A New Adventure

[Steve Manning]

Figured I'd show a few pictures of the last area of upgrades to the shop, where I do any finish application. I replaced the hanging tarp setup with a track system and some heavy duty clear curtains. For the most part I can leave everything in place, close the curtains and get to work.

Here are some pictures of the cabinet parts getting a coat of primer ....











Of course it became apparent that I now need build a drying rack for parts .... it never ends.

[JonMarsh]

This thread has finally coaxed me out of lurking after many long years absence

I am currently in the planning phase for a 3 way floorstander to replace my stalwart Modula MT's with the seas metal dome tweeter. These have served me well and are a great reference speaker; but over time and with more experience, I have come to realize I'd really like to get the extra midrange detail and 'sweetness' that I detect in drivers like the ZA14 and even the old CSSWr125. And that, combined with a desire for better amplification, has spawned a new project! 3-way active, power and DSP from a Hypex nCore fa123 plate amp. Current plan is to use the Vifa ne149 as the midrange, and Peerless SLS woofers (either 2x8" or 1x12") for the bass.

What brings me to this thread is the tweeter: I have been evaluating candidates, crossing them actively to a test box with CSS FR125 drivers standing in for the eventual mid. Doing fairly rough measurements and just playing around with PEQ/slopes, measurement and listening all done in the nearfield. I have tried several SB tweeters, scanspeak discovery ring radiator, the Hivi Rt1.3we, css ld22c, even the Linaeum dipole. But the one that has stood out is this peerless 25mm corundum dome. I hadn't planned on using it in this project, as a 3 way with 5" mid doesn't really need the power handling or extension on the bottom end. But I hooked it up just to test, and I'll be damned if it doesn't just sound best out of them all! the others have their strengths and the 1.3WE in particular has a lovely natural presentation (for lack of a better descriptor)... but I can't deny that the Peerless just seems to be finding information in the recording that the other's aren't; mostly noticeable in room ambiance, subtle inhalations of breath, or on very 'busy' electronic music. I'm frankly quite surprised by this, was not really expecting this to be a standout beyond its robustness/versatility.

And here I see Jon's (whose work has been MOST formative to my DIY education) evaluation and better measurements, and am feeling vindicated. Though still not sure I'll end up using it in this particular design.

And the prospect of a waveguide for it, whether that will be a DIY design we can copy with CNC/3d printing, or a product we can order, is enticing.. do I understand right this may be in the offing?

I am not surprised at all that you notice this. I went through both a measurements and listening evaluation of quite a few tweeters in the $200-$400 range and keep coming back to the DA25, with all it's quirks- sonically, it's very good, and measures quite well, too, as you can see. I can speculate as to why- I suspect the unusual rear chamber design, flattish dome, and the absolutely flat front panel with minimal diffraction effects all play their roles.

OTOH, getting it to mate well with a waveguide is not at all easy. This is always the case, in my experience with hard domes, one exception being the original RS28a tweeter; it's phase shield and flat faceplate construction and just where they put the boundaries of the protective screen work very well as regards measured response on and off axis.

The problem with the DA25 seems to be reflections with the dome and throat interface that make that quite tricky. If you PM me, I can email you some of the measurement results with different waveguide experiments. The last one was close, and I have some further ideas for new profiles, but for now that has been set aside- especially considering the performance we get in a conventional direct radiator mode- look at the distortion plot above, the DA25 is not holding that MT back in any sense.

In fact, I just recalled this week conversations I've had with Wkanna in the past about a NatP successor, a NatP MkII if you will, and this MT is clearly a sound basis for that, as the current MT test demo has remarkably good vertical integration considering the CTC distance is 13". Plenty for an MTM. I've settled on the preferred HF crossover input resistor and can easily work out a dual 8 ohm version MTM soon.

