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

[meb46]

Ergo - yep, that's what I have been using, but I suspect my issue is my high expectations that the DXF/DWG get exported to the same resolution/accuracy. I'm using the same settings as you, just a little concerned at the deviation to actual. I guess I wont know until I fire up the router and make some sawdust...

[meb46]

Finally have the completed part drawings... Private Messenger me if anyone wants to see the PDF drawings.

Next stop, the start of nesting files for the CNC Router!

[JonMarsh]

On the flip side of things, as part of the development "exercise" (as in practice and repetition of a technique) I put the original Isiris cabinets through a 00 - 60 degree measurement set, partly for practice, and partly to follow up on my earlier "what ifs" for adding the mid bass module to the existing design, as proposed in VituixCAD earlier in this thread.

I did some polar measurements previously in the development of the original design, but didn't have a tool at that time with which I could conveniently use that data in the design process.








The original design used crossover frequencies of 350Hz and 2500Hz; I might tweak that to 2400Hz in this implementation, the main potential update is moving to an LR6 instead of nominally LR3 transfer function. I have better point of acoustic origin data now, too, so that should help.

So, I'm going to repeat the design process, based on these measurements and my initial assessments in VituixCAD just for the three way configuration, but looking at building off that for the four way setup. I don't know for certain if I'll actually build it, or see how much I can accelerate the construction of the mid bass module- I have enough LBL, and think I have enough tooling grade BB ply in storage to cover this, but I've got to check. And get up to speed on Fusion 360- I've promised myself I would NOT take the easy way out and do this in Shark, as I want to work on developing the collaboration aspect.



And as an experiment, as I've modeled the AS190 already in VituixCAD, in a basic sense, now I plan to add the enclosure baffle step model, for a specific enclosure, and compare that to the driver measured in that enclosure; as the AS190 is claimed to be very linear between 100Hz and 1kHz, this should be an interesting test case. in the completed system it would have a crossover no nigher than about 450 Hz, so I expect fairly good agreement between the two. I'm going to be trying an odd driver mounting setup for the drivers (more on that later) but as for the combined diameters I shouldn't have any beaming issues until about 900Hz, I don't expect problems with that. (famous last words, right?)

[JonMarsh]

This post may only be of historical interest to a very few people- if that- but having measured things all over again, and generated scaled minimum phase polar data and sorted stuff out nicely, I've also gone back to the original Isiris designed in VituixCAD and worked up an updated release, after looking at a lot of details.

Mostly it's based on insights from using the software and being able to see so many things all at once- that, and tweaking crossover points (tweeter from 2400 to 2000), doing some things to the transition band behavior to lessen the workload on the drivers (conjugate networks that are half way to being elliptic networks, and an octave beyond the crossover point crank up the attenuation) and more attention paid to attenuating the woofer break up and controlling the slope. you know, a lot of anal retentive OCD stuff that often doesn't get paid much attention due to cost- even at the DIY level, much less the commercial...

And I've also checked it to be sure I can scale up the midrange and tweeter level 5 dB with minor modifications for the Osiris Jr. Build. That way it will match up with paralleled AS190 Accutons on each side, after they've had BSC applied.







will I build it? Good question....

Given the ability to translate it to the new update, yeah, I should be looking for coins under the sofa cushions and seeing about ordering some parts...

[JonMarsh]

These guys are getting to be real favorites for me...

http://www.hificollective.co.uk

Check out the range of parts they carry, and prices. Just placed another crossover part order with them. My 3rd so far. and biggest... just caps and resistors, but at good prices.

They have a lot of good parts for electronics DIY, too.

[JonMarsh]

More parts ordered, and a more "proper" working schematic is drawn up...




oops, need some additions, but it's getting close- no time now...

Updated.

Again. 5/19/2016

[JonMarsh]

Schematic updated; parts order from UK shipped, should arrive tomorrow!

Hypex DS8.0 ordered for testing. Should fit nicely into one of the 1 cu ft PE sub cabinets I have...

[JonMarsh]

HiFi Collective in UK delivers the goods...




These arrived today- ordered two days ago.

They have a wide selection, good inventory, good prices, deliver fast- what's not to like? They're getting business now that Madisound and PE used to get... because they're more competitive on every front- stock more Mundorf parts than Madisound, better prices than Madisound, stock more Jantzen parts than Parts Express, and better prices than Parts Express- and they deliver often in just one day, at a very competitive rate.

Hard to beat, in my opinion- thanks to all the guys that got me to start looking at European vendors more closely.

