Jbl scl-2

[lesliew]

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Does anyone have a part number for the woofers JBL are using in the SCL-2, they have published the part number for the CD but apart from a description I've seen nothing else posted about the woofers.

Description
"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."

I would like to kick off a mini project for purely educational reasons of course to digitise the M2 waveguide and turn that into a cad file of the SCL-2 baffle that can be cut using a CNC machine to produce my own clone SCL-2. The file could also be 3D printed provided you had access to a large enough 3D printer. The Baffle and crossover will be the trickiest parts to reconstruct. The cabinet is very basic.

I would probably start out doing a proof of concept using MDF, but the final baffle would be cut out of 1" thick Black expanded PVC which is available in 4x8 sheets which may need to be bonded together to obtain a sheet deep enough to cut the waveguide from.

Well in fact my M2's are probably too large to go under the CNC to digitise so I just purchased a pair of the LSR308's which will be much easier to work with.

So please if you have any thoughts or information on the woofers or crossovers just chime in I think this could be a fun little project.

[bubbleboy76]

79542

795457954379544


79546

Does anyone have a part number for the woofers JBL are using in the SCL-2, they have published the part number for the CD but apart from a description I've seen nothing else posted about the woofers.

Description
"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."

I would like to kick off a mini project for purely educational reasons of course to digitise the M2 waveguide and turn that into a cad file of the SCL-2 baffle that can be cut using a CNC machine to produce my own clone SCL-2. The file could also be 3D printed provided you had access to a large enough 3D printer. The Baffle and crossover will be the trickiest parts to reconstruct. The cabinet is very basic.

I would probably start out doing a proof of concept using MDF, but the final baffle would be cut out of 1" thick Black expanded PVC which is available in 4x8 sheets which may need to be bonded together to obtain a sheet deep enough to cut the waveguide from.

Well in fact my M2's are probably too large to go under the CNC to digitise so I just purchased a pair of the LSR308's which will be much easier to work with.

So please if you have any thoughts or information on the woofers or crossovers just chime in I think this could be a fun little project.

It seems to be a common misunderstanding that all the horns that resembles the M2-horn is a M2-horn. The SCL line has a newer generation of horn. It is not the same as M2.
Another example, LSR305 has not the same horn as LSR705, although they might look the same at an glance.
Every horn is an specific adaptation for the driver it will be used with. That is my understanding of it.

[lesliew]

It seems to be a common misunderstanding that all the horns that resembles the M2-horn is a M2-horn. The SCL line has a newer generation of horn. It is not the same as M2.
Another example, LSR305 has not the same horn as LSR705, although they might look the same at an glance.
Every horn is an specific adaptation for the driver it will be used with. That is my understanding of it.

Yes that's my understanding too and I'm kind of planning an iterative approach to this, digitizing the 308 horn is the easiest and quickest way to try the process to see if this is do-able. I picked up a pair of the 308's new from B&H photo for $260 so it was really a no brainer to kick this off. If the digitizing works and I can create a 3D file that I can then use to recreate that waveguide, then I would probably go ahead and take the waveguide off my M2 and give that a shot. LSR 708i's are slowly coming down in price so who knows, later on I could probably order one of these digitize the waveguide and return it in the 30 day window if I decide not to keep it. Its far too early to expect to see an SCL-2 on the used market but in time it will happen or by then I may have enough 3D models to be able to produce something pretty close to the full SCL baffle without having one.

In terms of hardware to get this done I already have 2 3D printers and have started ordering the parts to build a larger machine based on the D-BOT design, the only problem building a 4ft 3D printer large enough to print the SCL-2 baffle is the rigidity but I also have a 4*8 CNC machine so this would be a really good project for me.

My end goal would be to clone the SCL-2 but that would be largely dependent on identifying and obtaining the woofers. The CD is already in stock at speaker exchange and since I am in Florida I will probably go and pick one of those up in the next few weeks.

[Val]

Interesting product. What makes it 2.5 way?

