Official Premature Arvo Pärt Picante thread

[JonMarsh]

The look I'm shooting for is influenced a bit by the old Genesis 350 speakers. Just a bit.



Much skinner side sections, and basic black in the center, and a nominal 45 degrees for the 3-1/2" side wings (which are there mostly for vertical stiffening - along with using LBL for the main Midwoofer panel.)

Not really a "V-8" retro kind of thing, more like an Arnie Nudell kind of thing.

[---k---]

Progress. :T

The screw holes is a bit odd. Is there some fancy reason given for that?

[JonMarsh]

You mean in the mid woofers?

The holes correlate with the three spars in the basket supporting the motor assembly.



This way the mounting spars are coupled as directly to the panel as possible. At least, I think that's their reasoning! :roll:

[---k---]

You mean in the mid woofers?

The holes correlate with the three spars in the basket supporting the motor assembly.

That is sort of what I figured. I'll have to start drilling extra holes in my woofer frames.

[JonMarsh]

Not retiring the BT3K/Craftsman

Retired the BT3k?

What's happened is that I find myself using them for specific tasks- like my routers!

Because of the front and rear rack and pinion fence and it's general construction, the DeWalt excels as a fast high accuracy rip saw, but isn't so hot for cross cut work- limited in the size of pieces it can handle. But for ripping it is super accurate and stable and fast- the best in my experience.



The Craftsman/BT3K hybrid (still have all the BT3K pieces and a spare motor that fits either) is OK for ripping, but not as fast to setup accurately as the DeWalt. But because of the crosscut sled table, and the size, and adjustability of fence position, it really excels as a cross cut platform.



No, I don't usually use it with out the blade guard, but the necessities of the Ardent project and some other tasks pushing the envelope have caused it's temporary absence.

[JonMarsh]

Biscuited and glued up the first front panel today, I think the look will turn out OK, and the panel is pretty dang solid even before the lateral braces I've got planned. No time for pics, hurrying to get ready for a dinner engagement soon.

Slow work takes time, but if you put in the time, the work gets done, as John L and others here can attest!

[JonMarsh]

Still at work

Assembling the 2nd front panel basics today.

Here's the overview of yesterday's work.

A full scale shot of the basic front panel assembly - waveguide dropped in for the moment - lateral braces not installed yet, but wouldn't be visible anyway in this view. Total height is 54".



Here's a closer view of the top part of the front panel, at a slight angle. The construction of the side wings is more obvious from this shot.



And a slightly above angle shot-



I like the way this is coming together so far- maybe it will work out acoustically and esthetically the way I want.

[Paul W]

Hey Jon...those skinny lil wings bring back memories!

[JonMarsh]

I wondered if you'd chime in! ;-)

[Johnloudb]

Slow work takes time, but if you put in the time, the work gets done, as John L and others here can attest!

I can attest ... I'm like the master at slow work, in more ways than just speaker building.

That Pau Ferro really sets off the front baffle nicely. This is going to be a pretty looking speaker. Are you going to paint the other wood?

[JonMarsh]

I can attest ... I'm like the master at slow work, in more ways than just speaker building.

That Pau Ferro really sets off the front baffle nicely. This is going to be a pretty looking speaker. Are you going to paint the other wood?

Yes, I'm hoping these turn out somewhat attractive compared with past efforts. The overall proportions are not unlike several Magneplanar models just seen from the front; but shorter and narrower.

The baffles will all be painted black (current plan of record), the desire is to set off the Pau Ferro a bit, for which I'm planing wipe on poly. I'm trying to keep this simple and fast (relatively) because of my time constraints).

Most of the pieces for the LF modules are cut; routing holes tomorrow, and starting assembly. Also some detail brace work for the panels.

The scary thing is how heavy the Seas L26R04Y are- at 22 lb each, the two will way more than the rest of the speaker put together, I suspect.

[5th element]

The scary thing is how heavy the Seas L26R04Y are- at 22 lb each, the two will way more than the rest of the speaker put together, I suspect.

At least they will help to keep the thing stable!

[JonMarsh]

At least they will help to keep the thing stable!

Yeah, like those bobbing knock over toys that always right themselves!


More good news yesterday, from Mark at Meniscus; Transducer Labs shipped to him on Friday, so they should ship to me sometime next week.







I have a plan for the mounting; now to see if it works, and if the response works out the way I hope/expect, given the mounting technique.

[JonMarsh]

Running update to LF configuration..

due to availability of pre-laminated materials in the storage unit! And some considered pondering...




Chilly out today, but making sawdust.

[CraigJ]

Yes, I'm hoping these turn out somewhat attractive compared with past efforts.

