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

[meb46]

Jon - you are a committed man, and I love it! I'm about to head to Ireland for 3 weeks over Christmas, so not much speaker work planned throughout that trip. I might leave a pile of other stuff for my machinist and metal finishing supplier on the next project... which I will start a thread on shortly!

[meb46]

Hit the send button too soon... I think the break over Christmas will be perfect for the Lacquer hardening process, so the enclosures will be ready for polishing by the time I return. Have had a fun weekend playing with the settings on the subwoofers, and the now missing significant grout in my internal brick wall, and will need to fix a few in ceiling light covers! Yep, the DS8.0 plate amps have "adequate" power

[cochinada]

Jon - you are a committed man, and I love it! I'm about to head to Ireland for 3 weeks over Christmas, so not much speaker work planned throughout that trip. I might leave a pile of other stuff for my machinist and metal finishing supplier on the next project... which I will start a thread on shortly!

Ah so here it comes that center speaker we were talking about. 8)

[meb46]

Ha, Cochinada... negative on the center speaker, I think I am nearly all "speakered" out, and I need to give my wife some time to adjust to the current setup. Focus is shifting to another part of the system whilst the crossovers are in design and the paint job hardens. More shortly... in fact in mere minutes

[JonMarsh]

Mike, save me some time looking this up, what is the internal volume of your AS250 cabinet, so I can get something from PE in the same range for testing?

BTW, I have an alignment worked out with three SLR26R passive radiators to turn that AS250 into a sub setup after I'm done testing for you!

And have a good time on your holiday trip to Ireland- that should be a nice break!

[meb46]

Jon - The cabinet volume behind the AS250 is 33.5L, this doesn't include any deduction for the volume of the motor and magnet structure consumes. One other thing, I have the AS250-6-552, so you will need to take into account the lower 6 ohm impedance. Just incase you don't have the details, I have added them below...

Re = 5.6033 ohms
Fs = 22.1359 Hz
Zmax = 110.2762 ohms
Qes = 0.2764
Qms = 5.1636
Qts = 0.2624
Le = 0.6928 mH (at 1 kHz)
Diam = 220.5397 mm ( 8.6827 in )
Sd = 38199.9984 mm^2( 59.2101 in^2)
Vas = 109.1387 L ( 3.8542 ft^3)
BL = 16.6383 N/A
Mms = 98.1879 g
Cms = 526.4869 uM/N
Kms = 1899.3824 N/M
Rms = 2.6447 R mechanical
Efficiency = 0.4024 %
Sensitivity = 88.0646 dB @1W/1m
Sensitivity = 89.6111 dB @2.83Vrms/1m
Krm = 1.860E-03 ohms Freq dependent resistance
Erm = 810.573E-03 Rem=Krm*(2*pi*f)^Erm
Kxm = 13.067E-03 Henries Freq dependent reactance
Exm = 675.350E-03 Xem=Kxm*(2*pi*f)^Exm


pct Fs-Hz Cms-um/N Vas-L Qms Qes Qts

25.0% 11.0680 2105.9477 436.5549 2.5818 0.1382 0.1312

31.5% 12.4234 1671.4917 346.4938 2.8980 0.1551 0.1472

39.7% 13.9447 1326.6638 275.0123 3.2529 0.1741 0.1653

50.0% 15.6524 1052.9738 218.2774 3.6512 0.1955 0.1855

63.0% 17.5693 835.7458 173.2469 4.0984 0.2194 0.2082

79.4% 19.7208 663.3319 137.5062 4.6003 0.2463 0.2337

100.0% 22.1359 526.4869 109.1387 5.1636 0.2764 0.2624 <- base TS

126.0% 24.8467 417.8729 86.6235 5.7960 0.3103 0.2945

158.7% 27.8895 331.6660 68.7531 6.5057 0.3483 0.3306

200.0% 31.3049 263.2435 54.5694 7.3025 0.3909 0.3710

252.0% 35.1386 208.9365 43.3117 8.1967 0.4388 0.4165

317.5% 39.4417 165.8330 34.3765 9.2005 0.4925 0.4675

400.0% 44.2718 131.6217 27.2847 10.3272 0.5528 0.5247

[JonMarsh]

Thanks much- saves me a bunch of time!