[Steve Manning]

HiFi Collective in UK delivers the goods...



These arrived today- ordered two days ago.

They have a wide selection, good inventory, good prices, deliver fast- what's not to like? They're getting business now that Madisound and PE used to get... because they're more competitive on every front- stock more Mundorf parts than Madisound, better prices than Madisound, stock more Jantzen parts than Parts Express, and better prices than Parts Express- and they deliver often in just one day, at a very competitive rate.

Hard to beat, in my opinion- thanks to all the guys that got me to start looking at European vendors more closely.

That's crazy fast on delivery .... I can't get a letter delivered across town in twice that time.

[cochinada]

That's crazy fast on delivery .... I can't get a letter delivered across town in twice that time.

x2 but you must have payed extra for such fast delivery.

Talking about European stores there are quite a few. I've already mentioned my favorite Compagnie Acoustique de Belgique and there is this other one as well. Both have better prices but don't have this latest model of Alumen Jantzen caps.

[JonMarsh]

For the big cap order, the shipping was about 20 pounds sterling, or about $30. Two days England to CA. For the cap order just before that, much lighter weight, it was 15 pounds sterling, and I got that one in one day. One day. I have no idea how, but it seems FedEx is determined to make their international priority courier service a fairly attractive proposition. It's cheaper than two day shipping in the US from my favorite vendors.

[sdl2112]

Hey Jon...I see you are using an electrolytic cap in the mid trap circuit. What's your thoughts on using them in circuits outside the passband or in impedance flattening circuits for tweeter, mid or woofer resonances.

[meb46]

Christmas definitely came early this year... finally the full suite of drivers for the big boys...

Scan Speak D2908
Accuton C168
Accuton AS250
AES TD15S x2

Now I just need some progress on the CNC Routing and I can then crack out some glue... maybe this week?

[cochinada]

For the big cap order, the shipping was about 20 pounds sterling, or about $30. Two days England to CA. For the cap order just before that, much lighter weight, it was 15 pounds sterling, and I got that one in one day. One day. I have no idea how, but it seems FedEx is determined to make their international priority courier service a fairly attractive proposition. It's cheaper than two day shipping in the US from my favorite vendors.

That's very reasonable and much cheaper than the equivalent cost from PE to Europe. :T

Christmas definitely came early this year... finally the full suite of drivers for the big boys...

:yeah:

[Steve Manning]

Christmas definitely came early this year... finally the full suite of drivers for the big boys...

Scan Speak D2908
Accuton C168
Accuton AS250
AES TD15S x2

Now I just need some progress on the CNC Routing and I can then crack out some glue... maybe this week?

[ATTACH=CONFIG]25840[/ATTACH][ATTACH=CONFIG]25841[/ATTACH][ATTACH=CONFIG]25843[/ATTACH]

Very nice Mike ...... seeing those 15's, those speakers are going to be some beasts!

[sdl2112]

I'm really looking forward seeing your build come together. Those Accuton bass magnets are huge!

[JonMarsh]

Hey Jon...I see you are using an electrolytic cap in the mid trap circuit. What's your thoughts on using them in circuits outside the passband or in impedance flattening circuits for tweeter, mid or woofer resonances.

Pretty much the only places I use them are impedance conjugate networks for midrange or mid bass driver Fb; usually in the situation that there is a crossover ahead of it and we aren't really seeing much signal level anyway, and the network is just to trim that level to where I want it- I'm not one of those guys who only pays attention to the top level SPL magnitude, but also to what the drivers are doing 20-30 dB down, as I find that influences the sound. Linkwitz didn't fix the issues with the W22 resonance properly (in my mind) until a few years ago, and found that that did a nice job of clearing up part of the presence range response in the Orion's.

In this case, I'm modifying an impedance conjugate network by lowering the resistance to also modify the roll off rate and reduce the level the driver is driven at, for the tweeter and the midrange. Sort of like cheating and increasing the order of the crossover network once past the initial transition band, but not spending more money on crossover components. I think that's particularly desirable for the tweeter.

With unlimited money and unlimited space, (think the old Avalon Osiris) you could do all that with film caps, but then the results is huge, and hugely expensive (note the crossover box behind them in the pictures in the Tesseract thread). I think this is reasonable...

[Steve Manning]

For the big cap order, the shipping was about 20 pounds sterling, or about $30. Two days England to CA. For the cap order just before that, much lighter weight, it was 15 pounds sterling, and I got that one in one day. One day. I have no idea how, but it seems FedEx is determined to make their international priority courier service a fairly attractive proposition. It's cheaper than two day shipping in the US from my favorite vendors.

