Isiris evolution to Osiris Jr? Summary of Isiris build and new update

[JonMarsh]

John this is an excellent writeup on how to get the deeper cuts. Is this something that can easily be attached in the woodworking tips section of the forum? I don't know how, or know if I can do that...

Thanks again for all of your great contributions!!

Yes, I do plan to put it in the woodworking section also- will have to see if I can just copy it there, but it's no big deal just to repost it, too.

[CADman_ks]

Yes, I do plan to put it in the woodworking section also- will have to see if I can just copy it there, but it's no big deal just to repost it, too.

:thanku:

[JonMarsh]

Side panel brace

The panels needing bracing in this cabinet design are the sides, and here is where I'm installing a brace like the one used on the Isiris cabinets:

[Steve Manning]

John this is an excellent writeup on how to get the deeper cuts. Is this something that can easily be attached in the woodworking tips section of the forum? I don't know how, or know if I can do that...

Thanks again for all of your great contributions!!

I was thinking of how to do this with a cross cut sled on a table saw, but once you have this in place setting angles and bevels would be much easier and faster.

Jon, will this only work on the DeWalt or can it be done on your Bosch as well?

[JonMarsh]

That's a good question. You see, when the DWS-780 was introduced, it was sort of an "open source secret" that it was designed so that this could be done. However, there is no mention of it in the manual.

You sort of had to be a woodworking insider, and read the right column? And as you know, that hardly describes me...

My Bosch is in storage- when I see it next, I'll have a close look. But to me, it's obvious that this was some sort of design consideration for the DWS780 for those more "knowledgeable" and "practiced in the arts" to get a bit of extra utility out of their DWS780.

Of course, being the wires and sparks guy, I have no right to be messing around with this, but then, this is WHY I bought the DWS780 to begin with, for the Isiris, because I knew I would need it. I don't know if this will work on any other DeWalt models. The key is the height of the back fence support (1-1/2") and those relatively short tabs at the back, plus the through holes that you can put the 3" long CSS Examples screws through.

[JonMarsh]

John this is an excellent writeup on how to get the deeper cuts. Is this something that can easily be attached in the woodworking tips section of the forum? I don't know how, or know if I can do that...

Thanks again for all of your great contributions!!

The deed is done!

Thanks for prodding me to get it done- I included my response to Steve Manning, also.

:T

[ColoradoTom]

Good Lord!!!!!

Leave the site for a few years and come back and find out Jon is dismembering miter saws and still working on the Isiris/Osiris projects!!! It's deja vu all over again!!

ColoradoTom

[CADman_ks]

The deed is done!

Thanks for prodding me to get it done- I included my response to Steve Manning, also.

:T

Thanks again for your contributions!!

[JonMarsh]

Good Lord!!!!!

Leave the site for a few years and come back and find out Jon is dismembering miter saws and still working on the Isiris/Osiris projects!!! It's deja vu all over again!!

ColoradoTom

Life is like a circle, yes?

Now that I'm retired, since early 2021, I'm getting back to unfinished matters... deferred gratification... there's a lot more waiting in the wings, but these items, an Isiris update (more performance, lower cost) and getting the Osiris upper range measurements done (mainly for MB, but who knows what other fallout might occur? Possible three way... )

And I'm still not really "up to speed", as we're in our second rental (first one sold out from under us) up here in Idaho, but projected to move into new home under construction since June this March. 3rd party inspection scheduled for late February.

As a few of my work colleagues observe, a lot of banked deferred gratification coming due...

[ColoradoTom]

Life is like a circle, yes?

Now that I'm retired, since early 2021, I'm getting back to unfinished matters... deferred gratification... there's a lot more waiting in the wings, but these items, an Isiris update (more performance, lower cost) and getting the Osiris upper range measurements done (mainly for MB, but who knows what other fallout might occur? Possible three way... )

And I'm still not really "up to speed", as we're in our second rental (first one sold out from under us) up here in Idaho, but projected to move into new home under construction since June this March. 3rd party inspection scheduled for late February.

As a few of my work colleagues observe, a lot of banked deferred gratification coming due...

Well "Life is a circle" is certainly accurate. I'm just about to get back into DIY speaker building again now that my wife and I are trying to turn our business over to our daughter. Hoping I can (partially) retire in the next three years.

I've been upgrading the inside trim in our house (something I did when I was building houses with my dad) and at this point I think we should have just moved and bought a new house. Cost of materials is crazy and that's if you can even find decent stock!

