custom SVG transducers

[werewolf]

Hello forum! Please indulge me, if i may, and entertain a question or two ...

Let's say a guy holds JBL's SVG (Super Vented Gap) motor in the highest regard (for management of distortion, inductance, heat) ... so much so, that this crazy guy wants to create "new" custom drivers with this technology. Is it possible (and is it wise?) to do the following :

1. 15" SVG : Bolt the magnet/motor assembly from a new, readily-available 18" 2242 to the frame of a new, readily-available 15" 2226. Use the cone of the 2226 (from a new re-cone kit, perhaps), but use the coil/former from a new 2242 re-cone kit. Spider from the 2242 re-cone as well, i'm thinking ... ??

2. 12" SVG : same idea, of course ... but using the frame, and cone, from a new, readily-available 2206.

Is this possible? Certainly not very "cost effective", but let's put money aside for the moment as we entertain the "thought experiment". I'm not particularly worried about the loss of efficiency that may result from a heavier cone and/or coil ... compared to a 2227, for example ... and would even welcome a lower resonant frequency (Fs).

Please share your thoughts, and, finally, please tell me who may be both skilled and willing to perform the necessary surgery with precision!

Thanks in advance! Great to be here,

Jeff S.

[1audiohack]

Howdy and welcome to Lansing Heritage.

What you are getting to is a SUB1500. 2242 motor and spider with a longer coil, low Fs in a 15" basket.

Barry.

[cooky1257]

Hello forum! Please indulge me, if i may, and entertain a question or two ...

Let's say a guy holds JBL's SVG (Super Vented Gap) motor in the highest regard (for management of distortion, inductance, heat) ... so much so, that this crazy guy wants to create "new" custom drivers with this technology. Is it possible (and is it wise?) to do the following :

1. 15" SVG : Bolt the magnet/motor assembly from a new, readily-available 18" 2242 to the frame of a new, readily-available 15" 2226. Use the cone of the 2226 (from a new re-cone kit, perhaps), but use the coil/former from a new 2242 re-cone kit. Spider from the 2242 re-cone as well, i'm thinking ... ??

2. 12" SVG : same idea, of course ... but using the frame, and cone, from a new, readily-available 2206.

Is this possible? Certainly not very "cost effective", but let's put money aside for the moment as we entertain the "thought experiment". I'm not particularly worried about the loss of efficiency that may result from a heavier cone and/or coil ... compared to a 2227, for example ... and would even welcome a lower resonant frequency (Fs).

Please share your thoughts, and, finally, please tell me who may be both skilled and willing to perform the necessary surgery with precision!

Thanks in advance! Great to be here,

Jeff S.
In the case of 1. Why not just buy an ME150H?

[werewolf]

Thank you guys!

1audiohack: the SUB1500 is quite interesting, but JBL might have gone a bit too far in cone mass (lowering both Fs and efficiency), if memory serves. And it's not readily available :( but i'll definitely search for one or two anyway :)

cooky1257: the ME150 (part number 317294-001) is VERY interesting, but it's not quite clear if it's still available:

http://www.audioheritage.org/vbulletin/showthread.php?39219-JBL-ME150H-woofer-WTB&highlight=me150

I'll be contacting Harman on Monday to see :)


Please keep the comments coming! I'm really feeling adventurous enough to build a few, and i'm thinking edgewound might be the guy to talk to directly ...

[Dave Zan]

...the ME150...but it's not quite clear if it's still available:
... Harman on Monday to see :)

Did you ever receive an answer on this?
The ME150 does look pretty nice.
There was an AES paper by one of the JBL experts that analysed and measured several manufacturers' hi-efficiency 15" drivers.
They were not identified by brand or model but it was possible to work most of them out from the specifications.
The ME150 did well in every measure, looked the best overall to my mind.

Best wishes
David

[werewolf]

Did you ever receive an answer on this?
The ME150 does look pretty nice.
There was an AES paper by one of the JBL experts that analysed and measured several manufacturers' hi-efficiency 15" drivers.
They were not identified by brand or model but it was possible to work most of them out from the specifications.
The ME150 did well in every measure, looked the best overall to my mind.

Best wishes
David
Thanks Dave,

I think the supply of NOS (new old stock) ME150s is all-but exhausted, but i might have a lead on a single one ...
Do you have more details on the AES paper (date or publication number)?

Jeff S.

[Dave Zan]

..Do you have more details on the AES paper...

