Official Premature Arvo Pärt Picante thread

[Jonasz]

I have four AE IB15's, you guys think these will be ok in a W-frame or will the resonances be so low in frequenzy that it's in reality unusable in this application?

Really want to make an IB with them but I'm yet not brave enough to cut holes in the ceiling... :twisted:

http://www.aespeakers.com/drivers.php?driver_id=8

[5th element]

It all depends on how high you want it to go. I am sure there is a high cut off point with W frames. I must admit I haven't read to much about them, but there is with a H frame so its reasonable to assume something similar for a W frame.

A W frame around a 15" is 1.5x bigger then what would be around a 10", so theoretically if the 10" could go up to 100hz, then your 15" might go down to around 65hz. Of course that's if everything was scaled up identically and you might be able to keep what would be the limiting factor of a W frame pretty much the same for the 15" as the 10".

[Jonasz]

Yep, if that's the case it feels kind of discouraging... :cry:

SL only uses the new tens to 92Hz, but that on the other hand feels kind of conservative when the old W-baffle with XLS12 was used to 100hz 2nd order. Can't say I hear any anomalies with them...

I wonder if 100Hz 8th order would be doable? I guess the only thing is to build it, measure and above all, listen... :g>

[JonMarsh]

That kind of reasoning is in the ballpark, but not necessarily on the money. I'd say you might want to test build one with inexpensive materials, measure right at the mouth, and see what range the peak occurs in and how hard it is to notch out. My gut feel is that getting 10's or 12's to work to 125 to 140 is doable, 15's you'd have to cut in somewhat lower, also depending on the degree to which you're wiling to fight the peaking.

If you review some of the published published projects, Stefan Munther's W-frame dipole subwoofer is probably most relevant to your interest, Jonaz, using two Dayton IB15 woofers. His design didn't try to equalize the area of the two W legs combined versus the central combined opening, though, which may (or may not!) be beneficial.

His raw response as measured outdoors showed the dipole peak (rear wave combining with front wave) at just below 200 Hz.



With the filter EQ, he was able to modify this, but he took a different path than I'd recommend, trying to go for maximum bandwidth.



The axial response curve doesn't look bad at all, BUT, the roll off is very steep, indicating a big phase change, and considering the raw response in the first graph, the off axis response will not follow a figure 8 dipole pattern, but will have a strong off axis component (look at the 90 degree curve, which peaks up to nearly the same level as the on axis curve). This means the room power response will be far from flat, and will have a big bump in the 175 - 200 Hz area.

Looking at these curves, and allowing 1 octave for a LR4 roll off, I'd suggest shooting for a target of -24 to -30 dB at 150 Hz, with a nominal crossover frequency of 75 Hz. That could work fairly cleanly.

I'm expecting the dipole peak on the Arvo Part Picante to be around 300 Hz. Let's hope it's not lower....

[Jonasz]

I feel 75Hz may be a little low, I would need a big midbass to be able to keep up with the AE15's. Maybe a 10" Revelator on a 15-17" wide baffle could work. Well, this build is not going to start until summer so I have plenty of time to change my mind still! :B

I'm expecting the dipole peak on the Arvo Part Picante to be around 300 Hz. Let's hope it's not lower....

This is the Phoenix W-baffle, the peak is at 290Hz so you should be fine!

[JonMarsh]

That's what I'm expecting, but as I haven't gotten to the measurement part yet, you may remember the old William Shakespeare quote, that there's many a slip twixt the cup and the lip!

Still, I'm optimistic!

[bbggg]

Stefan Munther's W-frame dipole subwoofer

Is there a link handy?

[JonMarsh]

I'll see if I can find one, but that work dates back from 2006- been kicking around on my hard drives a while, and you know things don't last forever on the internet.

Just look at what's happened to Tony Gee's site.

[Jonasz]

You can still find Tony Gees work in the download section.

http://www.humblehomemadehifi.com/download.html

[Rudolf]

Last time I measured 15" driver resonances in W frames one was just below 200 Hz and one even near 300 Hz. 300 Hz was a PA driver with stiff accordeon surround.