I've spent the last couple of years recovering from multiple surgeries related to physically abusing my body since high school (three hernia operations, blown disc leading to microdiscectomy/laminectomy resulting in permanent nerve damage to my left thigh) - I'm slowly learning that I need to stop lifting lumber that is heavier than me!!

Been getting by with a pair of OB speakers (Pure Audio Project Quintet Horn1) and truly loving Roon, Tidal, and Qobuz. I upgraded my shop with 240V lines, multiple Festool items, and a SawStop tablesaw. VERY interested in the Isiris project!! I've got ~4000 board feet of lumber (cherry, walnut, ipe, tigerwood, butternut) and 500 sq ft of prime rosewood veneer!! Itching to make some sawdust!

Tom

[Swimerz]

I just discovered this interesting thread that features Accuton drivers. I thought you might enjoy my recent all-Accuton build that uses the AS190-9-251 cell woofers, C90-6-724 cell midranges and C25-6-158 cell tweeters in a D'Appolito configuration with all active/digital crossovers. I call the system Apex, and it is supplemented with four 18" and one 15" sub woofers. Here's a link to a video of my Powerpoint presentation to my audio club. https://www.youtube.com/watch?v=w-SLYX43LGo

[JonMarsh]

I just discovered this interesting thread that features Accuton drivers. I thought you might enjoy my recent all-Accuton build that uses the AS190-9-251 cell woofers, C90-6-724 cell midranges and C25-6-158 cell tweeters in a D'Appolito configuration with all active/digital crossovers. I call the system Apex, and it is supplemented with four 18" and one 15" sub woofers. Here's a link to a video of my Powerpoint presentation to my audio club. https://www.youtube.com/watch?v=w-SLYX43LGo

I'll have to put that on my list to check out!

[JonMarsh]

Well "Life is a circle" is certainly accurate. I'm just about to get back into DIY speaker building again now that my wife and I are trying to turn our business over to our daughter. Hoping I can (partially) retire in the next three years.

I've been upgrading the inside trim in our house (something I did when I was building houses with my dad) and at this point I think we should have just moved and bought a new house. Cost of materials is crazy and that's if you can even find decent stock!

I've spent the last couple of years recovering from multiple surgeries related to physically abusing my body since high school (three hernia operations, blown disc leading to microdiscectomy/laminectomy resulting in permanent nerve damage to my left thigh) - I'm slowly learning that I need to stop lifting lumber that is heavier than me!!

Been getting by with a pair of OB speakers (Pure Audio Project Quintet Horn1) and truly loving Roon, Tidal, and Qobuz. I upgraded my shop with 240V lines, multiple Festool items, and a SawStop tablesaw. VERY interested in the Isiris project!! I've got ~4000 board feet of lumber (cherry, walnut, ipe, tigerwood, butternut) and 500 sq ft of prime rosewood veneer!! Itching to make some sawdust!

Tom

Life can definitely be "rugged and rude" at times, and you sound like you've had your fair share, but just keep forging ahead!

I can relate to the back stuff- my rock and roll days did a number on my L5/L6 disk, but that was repaired via a microdiscectomy about 15 years ago, when that was a really new procedure! (I got luck getting referred to a doctor who was one of the earliest in the SF Bay Area doing that- full healing still took over a year, but I had surgery on a 75% occluded hernia on Tuesday, and on Friday flew out to a conference on the East Coast to present a paper- initial recovery from a laminectomy is much longer.

My repair efforts lately are one hip replacement in 2017, and another in 2020. Too much heavy duty hiking on top of the rock and roll- and my long term gal at the time had just had the done a couple of years earlier, got her through that so I knew what to expect, but her excuse was way, way to much competitive amateur running- she had about 14 medals placing in the Devil Mountain Run for her age group in Danville. 1sts, 2nds, and 3rds. She passed away from pancreatic cancer in early 2018. But I'm still picking up and moving saws of various sorts, and guess what, I followed Steve Manning's example and got a SawStop, too!

There are a number of other interesting projects and efforts I've been doing with Steve and some of the other guys on the forum.

The "little" Ardent D uses some Accuton Cell woofers (very interesting parts) and a maple ply front panel with LBL sides, top, bottom and back; industrial design taking after the Vimberg speakers;

One cabinet finished here:




My pair for listening checks:




And the initial TTC concept of this design in the tensioned translam construction (before the updated front panel concept) that Steve put together (there have been other systems we've developed for this concept)




And a picture of Sven's HT room with the first TTC build he did plus the Ardent D Version:

[Scottg]

:T Sven's got something going on in his HT that I still need to do..