Of course, other things could be interesting, like the 6" Satori as a midrange and dual WO24's on the bottom end, presuming one wants a high sensitivity system and can handle the size, or a high cut off frequency if you put two of those in a 2 cu ft enclosure sealed and go with subs below 50Hz.

You should be able to get good results with the NE149W; I've measured a few of the NE series in the past, but never had time to do anything with them... I suspect they're in storage in Idaho right now, though they could still be in Livermore!

But if you haven't already bought your NE149W's, take a close look at the similar Satori parts. A bit newer designs by basically the same people. Seem to be better behaved cones, less issues to deal with.

OTOH, I'm looking at the EighteenSound 6ND430 as my next midrange driver candidate (for non Accuton type systems ) in addition to the Satori 6's I've got.

Let's face it, the Accuton C168 is in a different sensitivity and price class. But if you're working with Accuton cell drivers, and crossovers, like a Duelund that only really work well with all drivers having the acoustic origin in the same plane, you have limited choices.

It's still summer time, a good time for stepping outside the normal development approaches!

BTW, I do like the new Hypex plate amps, though I haven't had a chance to check them out. I have one of the Accuton DSP board sets, and would be more interested in that if I wasn't such a DAC tweak head (TotalDAC and Denafrips Terminator- new DSP board for the latter should hit the dock on the 5th!)

Retro Rulz!

[Steve Manning]

This thread has finally coaxed me out of lurking after many long years absence

I am currently in the planning phase for a 3 way floorstander to replace my stalwart Modula MT's with the seas metal dome tweeter. These have served me well and are a great reference speaker; but over time and with more experience, I have come to realize I'd really like to get the extra midrange detail and 'sweetness' that I detect in drivers like the ZA14 and even the old CSSWr125. And that, combined with a desire for better amplification, has spawned a new project! 3-way active, power and DSP from a Hypex nCore fa123 plate amp. Current plan is to use the Vifa ne149 as the midrange, and Peerless SLS woofers (either 2x8" or 1x12") for the bass.

What brings me to this thread is the tweeter: I have been evaluating candidates, crossing them actively to a test box with CSS FR125 drivers standing in for the eventual mid. Doing fairly rough measurements and just playing around with PEQ/slopes, measurement and listening all done in the nearfield. I have tried several SB tweeters, scanspeak discovery ring radiator, the Hivi Rt1.3we, css ld22c, even the Linaeum dipole. But the one that has stood out is this peerless 25mm corundum dome. I hadn't planned on using it in this project, as a 3 way with 5" mid doesn't really need the power handling or extension on the bottom end. But I hooked it up just to test, and I'll be damned if it doesn't just sound best out of them all! the others have their strengths and the 1.3WE in particular has a lovely natural presentation (for lack of a better descriptor)... but I can't deny that the Peerless just seems to be finding information in the recording that the other's aren't; mostly noticeable in room ambiance, subtle inhalations of breath, or on very 'busy' electronic music. I'm frankly quite surprised by this, was not really expecting this to be a standout beyond its robustness/versatility.

And here I see Jon's (whose work has been MOST formative to my DIY education) evaluation and better measurements, and am feeling vindicated. Though still not sure I'll end up using it in this particular design.

And the prospect of a waveguide for it, whether that will be a DIY design we can copy with CNC/3d printing, or a product we can order, is enticing.. do I understand right this may be in the offing?

Hi Morbo,

As to the mechanical side of things, our intent, assuming we can determine a profile suitable for this tweeter, or others, is to provide waveguides that are available to purchase. It could be stand alone or machined into a baffle directly .... though most of our efforts are working with stand alone waveguides for testing at this point. Rather than having the typical plastic versions that one sees these days, we're looking at different hardwoods, lbl, etc ...... something more pleasing to the eye than the standard fare.

Jon can speak more to the acoustic side of things, since he is the master in that department.