I think they must be using Hogwarts Airways to get that kind of delivery .....

[sdl2112]

Pretty much the only places I use them are impedance conjugate networks for midrange or mid bass driver Fb; usually in the situation that there is a crossover ahead of it and we aren't really seeing much signal level anyway, and the network is just to trim that level to where I want it- I'm not one of those guys who only pays attention to the top level SPL magnitude, but also to what the drivers are doing 20-30 dB down, as I find that influences the sound. Linkwitz didn't fix the issues with the W22 resonance properly (in my mind) until a few years ago, and found that that did a nice job of clearing up part of the presence range response in the Orion's.

In this case, I'm modifying an impedance conjugate network by lowering the resistance to also modify the roll off rate and reduce the level the driver is driven at, for the tweeter and the midrange. Sort of like cheating and increasing the order of the crossover network once past the initial transition band, but not spending more money on crossover components. I think that's particularly desirable for the tweeter.

With unlimited money and unlimited space, (think the old Avalon Osiris) you could do all that with film caps, but then the results is huge, and hugely expensive (note the crossover box behind them in the pictures in the Tesseract thread). I think this is reasonable...

Thanks for sharing your thoughts on electrolytic cap usage. I would like to avoid them but as you say size and cost becomes an issue. I'm also using impedance conjugate networks to increase the roll off at the low end in my Duelund network. It does require quite a demand on the drivers and if I can accelerate the roll off after 20db or so I think that will lower driver excursion demand.

[JonMarsh]

Thanks for sharing your thoughts on electrolytic cap usage. I would like to avoid them but as you say size and cost becomes an issue. I'm also using impedance conjugate networks to increase the roll off at the low end in my Duelund network. It does require quite a demand on the drivers and if I can accelerate the roll off after 20db or so I think that will lower driver excursion demand.

Yeah, when I've done Duelunds I've always found the driver response needs a lot of massaging to get the desired acoustic transfer function, whatever value of aleph you've chosen... I'm thinking about a couple of projects that might use that approach again, and being very careful about driver selection as a result, in order to lessen the issues getting things in line... Motus woofers, mid woofer, and still debating the tweeter...

[meb46]

Dust dust dust...

Finally some progress... well some Bamboo dust anyway...

All of my CNC routed internal parts and sides have been completed, and I can now start the test build up process of the main cabinets. Currently I am just working through the clean up of the parts, the internal brace chamfering, and checking dimensions. As per usual, the CNC accuracy is awesome! Bamboo is proving to be relatively easy to work with, and aside from the occasional burn mark from machine tool blade sharpness, I am really liking it. A couple of things thus far that are coming to reality...

1 - The size of these things is already starting to make me a little nervous. Its mainly the width, at 500mm they are BIG.
2 - The associated weight of the overall structure has made me nervous on the glue front. I am therefore switching to using epoxy glue through-out for additional strength and also incorporating the use of biscuits in most of the side panel joints.
3 - They are going to be heavy... just as well I have a fork lift and 20T overhead cranes to move them throughout the build process.

A few photos to show progress...

[meb46]

Apologies for the orientation of these photos... will need to correct!

More photos coming this weekend after I make some additional progress. Also hoping to have some of my bench saw cut panels complete and that will start to give a better feel for overall height and side profile.

Better get some epoxy ordered!

[JonMarsh]

Gee, Mike, I dunno, forklifts and 20T cranes? Maybe this is taking DIY a bridge too far... :W

That's something I do think about frequently these days- my Bamboo Isiris were somewhere around the limits of cabinet stuff that I feel I can reasonably deal with- I think as long as you don't initially glue these all together, but keep it as a stack, then it shouldn't be too bad. Of course, I'm at that age where I'm not getting stronger anymore; were I 20 years younger I might think otherwise. Think about that Tidal Akira- I wonder what those weigh, haven't found specs online- but the slightly larger Contriva G2 from Tidal "weighs in" at about 385 lb, which I KNOW is beyond what I care to deal with.

In more relevant news, a sample of the Hypex DS8.0 arrived yesterday, but I was so busy with my to-do list and work that I haven't had time to unpack and admire it. Hopefully this evening...

It's like I considering some of the loudspeaker systems my friend in Munich as been interested in, or even what he has right now (Eggleston Savoy's) - when the speaker on each side gets into the 200-300 lB range and up, like some of the big Magico's, well, you just have to take a different approach to the concept of mobility or installation. I think you're crossing that threshold, too. But then I think you were approaching it with your version of our last joint build.