[Don C]

I don't think that JBL is giving names to these woofers, just part numbers. They may not be JBL products. From the back they look the same as Revel woofers. The similar 6.5 inch drivers in my Sam3s are p/n 361030-001
The number in these photos are too small and blurry, but it looks like 361072-001.
The 2.5 way term is probably referring to a different filter frequency for the third woofer.

[lesliew]

I don't think that JBL is giving names to these woofers, just part numbers. They may not be JBL products. From the back they look the same as Revel woofers. The similar 6.5 inch drivers in my Sam3s are p/n 361030-001
The number in these photos are too small and blurry, but it looks like 361072-001.

Yes that certainly makes sense if they are using Revel drivers why they would not refer to them in the literature. Do you have a link to the 6.5" revel drivers, google does not return anything meaningful when I do a search.



The 2.5 way term is probably referring to a different filter frequency for the third woofer.

[/QUOTE]

That was also my first thought

[Val]

The 2.5 way term is probably referring to a different filter frequency for the third woofer.

Sort of makes sense. So I guess that makes the Everest DD67000 a 3.5 way. :)

[Don C]

I don't know that Revel makes their own drivers. The salon 2 woofers are similar, not identical. They have inverted domes, like the JBL performance series. And the frames are cut to make them fit closer together on the baffle. But the family resemblance is unmistakable.

http://revelspeakers.com/revel-ultima2.html

[grumpy]

Looks a lot like a rear-mounted synthesis-8 driver... perhaps with different "soft" bits (e.g., cone description sounds slightly different... more Infinity-like. Harman has a lot of drawers to pull bits and tech from)

[pos]

Hello lesliew,

I am toying with a similar idea myself: http://www.audioheritage.org/vbulletin/showthread.php?35490-D2415k&p=402536&viewfull=1#post402536

A 1/1.8 (or so...) version of the M2 waveguide would probably be the best bet here.
The LSR308 waveguide will not work properly with a compression driver because it is meant to accommodate for the non planar wave front of the dome tweeter, whereas a compression driver like the D2415K will present a flat wave front up to the UHF. The LSR708 waveguide would be a better bet (scaled up to match the exit of a D2415K), but with a narrower vertical directivity that will necessarily result in a more descending power response.

Regarding the woofer, as grumpy noted it looks very similar to the synthesis 8:
http://www.audioheritage.org/vbulletin/showthread.php?22534-Synthesis-8
http://www.audioheritage.org/vbulletin/showthread.php?36103-SAM2LF-unboxing-to-the-bone

I have a pair of D2415K at hand, as well as a pair of synthesis 8 woofers, so I am eagerly waiting for your progress :D

The arrangement with three 8" woofers (two helpers I guess) is interesting with an inwall configuration, but if depth is not a problem a 12" or 15" woofer would probably do fine togheter with a single 8" and a crossover around 200Hz.

[pos]

The number in these photos are too small and blurry, but it looks like 361072-001.
In that case it is indeed a synthesis 8 woofer :
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=63092&d=1410034740

[lesliew]

Hello lesliew,

I am toying with a similar idea myself: http://www.audioheritage.org/vbulletin/showthread.php?35490-D2415k&p=402536&viewfull=1#post402536

A 1/1.8 (or so...) version of the M2 waveguide would probably be the best bet here.
The LSR308 waveguide will not work properly with a compression driver because it is meant to accommodate for the non planar wave front of the dome tweeter, whereas a compression driver like the D2415K will present a flat wave front up to the UHF. The LSR708 waveguide would be a better bet (scaled up to match the exit of a D2415K), but with a narrower vertical directivity that will necessarily result in a more descending power response.

Regarding the woofer, as grumpy noted it looks very similar to the synthesis 8:
http://www.audioheritage.org/vbulletin/showthread.php?22534-Synthesis-8
http://www.audioheritage.org/vbulletin/showthread.php?36103-SAM2LF-unboxing-to-the-bone

I have a pair of D2415K at hand, as well as a pair of synthesis 8 woofers, so I am eagerly waiting for your progress :D

The arrangement with three 8" woofers (two helpers I guess) is interesting with an inwall configuration, but if depth is not a problem a 12" or 15" woofer would probably do fine togheter with a single 8" and a crossover around 200Hz.