[morbo]

This thread has finally coaxed me out of lurking after many long years absence

I am currently in the planning phase for a 3 way floorstander to replace my stalwart Modula MT's with the seas metal dome tweeter. These have served me well and are a great reference speaker; but over time and with more experience, I have come to realize I'd really like to get the extra midrange detail and 'sweetness' that I detect in drivers like the ZA14 and even the old CSSWr125. And that, combined with a desire for better amplification, has spawned a new project! 3-way active, power and DSP from a Hypex nCore fa123 plate amp. Current plan is to use the Vifa ne149 as the midrange, and Peerless SLS woofers (either 2x8" or 1x12") for the bass.

What brings me to this thread is the tweeter: I have been evaluating candidates, crossing them actively to a test box with CSS FR125 drivers standing in for the eventual mid. Doing fairly rough measurements and just playing around with PEQ/slopes, measurement and listening all done in the nearfield. I have tried several SB tweeters, scanspeak discovery ring radiator, the Hivi Rt1.3we, css ld22c, even the Linaeum dipole. But the one that has stood out is this peerless 25mm corundum dome. I hadn't planned on using it in this project, as a 3 way with 5" mid doesn't really need the power handling or extension on the bottom end. But I hooked it up just to test, and I'll be damned if it doesn't just sound best out of them all! the others have their strengths and the 1.3WE in particular has a lovely natural presentation (for lack of a better descriptor)... but I can't deny that the Peerless just seems to be finding information in the recording that the other's aren't; mostly noticeable in room ambiance, subtle inhalations of breath, or on very 'busy' electronic music. I'm frankly quite surprised by this, was not really expecting this to be a standout beyond its robustness/versatility.

And here I see Jon's (whose work has been MOST formative to my DIY education) evaluation and better measurements, and am feeling vindicated. Though still not sure I'll end up using it in this particular design.

And the prospect of a waveguide for it, whether that will be a DIY design we can copy with CNC/3d printing, or a product we can order, is enticing.. do I understand right this may be in the offing?

[JonMarsh]

I've been building a bit bigger things than speakers over summer - though some guys might have subwoofer about the same size as the "tiny house" style summer cottage we are doing up. It's about 16m2 or 180 square feet total inside , but now has toilet, shower, kitchen and all other essentials.

The OLA project is also still ongoing. We've just agreed another listening and Xover tuning session for this Saturday with my friend, so after that I should have both the latest measurements and impressions to share in the OLA thread. Don't wanna steal Steve's thread too much

Now THAT's the way to spend your summer! But it's great you're still moving forward on the OLA project and not completely neglecting audio this summer- though I couldn't fault you if you did with a project like your summer cottage! You're doing some interesting work there, and it inspired me to get a two pairs of the BlieSMa tweeters, though I had some problems with that first set which Solen put right.

And it's August already... just to show show you how I think the summer has sped by, when I was falling asleep last night I was thinking I would have a long weekend because of Labor Day on Monday, but that's not until the first Monday in September! But I do feel as though my summer has been taken away from me by the 7 day weeks since the end of April. That is ending this weekend; but I'm putting Liubov on a plane to visit her older daughter's family in Seattle; I'm not on that plane because until very recently it was expected I would be working this weekend, too....


So maybe some speaker camp instead! There's lots to do, and a box of crossover parts on the way to arrive today...

[ergo]

Ok, based on off axis plots I was guessing this is a tweeter on it's own, but wanted to verify.

I've been building a bit bigger things than speakers over summer - though some guys might have subwoofer about the same size as the "tiny house" style summer cottage we are doing up. It's about 16m2 or 180 square feet total inside , but now has toilet, shower, kitchen and all other essentials.

The OLA project is also still ongoing. We've just agreed another listening and Xover tuning session for this Saturday with my friend, so after that I should have both the latest measurements and impressions to share in the OLA thread. Don't wanna steal Steve's thread too much

[JonMarsh]

Graphs look very promising indeed and that DA25 is a great find. Very good to see this project progressing steadily. Steve you have to keep Jon on a short leash though as it seems he's coming up with more new and old/new projects to last him for years to come

Seems I've dropped off a wagon for a bit though. Are these latest graps with DA25+ waveguide or a regular baffle mounting?