Black-out the areas around the screen. ops: (I get WAY to much reflected light off of the white surrounding walls/ceiling/and a white cabinet to one side.)

..he seems to have pushed further into 2-channel listening while I went the other way by pulling apart 2 separate 2-channel speakers systems to make my HT. (..given Covid and going to theaters, this choice worked out pretty well for me these past 2 years.) :B

[JonMarsh]

Yeah, seems he's got a dedicated room (basement?) and can do the full blackout.

I'm not going to have that freedom in the new place, and ambient light control will be an issue. But I ordered and received a Screen Innovations Black Diamond with a gain of 1.4, so we'll see how that works out with the Epson 4K projector.

I just saw in the last week or two that JVC has introduced a new "conventional" 4K D-ILA projector with great specs and a remarkable price considering what the same performance would cost 3-4 years ago. Maybe that will be a viable candidate in a few years. There's a fair amount still to evaluate about that- and a lot of other ground to cover between now and then.

I tend to go 2.1 or 3.1 on HT, and given the room this will be going in, that's all that's likely practical again, but my Ardent D's will almost certainly be the HT mains! Though I have a plan for a line Array system that would go in the corners with a very small footprint, which might make Liubov happier. WAF and all. We'll see.

What I haven't really figured out is where I'll put the music mains- it's most likely (in my mind, currently) going to be at the back end of the great room, at 90 degrees to the HT setup, firing back down to the front of the house.

This floor plan might make it easier to visualize...

OTOH, getting it to all work together may still be a challenge!

[Scottg]

Unless you need your listening to be "communal" (which can be a placement problem with spouses unless you go to bed later than your wife - when you can start listening).

As long as you don't need the extra bedrooms, I'd probably put the listening system as far from the Master Suite as possible: Bedroom 2. Listening Seat abutting the wall right next to Bath 2 Sink (with Listener looking toward window), with speakers placed about *60% of the way into the room (from the window) and about 7 feet apart (effectively "centered" in-room). Closet should have lots of hanging clothes and below them as much of a stack of rockwool as possible (turning the closet into an effective bass absorber). I'd specifically get a tight-seal (all around it) SOLID door for that room and put in rockwool in the hallway wall near the door. I'm guessing that would put you about 6 feet from either speaker and up against the wall (for good bass support) - both of which would provide more spl to you and less to your home. With you so close the "rear" wall it would also reduce secondary reflections. Finally I'd make some fabric-over-rockwool panels to cover the "rear" wall and the "side" walls "up" to the front baffle of the loudspeakers (basically "blanketing" the area around your listening chair up to the speakers, except perhaps the ceiling). Adjusting the speakers as necessary closer toward the window (further from the listening chair) to get the driver integration you need for the design.

*about in-line with where the closet door is shown "open". Note thought that the sliding closet **door should be closed to provide a similar reflective surface as the parallel exterior wall for even channel balance (with the "right" speaker about 2-3 feet from the closet door and the "left" speaker about 2-3 feet from the exterior wall).

**also if the sliding closet doors are hollow-core, get rid of them as well and switch to a solid door(s) (..which often requires a bit beefier hardware for the slider).

I always do this sort of placement with my 2-channel listening (when possible) - subjectively I get more depth, a little more width, more bass, and a more dynamic result.

[theSven]

:T Sven's got something going on in his HT that I still need to do..

Black-out the areas around the screen. ops: (I get WAY to much reflected light off of the white surrounding walls/ceiling/and a white cabinet to one side.)

..he seems to have pushed further into 2-channel listening while I went the other way by pulling apart 2 separate 2-channel speakers systems to make my HT. (..given Covid and going to theaters, this choice worked out pretty well for me these past 2 years.) :B

When I first started this hobby I had the theater on the other side of the basement. 5 years later I decided I wanted it in a dedicated room. That meant I had to move the pluming and electrical for the washer/dryer, install a new dryer exhaust, and gut the room. Funny fact that when I gutted that room I finally found out why it was so cold in the winter. You could see daylight through the wall where the line to the heat pump goes out. With the pain on the outside you couldn't tell, but from the inside it was clear that it was a material taht did not seal and let in the cold or humid summer. After sealing that all up the room can be enjoyed.

