D2415k

[pos]

A new D2 compression driver now appears in the VTX series: the D2415K 61641 61642 We had been warned (http://www.fohonline.com/images/stories/12/02/current/30.200.1202.pdf):
Prototypes having voice coils with diameters of 1.5-, 1.75- and 2- inches and 1- or 1.5-inch exits have also been developed by JBL. Probably a 1" driver. Would be interesting to compare to a 2407H or 2408H !

[martin_wu99]

Do you get more info about D2415k?

[macaroonie]

Well , that didn't take too long to pop out of the sausage factory. I wonder why the little one needs all those fins whereas the
big one has none.

This is the driver I think we will see a lot of in the future. Keen to get info on this as it emerges, Thanks POS.

There is also a VTX F series of 2 way boxes that might be of interest to some of the gang here.

D2 inside with a diff drive woof. No prices that I can find yet.

[Ed Zeppeli]

Interested in this too.

Thanks for posting!

[pos]

62599

[pos]

63669

63670

63671

[macaroonie]

As far as I can discern it's so far only in the small VTX line array. I'm sure we will see much more of this one as time goes on.

Good pix.

[ivica]

Hi POS,

Thank You for the info.

regards
ivica

[martin2395]

What is that yellow wire used for, connecting both positive poles of the diaphragms with each other?

[1audiohack]

The voice coils are connected in series so the jumper goes from front negative to rear positive. At least that's how the D2430K's were that I had here.

Barry.

[pos]

It appears the D2415K is actually a 0.8" exit driver, 21mm exactly:
http://www.jblpro.com/ProductAttachments/VTX-V20_SpecSheet_5.12.15.pdf

The diaphragms are 1.5" rings, similar to the single one in the 2407H.

It is basically a halved D2430K !

Now picture yourself a 1/1.8 version of the M2 waveguide, 25cm x 20cm, usable for 1.5kHz and up, and maintaining its 120° pattern up to the UHF...

[audiomagnate]

I know the D2430K is readily available for purchase, but does anyone know of a source for the D2415K? I think it would be fun so slap a pair into my big ol' SVA's, do a little DSP magic and see what comes of it. If not I might just have to try the 2430's in the same application.

[dubkarma]

Dumb question of the day: What bolt size does the D2430K require?

I assumed 1/4-20 thread in the standard 4-bolt pattern, but they seem to be slightly too large. Or at least they don't screw in all the way. And metric M6 doesn't fit at all.

TIA,

Joel.

[Flaesh]

http://reconingspeakers.com/product/jbl-5020810x-d2415k-high-frequency-driver-d2/#prettyPhoto -$330.00

[pos]

The photo is one of the two units that are on their way to me right now :D
Expect more photos to come, and response measurements once I make a proper horn or adapter.

part number is 5020810X

[bubbleboy76]

The photo is one of the two units that are on their way to me right now :D
Expect more photos to come, and response measurements once I make a proper horn or adapter.

part number is 5020810X

Nice :)

What kind of horn do you plan to use?

[NWCgrad]

Can this CD be used in a 1" exit horn? I assume no, but assumptions are often wrong.

[pos]

It is supposed to be a 0.8" driver.
In the long run I'd love to use it with a 8" driver underneath (synthesis 8 in a 2 way, or maybe 2250HPL in a 3 way) with a 1/2 scale M2 horn: http://www.audioheritage.org/vbulletin/showthread.php?35490-D2415k&p=379272&viewfull=1#post379272

But first I will most probably make a 0.8"/1" adapter with a flare similar to 242x drivers.
The only bold-on 1" horns I have here are the 2344, so I might as well try that.

[pos]

I received the units.
They are surprisingly tiny !

Exit is 21mm, bolting pattern 40mm, 4 screws.
Still have to determine the screw diameter, which is not an easy task when you only have metric screws at hand.
Inner diameter is around 3.6mm/0.14", if that rings a bell to anyone more used to imperial screws than I am :dont-know:

[bubbleboy76]

I received the units.
They are surprisingly tiny !


