drove down to Steve's house this weekend to listen to the new adventure project. Steve gave me a tour of the workshop and a listening session. After the listening session I was sold, I knew I wanted a pair! The beauty is that I can still have some part in the process by getting to paint and assemble. The sound was amazing along with the high wife approval factor design, and I like them better then the wharfdales I'm using now. Needless to say I'm extremely excited to get a pair of these, and to see what John and Steve are creating for the HT design. Great work Steve and John on this project!

Sven

[Evil Twin]

Very similar concept:

https://www.hifitest.de/test/lautsprecher_stereo/gauder_akustik-berlina_rc8_13977

https://www.hifitest.de/test/lautspr...lina_rc11_8508

It is not the type of construction technique available to a home builder, yet with the proper execution it bypasses the issues common to DIY translam designs- something Steve and others on the board have frustrating experience with. It uses components in their most optimum mode, under compression, considering the pluses and minuses of available materials....

[Steve Manning]

Very similar concept:

https://www.hifitest.de/test/lautsprecher_stereo/gauder_akustik-berlina_rc8_13977

https://www.hifitest.de/test/lautspr...lina_rc11_8508

They were a big part of the inspiration for our design.

[Zvu]

Very similar concept:

https://www.hifitest.de/test/lautsprecher_stereo/gauder_akustik-berlina_rc8_13977

https://www.hifitest.de/test/lautsprecher_stereo/gauder_akustik-berlina_rc11_8508

[Evil Twin]

That is useful feedback, and I will have to complete my own investigations as planned...

[wolf_teeth]

More or less, I was saying they weren't my project or usage, and that someone else did the design. I heard the 2 versions of the Bromo kit from SB Acoustics, one withe black aluminum and one with ceramics. Both use the same xover network. I preferred the detail of the ceramic design and how more refined it sounded.

I know more people were also in agreement of one over the other, typically of the same opinion. We got to hear both in succession at the CSS/Meniscus DIY in September.

Unquantifiable as I can't quantify my findings since I don't have them myself,
Wolf

[augerpro]

Whilst knowing full well that this will elicit a remote Force Choke, the Khyber Lenses from the Professional Augurer (disguised as a simple person who makes holes for pay) might make a combination with the 26ADC model from the Sinar Baja system a worthy competitor to the Corundum conundrum. I believe that his model A.625 will offer an effective weapon against both the forces of "CTC" and those whose efforts seek to disturb the alignment of phase compared to the most worthy current champion of Coruscant.

Some files obtained by Bothan spies are being transmitted to the head of TIE Industries now.

3D printing isn't quite up to Fleet contractor standards, more for dirty Rebs, but if ET is interested I can send two existing prints to test. One is for the SB26ADC and has a small throat, the other was for the TLabs ceramic. Because of the options the Peerless leaves you to mount it, it would be a good idea to test both versions, because while the smaller throat is preferred it might cause a problem with creating a cavity outside the surround, so we might be forced to use the larger throat.

I can also easily design something proprietary and just send an .stl or .step file. ET, IIRC the faceplate cannot be removed because the diaphragm is glued to it, correct?

[morbo]

This is a reasonable suggestion on your part, but I do not believe the availability question is clear cut.

At this time, the sw182bd02 is not available from the US distributor. Solen in Canada has 4 pieces, priced at close out pricing, and with no backorders allowed. The normal MSRP for this driver is about $160 USD, but it seems to not really be available on an ongoing basis anymore.

Understood. I had only looked at the pricing quickly at solen, which is currently quite appealing. Didn't realize it was a closeout, or the there was no US distribution. I would probably prefer the anarchy anyway, but there's no canadian distribution, and DIYSG is not interested in shipping outside the USA so I have never considered it seriously. It certainly looks like a great driver though! I do like the direction this project is going, will be watching with interest!

[Bear]

This one may be strong in the Force...



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And Steve tells me he finds the color most attractive....