[mkc]

Hi Jon,

Sorry for going off-topic. A question regarding the measurements shown in #268. Are they spliced near- and farfield measurements or just farfield? I suspect farfield only as you measure off-axis also. if so, what gating time? I'm sort of impressed if they are farfield with long gating time and just smothing.

Mogens

[JonMarsh]

Farfield with gating, but long enough to preserve low frequency information, and using a Half Hamming window. Some care about positioning- measured in a tall ceiling room on a fairly high platform, and with extra moving blankets and down comforter's to minimize early reflections. I.E., the way I usually do it! (it's too cold out for outdoor measurements this time of year!)

I know lots of folks who do splicing, but I'm not personally a fan of the technique- makes some things look much better than they really are.

[Renron]

Meb46,
Those are spectacular. Quite the family of auditory nirvana your acquiring. I'm impressed with just the cabinet work needed.
Why are you using lacquer? Is it a true Lacquer or a modern urethane with a lacquer pseudonym?

Could the aluminum oxidation issue be resolved with and anti oxidation compound similar to what's used in Electrical Service Buss panels?
Ron

[mkc]

Farfield with gating, but long enough to preserve low frequency information, and using a Half Hamming window. Some care about positioning- measured in a tall ceiling room on a fairly high platform, and with extra moving blankets and down comforter's to minimize early reflections. I.E., the way I usually do it! (it's too cold out for outdoor measurements this time of year!)

I know lots of folks who do splicing, but I'm not personally a fan of the technique- makes some things look much better than they really are.

Thanks Jon. Sure is nice measurements.

Mogens

[JonMarsh]

Well, Mike will be happy to see my AS250 test sample has arrived- it's a fine looking specimen if I do say so, not hard to figure out why they cost so much...




This means I've got to get the test enclosure put together, I'll likely re-use one of the knock down sub cabinets if I have one I haven't cut a large hole in yet...

What I'm tempted to do, though, is model it in Unibox, and figure out what kind of PR alignment might work favorably with it, and just build that- then I'd only have one build to undertake and store!

[JonMarsh]

Following up on this and setting up what will be the needed test enclosures- for Mike we're talking a mid bass application... the drivers are so similar that the main thing to take into account is the difference in sensitivity due to Rdc. Even for the 8 ohm version, the sensitivity is pretty good, at about 87 dB.





The 8 ohm version is a true 8 ohm driver; the six ohm is what most companies would call 8 ohm, with a six ohm RDC.


Sealed in the size Mike is using should be fine as a mid bass driver, with considerable output capability above 80 Hz- below that, excursion imposes some limitations, to around 102 dB at 50Hz.





So what can I do with this beast after finishing testing it? Hmm, maybe a 2.1 system?

Because of the high sensitivity and T/S parameters, going low requires a largish enclosure- if we set an upper limit of 3 cu ft, we still can muster some decent response, and without needing a lot of power.




This alignment uses two unmodified SL26R passive radiators (*no extra weight) and is nearly flat to 30Hz, with an Fb of 26Hz before the driver starts unloading. For music this should be pretty reasonable.



25 watts puts things just at the limit for the driver excursion down low-



The tuning is something of a compromise- one might like to have the excursion of the driver reduced more in the 30-40 Hz area, but then the PR mass would need to be reduced, and the Fb moved up to around 30Hz, and then it might be unloading too much below that point with some program material. Also, with the relatively low PR output above 40 Hz, the subjective bass quality and transient response will be determined mostly by the drive, and I think that's a good subjective choice.

But this isn't how I'd recommend going about designing a 3 cu ft sub, normally... it's more a matter of making lemonade if you've got a bit lemon sitting around (and I don't mean that in the pejorative sense, just to fit the saying.)

Some very expensive systems combine the AS250 with the AS190 as the mid bass/midrange driver- that's what Accuton has in mind. Mike is taking a bit different path... :B

[JonMarsh]

Looking at this, it just occurred to me that one could make a seriously wacked out DTQWT using the AS190 as the mid woofer, the AS250 as the 0.5 woofer, and a nice big waveguide and tweeter assembly. I even know a way we could probably wind up with a transient perfect crossover, but I'm not saying how... :naughty:

Paging Steve Manning, paging Steve Manning - please report to the Osiris thread... :B

:rofl:


:alol:


:rf


:roflmao:

[Steve Manning]

Looking at this, it just occurred to me that one could make a seriously wacked out DTQWT using the AS190 as the mid woofer, the AS250 as the 0.5 woofer, and a nice big waveguide and tweeter assembly. I even know a way we could probably wind up with a transient perfect crossover, but I'm not saying how... :naughty:

Paging Steve Manning, paging Steve Manning - please report to the Osiris thread... :B

:rofl:


:alol:


:rf


:roflmao:

You rang .......