With impressive size-to-"noise"-ratio then, I presume :)

[pos]

Let's hope they can do more than just noise :D

[JeffW]

I received the units.
They are surprisingly tiny !

Exit is 21mm, bolting pattern 40mm, 4 screws.
Still have to determine the screw diameter, which is not an easy task when you only have metric screws at hand.
Inner diameter is around 3.6mm/0.14", if that rings a bell to anyone more used to imperial screws than I am :dont-know:

I'd guess #8, #8-32 is a pretty common size here.

[pos]

Thanks :)

[audiomagnate]

Reminds me of the Weber side drafts on my old coupe. They look like they mean business.

[dprice]

Looks like a Rock & Roll machine :bouncy:

[pos]

This driver is now used in the just released SCL-2 :
http://www.twice.com/thewire/harman-s-jbl-synthesis-introduces-scl-2-ultra-high-performance-wall-loudspeaker-ise-2017/64254


The SCL-2 is designed with a 2.5-way, triple 8-inch (200mm) driver configuration for low-frequency extension with high output capability and powerful dynamics. A D2415K dual voice coil, dual 1.5-inch (38mm) annular ring diaphragm Teonex® compression driver with advanced HDI geometry horn works in conjunction with powerful cast-frame, 8-inch (200mm) Advanced Aluminum Matrix cone woofers with low distortion motor structures.


The older SCL-3 and SCL-4 use the tiny 2409H driver already used in the 705i/708i

The SCL-2 seems to be exactly what I described here :

Now picture yourself a 1/1.8 version of the M2 waveguide, 25cm x 20cm, usable for 1.5kHz and up, and maintaining its 120° pattern up to the UHF...
:D

Perfect fit for a 8" woofer...

[pos]

Here are some pictures of the new SCL-2, alongside the SCL-3 and SCL-4, courtesy of Skylinestar on the AVS forum (http://www.avsforum.com/forum/89-speakers/2515137-official-jbl-synthesis-pro-revel-home-theater-thread-45.html#post50602961) :

75930

75931

[baldrick]

A guy here were on ISE show were they were JBL running 3xSCL-2 in front and SCL-4 elsewhere and 4xS2S-EX. He was very impressed and had no doubt that JBL were "ISE best in show".

[JuniorJBL]

POS,

Have you done anymore with your 2415's yet?

[pos]

nope :o:
I was to busy/lazy to build the 0.8"/1" adapter.

I will put this on hold for now in the hope of seeing it appear in the install series with a detachable (and available!) HDI waveguide.
I doubt the baffle of that synthesis speaker can be obtained as part (or can it?)

[JuniorJBL]

Yep, I would hope to see an additional WG to play with as well. Might be kind of hard to use the other even if it was available.:(

[AudioFan]

Yep, I would hope to see an additional WG to play with as well. Might be kind of hard to use the other even if it was available.:(

I am bumping this thread to see if anyone has attempted to build or modify a horn/waveguide to fit this Jr. D2 HF driver. I thought perhaps a 2404 horn might fit???

[Stéphane.B]

Hi there folks, first message here on the forum but I've be looking around since a looooong time and finally took the chance to contribute to the forum and give a little back myself.

So. I'm the happy owner of three new D2415K compression drivers I bought for my DIY projects and I wanted to share some pictures and findings that followed their unboxing.

First, a picture to illustrate the size of the driver next to an SEOS 12 waveguide :
81097

With the SEOS 12 on top
81098

Driver size is really small when you compare it to this 12" horn, we will need an adapter plate to attach it to an 1" Waveguide or a custom one. More on that later. Note that spacing between mounting holes on the driver are about 40mm.

Next is a closeup of the throat. I just quickly throw the SEOS 12 on top to snap some pics, here are the results
81099
81100
81101

Closeup pic reveal the protective mesh ring that is about one inch in diameter. Speaking of which... (see next post for more pictures, Audio Heritage limit is 5)

[Stéphane.B]

The mesh ring can be popped up !