[JimS]

As my "normal" esetup is Quad rates on the input with 174 kHz input from Fidelia, using Izotope SRC, DSP processing power is at a premium.

Jon - have you tried the integer beta driver? Noticeable improvement on my system to my ears today running integer mode in BitPerfect 1.0

[JonMarsh]

Hi Jim,

I'm out in Orlando FL since last Friday for the IEEE APEC conference. I haven't had a chance to finish configuring the new Macbook pro for music duties, and I don't have any of the MH software loaded on it. I've heard the beta is for Snow Leopard, but I'm running Lion, as that came on the laptop, and as a registered developer, I was running Lion betas for sometime before release- quite stable and useful.

I hear anyone can get the beta if they just contact MH. Haven't done so yet, though...
how did you contact them?

Are you still running Snow Leopard? Which player are you using- Pure Music?

I've had so many other things to work on, looking into the integer mode has been a comparatively low priority. What are your impressions?

[JimS]

Yes Snow Leopard only as Apple doesn't support in Lion.

I'm running 2010 mini with BitPerfect as the player ($5 minimalist player that plays nicely with iTunes library management and allows me to use the iPad remote app for album art - I found BP pretty buggy in the beta versions but has been stable so far in v1.0).

Just e-mail Jon at support@mhsecure.com for the MH beta firmware and driver. I don't know if Fidelia supports integer mode or not though.

It just sounds "better" won't get into too much subjective impression, but Eva Cassidy and Holly Cole were in the room today . . .

So, well worth trying out (after you finish up the Arvos, of course :B )

[JonMarsh]

Well, I hope you said hello to them while they were "there"!

Seriously, any thing that works and gives you more "there" is a good thing. However, for several reasons I don't think I'll be able to use it. Overall I'm pretty happy with Fidelia, and my usage model with many sample rates is well supported by it with the advanced module installed. But now I need to set I up on the new MBP with SSD's. Actually, it's the MH software I need to set up, Fidelia is already working over USB to the NAD M51, but haven't had any time for significant listening- just been spinning disks on it, since the Mac Mini was turned.

[bbggg]

Lion does not support integer mode at all, even though some players loaded on it indicate (falsely) that it does. I asked MH about it. I also asked them if integer mode mattered. They told me how to create a difference signal, which should be null, and listen to it for myself. Frankly I'd rather take their word for it than start messing with multiple OS's. Nevertheless the issue mattered enough for them, so as to raise it with Apple.
Sorry for the OT.

[JonMarsh]

Not OT at all from my viewpoint, as it's relevant to the music and to this thread, in that it's about a speaker project to use the MH DAC's DSP for crossover! (at least, primarily or first). Thanks for sharing your knowledge!

[EdL]

I fell out of touch with this thread back in early February. I had not seen Jon's question until now:

What 10's are you going to be trying out?

They will be Scan Speak 25W/8565-01

http://www.madisoundspeakerstore.com/approx-10-woofers/scanspeak-classic-25w/8565-01-10-woofer/

[JonMarsh]

Cool, Ed.

Work's been a b*tch this month, and weekends haven't been mine- everything is stalled for now- leaving for Munich this Saturday on business.

Hopefully April will be better. But I already know nearly all of late April and May is international travel... this year is one for the books!

[JonMarsh]

Back from Munich

Hoping to make some progress this weekend...

The workbench project is about 2/3 completed.



Rough cut wood for another project being moved to my "local" storage, have got another two pair of the Transducer Lab N26c, and moving the Picante baffles back into the "work" area once the bench is completed. Hope to do tweeter measurements this weekend, too.

[JonMarsh]

Finished the workbench this weekend, and brought the Arvo Part Picante cabinets out of storage and back home...

[Hank]

late April and May is international travel... this year is one for the books!

Jon, THEY have taken over your life yet again. This year I've managed to not have to travel to China in Q1!
Nice looking workbench. Woodcraft has bench tops on sale right now at a good price, in case anyone is comtemplating building a bench. A few years ago, I took the easy way out and ordered this HD leg set from Grizzly: http://www.grizzly.com/products/Supe...g-System/H2612
I went to Home Depot, found a solid core door with a dent on one side, negotiated a low price, and had a nice, heavy duty work table for low cost and effort.