Also I assume the drive level is your usual 2.83V and measurement at 1m (just to but THD plots in context).

Hey Ergo!! Hope you're having a good summer!

No waveguide involved here- this is the "basic" MT design as a proof of concept for the new cabinet construction technique Steve has been woking on. Intended as a "demonstrator" of sorts, but also a decent basic design with some new drivers (for me).

Driver levels are the typical 2.83 VRMS- of course, the tweeter is padded down to match the woofer sensitivity. But it looks about the same running direct by itself.






I'm guessing that due to the relatively flat dome and the flat mounting plate, this accounts for the very consistent behavior on and off axis with just a steady drop off in level off axis with increasing frequency. I've measured a LOT of tweeters this summer and I just haven't been finding this level of consistency. If the motor wasn't good and clean, and capable of handling some power, that wouldn't be worth warm spit, but apparently the part was designed for high power handling and does quite well.

Now, I have done some weird things.. (not with the ones on this measurement setup above) - taken 4 apart, beefed up the kapton insulation and glued two of the faceplates together to make a stronger faceplate, leaving me with a couple of extra motor assemblies for a $100 each tweeter- net total cost.

Anyway, with the crossover design as it is, I can adjust the voicing just by changing the input resistor to the HF network. I think I'm close to a final value, checking and listening for hours (while I'm working!) but I've got a new DSP board coming in for the DAC so I may give it some time on that, too, before making my final suggestion to Steve. In the end, he'll listen and tweak too, I think.

Current listening setup is a Tascam transport driving the Denafrips Terminator DAC (haven't had time to get the music server up and running or my I2S setup going), feeding a Hestia Preamp into a Hyperion amplifier- it's a condo system, all my big guns are in storage in Idaho. Got to bench and report on them soon, too, but very good sound for the money. But I'm sure it's a leap of faith for people to buy stuff from Singapore sight unheard.

[Steve Manning]

Just to show Jon's not having all the fun of late and an idea for those interested in sprucing things up a bit. Here is a project just shipped out to a fellow group member who wanted to kick things up a notch.

The process started with selecting a nice piece of quartersawn Sapele.



A little water showing what it will look like after finish is applied.



Machining in progress ....



Finished parts.



Baffles have hidden magnets to work with existing grills.

[Steve Manning]

Graphs look very promising indeed and that DA25 is a great find. Very good to see this project progressing steadily. Steve you have to keep Jon on a short leash though as it seems he's coming up with more new and old/new projects to last him for years to come

Seems I've dropped off a wagon for a bit though. Are these latest graps with DA25+ waveguide or a regular baffle mounting?

Also I assume the drive level is your usual 2.83V and measurement at 1m (just to but THD plots in context).

Ergo, the problem with putting Jon on a leash is that he just keeps running in circles until you get tied in a knot and once you fall over he just drags you along for the ride anyway.

[ergo]

Graphs look very promising indeed and that DA25 is a great find. Very good to see this project progressing steadily. Steve you have to keep Jon on a short leash though as it seems he's coming up with more new and old/new projects to last him for years to come

Seems I've dropped off a wagon for a bit though. Are these latest graps with DA25+ waveguide or a regular baffle mounting?

Also I assume the drive level is your usual 2.83V and measurement at 1m (just to but THD plots in context).

[Steve Manning]

I am looking forward to these projects!

And there being built just around the corner from you.

[1Michael]

I am looking forward to these projects!

[JonMarsh]

A look at the individual drivers.

And how do the drivers look individually with their crossovers?


MW19P-8




DA25-TX002



You can certainly say it's a quirky build for the DA25, but with it's flat plate, stiff diaphragm and reasonably high performance motors, it's one of the best $300 tweeters I've ever measured of late... and the best one that doesn't cost $300.