I First give a try with my nail and feeling that it could come off, I grab a flat precision screwdriver, gently lift and the ring came out effortlessly with breaking or bending. In fact, there is only little glue bonding it and the remnants can be easily removed.
81116

Closeup of throat
81117

Closer
81118

From a different angle we can see better the exit of the phase plug
81119
81120

For the next stage I made some basic impedance measurements...

[Stéphane.B]

And was pretty surprised to see the two drivers in series were 17.9 ohms !
81121

Each driver are respectively 9 and 9.2 ohms
81122
81123

I measured the other two drivers and also found an impedance around 18 ohms
81124


Driver physical measurements done with a digital caliper. Of course I rounded some values but if one want to make a precise Waveguide or scaled down M2, I think we need some precision.


Throat 19.6mm/0.77"


Outer ring 25.9mm/1.02"


Throat depth 30.2mm/1.19"


Ring mesh outside 25.35mm/0.998"


Ring mesh outside 20.86mm/0.82"


Ring mesh height 1.3mm/0.047"


Mounting holes 40mm/1.575"




Driver dimensions


Height 73.24mm/2.88"


Diameter 70.2mm/2.76"


Mounting ring diameter 45.9mm/1.8"


Mounting ring height 6mm/0.236"


The biggest disappointment for me is that I couldn't find the exit throat angle of the D2415K, I even asked Speaker Exchange but they could only get for me the same data as in the VTX-V20 brochure... bummer.

Any JBL Gurus out there who help us find this information ? Or is there any DIY way to get it, for instance, make a mold of the throat ? Or find a way to measure more deeply inside the throat with a caliper ?
Thanks.

[macaroonie]

Hi Stephane , thanks for taking the time to post these excellent pics and info.

To guage the exit angle I would suggest you make a round ball of childrens play putty and gently work it into the throat. You should be able to get enough of the angle left on the material so that you can measure it.

You will be safe doing this as the moving parts are not near the throat.

As it happens I am helping POS with the problem of mounting. In your case mounting to a bolt on , in his case mounting to a 1 1/8" screw on.
If you can find the angle it will be easy to design an adapter for bolt on.
Screw on has some complications but we think we have a solution , waiting on adapters that will then be modified.

[macaroonie]

81213

81214

Anyone have the faintest idea of the mounting screw guage ? metric or imperial ?

[pos]

:hurray:
I am so glad you are helping me with this!


Regarding bolt size, here is the info I was able to gather so far:
http://www.audioheritage.org/vbulletin/showthread.php?35490-D2415k&p=397881&viewfull=1#post397881
0.14" inner diameter, and I could not find any metric bolt that fits.
could be #8-32 : http://www.audioheritage.org/vbulletin/showthread.php?35490-D2415k&p=397891&viewfull=1#post397891
I can't remember if I tested this, and I don't even know if I have 8-32 bolts at home.

[pos]

The biggest disappointment for me is that I couldn't find the exit throat angle of the D2415K, I even asked Speaker Exchange but they could only get for me the same data as in the VTX-V20 brochure... bummer.

Hi Stéphane,

I don't think you need to match the exit angle here.
This compression is supposed to present a flat wave shape at its exit up to the UHF, so that means the best bet is probably to consider it a 0° exit angle.

Regarding the best horn to use, a scaled-down version of the D2 waveguide would be the ticket as you mention.
It would be usable down to 1600Hz with a 8" woofer underneath, à la SCL-2: http://www.audioheritage.org/vbulletin/showthread.php?40470-Jbl-scl-2

Scanning a D2 waveguide and printing the scaled down version would be a solution (hint: I have the D2 waveguides here, if you have the scanner and printer ;) )

I plan to measure this compression with a 6" PT waveguide (the one used in the AC16), and compare it to the 2407 on the same waveguide (including off axis measurements).
All that should be possible soon thanks to the wonderful work Mac is doing on the adapters! :bouncy:

[macaroonie]

Just in case anyone out there is looking to use the 2415 on a thread in horn herels how I went about getting a fit.

The driver is tiny , and as described and measured the exit is 20mm . Most adapters are 24.5mm entry and for some reason a smidge smaller at the exit ( 0.94" ) but that seems to be the entry diameter for 1 3/8" screw on.