I have 5.1 setup, but the goal that I had was to have a very nice 2.0 for listening to music and also being able to enjoy movies. I have been working with Steve and Jon AKA SMJ Audio since 2019. That journey began after my friend moved into a house who had lived in a townhouse for years. His wife couldn't stand looking at his wharfdales in the master bedroom. He didn't want them out of the room for fear of the 3 young kids ruining them. I asked if I could put them to use and he let me use them for 6 years.

I had been looking at the Wavecore Ardents and the Bordeaux. Then Steve posted the thread on his new adventure. Some could consider this Karma... There was mention of wood work for cabinets and I thought that would be an excellent idea to get a DIY build done faster to use since the Wharfdales had to be returned. Steve mentioned he was working on a project that would be ready soon and I could come down and hear. In Nov 2019 I drove down for a listening session with the Calliope. 1 hour later I knew I wanted a pair and I could have a kit that I could assemble for that DIY feel while also knowing from the OCD side that all the cuts were perfectly done and everything would line up.

I knew I still wanted to get a true reference speaker though, and the Ardent D's were high on the list. By August 2020 Steve said the build could begin. The next adventure began and that led to the photo John shared above when I got the Ardent D's operational in December 2021. The next project I have is to build a new center channel. Steve has shared the drawings here on the forum, but I think they have the older baffle which is recessed in like the Calliope. Steve has updated the design to have the baffle flush with the ribs like the Ardent D's. Once the CC is completed I will be asking Jon and Steve for help on making new surrounds for the sides and ceiling.

In a nut shell yes I did push a bit harder to 2.0, but I still want to have a functional HT setup. I will probably be investing in a 2 channel amp sometime soon. I really want to get a Purifi build, and I have been following some of the DIY's, but haven't pulled the trigger on anything yet.

[JonMarsh]

Well, good news, I found some binding posts in storage here, because the fancy "premium" binding Dayton binding posts don't fit in the Dayton binding post plates- literally, a square peg in a round hole.


The more serious problem that has been discovered this morning is that the CNC front panel that Micheal Bell sent me to create a test cabinet for getting driver measurements has a "slight" issue- the hole for the midrange driver is NOT large enough to actually pass the C168-6-990 driver magnet assembly through... at least not the one I have.

And when you consider how the driver is constructed, this is not a trivial issue...







Another unfortunate issue with this driver is how the connections are made- the tabs go closely right over the field plate assembly, with very little clearance.

And the updated information from Accuton recommends a series of semicircle scalloped cut outs in the mounting area, to provide pass through from the side exposure of the driver to the enclosure. I suspect this has a big impact on how the rear wave is handled.




In my own rectangular test enclosure built previously, I mounted the driver on 1/4" phenolic sheet which was glued to a more conventional baffle with a larger rear opening. This solved the mounting issues fairly well, including the issues Accuton has more recently raised.

Well, let's see what I can do with Michael's front panel...

[JonMarsh]

Moving forward...

This reminds me of my favorite old "Gentle Giant" album and song (extra points to anyone who remembers who they were) "Free Hand" (and triple extra points to anyone that can recall the lyric for the first line of the first verse (trying to make this easy...).

There's even a 35th Anniversary remaster version of this album out, which includes live cuts from concert (not on the original album.)

Finally, 5x points to anyone that's actually seen them in concert (besides me, that is...) OR to anyone that has the Steve Wilson 2021 remix. ( you can actually get that at Target online right now...)





Done with a DeWalt trim router, hand held... aka, "Free Hand"


Just 1/32 off the inside diameter near the bolts; the rest based on a 78mm/3" Diameter circle, roughly.




Probably not my best work, but considering the conditions, not my worst, either.




And it passes the important test.

[technodanvan]

Scary stuff going freehand with a router. I've done it before too, but I'm never a fan of it!

[JonMarsh]

well, things are moving forward... after a trip to the hardware store for some different sizes than I'd previously estimated.




Buttoned up tight now.


Impedance data looks solid for the C168-6-990





As does the Scanspeak 7140 tweeter.




Plan is to get the AS250 cabinet loaded up tomorrow morning, and get some measurements.

[Scottg]

:T

-It's nice to see detail on expensive drivers, even if it's not always great news. Gives a better perspective on what's excellent and where you can run-into some problems with design or build. 8)

[JonMarsh]

Interesting factoids

The Accuton AS250 woofer has a diaphragm diameter of about 9-1/2".

The Seas SLR26R PR has a diaphragm diameter of about 6-3/4".


Both are nominal 10" devices.

This is combined in a 2 cu ft test enclosure.





The modeled performance for a 56L net enclosure is:




But the built test enclosure is 56L gross- so extension and tuning will be off from this estimate.