:rofl: Sweeeeeet! They are going to be gorgeous. I see a new design in my future...Well, maybe not with those exact driver. A very creative way of hiding what could be an ugly w-woofer (like mine).

Cj

[JonMarsh]

Sweeeeeet! They are going to be gorgeous. I see a new design in my future...Well, maybe not with those exact driver. A very creative way of hiding what could be an ugly w-woofer (like mine).

Cj

You hanging 'round with ugly woofers again Craig? What have I told you about that?! :roll:

Well, if these are any inspiration to help you deal with that, then health to you!

I realize also that these speakers are benefiting from my hoarding tendencies-

The side panels are coming from phenolic veneered high density birch ply I bought on sale from Rockler online, all of the LF woofer panel pieces are re-cycled extra laminated stuff for building another possible pair of Ardents, and the mid woofers are borrowed (for now).

Plus I've got piles of crossover parts and the Jantzen waveguides which were actually intended for something else... Well, make do, I say.

Even in this project I'm having a hard time not indulging hoarding tendencies, as I ordered two pairs of the N26c tweeters- based on the published curves and data measured at another forum, they look to be a real Accuton competitor at more of a Scanspeak Discovery price.

A tip of the hat to Jeff Bagby

First, at 90 dB.



Yes, these sweeps were measured at 100 dB. Not at the same time, which I suppose accounts for difference in SPL FR.

[CraigJ]

You hanging 'round with ugly woofers again Craig?...
I realize also that these speakers are benefiting from my hoarding tendencies-

Even the Aura NS12 looks bad in the standard plywood Linkwitz designed W-woofer. Speaking of hoarding, what color was that Corian of yours?
Yes, I saw Jeff Bagby's measurements of the N26c at PE, and it looks like a very nice tweeter.

Have fun and I look forward to a finished Picante. I'll go back to building clocks.

Cj

[dlneubec]

Yeah, like those bobbing knock over toys that always right themselves!


More good news yesterday, from Mark at Meniscus; Transducer Labs shipped to him on Friday, so they should ship to me sometime next week.







I have a plan for the mounting; now to see if it works, and if the response works out the way I hope/expect, given the mounting technique.

Hey John,

I have a pair of those in my hands, waiting for me to dig out my measuring gear and get at it. I've got 3 different size waveguides I'm going to test them in, ranging in size from 4.5", 5.5" and 6.5". All are 39mm deep with a throat of 36mm. The face plate opening on the N26C is 35.5mm, according to the guys at Tranducer Labs.

These waveguides are all 39mm deep. DanP over at Techtalk made these at work using an additive manufacturing process that sinters (lightly melts with a laser) succesive 0.15mm layers of nylon/glass powder. Therefore, the possible geometries are not limited by traditional CNC or molding restrictions.

I guess these can be painted, as long as they are sealed first, otheriwse they soak up the paint. They actually look pretty cool as they are, can be sanded and will hold screws like a dense wood, according to Dan. Of course, they could be used as patterns to have waveguides either turned or created with a tool like a radarcarve. The latter is how the ones that Pete S. used in his Aurora 2ways were done, which were also patterned from waveguides like these that DanP fashioned for him to test.

I like the way he has embossed the waveguide dimensions into the sides. Pretty cool stuff.

He's going to try and make me a couple rectangular ones to try on a BG Neo3, once I get him some throat dimensions to work with, as well as height and width. I don't happend to have a Neo3 in my hand at the moment, however. For my purposes, I'm thinking of something like 6" wide by 4" high outside dimensions. Anyone out there have dimensions to the outside edges of the holes in the face plates of the Neo3 that I could use to come up with a throat size?

Attached are some photos, one with the 6.5" WG sitting on the N2dC. That photo is a little blurry, but I was too lazy to retake it. :Z

BTW, typically when Mark @ Meniscus (great guys to work with, BTW) ships out the N26C's he sends them with these little metal grills to fit over the ceramic dome to protect them and he hot glues them on. You probably want to make sure yours are not hot glued on when he sends them to you.

[JonMarsh]

Have fun and I look forward to a finished Picante. I'll go back to building clocks.

Cj

I've been after Lex to setup a sub forum for that, but so far it's a no-go. :nonod:

Maybe in the new year....

[JonMarsh]

Hey John,

I have a pair of those in my hands, waiting for me to dig out my measuring gear and get at it. I've got 3 different size waveguides I'm going to test them in, ranging in size from 4.5", 5.5" and 6.5". All are 39mm deep with a throat of 36mm. The face plate opening on the N26C is 35.5mm, according to the guys at Tranducer Labs.

These waveguides are all 39mm deep. DanP over at Techtalk made these at work using an additive manufacturing process that sinters (lightly melts with a laser) succesive 0.15mm layers of nylon/glass powder. Therefore, the possible geometries are not limited by traditional CNC or molding restrictions.