[Steve Manning]

Did you try modeling the SS 30W PR? You might like ......

[JonMarsh]

In for a dime, in for a dollar...

You mean something like this?



Did that a while ago when Mike and I first started talking about the Osiris after he visited Accuton in March.


It is possible to do asymmetric ported and PR systems- Did that with the Slamm clones. I don't know how to model combining an AS10 and AS250 into a 2.5way, as regards a PR setup, but I suppose just building one to test wouldn't be out of the question.

And 100L is small than 120L (DTQWT).

Hmm.


I think this shouldn't be classified as a "Butterfly", but as a "Unicorn". :B

Do your product concepts include Unicorns? :W

[Steve Manning]

Seems to me there was another thread around here with the mention of Unicorns that might have come into play already.

https://www.htguide.com/forum/showthread.php?43121-Of-Unicorn-dreams-and-Tesseracts&highlight=tesseract

[csmielke]

Guys,
Dumb question, has the SS26W/0-00 fallen out of favor? It's a little cheaper than the Seas PR with greater Xmax excursion. I didn't load it up and try it so perhaps it is not a good match with the Accuton driver. Another option is the Wavecor PR that I will be using this spring in a PR version of the Finalist. They are more pricey and I got mine when Solen had them on sale for peanuts about a year ago. Probably an obvious reason I missed, sorry.
Chris

[JonMarsh]

No, it hasn't fallen out of favor- the 30W is the 12" version- what one needs may vary depending on the Sd interface required.

I would be careful about drawing conclusions regarding the 26W versus the SL26R- though they are spec'd the same for mechanical travel, the basis of those specifications is not given, and I know from correspondence that Seas put particular attention into linearizing the suspension compliance over a long range of travel. I would suggest examining and measuring both, as I have, before making judgements. If Seas made a 12" version of the SL26R I would be very interested in it...

[csmielke]

Jon,
Point well taken, I used a pair of the 26Ws in a sub with the SDX10 but alas no measurements to support conclusions other than listening to the one I built and being satisfied. Thanks for your insights and explanation, I continue to learn every time I visit.

[meb46]

Jon - It would seem you have been a lot more dedicated to "the cause" over Christmas/New Year period than I... I have been frivolously wasting my time touring Ireland, attending Weddings, drinking too many pints of Guinness and depressingly filling out any spare space in my jeans with the great hearty Irish pub meals. But definitely enjoying the trip!

I am due back in Singapore late this coming weekend and will then be head down/tail up, getting the balance of the speakers ready for crossover stage. I still haven't received my speaker tester module even after numerous follow ups with the manufacturer. This will be top of my list on return to then enable me to tune the cabinets. I will get the polishing process started also and this will have to share time with my Amplifier project... which has now made the commercial switch. Design will be nearing completion in the coming weeks and the prototype is currently in compliance testing. I'm sure balancing the two projects and now commercial amplifier offering wont be too taxing on my non-day-job hours and fatherly responsibilities. I'll sent you an email later in the week with full details...

I guess you now understand first hand my comments on the AS250's... aren't they utter "beasts"! Perhaps we can convince Accuton to make an uncompromising 15" equivalent, coupled with their diamond tweeter for an all-Accuton Isiris... ouch, the sheer thought of cost makes my eyes water!

[JonMarsh]

Well, I suspect you really needed the time off.

I spent a fair amount of this "break" actually working on work stuff, but got some audio stuff evaluated- and yes, I think this is a "beast" of a driver, perhaps not an optimal sub woofer (9mm Xmax) but I'm very curious to see how the distortion looks at normal drive levels- if it's anything like the AS910, it's going to be quite nice.