So the problem is that in the absence of ready made adapters and not having a lathe readily to hand i figured out a cheap way to McGuyver the modification of an off the shelf adaptor.

POS and I stumbled a little at the first hurdle , we got an adapter from Blue Aran here in the UK. Nice enough unit but it had a strange constriction in the middle where the bore reduced to about 16mm. I'm not sure what that was meant to do but it was not a fit for our cunning plan. Back they went.

So , POS went on the hunt on the www and among others came up with this.

https://www.ebay.fr/itm/282944921113

and about a week later they arrived in my post.

I was immediately impressed with the machining quality and overall finish , plus , the mounting slots and pre drilled holes offer just about every option you are likely to encounter.

So I'm looking to reduce the entry diameter to 20 mm. This drill has a 20mm step on it so .....

81225

I then got some worktop laminate ( melamine ) that I had kicking about and drilled a hole in it. It helps if you drill a backing hole as the laminate is brittle so needs support. Then I cleaned off any rag edges and stuck it on the entry side of the adaptor. I just used solvent based household glue. Nothing too permanent.
Then I centered it by eye to get this Let it set.

81227

The next step is to apply 2 part filler ( Bondo , Isopon etc ) It will help to scratch the surface inside first. Use a popsicle stick or similar and build up the taper. Don't be too heavy with the filler , you will end up with more sanding than you need to do.
Sanding can be done with copper pipe and 80 grit.

81228

81229

As is the way of these things the second one went much easier than the first. I found that it is best to sand from the snout end as this allows more control over any chance of expanding the entry hole
Let that cure and then remove the hole template and clean up glue residue.

The next step is to provide the mounting holes for the 2415. These are on a 40mm PCD and the snout threads are 33mm so there is only 3.5mm from the center of the hole till you whack the threads.
As far as I can gather the mounting screws are 4mm dia max so a 5 mm hole will be ample and allow some wiggle room to center the entry with the throat of the driver.
I did think about just extending the slots and started on one. Too much work.
I have a plan but I need to get in a pillar drill to get these accurately placed.

Carry on ....Mac










81226

[dn92]

:hurray:
I am so glad you are helping me with this!


Regarding bolt size, here is the info I was able to gather so far:
http://www.audioheritage.org/vbulletin/showthread.php?35490-D2415k&p=397881&viewfull=1#post397881
0.14" inner diameter, and I could not find any metric bolt that fits.
could be #8-32 : http://www.audioheritage.org/vbulletin/showthread.php?35490-D2415k&p=397891&viewfull=1#post397891
I can't remember if I tested this, and I don't even know if I have 8-32 bolts at home.

I was in USA last month and I bought some screews, I could have bring some to you.
#8-32 are screews used for 2402 mounting plate, if I'm not wrong, I've some but not with a flat head.

[pos]

I just tried 8-32 UNC and... it does not fit.

[hlaari]

I just tried 8-32 UNC and... it does not fit.


1/4-20 X 3/4 are the right screws you need




Ari

[pos]

Hi Ari,

Thank you.
Are you sure of that? It looks much bigger than what I measured.

[macaroonie]

There seems to be some confusion regarding the mounting screw spec for these tiny drivers.
It is NOT the same as on the D2 2430K. In European size the hole is just less than 4mm which translates to 5/32" Anyone have the faintest idea what thread this will most likely be ??

Anyway I pressed on and after much measuring I came up with this.

Using a 6mm drill and resting against the threads I drilled the 4 holes. As it turned out this provides a very good 40mm PCD for the holes , just what is called for on the driver.
As you can see I have filed away a little at the base of the snout to allow the screw head to seat properly.
Depending on the screws that POS gets he may have to do a little more filing.....
otherwise I think he will be good to go :)

81275

81276

81277

Hopefully this will help anyone wishing to get a 2415 HF working with a screw on W/G or Horn

[hlaari]

Hi Ari,

Thank you.
Are you sure of that? It looks much bigger than what I measured.