[JonMarsh]

Slow work takes time...

But it eventually gets done! sometimes...

This is a test setup with just a 1 cu ft sealed enclosure on the woofer, no attempt to address sub 100Hz yet. Measured in room with a 200ms window; 1/24 octave smoothing- no trying to make things pretty and smooth with 1/3 octave smoothing.




For those that are curious, with and without the notch filter, showing distortion products. With this tweeter, you could likely leave it off without issues...





With ultrasonic notch filter



Polar response, 0 - 30 degrees, 10 degree increments- this would constitute the typical direct sound listening axis.




Polar response, 0 - 70 degrees, this is the forward 140 degree arc. These sound very good walking off to the side compared with most speakers.

[JonMarsh]

As a preemptive measure to the hair pulling, you could always do the Yul Brynner look.

Not quite ready to go there, but some days it is tempting...

[Steve Manning]

As a preemptive measure to the hair pulling, you could always do the Yul Brynner look.

[JonMarsh]

BTW, Steve, I had a much longer post in progress earlier but lost it, discussing power response and off axis measurements and how Kimmo’s VituixCAD makes it easy to address those points and analyze quickly what the power response actually looks like for a significant forward angle. For anyone interested in speaker measurement and design, I really recommend looking at the VituixCAD manual, and trying working with the software. I had two copies of the paid version before he made it freeware/donation ware, and I have donated to him recently because of what I perceive as value and will again soon due to some capabilities recently uncovered. I have no idea how hold he is or where he got the experience for writing that software, but he’s a first rate guy!

:T

And in my continuing role as Captain Obvious, it's a really great idea to take a look at any driver you're considering with multi-axis measurements (say, in 10 degree increments from 0 to 60 degrees) and process and import into VituixCAD and assess both the nominal SPL response PLUS the total power response- you can catch some funny behavior of drivers and identity issues with the cone dispersion pattern that need to be taken into account when choosing crossover frequencies. I've found this to be especially true for paper cone drivers with conventional geometries, but it's worth employing for any and all drivers.

Of course, I must warn you, this can lead to hair loss... the more you know, the pickier and more frustrated you may get, even doing things like measuring $400 tweeters... can result in a lot of personal hair pulling! :roll:

[JonMarsh]

@Jon - I'm interested in your voicing procedure and whether you have a target on-axis or power response that sounds pleasing to you across your test music (and what that looks like)... and how long it takes? It took me ages to voice my 3-ways to a point I liked (maybe I am using voicing as an excuse to cover up planning and design errors :-). If I was selling speakers, I'd be paranoid about getting the best out of them and ensuring satisfaction for any who bought them. Can't please them all must still apply.... Anyway, like many here, I'm following your progress with interest.

There are many thoughts about this- basically I agree that power response is just as important as axial response- and more difficult to manage.

A big factor often neglected is room setup- with conventional speakers and even most dipoles, your best off doing a Cardas room setup - neglect that and a lot goes out the window- you're listening to your room as much as the speaker.

But someone who made a big impression on me was Sigfried Linkwitz and the thoughts he had on that after one of his last upgrades to the Orion dipole design, and figuring out why he wasn't happy with it still. It came down to a fundamental voice choice about your design target- flat, or something else?


He did a fair amount of best practice research as well as his own investigation- saved me a lot of time!

So I "borrowed" the concept and designed an inline filter to do the same thing- it's described in this thread:

https://www.htguide.com/forum/showthread.php?43337-Report-back-on-stereo-speaker-voicing-investigation&highlight=Voicing+module

When Ergo was in the US on business and had a chance to drop by and give the Wavecor Ardent's a listen at a close friend of mine from work, those filters were installed in Jens's system- and we told Ergo about it ahead of time.