And yes, there are more entertaining ideas about what could be done with these than there is time at this point. A knock down enclosure from PE is on it's way for the testing the AS250 in your application. I don't anticipate any issues scaling the results for the different impedances and sensitivity- I'm tempted to put a box together later this year and test out a PR configuration just for the heck of it. But whether that will happen or not is an open question with all the things going on, and of course how GF does on chemo will be a big factor in plans. She's getting the port put in this week, check out two days later, then should start next week.

Travel safe coming back!

[meb46]

Forum Groupees... After a serious hiadus on this project, I am now emerging from a somewhat frantic year of work travel (22 countries), and hopefully get a few days on these speakers. Over the past 6+ months, they have sat there with the Subwoofers running and then my first generation speakers as the main source of music. Now I have a few days spare, I am aiming to get the woofers tested/tuned using the Smith and Larsen Woofer Tester... hopefully have all the woofers complete with base plate... Seems like an eternity since I did anything on these... Nearly embarrassing that I havent done anything on these.

Jon - Will get you an email in the coming days of some progress...

[JonMarsh]

Got your mail- responded this AM- I've been buried alive the last few weeks. not much fun. It's been crazy at work, and other stuff hasn't been going all that well, either. Trying to dig out from under... at least the FAE training is done, but there have been side things like hiring interviews and a weird personal improvement plan for another employee that I've been roped into supervising the technical aspect...

Sort of like the old Chinese curse, may you live in interesting times...

[meb46]

Some solid updates including wise council from Jon over the last 48 hours...

Have started the tuning process of one cabinet using the Smith and Larsen Woofer Tester. Very straight forward to use, and have been progressively adding stuffing to the cabinets and watching Fs and Qts numbers for the optimum point. I forget how large these cabinets are... thus far they have consumed 3x 5lb Bags of Parts Express Acousta-Stuff. I have been fluffing up the stuffing and slowly adding in 2.5lb increments. Still seeing reduction in Fs and Qts still okay after 15lb of stuffing. Have just ordered another 5 bags of the stuff from Parts Express as I still need to add a little more from my current measurements, and also apply to the second subwoofer cabinet as well as the same process for the AS250. Slow progress, but any progress after such a break is good progress!

Current measurements as follows:



And this currently looks as follows:



While I await the shipment of Acousta-Stuff, I can at least carry on with the second cabinet and getting the Base/Separator Plates added, then start the wiring of the Upper Three speakers ready for Testing.

[cochinada]

Very educating experience! What were the values before filling and during the process? Did you save those charts or at least the numbers? It would be very interesting to have a table or even better another chart correlating Fs and Qts with the amount of filling used. BTW they look now pretty filled except for the sides (any plans here?) or maybe compacting them a bit more.

[meb46]

Hello Joaquin - I see your speakers have developed a lot in the past 6-9 months, great work!

For the Stuffing Test, I have only saved the numeric data, and then the current plot as shown above. The numeric data of the six stuffing configurations shows a flatenning off of the change in both Fs and Qts. I expect i will need another 1lb or so before I reach the optimum point... which I expect to be around Fs= 39.2Hz and Qts = 0.73. This is based on plotting the information you see below... and making a couple of assumptions. This will be verified by measurement obviously!



The stuffing is mainly kept in place by the internal bracing and the adherance it has to the felt lining on the walls. If you remember from earlier posts, these have a lining of Bitumen sheets, then wool felt on all inside wall surfaces. For the last 1lb of stuffing, I may just use a small about of spray adhesive to apply some to the walls in which you see bare felt.

Weekend progress has now got me "jazzed" for more activity tonight... Have cracked out the plastic/ABS Sheet I purchased sometime back to build crossovers on. Will get these measured up tonight and hopefully cut toshape tomorrow. I have made allowances to put the Mid/Tweeter crossover in the top cabinet, and the Woofer crossover in the middle cabinet with some shielding between it and the Subwoofer amplifier.

[cochinada]

Thanks Mike.

Assuming stuffing 1.5 = 7.5lb and 2.5 = 12.5 lb this is the chart I come up with (linear trends depicted as well):


Image not available


I didn't use any glue on my stuffing as I didn't find the need since the material is both light and sort of sticky but maybe it's a good idea to use some spray at the walls like you mention.

Those plastic sheets for the crossover look good. How do you plan to fix the components on it?

[Steve Manning]

Mike with all that stuffing going in, wouldn't it be easier to stuff a couch or two in there? Those things must be a beast to see in person. Thanks for sharing the data with the stuff process though, very informative.