[JonMarsh]

Jon, THEY have taken over your life yet again. This year I've managed to not have to travel to China in Q1!
Nice looking workbench. Woodcraft has bench tops on sale right now at a good price, in case anyone is comtemplating building a bench. A few years ago, I took the easy way out and ordered this HD leg set from Grizzly: http://www.grizzly.com/products/Supe...g-System/H2612
I went to Home Depot, found a solid core door with a dent on one side, negotiated a low price, and had a nice, heavy duty work table for low cost and effort.

Hey, congrats on that! I'm spending more time in aluminum tubes the first six months of this year than I usually do in several years!

I hear the pitch for the simple cheap approach, but I really do like the construction and solidity of this beechwood bench from Rockler. No regrets. Now, I just have to find some time to put some stuff together- got some hardwood trim stuff to finish on these Arvo baffles, then will start "loading them up"! Well, at least one, anyway, so I can get some measurements done.

[JonMarsh]

Just before I left for Austria in late April I did finish gluing the hardwood trim, and also milling and painting the tweeter mounting plates- also checked the tweeter fit and waveguide alignment, which looks OK. I have two sets of waveguides to possibly try, one with a wider opening like was used with the BeO SS tweeter, and one a bit narrow-er will try the wide first.

Though I'm enjoying Prague and looking forward to some early morning photography tomorrow and the rest of the week, this place is overun by tourists- it's like rats on a poorly maintained ship! The trick to keep my sanity is finding places and times to do things when and where they aren't around...

[PMazz]

If it's tourist season, how come you're not allowed to shoot them?

[Hank]

Nice Pete, very nice

[Carl V]

If it's tourist season, how come you're not allowed to shoot them?

Silly wabbit...it's catch & release only. no live bait either 8O

[JonMarsh]

Silly wabbit...it's catch & release only. no live bait either 8O

Alas, Carl is correct about the rules- much as I'd rather use Pete's!

[JonMarsh]

I love the smell of satin black enamel in the morning...

They don't look like this anymore--





And Geez, those Seas 10's are HEAVY!

Film at 11.

[wkhanna]

It’s OK, everybody. Don’t worry.

I have alerted the web site admin that someone posing as Jon actually working on a speaker has infiltrated the forum and is leaving posts in one of his threads.

I am sure this dark & evil imposter will be uncovered swiftly and dealt with in proper and appropriate fashion.

[Johnloudb]

Hang on Bill, if he's gonna finish this thing, I say leave him alone. :T

[wkhanna]

Poor Jon.

So much desire & tallent.......
......so little time.

[Evil Twin]

The Force is strong with this one...

It’s OK, everybody. Don’t worry.

I have alerted the web site admin that someone posing as Jon actually working on a speaker has infiltrated the forum and is leaving posts in one of his threads.

I am sure this dark & evil imposter will be uncovered swiftly and dealt with in proper and appropriate fashion.

Impressive... most impressive!

Imperial spies last observed Jonmarsh walking down the corridors of the Enterprise R&D group of a major US computer manufacturer in Houston Texas two weeks ago- his whereabouts since then are unknown.

Contacting the site administrator would be pointless, as I had agreed to keep up the appearance of Jonmarsh's participation while the search for him goes on. Obviously I underestimated the perspicacious forum members who would readily detect and assess out of character behavior by a doppelgänger.

In this matter, the work involved significant efforts with black, something that comes natural to me- perhaps that accounts for my misplaced enthusiasm and efforts.

Regardless, the Chancellor has directed that this particular project must proceed, even if under the aegis of Jonmarsh in name only. He does not care who actually does the work, as long as we do not fail to meet his new schedule.

[Hank]

Houston extraction mission being planned by black ops in Austin...

[Evil Twin]

It would be prudent to share plans so as to avoid cross fire or unintended collateral damage.......

My agents have heard disturbing reports of interrogations under duress, attempting to fathom the "secrets of a fruit themed computer company"- I presume this is some secret code, as it makes no sense, otherwise. It may relate to other computing segment work Jon Marsh is engaged in by his employer.