I guess these can be painted, as long as they are sealed first, otheriwse they soak up the paint. They actually look pretty cool as they are, can be sanded and will hold screws like a dense wood, according to Dan. Of course, they could be used as patterns to have waveguides either turned or created with a tool like a radarcarve. The latter is how the ones that Pete S. used in his Aurora 2ways were done, which were also patterned from waveguides like these that DanP fashioned for him to test.

I like the way he has embossed the waveguide dimensions into the sides. Pretty cool stuff.

He's going to try and make me a couple rectangular ones to try on a BG Neo3, once I get him some throat dimensions to work with, as well as height and width. I don't happend to have a Neo3 in my hand at the moment, however. For my purposes, I'm thinking of something like 6" wide by 4" high outside dimensions. Anyone out there have dimensions to the outside edges of the holes in the face plates of the Neo3 that I could use to come up with a throat size?

Attached are some photos, one with the 6.5" WG sitting on the N2dC. That photo is a little blurry, but I was too lazy to retake it. :Z

BTW, typically when Mark @ Meniscus (great guys to work with, BTW) ships out the N26C's he sends them with these little metal grills to fit over the ceramic dome to protect them and he hot glues them on. You probably want to make sure yours are not hot glued on when he sends them to you.

Pretty cool, Dan, please post your results of testing if you're willing- I'd be curious to see how they turn out in different sizes and profiles.

Mark said he would supply the grilles, but didn't mention hot gluing them on. Well, with a small iron, that which is hot glued can be un hot glued. Have to give that a look-see! Thanks for the heads up, I sent Mark a note to NOT hot glue them.

Happy New Year, Dan!

[cjd]

Dan, I have Neo3's somewhere in the stash - if I don't PM you with data, just remind me.

[dlneubec]

Sure, I'll post my results, though I'm measurement challenged currently. Due to some tragic circumstances, we moved my daughter and 2yr old granddaughter back home with us this summer. As a result, our upstairs family room is now part of their apartment and that's my old measurement studio, you might say. :W

I may have to experiment with Jeff's technique of laying them on the floor and measuring straight above.

Happy New Year to you, as well.

[dlneubec]

Dan, I have Neo3's somewhere in the stash - if I don't PM you with data, just remind me.

Thanks, I'll do that.

[JonMarsh]

Sure, I'll post my results, though I'm measurement challenged currently. Due to some tragic circumstances, we moved my daughter and 2yr old granddaughter back home with us this summer. As a result, our upstairs family room is now part of their apartment and that's my old measurement studio, you might say. :W

I may have to experiment with Jeff's technique of laying them on the floor and measuring straight above.

Happy New Year to you, as well.

Hope the family is OK- sorry about the tragic circumstances. Jeff's trick is the easy way to get a quasi infinite baffle measurement pretty quickly!

- Jon

[JonMarsh]

Not just sitting around nursing a hangover...

A lot of other things going on yesterday, but made a bit of progress in some areas...







And the acid test, they fit perfectly....

[JonMarsh]

Progress

Did the front panel basic sanding, oh thank heaven for Porter Cable orbiting sander and Abranet sanding disks :T



my absolute favorite because of how they support dust collection with their inherently porous surface.


Also pilot drilled and biscuited the woofer panels and cut some additional 3/4" X 1-1/2" maple braces, and glued up one of the woofer plate sets to a front baffle after dry fitting.



You know, even if these open baffle speakers are theoretically missing a bunch of enclosure walls, it sure seems like there's plenty of parts, and they can be something of a PITA to put together! :roll:

Some day I'll get the hang of it... maybe... let's face it, I'm a wires and sparks guy, not a wood worker! Just faking my way through it as I go! :B

Oh... and the rubber mallet? That's for when you just need to beat it into submission! :rofl:

[gainphile]

Great execution of a project! I'm following with keen interest. :T

That "all-excel dipole" on previous page is also so lovely!!

[5th element]

I love my Orbital sander. I know I think that my router is my number 1 piece of equipment, but the OS comes a close second I think, simply because of the time and most importantly effort it saves from hand sanding.

[JonMarsh]

Great execution of a project! I'm following with keen interest. :T

That "all-excel dipole" on previous page is also so lovely!!

Thanks!

Nice blog site you're running, interesting articles- this project is definitely pushing in the same direction, we'll have to see in the end how well it works out!

[JonMarsh]

MiniDSP came in...

Got in the alternative signal processing solution, aka, the NOT Metric Halo LIO-8, and have to say it's more than I expected, though I was in a hurry ordering online and maybe didn't pay as much attention as I should have... ops:




I've also got the SPDIF I/O module, and the beta software download for Mac. Once I get the speakers built and a first pass design done with the LIO-8, I'll have to dig into this and see how it works, and how I want to package it. I'm hoping that given everything just runs off local clocks, there will be fairly decent performance on analog inputs.