Whilst knowing full well that this will elicit a remote Force Choke, the Khyber Lenses from the Professional Augurer (disguised as a simple person who makes holes for pay) might make a combination with the 26ADC model from the Sinar Baja system a worthy competitor to the Corundum conundrum. I believe that his model A.625 will offer an effective weapon against both the forces of "CTC" and those whose efforts seek to disturb the alignment of phase compared to the most worthy current champion of Coruscant.

Some files obtained by Bothan spies are being transmitted to the head of TIE Industries now.

[Evil Twin]

That one is in the same shipment, but Steve has expressed a preference for the black cone material, and this is targeting the lowest feasible cost without sacrificing performance. But your input is duly noted and sets a specific target comparison for the planned listening tests.

How would you describe what the differences in sound are, and have you measured and correlated it to specific performance characteristics?

Unquantifiably better sounds as if you find that you prefer it, but you cannot quantify why- these situations arise, but generally they both merit and require more detailed investigation.

[wolf_teeth]

It might be a cost thing, but I prefer the ceramic model to the aluminum. The sound is IMO unquantifiably better.
Later,
Wolf

[Evil Twin]

Is there another?

This one may be strong in the Force...
















And Steve tells me he finds the color most attractive....

[Evil Twin]

Thank you Jon for educational material too. Interesting reading as always and a great idea to play these things through with ideal drivers. I for one should be doing that some more.

For me, beside the Xover tuning for the slope and summing etc is to get the 'home made in room' measurements conditioned so that I can trust the low frequency part below 1k. Not having too big a room and especially ceiling thats only 5.2m/8.1feet will limit the useful gating window too much. I've yet to come up with a good solution, but for now the best approach seems to be either to
a) merge the short gated response and a long about 80ms gated and strongly smoothed response together with Merger ... leaves still very visible room modes and floor reflection into the response
b) merge a short gated response and a near field response + baffle simulation together - makes a much smoother low end. I do verify that against the long gated one still to try to eyeball the reasonable match.

For 2 ways it's been working reasonably well, but now with latest OLA 2.5way design where woofers share the box, but later have a different Xover - there I've struggled a lot to get it right. The speakers are now finally at my friends place where they belong in the end. He's still tuning them even though we have gone through many physical Xover revisions already. I should just go the route Zvu presented in the other thread and rent a 'basketball court' and do it once and right

Anyhow, open to hearing your design flow and methods of tackling that aspect... or maybe you do not obsess that much about it at all in end and tune the low end by listening ?

Your questions are very valid, and yes, it might be interesting to do a complete discussion of current design flows in a separate thread- time constraint may delay that until December.

Anyhow, open to hearing your design flow and methods of tackling that aspect... or maybe you do not obsess that much about it at all in end and tune the low end by listening?

This is not left to chance or last minute listening test when the design is far along. For some system designs, such as bookshelf, there is not much one can do to control the final positioning. For more complete floor standing systems, this deserves considerable theoretical and practical evaluation before building cabinets. It should be addressed as part of the design flow discussion...

In my own situation, there are several "design studies" begun this year, for specific applications and sets of drivers which, regrettably, due to the press of any obligations and tasks for the Empire, must be temporarily set aside and put in abeyance. Or, specifically, in storage in the Outer Rim, where I plan to relocate in about 14 months.

I would offer one axiom, about design flow- there is not one "correct" design flow, but there are many "incomplete" or vulnerable design flows, which might leave important characteristics to chance. And there are some which could be labeled fatally flawed, too.... There has been a clear evolution of understanding on this topic on this and other boards over the last 15 years... at times interesting, most interesting....

[Evil Twin]

I have to concur with the sentiment expressed above about the ZA14 - it has the cleanest midrange I have heard in my admittedly limited experience. I really think it's overlooked by many, I'm not sure if it's the cost, the looks, or limited distribution. In a way it's much like the Peerless tweeter; folks often seem to relegate them to budget builds when their performance is anything but.