Yes, I think so, just buy one bolt and try him?

[macaroonie]

The mounting screws are item no. 48. This is a snip from the VTX20 service doc.

I take it that the 1/4" screws mount the plate to the waveguide


81287

The solution to the puzzle for anyone in Europe stuck finding the correct screw is :

803-13014-06


SCR, 8-32 X 3/8, FLT, HEX DR, BLK, ALLOY

[hlaari]

The mounting screws are item no. 48. This is a snip from the VTX20 service doc.

I take it that the 1/4" screws mount the plate to the waveguide


81287

The solution to the puzzle for anyone in Europe stuck finding the correct screw is :

803-13014-06


SCR, 8-32 X 3/8, FLT, HEX DR, BLK, ALLOY


Ok, great at you did find the right size:)

[dn92]

.

[macaroonie]

Ok, great at you did find the right size:)

That is the correct spec. and part number

I know it's a wonky system . One day the US will wake up and start using metric :)

[1audiohack]

...One day the US will wake up and start using metric :)

Do you really think we don’t?

Using both keeps the tool companies busy. :)

Barry.

[sguttag]

There are two types of countries. Those that have been to the moon and those that use the metric system:p

In truth, it all depends on what industry you are in as to how you measure things. Heck, in my industry, cinema, we've always measured width in metric but length in imperial. Think about it. It is 35mm film but shot/consumed in footage!

Back when I was in college (quite some time ago now), one of my Engineering profs felt that what was keeping "SAE" units was the 1/4-20 fastener. While still popular, I'm sure metric fasteners has encroached on its dominance. And in Digital cinema, just about everything is metric now.

That said, the D2430K uses 1/4-20 fasteners and I'd presume the D2415K (I haven't used that one yet).

[hlaari]

[QUOTE=sguttag;415190]There are two types of countries. Those that have been to the moon and those that use the metric system:p


Do you really think at someone have been on the moon?

[1audiohack]

[QUOTE=sguttag;415190]There are two types of countries. Those that have been to the moon and those that use the metric system:p


Do you really think at someone have been on the moon?


Topic swerve!!

I do. :)

Barry.

[Ian Mackenzie]

I think it’s more about tooling and the business impact of a change to metric
Then there is the busines impact on the industry user with product.

I don’t think they were bargaining on too many diy guys getting in on the act.

Having done a stint in business platform transformation l can tell you “change” has lots of consequences directly and indirectly. People are so accustomed to a standard practice they are on autopilot.

[dn92]

As long as it fixes two pieces together we don't care.
But for us in EU it might be impossible to find some models of imperial units screws as they are simply not available. The online shops having them available are not delivering outside USA. In USA as you have both you don't care. But imagine you want to test a compression driver coming from EU (BMS, 18s, Faital....) and the screws to attach them were not available.

PS: It is better to go to the Moon/Mars and beyond alltogether

[Ian Mackenzie]

I have the Bolt shop within 15 Km

Email and PayPal are a powerful thing for diy

[hlaari]

As long as it fixes two pieces together we don't care.
But for us in EU it might be impossible to find some models of imperial units screws as they are simply not available. The online shops having them available are not delivering outside USA. In USA as you have both you don't care. But imagine you want to test a compression driver coming from EU (BMS, 18s, Faital....) and the screws to attach them were not available.

PS: It is better to go to the Moon/Mars and beyond alltogether


I am totally agree with you:)
this was just small of topic answer from me

[pos]

I have 8-32 UNC scew here and I can confirm they do not fit.
Could it be 8-36 UNF screws? Could JBL spec sheet possibly be wrong?...
http://www.carbidedepot.com/formulas-tap-standard.htm

As for getting imperial screws in Europe, I have had great success with this German webshop in the past:
http://www.zollshop.de

So if the thread is actually 8-36 UNF here is what I will get:
http://www.zollshop.de/de/zollschrauben-edelstahl/innensechskantschrauben-edelstahl-unf/no-1-12-innensechskantschrauben-edelstahl/no-8-36-unf-innensechskantschrauben-edelstahl/8-36-unf-x-3-8-zoll-laenge-9-53-mm-edelstahl-a2-innensechskantschraube
http://www.zollshop.de/de/zollwerkzeuge/innensechskantschluessel-zoll/innensechskantschluessel-9-64-zoll

Here are the 8-32 UNC I tried:
http://www.zollshop.de/de/zollschrauben-nr.-1-12-unc/-empty-2/-empty-6
Does not fit by hand past the first fraction of millimeter.
Anything I might have overlooked?