[Hank]

Austin outpost of 3-letter initials company has products "Made for..." fruit-themed company. It took quite a while to get past large force field of that company and speak to their council. Said company is building its own large outpost in Austin.

[wkhanna]

Seeing as how the Empire’s High Court of the Texassian Sector has ruled harshly against rebel backed computer manufactures competing with said ‘fruit themed computer company’, they have relayed information to me regarding the offer of cooperative assistance in the extraction mission, provided an agreeable detente be accommodated between the Empire and their top-notch Guerrilla squad.

It seems Jonmarsh is considered a most valuable asset to both parties.

[Johnloudb]

Austin outpost of 3-letter initials company has products "Made for..." fruit-themed company.

I really like the those fruit-themed company's sticky logos made by said 3-letter company? It would appear the Dark Side could gain considerable market share ... the rebel forces seem to be taking a beating.

[Hank]

I really like the those fruit-themed company's sticky logos made by said 3-letter company? It would appear the Dark Side could gain considerable market share ... the rebel forces seem to be taking a beating.

Think "pocket projector" young Skywalker.

[Evil Twin]

Carbonite?

Our agents have recovered a carbonite slab with curiously familiar features... once it has been shipped to the local orbital platform, we will determine whether the contents are as alleged...

[gainphile]

Pics... please ... !!

[cjd]

And Geez, those Seas 10's are HEAVY!

10's? That's a mid, right?



(I just got done staring at the 18's in the corner wondering... "what am I DOING?! *giggle*")

What planetary time system are we in? Anticipating "11" for those pics, and wondering if you're on a planet that only goes to "10" ...

[JonMarsh]

10's? That's a mid, right?



(I just got done staring at the 18's in the corner wondering... "what am I DOING?! *giggle*")

What planetary time system are we in? Anticipating "11" for those pics, and wondering if you're on a planet that only goes to "10" ...

OK Chris, that's the most sensible and understandable thing I've come across since waking up this morning... how I got here from the last thing I remember (walking down a corridor to a meeting with people I can't identify) is beyond me... and what's with this splitting headache? Guess I need to lay off the Mountain Dew, I know it's not good for my blood pressure.

And what are all these weird looking tools doing in my workshop, like something from the set of a B grade sci-fi movie from the 70's?

And someone's been messing with my Pentax camera... maybe these are the pics you want, Chris and Gainphile?

At least some work got done on the Arvos while I've been out of it... but how? Well, I gotta admit this one racheting right angle driver I found on the bench is really cool, can see how it would be useful mounting the 10" midranges, er, woofers! Was wondering a while back how I was going to do that...

[wkhanna]

welcome back.....errr....ahhhhh.....

I mean.........

Looking good, Jon!

And yeah, you might want to try some pomegranate juice as a substitute for that MD. :W

[CraigJ]

Looking most excellent Jon!

Will you be using the MiniDSP to simplify and speed things up a bit? Oh, and before Ryan comments, is that tweeter upside down? :W

Welcome back, if only temporary,

CraigJ

[JonMarsh]

Yes, well, the waveguide does an inversion in the focus so by the time you hear it, the treble is right side up... :rofl:

The Mini-DSP is a "backup" solution after test and development using the Metric Halo LIO-8. That was the original plan, and if I can ever get some time to learn the ins and outs of configuring it for this application, it should be pretty dang quick to setup. Once the transfer functions are defined I'll verify the feasibility of transferring to the Mini-DSP.

Remember, these were supposed to be a quick hack job to test out the feasibility of using the LIO-8/ULN-8 in a two way system with at least dipole low end EQ. Well, they're still a hack job, as regards design and build quality, but obviously they have no hope of being considered "quick" at this point! :roll:

And last but not least in the reminder category, the upper section will be a passive 2.5 way- will only need biamping for the complete system. At least that's the theory, ... er, plan. Cambridge Audio 840W on the top end, Aragon 8008X3 on the bottom end. Or a pair of Palladium monoblocks if I think I need that much power... doubt it, frankly.

I gotta get these working soon, so I'll have something to listen to after I tear apart the Modula Xtreme's to rob them of components and free up space for the Isis/DeathStar.