In terms of the woofers used for this project; is the anarchy going to be it for sure? I ask because it seems to be even more limited in availability than the ZA14; at least madisound will ship internationally. I wonder if it might be possible to have an option using the Wavecor sw182bd02 - I understand it's very close to the anarchy woofer, only with an aluminum cone and wavecor motor instead. A pair of them models nicely in a moderate sized ported tower tuned low, something I've been eyeing lately.

This is a reasonable suggestion on your part, but I do not believe the availability question is clear cut.

At this time, the sw182bd02 is not available from the US distributor. Solen in Canada has 4 pieces, priced at close out pricing, and with no backorders allowed. The normal MSRP for this driver is about $160 USD, but it seems to not really be available on an ongoing basis anymore.

There are composite glass fiber and paper versions, and paper cone versions, but they are have pronounced disturbances in the 1 - 1.5 kHz area response and the impedance curve which, for me, render them less desirable. The do not approach the linearity of behavior of the SW223BD02. And the pricing is close to 3X that of the Anarchy Exodus. While I am reasonably certain the design could probably be adapted to the Wavecor 182 series, provided sufficient motivation, at this time, that motivation does not seem to exist.

This is a special project for Steve Mannings “New Adventure” and the overall parameters require ruthless examination and implementation of all reasonable requirements. Perhaps, the unreasonable ones, too... Reducing the driver BOM cost by 85% is not a trivial undertaking... while targeting maintaining a demonstrably high degree of linear and non-linear performance.

I wholly agree with comments about the ZA14 being an over looked part. There is also one other type just ordred yesterday which may- or may not- give it some competition.

[morbo]

The Anarchy has a black aluminum cone as well, so materials are not different.

Which Peerless tweeter? DQ25 (relevant to ZA14 discussions)? If that is the one you refer to, I find it to be a pretty cheap sounding junk driver and don't like the broadband glare it emits. Other Peerless tweeters are great, like the Corundum TX line.
Different strokes for different folks.

Later,
Wolf

The corondum DA25TX; as I understand it's the one being suggested for the designs discussed in this thread.

Didn't realize the anarchy had an aluminum cone as well, for whatever reason I tend to conflate it with the old extremis. I just remember reading Rick Craig somewhere saying they were essentially the same drivers as the Wavecors with different motors. I don't know how much (if at all) better the xbl^2 motor is than the wavecor 'balanced drive' motor, but if they're comparable it could give the design more longevity and wider appeal.

[wolf_teeth]

The Anarchy has a black aluminum cone as well, so materials are not different.

Which Peerless tweeter? DQ25 (relevant to ZA14 discussions)? If that is the one you refer to, I find it to be a pretty cheap sounding junk driver and don't like the broadband glare it emits. Other Peerless tweeters are great, like the Corundum TX line.
Different strokes for different folks.

Later,
Wolf

[morbo]

I have to concur with the sentiment expressed above about the ZA14 - it has the cleanest midrange I have heard in my admittedly limited experience. I really think it's overlooked by many, I'm not sure if it's the cost, the looks, or limited distribution. In a way it's much like the Peerless tweeter; folks often seem to relegate them to budget builds when their performance is anything but.

In terms of the woofers used for this project; is the anarchy going to be it for sure? I ask because it seems to be even more limited in availability than the ZA14; at least madisound will ship internationally. I wonder if it might be possible to have an option using the Wavecor sw182bd02 - I understand it's very close to the anarchy woofer, only with an aluminum cone and wavecor motor instead. A pair of them models nicely in a moderate sized ported tower tuned low, something I've been eyeing lately.

[ergo]

Thank you Jon for educational material too. Interesting reading as always and a great idea to play these things through with ideal drivers. I for one should be doing that some more.

For me, beside the Xover tuning for the slope and summing etc is to get the 'home made in room' measurements conditioned so that I can trust the low frequency part below 1k. Not having too big a room and especially ceiling thats only 5.2m/8.1feet will limit the useful gating window too much. I've yet to come up with a good solution, but for now the best approach seems to be either to
a) merge the short gated response and a long about 80ms gated and strongly smoothed response together with Merger ... leaves still very visible room modes and floor reflection into the response
b) merge a short gated response and a near field response + baffle simulation together - makes a much smoother low end. I do verify that against the long gated one still to try to eyeball the reasonable match.