I think he liked what he heard, because he went back home and experimented with it- here's a quote from his comments:

"What I hear as a difference is much more than I expected. One would of course expect a bit of a change in sound balance, but what I experience is something more. Somehow the in a soundfield something 'clicks' to place. Without the mod especially with complex music the imaging tended to smear and the depth layering was not quite good. With this voicing curve both of these aspects change. I experience better imaging and depth even with double bass etc. I tried this cautiously multiple times and with different time intervals spent on either setting. I am in end confident enough to say that, yes - I do hear and like this setting a lot.
A good sign is also that it is all in all very hard to remove the setting and I end up listening long just for fun each time as it sounds so good.
Anyhow. I share my thoughts first via e-mail. "

I also agree with observation that this curve allows or even encourages to turn up the volume. Seems to sound especially good with higher volumes.

Higher volumes, as in one where the playback level is close to the original sound level.


Anyway, I suggest reading the thread if you haven't before, or maybe going back and resisting it.

For this current effort, I've got a test article that can use one switch and go back and forth between "flat" and "Voiced". Those will get sent back to Steve once I have a stereo pair built and tested.



Flat




Voiced





My preference would be just to go with the voiced mode, I think, but Steve owns this, and he's the one to make the call on what his preference is.

[Dave Bullet]

@Jon - I'm interested in your voicing procedure and whether you have a target on-axis or power response that sounds pleasing to you across your test music (and what that looks like)... and how long it takes? It took me ages to voice my 3-ways to a point I liked (maybe I am using voicing as an excuse to cover up planning and design errors :-). If I was selling speakers, I'd be paranoid about getting the best out of them and ensuring satisfaction for any who bought them. Can't please them all must still apply.... Anyway, like many here, I'm following your progress with interest.

[JonMarsh]

I'm still putting together some basic test cabs- have a new batch of crossover parts that should arrive today- 2nd pass on the crossover, with higher precision time offset data, and some tweaks to the design concept. Should be looking good- we'll find out. And testing two driver layouts. There's some other "different" things going on in these test cabinets we'll tell you about later if they work out.

Slow work takes time...




Ugly at this stage, but they will be sanded and painted when finished, (probably!) nice enough for workshop speakers.

[JonMarsh]

Definitely interesting and inspiring work that I'll continue to watch with interest. I have a small 6040 cnc, and of course one of the first main projects is to use it to build a bigger CNC :-). I'm in progress on a 4'x3' envelope build, and a 'statement' speaker project is definitely a motivating factor. I'm hoping to do something in the Sonus Faber Elipsa/Stradivari style, so definitely have a bit of design work ahead of me.

Yeah, but that's going to be a lot of FUN design work ahead of you!

:T

[dwk]

Definitely interesting and inspiring work that I'll continue to watch with interest. I have a small 6040 cnc, and of course one of the first main projects is to use it to build a bigger CNC :-). I'm in progress on a 4'x3' envelope build, and a 'statement' speaker project is definitely a motivating factor. I'm hoping to do something in the Sonus Faber Elipsa/Stradivari style, so definitely have a bit of design work ahead of me.

[scottvalentin]

Wow guys - I have been absent a bit from this board, and man what I missed!! This is excellent stuff!! Looking forward to those tweeter and WG test results Jon! Also good to hear you have picked a retirement window, even if the in-between is looking pretty full.

[Steve Manning]

Looks real nice Steve. How are you making the plates? Someone local with an etching machine of some sort?

You're using threaded rod to assemble this, are you using inserts in the top panel? Did you cut a slot in the rod on the bottom so you can use a flat screwdriver to bring everything down, or some other system to get it all tight together?

Just re-sent the email, we'll see how it goes. Bit rumbly out here this morning!

Thanks ..... No I made the plates myself on the CNC. That was the first one, I made a few more that I tweaked a few things for better results.

There are inserts all over the place in these ..... I should own stock in EZ Lock.

[technodanvan]

Looks real nice Steve. How are you making the plates? Someone local with an etching machine of some sort?