Hi POS

Happy new year

Are the Synthesis 8 woofers available through special order, seems like they have been available for some time but I don't see them listed anywhere. My plan would be to produce clones that I can mount in-wall so I would definitely like to pick up a few of these if I can.

Probably will start with the LSR308 just to test the process out, never used a digitizer on my CNC before so I can imagine it's going to take quite a few attempts before I come up with a process which is accurate and repeatable, so at this point I'm not particularly bothered that I can't mount a regular CD on whatever comes out of my first attempts. As mentioned above if the process works then I can try it on one of the M2 waveguides and move on from there.

Glad to hear that your also interested in producing something similar - alot more likely that we'll come up with a working solution. :)

[pos]

The more the merrier!

When the SAM2LF came out member 4313B tried to order a few of these woofers for members, but it did not work out.
I had to buy a used SAM2LF to get hold of these, and this is probably still the best way to get them.
SEAS magnesium drivers (http://www.seas.no/index.php?option=com_content&view=article&id=360:e0022-08s-w22ex001&catid=49:excel-woofers&Itemid=359) could be an interesting alternative.

[Ian Mackenzie]

Keep and eye on reconers website

On the wave guide have a look at Patrick Batemans thread over on diy Audio.com

Patrick had used his CAD skills to re engineer the M2 and derivatives using semi spheres http://www.diyaudio.com/forums/multi-way/315625-wave-biradial-horn.html

[lesliew]

Keep and eye on reconers website

On the wave guide have a look at Patrick Batemans thread over on diy Audio.com

Patrick had used his CAD skills to re engineer the M2 and derivatives using semi spheres http://www.diyaudio.com/forums/multi-way/315625-wave-biradial-horn.html

Thanks for the heads up, totally different approach but makes an interesting read.

[pos]

Did you purchase the D2415K?

Looking at the wiring and manual it looks like only one woofer reaches 1.3kHz, and that would be the middle one, right under the horn (white wire vs green ones).
This is also hinted by the position of the listening axis in the manual, right between that woofer and the horn:
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Now, the SCL2 being a 2.5 way (as per its spec sheet), that particular woofer does not have a 225Hz high-pass filter.
Having the three woofers playing in the < 225Hz range gives a 3.5dB SPL capacity boost compared to only two, but at the cost of more IMD in the 225HZ-1.3kHz range.
Makes me wonder why they did not use other woofers more suited for LF (and cheaper with more conventional cones and motors) in the < 225Hz range, letting the pricey synthesis 8 woofer concentrate on the > 225Hz range.


... or maybe my guessing on the SCL2 crossover topology is completely off :D
(that 6 ohm / 92dB/1W/1m spec sure looks suspicious...)
Could the upper and lower woofers (green wires) be the ones that go up to 1.3 kHz, and the middle one (white wire) be the help woofer??
That would match the sensitivity rating, and even match the listening axis advice in the manual, but I find it hard to believe... :blink:

[lesliew]

^^^

No didn't pickup the CD yet, been distracted by a few new toys.

Interesting thoughts on the woofers, I saw the SCL-2's at CEDIA last year wasn't particularly attracted to them at the time but I now wish that I'd paid closer attention to them.

[jlyons]

[QUOTE=lesliew;411639]^^^



Interesting thoughts on the woofers, I saw the SCL-2's at CEDIA

I found three of these Synthesis 8 lf transducers, as shared in SAM2LF and the SCL 2, and note the application in each case is a sealed backbox or cabinet. I wonder about the effect of using a vented box, and what might be proper tuning. I want to maximize the low distortion of this woofer rather than efficiency and extension, which seem to be the goals of plural woofers in SAM and SCL.... thank you, JLyons