"Design Parameters and Trade-Offs in Large Diameter Transducers"
D.J. Button, JBL Harman
91st Convention, October 4-8, New York.

Best Wishes
David

Haven't checked the T/S parameters but isn't your first proposal basically a 2227?

[werewolf]

"Design Parameters and Trade-Offs in Large Diameter Transducers"
D.J. Button, JBL Harman
91st Convention, October 4-8, New York.

Best Wishes
David

Haven't checked the T/S parameters but isn't your first proposal basically a 2227?

Regarding the 2227, the answer is, essentially, yes ... with a few possible exceptions :

- a stiffer cone (from the 2226), i think, with perhaps slightly more moving mass for a slightly lower Fs (and slightly worse efficiency). This is assuming that a 2226 cone with the 2227-like former and coil will result in higher moving mass than either the 2226 or 2227.

- readily available with new parts!! (although not really "cost effective")

Thanks for the AES reference! :)

[1audiohack]

Regarding the 2227, the answer is, essentially, yes ... with a few possible exceptions :

- a stiffer cone (from the 2226), i think, with perhaps slightly more moving mass for a slightly lower Fs (and slightly worse efficiency). This is assuming that a 2226 cone with the 2227-like former and coil will result in higher moving mass than either the 2226 or 2227...

I have a pair of these. They sound and measure pretty much like a 2226. Softer suspension would make them better.

Barry.

[Dave Zan]

Regarding the 2227, the answer is, essentially, yes ... with a few possible exceptions :

- a stiffer cone (from the 2226)...

I suspect that the 2227 is basically a 2226 cone with the SVG voice coil.
The difference in voice coil mass due to a little extra wire is fairly small.
So JBL have done what you propose, without the need to dismantle two speakers to produce only one hybrid.


Thanks for the AES reference! :)

A pleasure, it's a pretty educational paper.
I also have the idea to produce some kind of "ultimate" 15" to replace my 2226s and it was part of the research.
I have an idea for an improved magnetic circuit, but not sure about the cone, maybe from a 1501.

Best wishes
David

[werewolf]

I suspect that the 2227 is basically a 2226 cone with the SVG voice coil.
The difference in voice coil mass due to a little extra wire is fairly small.
So JBL have done what you propose, without the need to dismantle two speakers to produce only one hybrid.
Well, the cone on the 2226 and 2227 are definitely different ... 2226 is ribbed, 2227 is smooth. But as far as the real difference in stiffness and weight? Who knows ....

And ... the chance to assemble what i've proposed from readily available (new) parts remains interesting to me :)


A pleasure, it's a pretty educational paper.
I also have the idea to produce some kind of "ultimate" 15" to replace my 2226s and it was part of the research.
I have an idea for an improved magnetic circuit, but not sure about the cone, maybe from a 1501.

Best wishes
David
Thank you, once again!
Jeff

[1audiohack]

Also the 2227 cone is straight walled while the 2226 is curved. The 2226 is thicker and more rigid.

So what is it you are working to build again?

Barry.

[werewolf]

Also the 2227 cone is straight walled while the 2226 is curved. The 2226 is thicker and more rigid.

So what is it you are working to build again?

Barry.
- 15" SVG transducer, with 2226-like cone ... with new (readily-available) parts. My plan is: 2242 magnet/motor, 2226 frame, 2226 cone, former/coil tbd.

- 12" SVG transducer, with 2206-like cone ... with new (readily-available) parts. My plan is: 2242 magnet/motor, 2206 frame, 2206 cone, former/coil tbd.

[1audiohack]

Sorry but I am still uncertain of your goal, wide range driver with low Fs like a 2235 or super subwoofer?

A more specific question or two from me might be in order:

What is the frequency response range you want this drivr to perform through?

Home HiFi or PA?

Desired efficiency?

Barry.

[ivica]

- 15" SVG transducer, with 2226-like cone ... with new (readily-available) parts. My plan is: 2242 magnet/motor, 2226 frame, 2226 cone, former/coil tbd.

tbd.

Hi,
I would expect the behavior as E140 with larger Xmax , and more power.

regards
ivica

[Dave Zan]

...while the 2226 is curved...
...but as far as the real difference...

Hi Barry

Thank you for the correction that the 2227 cone lacks the ribs of the 2226.
But the 2226 cone is not curved, it's a simple cone, my pair was new from factory in 1994, definitely not recone parts.
The mass of the two cones is very similar, Mms is a little more for the 2227 but explained by the voice coil a little heaver.
So, mostly minutiae I suspect.

Best wishes
David