Lx5 whithout autoformer ?

[kalkan0]

Hello:bouncy: :bouncy: :bouncy: to all the JBL lovers !

Is it possible :banghead: to find an equivalent schematic of LX5 (3115) crossover without autoformers ?
I want to do this crossover for a LE 15A ( 8 ohms) filtered at 500 Hz and for a 375 in a Iwata Horn.
Thank s a lot for your answer
Maurice

[Maron Horonzakz]

What do you have against autoformers?:blink:

[Zilch]

What do you have against autoformers?:blink:Can't get 'em, mostly, and the resistors ahead of them are, ummmm, wasteful (see below).

Former member Giskard once started a great debate about using them in another thread here with the thesis: "Why bother?"

There were no replies.... :p

http://audioheritage.org/vbulletin/showthread.php?p=49233&#post49233

[carolus]

Hello:bouncy: :bouncy: :bouncy: to all the JBL lovers !

Is it possible :banghead: to find an equivalent schematic of LX5 (3115) crossover without autoformers ?
I want to do this crossover for a LE 15A ( 8 ohms) filtered at 500 Hz and for a 375 in a Iwata Horn.
Thank s a lot for your answer
Maurice

Bonsoir Maurice,
Une suggestion, i give you a suggestion:
Consult Benny de chez Aqua Bleu (Ant/Be).
He did a very good musical (and spectacular) X-over for my multihorn concept.
Bonne chance.
Salukes.
Karel

[Zilch]

http://www.jblproservice.com/pdf/Network%20Schematics/LX5.pdf

http://www.jblproservice.com/pdf/Network%20Schematics/3115%20Network.pdf

http://www.jblproservice.com/pdf/Network%20Schematics/3115A%20Network.pdf

Use 3115A 'til you figure out what you ACTUALLY need from performance measurements.

[soundmotor]

Can't get 'em, mostly,

You could however fab something nearly equivalent. Autoformer or tapped inductor = the same thing. 4x 1mH laminated-core inductors in series would be ~close, just not on the same core. Connect the switch at each series junction for attenuation.

[Earl K]

You could however fab something nearly equivalent. Autoformer or tapped inductor = the same thing. 4x 1mH laminated-core inductors in series would be ~close, just not on the same core. Connect the switch at each series junction for attenuation.


- Techbots' thread on "Tapped Autotransformers" (http://audioheritage.csdco.com/vbulletin/showthread.php?t=5376) is quite informative by laying out most of the theory behind building a tapped autotransformer .

- If you so desire, use it to buildup a coil offering a 3 db tap. Follow the logic you've just laid out. The theory in that thread ( does somewhat ) suggest one needs 2 duplicate value coils to successfully create a 3db tap .

- The results surprised me .

:)

[soundmotor]

- Techbots' thread on "Tapped Autotransformers" (http://audioheritage.csdco.com/vbulletin/showthread.php?t=5376) is quite informative by laying out most of the theory behind building a tapped autotransformer .

- If you so desire, use it to buildup a coil offering a 3 db tap. Follow the logic you've just laid out. The theory in that thread ( does somewhat ) suggest one needs 2 duplicate value coils to successfully create a 3db tap .

- The results surprised me .

:)

Staggered values make sense so it is really just a question of getting an example coil and putting it on a bridge for DCR & L measurements.

I'll volunteer as I've access to a lab standard bridge.

[Zilch]

The inductances don't add as assumed:

http://audioheritage.org/vbulletin/showthread.php?t=5629

[Earl K]

The inductances don't add as assumed:

- Zilch, Thanks for the link to that thread .

- I had missed all that info on "asymmetrical summing" . ( All I knew was that they didn't add )

Cheers

[soundmotor]

The inductances don't add as assumed:

http://audioheritage.org/vbulletin/showthread.php?t=5629

I'd like to measure one of these with a bridge. I cannot think of any reason why it would measure one net inductance in one direction and a different net in the other? A neat puzzle.