[meb46]

Steve - Ha, you are probably right It's a lot more stuffing than I thought it would need/take, but I guess thats yet another lesson on making big speakers. I had the same issue recently when I went to get my car serviced... got the bill and struggled to understand the expense of parts. Seems like it was twice as expensive as my previous car to service... then the penny dropped... my current car is a Twin Turbo V10, thats pretty much twice the number of spark plugs than a normal car, with individual igniter packs per plug... OUCH! Serves me right for having a bigger is better approach to toys

[meb46]

First pictures of the cabinet with all Drivers mounted... pretty happy with the way this has turned out... but now run the temptation of connecting up the Mk I crossover to get a taste for sound!







Jon - Once I get my final bags of stuffing, I will get the final impedance measurements and plots and send them through to you, including the mid-range.

[Steve Manning]

Those look awesome Mike. :T

[cochinada]

Those look awesome Mike. :T

x2 :T

How much do these beasts weight?

[Renron]

Wow, just wow.
My personal tastes run to wood finishes rather than painted speakers, but those are stunning. Wow.
Gorgeous Mike, very , very elegant. How tall are they?
Ron

[meb46]

Hmmm - Weight... I actually have no idea. I might have to do some calculations but would expect them to be well over 200kg each.

Height - 1930mm

[Horio]

Holy moly Mike, those things look amazing! For your neighbor's sake, I hope you're walls are nicely damped. I'm looking at following your lead and painting my Wavcor Ardents which I hope to start in the new year.

[Renron]

Horio,
I'm excited for you too. Nice Christmas present to yourself.
Ron

[dar47]

Wow Mike I think you might be the one guy who can out spend Jon!

How big is the room these are going in and you have to share with us the front gear that's going to drive these battle Stars. Great to see these come together so nice!

[5th element]

That is a whole lot of speaker!

[scottvalentin]

Wow, those are really something - can only imagine what those are going to sound like.
Great job!

[meb46]

So progress continues in the last couple of days as follows:

1. Completed Tuning of the Subwoofer Cabinets, with as much expected results... see below...



2. Continued with basic Impedance Tests on the Tweeter and Mid Range... see below... Still pending review and understanding these. Will work through this in the coming days.





3. Managed to get all of the Crossover Boards Cut and will be test fitted for mounting locations in a couple of weeks time. The intention is to split the Crossovers into the Base Cabinet for the AS250, and then the Top Cabinet for the C168 and R2908. The later being a stacked approach across two boards, and the AS250 one in the Base Cabinet have a shield on it to protect from the DS8.0 Plate Amplifier also sharing the same cavity.



In terms of whats going to power these things front end...

1. Source - Typically using my Surface Pro 3 and Tidal HiFi for my music these days, plus on the occasion FLAC JRiver
2. DAC - NAD M51
3. PRE - Auralic Taurus PRE
4. Amplifier - Still using my Rotel RB1092, which has power to burn, but a very clinical sound. Current plans are to first try the beasts shown below... These are my Hypex NC502MP Powered Amplifiers that will each be run in Brigde Mode (~1KW/Channel). Failing this, if I decide I dont like these, I may switch to a NAD M22, or possibly even two M22's in a bridge configuration. Yes, it would seem I have an appetite for power, but having heard the difference on my earlier versions of speakers between the Rotel RB1092 with ~600W/Channel, and the Bel Canto ~300W/Channel, I am simply not going to power the beast with anything less than 500W/Channel. Please bear in mind, the Subwoofers are actively powered by Hypex DS8.0 PLate Amplifiers that reside in the back of the speaker...

[meb46]

Room size... well that can wait until the house is a little cleaner before I post a picture of that

[dar47]

Interesting the NC502b and nice cases!

I have found that my NC500 has no sound signature per say but I think my DAC and preamp create the sound. I bet when you get setup you could run the M51 without the pre in to hear what the DAC sounds like then add the pre in as it my give you an indication of working with the sources to get the sound you like. Going to be fun while you get them dialed in.

[Carl V]

have you looked in to the newest ICE 1200AS module

http://www.icepower.bang-olufsen.com/files/solutions/iceedge_brochure_final_20150624.pdf

file:///C:/Users/Carl/Downloads/ICe%20Edge%20Amp.jpg