You're using threaded rod to assemble this, are you using inserts in the top panel? Did you cut a slot in the rod on the bottom so you can use a flat screwdriver to bring everything down, or some other system to get it all tight together?

Just re-sent the email, we'll see how it goes. Bit rumbly out here this morning!

[Steve Manning]

Any chance for a pic from the rear? Looks like you have an area flattened out somewhat for an input plate?

Also - I think your email server is down or something. I tried to get back to you earlier but I keep getting an error.

Here you go Danny




Playing around with name/binding post plate.



As an FYI the largest size can have a flat area large enough for a plate amp .... If one wanted to go with a powered bass section.


Not sure what was up with my email, I've been getting stuff today.

[technodanvan]

Any chance for a pic from the rear? Looks like you have an area flattened out somewhat for an input plate?

Also - I think your email server is down or something. I tried to get back to you earlier but I keep getting an error.

[Steve Manning]

Nice!
What do you plan on doing regarding paint?
Type, color, production metod - and will you do it or outsource it?

Thanks TEK.

Finish is going to be a waterborne tinted lacquer, comes out looking like paint, at least for mdf. If one were to go with Baltic birch or bamboo you would use a clear finish. I'm looking at a light grey for the bulk of things with black for the spacers. I'll be spraying it myself.

Now, the intent is to sell the machined parts and let the customer do the assembly and finishing themselves. Though for those interested finishing will be available.

[TEK]

Nice!
What do you plan on doing regarding paint?
Type, color, production metod - and will you do it or outsource it?

[Steve Manning]

To follow up on an earlier post by Jon .... We turn some renderings into reality.










The new router bit worked out well for the chamfers.

[JonMarsh]

Finished putting it together for test..

A new binding post plate and some RTV to do the job... testing on Thursday.






Who ever heard of testing a tweeter waveguide in a subwoofer cabinet? Clearly a sign of desperation... non-removable back, so a few dots of RTV to hold the wave-guide in place.

[JonMarsh]

Slow work takes time...

Who would believe the fastest way to get setup for testing a waveguide is a small sub enclosure?







Binding post plate ready to mount, might be able to find time to test Thursday....

[Bear]

I'd love to see how this compares to the SB26ADC in one of Brandon's (Augerpro) waveguides. They have similar sensitivity, but the SB26 is a 4 ohm part.

[JonMarsh]

Up for testing soon...

It's near the front of the queue....

















I have to finish a primary test baffle first...

[Steve Manning]

Yes- I have a lot of time in these. A full 2' x 4' 1" thick 8-ply was easily 50 pounds. To make the pair of boards, I troweled on the Titebond between layers to get coverage, then laid on the next piece and kept going, alternating rough/smooth sides to keep bow at a minimum. I had a clamped straight edge on one end using a 2' x 4' sheet of MDF as the clamping surface while drying. The perimeter was clamped, and large 25# weights placed in the middle to push it down. I do have a slight bit of bow to attend to yet, but that is fixable. It took just shy of a gallon of Titebond to make the 2 boards. At ~$6/sheet, multiplied by 16, and add a gallon of TB, and that is the cost of the material for me.

The slabs will flank the middle like this:
[ATTACH=CONFIG]29462[/ATTACH]

It's not unlike the Nimbus or Aurora from Vapor, except the fact that this has more layers and is non-curved. The central portion is a mix of HDF and 1/4" ply underlayment for a total of 45 pieces between the outer pair of plywood layers.

Time consuming, and not for everyone.
Wolf

Very nice Wolf. I did some playing around with some slightly thicker HDF for a test for a stand design. Kind of a proof of concept ..... just because you can draw it doesn't always means you can make it. :W Only 4 layers and it certainly is a solid mass when your done.