For 2 ways it's been working reasonably well, but now with latest OLA 2.5way design where woofers share the box, but later have a different Xover - there I've struggled a lot to get it right. The speakers are now finally at my friends place where they belong in the end. He's still tuning them even though we have gone through many physical Xover revisions already. I should just go the route Zvu presented in the other thread and rent a 'basketball court' and do it once and right

Anyhow, open to hearing your design flow and methods of tackling that aspect... or maybe you do not obsess that much about it at all in end and tune the low end by listening ?

[carlthess40]

I’ll post the models and specs of the drivers when I have some time
Great work you’re doing


Sent from my iPhone using Tapatalk

[Evil Twin]

A practical two way example- the NatlieP

How would this crossover you’ve posted work for two 8ohm 8” woofers and one 8ohm tweeter? Will like to run the woofers at 4 ohms. And the crossover point is what I’d like to get to
I’m using two Dayton audio woofers and a seas tweeter with a diy wood conical lens



Sent from my iPhone using Tapatalk

This approach can probably be easily adapted to your requirements.

Do understand that the presented crossovers above are for "ideal" flat drivers to show electrical filter and time domain behavior, and do not include alterations necessary for baffle step compensation, driver equalization, and dealing with breakup modes.

For example, a practical realized filter using this approach was first developed for the NatlieP project, which was a two way system using Dayton RS180 and RS28a tweeter. Because of some "interesting" side benefits to the technique, I also made it a series crossover configuration, as some parts then do double duty.

Many are not used to the type of Dark side thinking necessary to intuitively envision the operation in this mode, and it was most amusing seeing them try...




Note that this system design dates back to 2005... we were all much younger then. I have had many requests for updates on this design, but now with the Peerless DA25 tweeter I have good reason to potentially revisit it- either with the same RS180 or another LF driver, pending further driver investigations.

If you are familiar with the overall steps needed to get data and arrive at a useful design, I won't recount them here- if not, let us know and I can outline the process, and possibly assist.

[carlthess40]

There is an optimum point, of course, but also some flexibility. The example shown, which is normalized to 1kHz, uses a 50mm offset- this produced the least overall perturbations when tweaked to as reasonably theoretically flat. This can be scaled directly from 1kHz for the chosen crossover frequency.

However, a larger time offset can be used with reasonably similar results, but then the optimization process will resemble "wack a mole" somewhat more, as flattening in one area will produce issues elsewhere. This a schematic assuming a 75mm driver time origin offset.


[ATTACH=CONFIG]29759[/ATTACH]


And the resulting SPL plot.


[ATTACH=CONFIG]29760[/ATTACH]


Now, Hawksford and others have published papers, some in the relatively distant past, about asymmetric crossovers, some using time offsets, most not. This can be thought provoking to research, and has resulted in an experimental concept for a couple of the recently proposed high efficiency/very low distortion design concepts.

An example for an 1800 Hz crossover is shown here....


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The result, while not to as tight a tolerance as many might desire, enables high performance with certain physical classes and combinations of drivers...


[ATTACH=CONFIG]29762[/ATTACH]


And has some very interesting characteristics... most interesting...

[ATTACH=CONFIG]29763[/ATTACH]

How would this crossover you’ve posted work for two 8ohm 8” woofers and one 8ohm tweeter? Will like to run the woofers at 4 ohms. And the crossover point is what I’d like to get to
I’m using two Dayton audio woofers and a seas tweeter with a diy wood conical lens




Sent from my iPhone using Tapatalk

[rsbonini]

Thanks dwk, augerpro, and ET, for the responses. Makes perfect sense now.

[Bear]

FWIW I'm pretty sure DanP was printing my guides at 100um. You can see the layering along wall, but fine detail is still really good.

I just got back the SLS print. It's much better than my prior PETG prints, though I still prefer the Resin overall (smoother, more of a matte finish).