E145 network

[delahais]

hello,
can someone tell me how cut a E145 at 800hz 12db/o with a good attenuation of the pics who appears in 500-700hz?
thanks for you help.

[Alex Lancaster]

How about using a JBL 3110 or 3110A network?

Alex

[delahais]

thank you alex,
i don' t find 3110a, is there a big difference with 3110 ?
regards.

[Mr. Widget]

The 3110A, like the 3120A etc. have a HF boost switch which gives a bit of HF extention.

http://www.lansingheritage.org/image...pro/page21.jpg

http://www.lansingheritage.org/image...pro/page20.jpg

[delahais]

Thank you alex, i think it' s ok !
regards.

[4313B]

If you go with the original 3110 you might want to change the 13.5 uF capacitor in the RC conjugate to a 16.0 uF capacitor for the E145.

The 3110A doesn't have a conjugate on the LF so nothing to change there.

*****

Ooops, yes it does; So if you use the 3110A you might want to change that 13.5 uF to a 16.0 uF to match the E145 as well.

[delahais]

Hello GISKARD,
thanks for your precious details, i must say you; that i have try a self made network like ndd55000 and i don' t understand, because it was' nt good with e145, could you please tell me why
jbl put 1.4mh on the LF network ?
actuelly i have the same problem with the tad 1601a; the level is too high at the cut off, i modify the network , it' s ok but phase, delay,etc...?
do you think the enclosure design or volume is bad ?

i hope i' m clear with my poor english, sorry !

[4313B]

"i don' t find 3110a, is there a big difference with 3110 ?"

Yes. The 3110 is the Pro version of the old LX13 network. The 3110A is improved. The 4671 uses the high pass of the 3110A, the low pass in that system has been changed from the stock 3110A so be aware of that if you're copying the 4671.

"that i have try a self made network like ndd55000 and i don' t understand, because it was' nt good with e145, could you please tell me why"

My first guess would be that it is a complicated filter and if you don't know the original voltage drive or even the DCR and tapped points for that 1.8 mH tapped autotransformer then you will most likely never be able to duplicate it properly. Plus, it is a very specific combination and substituting other horns/drivers would most likely yield poor results.

"do you think the enclosure design or volume is bad ?"

I suppose you could have a balance issue. How does the bass driver sound without any filters in the path? The E145 has one hell of a spike between 1.5 kHz and 2.0 kHz (~ 8 dB).

[delahais]

Originally posted by delahais
Hello GISKARD,
thanks for your precious details, i must say you; that i have try a self made network like ndd55000 and i don' t understand, because it was' nt good with e145, could you please tell me why
jbl put 1.4mh on the LF network ?
actuelly i have the same problem with the tad 1601a; the level is too high at the cut off, i modify the network , it' s ok but phase, delay,etc...?
do you think the enclosure design or volume is bad ?

i hope i' m clear with my poor english, sorry !

[4313B]

Nice picture.

What networks have you tried so far? Just your build of the Everest network?

[delahais]

Originally posted by delahais

this is my actual network values.

[4313B]

How did you arrive at all these values?

You're running a 2370 with a 2425H?

You've tried the low pass of the ND55000 already? Verbatim? Not with a modeler but with actual components?

[4313B]

Originally posted by delahais
thank you alex,
i don' t find 3110a, is there a big difference with 3110 ?
regards.

3110 schematic is here:

http://www.jblproservice.com/navigat...chematics.html

3110A schematic is here:

[delahais]

Originally posted by Giskard
How did you arrive at all these values?

You're running a 2370 with a 2425H?

You've tried the low pass of the ND55000 already? Verbatim? Not with a modeler but with actual components?

hello GISKARD, good morning,
yes i have a 2370 because i can' t find a 2346, it' s not a good horn but ...
I arrived at all these values after many, many, many years, months, days, hours of work !
as you can see on the picture the enclosure is a prototype!

do you think i' m wrong with these values?
i run like that since severals months, i just adapt a little the level at 1.5khz with my préam c40 mac,
it's the best sound i ever obtain, so i be careful
i tried all the 55000 network when i used e145 in the box but i never got the actuals results.
actually i run with the filter you have seen the frequency result on the picture.

[4313B]

Hello delahais,

Well, as Alex and Mr. Widget have suggested, the 3110A is the generic 800 Hz passive filter to use. I used it with the 2370/2425H and a 2235H and it worked ok. You might want to give it a try and see how it works for you.

"I arrived at all these values after many, many, many years, months, days, hours of work ! as you can see on the picture the enclosure is a prototype! do you think i' m wrong with these values? i run like that since severals months, i just adapt a little the level at 1.5khz with my préam c40 mac, it's the best sound i ever obtain, so i be careful"

Well, if you feel you're getting close with what you currently have then you may want to try a parallel notch filter on the LF centered around the 1.65 kHz point. Something like a 0.45 mH inductor in parallel with an 18.2 uF capacitor in parallel with a 10 to 20 ohm resistor. Vary the resistor value until it sounds right. Start with 10 ohms and go up to 20 ohms. It might help and it might not. You may need to adjust other LP values to compensate for it though.