[Steve Manning]

Very nice Mike ..... Going the CNC route, all of a sudden you have a pile of parts. Those do look they are going to be some beasts ....... that fork lift will come in handy, does it fit in your living room?

[JonMarsh]

Very nice Mike ..... Going the CNC route, all of a sudden you have a pile of parts. Those do look they are going to be some beasts ....... that fork lift will come in handy, does it fit in your living room?

Good point, I forgot to ask him that- and can you get it up the stairs to your apartment/condo? The forklift, that is? :W


I know, I know- my problem is that I'm just jealous of Mike- I can't hardly get space for a cubicle with enough room for my gear at work, in spite of my global grade (almost all others at my grade have separate offices, but technical ladder don't get no respect...) and he's filling a shop floor with his goodies! :W

Well, I just better put you guys with all your fancy schmancy CNC like Steve and Mike on notice that I'm gearing up to retailiate- I did just recently buy a DeWalt DWE7491RS saw... I bet you're all trembling in your booties, or more likely, laughing into your beer!













Maybe we need two sections to the forum now? The CNC builds, and the TS models... :B

[JonMarsh]

Mike- do you have that 358 cell tweeter around still? would like to get some test data on it.

[dar47]

Gees I didn't catch you were going to use LBL for bracing, thought BB! It will be heavy but it will be quiet (well damped) and silent to the touch when they roar, me likes.:T

[sdl2112]

Mike...your not playing around.:E Looking good. What finish do plan for these?

[Evil Twin]

Though matte automotive black or a piano black finish would be very visually striking, I believe Mike sees himself as a light side practitioner of the art, and most likely might repeat the finish of his last build.

[5th element]

Wow that's a lot of driver!

[Evil Twin]

In the local system vernacular, I believe the expression goes, "If some's good, more is better, and too much is just enough".

[meb46]

Haha - Love the expression "If some's good, more is better, and too much is just enough". I think that is probably spot on with respect to my way of thinking

Jon - Accuton 358 Tweeter found a new home a while back. I was lucky to have someone take this off my hands given they are sold in matched pairs. I believe the new owner was happy with it, and I suspect it was for testing purposes. I'm looking forward to the DS8.0 review, this is obviously still an option for my new construction. With respect to your new bench-saw... what I wouldn't give for one of those right now. The downside of the CNC is the complex angles on the sloped surfaces. A CNC doesn't really do anything other than 90 degree angles. I have outsourced the cutting of these panels and hope to get them back this coming week. All it really takes is a super accurate bench saw and a protractor... I sadly lack a bench-saw of suitable caliber. Furthermore... I didn't even use my own CNC, I lazily outsourced it to a supplier of mine as they have a much larger machine, and frankly I was running shy on time. They have turned out well, so once again happy to push the CNC machining approach... its just so easy.

Steve - Luckily, I have plenty of room in my living room... downside is that I can't bring the forklift into it, so I'm going to be up for some "struggle-town" getting them set up after completion!

dar47 - Given I had to order my Bamboo Ply from China and ship it to me in Singapore, I thought, what the hell, lets get enough to do the how cabinet in Bamboo. I got it for a pretty reasonable price, 20mm and 25mm for under $100 USD/sheet including freight...

sdl2112 - As the Evil Twin points out, I'm definitely on the lighter side of things, and not a huge fan of real wood veneer after my last experience. My wife and I prefer a very contemporary look, and after finishing my first set in a flat/matte white, I have grown to really like it. So, flat/matte white it is again. It also goes quite well with the Black/White contrast of the Accuton Drivers. It may possibly even me a lacquer finish this time, or an automotive 2Pak Matte white... option options...

Todays fun was the completion of mobile cradles for the sub cabinets. I figured these are going to weight an impossible weight, so I have two sets of cradles. One to house them lying flat on their back, and the second standing.



Secondly, I wanted to have really accurate reference jigs to build the internal bracing structure... so I have knocked up to jigs to glue the Mid/Tweeter and Bass internal bracing. The glue and clamps have made an appearance, and should be all ready for my first set of epoxying on Monday next week...

[Steve Manning]

Holy crap Mike that's a shop and half ...... love the new carts.

CNC is easy if you have someone up to speed with their machine and is used to doing the type of work your asking of them. Other wise it can be a learning experience shall we say.

That's a heck of a deal on the bamboo, as in cheap to what it is here. How is it for void issues?