I have located my brute X1 electronics crossover, though I think that to do this system justice with an "ASP" I'll need to do another board spin to add a notch filter for the W woofer peak, and upgrade the opamps AGAIN. (maybe something like the LM4562 family)

[---k---]

Sounds like you've been playing with new toys rather than making sawdust. Back to work!

[JonMarsh]

Yes massuh!


Here's the second cabinet LF module just biscuited and glued up!

[Bear]

Mmmmm. Transformers.

[JonMarsh]

Technically, one inductor, one transformer. I've got four of those custom built inductors, from Plitron. For an amplifier project with passive PFC and inductive regulation. That one's been on hold a LONG time!

Seems a little quaint these days, as the next thing I do along those lines will probably be a pure SMPS solution, interleaved quasi resonant PFC with a 1200 watt LLC resonant output regulator. Very compact, very efficient, very low noise.

actual amplifier solution will either be an open loop circuit I've been working on, or a new Class D project with some of our newest 200V FETs, actually working on that at work right now- I want to move from a 2nd order phase shift self oscillating design to a 4th order (to make switching frequency more constant and lower distortion), and add ripple current steering to the output filter, to lower output noise. Believe it or not, I'm actually getting paid to work on this! :B

[JonMarsh]

Woo Hooo! :banana:

Transducer Labs tweeters hit the docs at Meniscus! Shipping to me shortly!

I told them I'd prefer tall tweeters, actually, not short ones!

:rofl:


Ah well, I'd say it's been a slow day, but actually it hasn't- been pretty d@mn busy!

[JonP]

At least they will help to keep the thing stable!

Yeah, like those bobbing knock over toys that always right themselves!

Good to see clouds of dust rising above Livermore once again, Jon... :W Things are shaping up nicely, she's a gonna be a looker...

But if 44lbs of Seas isn't enough to keep the Weebles wobbling and not falling down, you could put one or two of these in the bases... hey, they're on sale!

http://www.woodcraft.com/Product/2004864/7535/Granite-Surface-Plate-9-x-12-x-2-A-Grade.aspx

Bought one, will help with keeping things flat. It is a bit of overkill, since you typically don't need your ballast weights flat to .0001", but hey, some of us are compulsive with their accuracy :B

Edit: They have a 12x16x3" one that weighs 80lbs, if this is too lightweight...

[JonMarsh]

Hey, that's cool! Maybe I could figure out a way to hollow it out and put the passive crossover inside?

[JimS]

Wow - you've all been busy while I've been away . . . looking good Jon :T

Two grandfather clocks in the same room is going to look a bit suspect ... :W

NYC and London time, perhaps

[JimS]

uh oh . . . just re-read the specs after seeing your progress and realized I glossed over wing width on first read, not only are these an inch taller than my part deux, they're two inches wider 8O

better sound good, cause the "I'm making smaller speakers to be sensitive to your needs" line just disappeared . . .

I will likely consider a reverse-color scheme again with veneer on the panel and TBL on the wings for the "slimming" effect.

[JonMarsh]

I will likely consider a reverse-color scheme again with veneer on the panel and TBL on the wings for the "slimming" effect.

Smart move! I almost went that way, what with the possibility of laminated bamboo on the front panel, but layering it up with 1/4" HDF, it made more sense to me to rebate the HDF and keep as much bamboo in the design as possible. I'm still planning some shallow cross spars (3/4" by 1-1/2" maple from HD) for braces above and below the waveguide opening.

You could get a really dark hardwood or do a venue style finish on it for the "wings"; then something like maple veneer in the center baffle? That's a possibility.

[JonP]

Hey, that's cool! Maybe I could figure out a way to hollow it out and put the passive crossover inside?

The worlds first granite pizza box?? Wow, maybe you could get that honkin MiniDSP in there as well?

I think you're going to be burning thru a lot of router bits... maybe a few router motors, too... 8O

[JonMarsh]

Nah, I figure to pull this off we gotta go high tech, you know, maybe a high power industrial laser?

Just joking! But the granite blocks are interesting...

[JonMarsh]

Meniscus delivered today...

Some fresh speaker porn...







Each matched pair received had measurement data for the pair, both drivers overlaid. Seems like a real quality build and quality design- if they test as they have for Jeff and others, they're a very good deal. Have to see if they work in this application with the waveguide and the "boundary/interface" damper.

So far I like what I see, but have a very busy week at work.

[Bear]

Shiny!!

[5th element]

Shiny indeed, going to be interesting to see how they measure with the wave-guide.