Please advice for JBL Crossover

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07-23-2011, 12:44 PM
tattoo

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Please advice for JBL Crossover

Hi everyone

I am doing my 2 way project with JBL 2235H (8Omh) and LE85 (8Omh) with horn H91. I have just finished building a 5cf vented box for 2235H. The LE85 with horn is put on top of the 2235H box. I am now having a headache for the crossover because I am not good at technical things.

I am looking at the crossover calculator and check up the 2nd order Butterworth crossover at 800Hz which show below:

Capacitors
C1 = 17.58 uF
C2 = 17.58 uF
Inductors
L1 = 2.25 mH
L2 = 2.25 mH

I am also wondering should I use the above calculator for my speakers or I can follow the design of L200B crossover network but it use LE85 16Ohm. I am not sure if that network can be used with my LE85 8Ohm?

Attachment 52175

Could you please help me which one I should follow or if you have any other better ideas would be highly appreciated.

Thanks.
07-23-2011, 01:14 PM
hjames

Don't know if it will help, but it may be a newer better approach.

I built some 3 way systems based on the L200 cabinet, 2235 woofer LE85 horn and added the 2405 slot .. basically equivalent to the 4333 3 way system, tho with the shorter length horn ...

I used the crossover member "4313" had designed and shared with the forum ...

http://www.audioheritage.org/vbullet...1&d=1257099850

Perhaps you could use the Bass and Mid legs (the upper 2 legs) of this design? Its well marked.

http://www.audioheritage.org/vbullet...1&d=1257099850
07-23-2011, 03:16 PM
ratitifb

Quote:

Originally Posted by hjames

Perhaps you could use the Bass and Mid legs (the upper 2 legs) of this design?

:no:

because the LE85 is lowpass filtered in its upper frequency range and without the lower leg + 2405 you'll loose all HF/UHF in the upper frequency range of the LE85 + horn response ...

Quote:

Originally Posted by tattoo

I am not sure if that network can be used with my LE85 8Ohm?

don't worry about 8 or 16ohms, in both cases LE85 have the same diaphragm & voice coil ;)
07-23-2011, 11:31 PM
tattoo

Quote:

Originally Posted by ratitifb

:no:
don't worry about 8 or 16ohms, in both cases LE85 have the same diaphragm & voice coil ;)

Thanks Ratitifb very much. So it means I can use the L200B design network with the LE85 8Ohm without any problem.

@hjames: I will keep your design network for my next project when I add a tweeter in the system.

I have one more question. I know that the L200B network has a high frequency boost which is C1uF + L0.16mH + R5Ohm. Could you please explain for me what does it use for? Can I omit that boost out of the network? Or if it is better to keep the boost then I will keep it.
07-24-2011, 07:59 AM
ratitifb

Quote:

Originally Posted by tattoo

Can I omit that boost out of the network? Or if it is better to keep the boost then I will keep it.

if you add the 2405 it would be better to omit this HF boost and to go to the 4333/L300 Xover designs (3133/N333 shematics). In any case adjust them till they sound good ;)

Take a look on the Zilch's #2 post at http://www.audioheritage.org/vbulletin/showthread.php?20083-L200-DIY-Upgrade
07-24-2011, 08:57 AM
hjames

I understand - but I think you'd find it worthwhile to go directly to the 3-way design ...
Just my opinion, of course, but having started with a original 4320 that I moved into the nicer looking L200 cabinet and then upped into a 3-way design ... start as a 3 way.

Quote:

Originally Posted by tattoo

Thanks Ratitifb very much. So it means I can use the L200B design network with the LE85 8Ohm without any problem.

@hjames: I will keep your design network for my next project when I add a tweeter in the system.

I have one more question. I know that the L200B network has a high frequency boost which is C1uF + L0.16mH + R5Ohm. Could you please explain for me what does it use for? Can I omit that boost out of the network? Or if it is better to keep the boost then I will keep it.