[wolf_teeth]

Yes- I have a lot of time in these. A full 2' x 4' 1" thick 8-ply was easily 50 pounds. To make the pair of boards, I troweled on the Titebond between layers to get coverage, then laid on the next piece and kept going, alternating rough/smooth sides to keep bow at a minimum. I had a clamped straight edge on one end using a 2' x 4' sheet of MDF as the clamping surface while drying. The perimeter was clamped, and large 25# weights placed in the middle to push it down. I do have a slight bit of bow to attend to yet, but that is fixable. It took just shy of a gallon of Titebond to make the 2 boards. At ~$6/sheet, multiplied by 16, and add a gallon of TB, and that is the cost of the material for me.

The slabs will flank the middle like this:


It's not unlike the Nimbus or Aurora from Vapor, except the fact that this has more layers and is non-curved. The central portion is a mix of HDF and 1/4" ply underlayment for a total of 45 pieces between the outer pair of plywood layers.

Time consuming, and not for everyone.
Wolf

[Steve Manning]

There's always DIY-laminated HDF-ply, as I've done. I will tell you though- the power tools will laugh at you when you go to cut it.
Attached is 4x 1" thick (8x 1/8" layers) slabs clamped together for sanding to the same dimension, and not completely finished sanding as some tool marks are still present.

And yes- this has been the most difficult material I've worked with.
Wolf

[ATTACH=CONFIG]29451[/ATTACH]

Now that would be time consuming, though rather solid when your done.

[Evil Twin]

Does not look like fun....

[wolf_teeth]

There's always DIY-laminated HDF-ply, as I've done. I will tell you though- the power tools will laugh at you when you go to cut it.
Attached is 4x 1" thick (8x 1/8" layers) slabs clamped together for sanding to the same dimension, and not completely finished sanding as some tool marks are still present.

And yes- this has been the most difficult material I've worked with.
Wolf

[cochinada]

Has any of you guys ever considered maybe building a speaker out of solid gold or even rhodium? After all you could build a fancy mold made of Panzerholz or Richlite.

[JonMarsh]

Ah, yeah... the stuff Gibson is using for some fretboards now, given they can't get ebony very easily...


Speaking of Panzerholz, you must be right about it being cheap, they're now even trying to sell phonograph cartridges made of it... of course, it doesn't take much per cartridge..

[Steve Manning]

I think he's talking about the panzerholzen or something- it's a special laminate made for armored cars, primarily.

So if you gotta stop bullets without hauling around a ton of metal, it's for you!

Yeah, I'm a cheap skate when building test enclosures, though not cheap enough to shop HD plywood.

Nope, Panzerholz is cheap compared to this stuff ..... this is Richlite. https://richlite.com/

[JonMarsh]

I think he's talking about the panzerholzen or something- it's a special laminate made for armored cars, primarily.

So if you gotta stop bullets without hauling around a ton of metal, it's for you!

Yeah, I'm a cheap skate when building test enclosures, though not cheap enough to shop HD plywood.

[Steve Manning]

I need some 1-1/2" BB ply for the test baffles for test enclosures on the Left Coast for finalizing crossover design and checking things out before the handover to Steve...

It's a shame, but the only thing close to that is the 1-3/8" maple Piano pin block ply, which is very fine stuff (see Kurosawa thread) but way too dear in price for this test box. So the only thing to do is to make it...


And to think Steve wonders why slow work takes time on the Left Coast...



[ATTACH=CONFIG]29434[/ATTACH]

I tried talking him into some of this lovely stuff ..... it comes in thicknesses up to 3". He didn't like the ~$3K per sheet price however. 8O

[JonMarsh]

When you can't buy 1-1/2" BB ply, you make it

I need some 1-1/2" BB ply for the test baffles for test enclosures on the Left Coast for finalizing crossover design and checking things out before the handover to Steve...

It's a shame, but the only thing close to that is the 1-3/8" maple Piano pin block ply, which is very fine stuff (see Kurosawa thread) but way too dear in price for this test box. So the only thing to do is to make it...


And to think Steve wonders why slow work takes time on the Left Coast...