[JonMarsh]

Long weekend here, but a lot of things to do-

I will bench the DS8.0 for the filters and EQ performance, and also do a 100Hz power sweep versus distortion (1kHz seems a bit pointless, eh?) Mostly I expect this is going to work pretty much like the DS4.0 I used on GF's sub, just more powerful and with balanced inputs to boot. When I'm setup for that, I'll also have a Y XLR bridging cable finished, and will run the M22 through it's paces. I have the feeling this weekend will mostly be putting test hardware and fixtures together; testing might not happen until later next week. We'll see- there's a variety of stuff going on, including a new driver test fixture.

I almost have that survey document finished to send you too- that's been an evening project when it's too late to do more hardware work.

Glad you found a home for the 358, even though it leaves me searching online for data without luck. (one site called Testing Loudspeakers show an unboxing in what I think is Polish, but no testing.) Xmas is rated +/- 1.2 mm, which if true would give them pretty stellar low end distortion performance, but that's not what I see in the measured Accuton results. So I have some thinking to do about sourcing and testing- those 7140's are still looking pretty good, but I'm going to do a motor evaluation against the Transducer Labs, since I can now get the Be version of that from Solen.

[sdl2112]

Fyi...The TL Be tweeter is available from Meniscus for $267.84 vs $312.93 if I used the correct exchange rate for Solen.

[JonMarsh]

Thanks- last time I checked there they didn't have it.

[meb46]

Progress on Subwoofer Cabinets

Made some great progress in the last couple of days on the Subwoofer Cabinets...





First Cabinet fully assembled excluding the front Baffle...



Rear look of first cabinet...



Internal Bracing and Two cabinets complete...



Next steps are to line these cabinets with Bitumen and then Felt... Ordered these today!

All outer panels use biscuit joints... Purchased a new Biscuit Jointer and its officially my new best friend. Makes alignment and assembly of the panels very easy!

[Steve Manning]

Looking good Mike ..... yep I love my biscuit jointer as well ...... a very handy tool.

[JonMarsh]

My DeWalt biscuit jointer is indispensable....

Looking good, Mike- moving that ball well down the field! Congratulations!

[TEK]

When you are using a biscut joiner.
Will it make a exactly flush joint or will there be a little overhang that you route away afterwords?

[JonMarsh]

If you've lined everything up properly when cutting the biscuit slots, things should be exactly flush. That usually means having a very flat working surface as your cutting alignment point- a cast table/cabinet saw deck is good, so is a good beech work bench. (that's what I'm usually using).

[meb46]

TEK - As Jon says "things should be exactly flush". Its not only the alignment, but as you come to stand panels up on a side, the biscuits over enough alignment for things to hold together before clamping. It also makes your dummy fit pre-gluing really easy. Obviously, the flush edges means minimal sanding afterwards

Bitumen and Felt ordered and shipped, next steps are to line the boxes. I'm expecting the last couple of panels for the mid and upper cabinets today, so maybe progress on these cabinets over the weekend! Touch work...

[Evil Twin]

Made some great progress in the last couple of days on the Subwoofer Cabinets...

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[ATTACH=CONFIG]25925[/ATTACH]

First Cabinet fully assembled excluding the front Baffle...

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Rear look of first cabinet...

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Internal Bracing and Two cabinets complete...

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Next steps are to line these cabinets with Bitumen and then Felt... Ordered these today!

All outer panels use biscuit joints... Purchased a new Biscuit Jointer and its officially my new best friend. Makes alignment and assembly of the panels very easy!

Consider how attractive these enclosures would be in a matte black finish... :T

[TEK]

TEK - As Jon says "things should be exactly flush". Its not only the alignment, but as you come to stand panels up on a side, the biscuits over enough alignment for things to hold together before clamping. It also makes your dummy fit pre-gluing really easy. Obviously, the flush edges means minimal sanding afterwards

Bitumen and Felt ordered and shipped, next steps are to line the boxes. I'm expecting the last couple of panels for the mid and upper cabinets today, so maybe progress on these cabinets over the weekend! Touch work...

Thanks both of you. I have a cheap one just to test it out and it makes one cide overhang the other.
It might be that it just are that crappy, or maybe there make some adjustment

[meb46]

Cabinets are making good progress and the first couple of Baffles arrived today...





The Baffles need a bit of a tidy up and cant be attached to the cabinets until they are lined with Bitumen and Felt... next weekends chore!

Test Fitting of Drivers will also happen next weekend to determine if any modifications need to be made... hoping all is spot on! Fingers crossed!