[JonMarsh]

A lot of measurements were done yesterday afternoon, including far-field and far-field polar, and quasi near field with distortion.

For reference to the basic driver characteristics, here are quasi-near field measurements:

Scanspeak 7140 Be tweeters (purchased for the Kurosawa project; chosen by MB for his Osiris project)




Typical Scanspeak distortion pattern for this larger Be tweeter- that is, significantly higher HD2 than HD3. Overall very low distortion, but displacement related distortion starts to show up below 2kHz.


Accuton C168-6-990




Correct mounting and venting technique is necessary to achieve best results. Resonance amplification of distortion products is an issue just above 2kHz, though level is still fairly low. Due to rise in HD3 and fall off in polar response, upper crossover should probably not be any higher than 2kHz.



Accuton AS250-9





With a high order crossover, and a break up notch filter, operation up to 400Hz could be considered, but 250Hz to 300Hz is most likely a better choice. The breakup is very high Q and produces a distinctive honk- standard filters will not be adequate. Like other Cell woofers, the off axis response is surprisingly extended for cones of this diameter. But then, it isn't a cone, but rather, a dome.

[JonMarsh]

Polar measurements

A quick review of initial polar measurements...


Scanspeak 7140 -





I think some of the behavior on axis is due to diffraction and edge effects from the cabinet, based on polar measurements done for the Kurosawa project, for which these tweeters were purchased.



Accuton C168-6-990





These measurements are pretty consistent with those previously made in a more conventional test cabinet.


Accuton AS250

Updated measurements

[JonMarsh]

Modeling the AS250-8-552 for enclosures.

Some enclosure modeling may be helpful for those considering the AS25-8-552 for different tasks- whether as a mid bass driver or a "full range" woofer.

Now, as a mid bass driver, like MB is using it, things are pretty simple- go sealed, and a net enclosure volume of ~28L will put you in the ball park for a maximally flat alignment with an Fb of about 50Hz.




But what if you want to extract the "maximum" full range woofer performance from this single 10" driver (MSRP about $1500 these days).


Well, things look a bit different, and a fairly optimal configuration is in a 70L enclosure with 2x RSS265PR with a single disk weight (275G MMS)











This is not a tiny enclosure for a nominally 10" woofer, but with an Fb below 30Hz, an an output capability of about 105 dB down to that cutoff, you are getting some reasonable output- an lord only knows you won't see AS250's at every local regional DIY meet!

I'm curious enough about the possibilities that I will likely build a net 70L test cabinet in this configuration after we get moved in and settled- perhaps a full system build, but likely using the C168-6-890's tucked away somewhere in storage, and BlieSMa T34B's tucked away too, (the 7140's are earmarked for the Kursowa build, still to be completed.)(lots of deferred plans and deferred gratification on hand..)

[JonMarsh]

After updating the AS250-8-552 measurements, to reduce reflections from the positioning turntable, I have finished an initial "flat neutral" crossover proposal, which has been forwarded to MB.

For fun, I setup VituixCAD 2 on my LG Gram 17, so I could work on the island in the kitchen great room, and after reconfiguring some things from my normal 4K setup, I found that worked pretty well- the LG Gram has a very nice display as PC laptops go- my standard of comparison being the Dell XPS15 I have as a dedicated controller for the Audio Precision analyzer.


For the obvious reasons, this bears some similarity to the recent Isiris crossover update, though note that driver impedances are all different, as are component values.






The target for this design pass was a flat profile at relatively "near" far field. A voiced version will be prepared soon.




This is the calculated SPL response with midrange phase inverted, showing fairly good nulls from phase cancellation. It is can be a balancing act between deepness of phase nulls and overall flatness of response. That latter takes precedence, to a degree.

[JonMarsh]

Supplementary plots of interest

Next up we'll have the Filter transfer function, the impedance, and estimated GD+Phase...


Filter transfer function



As you can see, the midrange transfer function must incorporate substantial baffle step compensation, given the target crossover frequencies and baffle sizes.


Impedance

The minimum impedance is no lower than about 5.4 ohms, and is usually at 6 ohms or above. LCR shunt networks could reduce the impedance peaks, but with any reasonably low output impedance amplifier that seems like an unnecessary embellishment. the impedance peak in the 34 kHz area is for the upper breakup mode suppression.





GD+Phase

[JonMarsh]

Voiced crossover network

As promised, a "voiced" version of the crossover network...





Blink and you might miss the changes...