[dn92]

"Does not fit by hand past the first fraction of millimeter"

Did you try with metric screews :D ?

[sguttag]

I would definitely try metric screws. The part number definitely is in the JBL system as an 8-32 but I wouldn't put it past them to get it wrong on the drawing. Remember the M2 crossover shows a wrong value on a capacitor. Things happen, people make mistakes. It isn't like most flown equipment doesn't use metric hardware rigging. It isn't like metric isn't in the JBL plants already.

I'd be flabbergasted if it was an obscure size like 8-36. It isn't until we get to #10 hardware that one sees UNC and UNF stuff. An Altec, they liked using 3/8 UNC AND UNF on the same stud for mounting the 288 and like drivers.

[1audiohack]

I have 8-32.... Does not fit by hand past the first fraction of millimeter.
Anything I might have overlooked?

You're just not trying hard enough! :p

Barry.

[pos]

I got the adapters from Mac today.
Beautiful work, kudos to him!
I hope to be able to measure the D2415K on the small 6" PT waveguide soon, and compare it with a 2407H.
I still need to find the correct screw (with a small head in both width and height), but measurements can be taken with the driver sitting on the floor, facing up.
81367
81368
81369

There is still a small discontinuity here, I might try to apply some clay here during measurements to see if that changes the UHF response:
81370

very little room for the screw head here, might have to use a sunken head, or maybe chop 2 or 3mm off the horn (see last picture in the following post)
81371

[pos]

cont.

full stack!
81372
81373

Should not be a problem to remove a few millimeters here using a belt sander, in order to get more room for the screw head:
81374

[macaroonie]

Looks good , glad the fit at the driver exit worked out OK. You will be nip and tuck with the screw heads , on balance I think the belt sander is the way to go so cancel my suggestion of using a grinder. I would use the first thread as a guide to keep things neat and tidy. You will get some plastic burr at the edges but a sharp knife will clean that up.

I'm looking forwards to seeing how well these wee guys measure up.

Delighted to be of assistance POS. :)

[ivica]

cont.

Should not be a problem to remove a few millimeters here using a belt sander, in order to get more room for the screw head:


Hi POS,

it would be interesting to show us F/R response and the 'dispersion' characteristics of such driver&horn combo.

regards
ivica

[pos]

I have 8-32... Does not fit by hand past the first fraction of millimeter.
Anything I might have overlooked?You're just not trying hard enough! :p

I though this was a joke, but it turns out you were 100% right there :o:

I ordered the "official" part from speaker exchange, the one that Mac found when digging VTX exploded views.
It did not fit by hand, just like the 8-32 I had here, but when using more force and a screw driver they did fit.
It appears the thread was a bit tight, but once screwed/unscrewd once they do fit by hand.

Sorry for the confusion: 8-32 UNC is the reference to use.

[Robh3606]

Could you fit an allen-key hex heads in there smaller pattern than a screw 8-32 should be easy to find.

Rob

[Stéphane.B]

Bon Pos, maintenant on veut savoir comment ça sonne ! ;)

Pos, now we want to know how it sounds !

[pos]

I did not try them yet :o:
I feel sorry because Mac was so quick and willing to help me and did a fantastic job with the adapters, but I simply do not have the time right now to conduct the experiment...

[300Z]

Any update on this?

[pos]

I am afraid not :(

[300Z]

Alright, thank you.

[AudioFan]

I just have to do it. (BUMP) I am still interested in this little compression driver, (D2415K).Has anyone actually used one in DIY speaker system yet? Are there any measurements from such a system?Thanks to anyone contributing to this inquiry.