JBL 4313 vs 4313B crossover differences?

I am looking at this diagram that has the 4313 and 4313B crossover schematic on it

( the two at the very bottom )

they appear identical to me, except the value of R3 looks like:

4313 = 2.5 ohms
4313B = 8.8 ohms

although maybe I am misreading the 4313B and it is written 2.5? in which case the two are identical?

Am I missing something?


I was under the impression the 4313B had a difference in the crossover vs the 4313

( R1 is listed as 50 vs 51 ohms...is a 1 ohm difference even quantifiable? esp with +/- 5% resistors )

The reason I am asking is I have a 4313B and a 4313 that are paired up. the 4313 is substantially lacking in bass, but the woofer has been reconed by someone. I suspect the recone may be the reason

I do see the driver is different between them. ( LE 10H vs LE 111A )

however from my research so far, JBL says the LE 10H and LE 111A have the same specs

thanks!



http://el34.coolpage.biz/images/filters.jpg

aha: after searching some more on this forum, I did find a post specifically related to this

http://www.audioheritage.org/vbullet...to-L-110/page2

user 4313B says:

"I wondered when someone would give the 3113/3113B filter a good look. The only difference between the two is a change in resistor values

Rev B was changing R1 from 50 ohms to 51 ohms, R2 from 5 ohms to 5.1 ohms, and R3 from 2.5 ohms to 2.4 ohms"

it is hard to make out the writing in those schems. will .1 ohm make an audible difference? I may try it anyway, for posterity

Also, I see the bit about adding POLY bypass caps to the 4313/4313B. which I may try as well. but first I will make the 4313 and 4313B are both working 100%

a big thanks to mr 4313B!!

Bypassing my 4313B's PETP caps removed a touch of harshness, at least in my head (which is the most important). Worth it.
Used cheap 22nf MKP 379 Vhisay caps.

All 4313 lovers, I would like to submit a drawing I made of the mystery 5 cap, 5 inductor, early 4313 crossover with serial #11914 and number 3113 on it. I don't think there is another drawing for this crossover available, and the moderators are welcome to use my drawing in the database of crossovers.

I bought a pair of 4313's with the desire to turn them into B versions, with bypass caps. At first I was just going to change the needed parts, but went ahead and bought new Solen caps for the big ones, and .01uf Audiocap thetas for the bypass points. All I am saving from the original crossovers is the L pads, and the .75mh mid freq inductor.
Here is my drawing in jpg format, noting its the early odd 5 cap 5 inductor version
If you see any error please inform and I will correct and resubmit.

Attachment 88108

Shown in the pictures attached are the early old crossover with my scratch built replacement and parts using.
I am pausing before soldering to get input on choices and inductor layout, which according to http://www.troelsgravesen.dk/coils.htm should be good.

My choices so far in the pictures are below, I am wondering if the iron LF inductor is the wrong choice, as after reading others on the board here, suggest a .4-.6 DCR coil is more suited to the legacy designs.
Its a tough chore looking at the choices from 3 sites and finding the best in stock match.
I may have made an error on the LF side choice?
Help would be great!
LF inductor
SL2.5 from madisound Steel Laminate 2.5 mH 15 AWG Inductors $17.40 each 77mm x 34mm x 47mm Dcr 0.164 ohm
or should I use instead a air core 2.50 PN 2.5MHL 19gage DCR= 1.00 59 x 32
or a 16 gage standard from solen.ca S162.7 26.35$ 2.7mH 16awg, 0.60ohms DCR, 19mm H x 76mm

MF inductors
use stock .75 or get Madisound 0.75 PN# .75 MHL 19gage DCR= 0.43
3.5 MHL Madisound 3.5 mH 19 AWG Air Core Inductor # 3.5mhl $ 13.30 Bobbin 58mm Ø x 36mm Tall Dcr 1.2 ohm

HF inductors
.3MHL Madisound 0.3 mH 19 AWG Air Core Inductor 3.60 each

Attachment 88122Attachment 88121Attachment 88123

Not sure about the efficacy of putting a steel bolt through air coil inductors...

Grumpy, thanks for the input. You are someone I highly respect on this board, and many of you have inspired me to do this work myself and get a deeper understanding of bad- good - better best. It would be no problem returning the 2.5Mh iron ones, and get the slightly higher priced air core. I like to do things right, and don't mind being called wrong on choices.

EDIT>
On second read of your comment, I see you noticed the bolts in the other (non iron core) inductors, to secure them from bouncing loose. I will try to use plastic bolts there, or switch to epoxy there. Though the original LF inductor on these cross overs do come with steel bolts, maybe it doesn't matter on the LF 1.2 due to size?

Are you saying the iron core 2.5 LF inductor is OK?

What would you choose in that LF inductor if choices were
Madisound air core 2.50 PN 2.5MHL 19gage DCR= 1.00 59 x 32
or a 16 gage standard from solen.ca S162.7 26.35$ 2.7mH 16awg, 0.60ohms DCR, 19mm H x 76mm
or would you look at something else?

My choice was based on whats available on 3 sites, and getting whats in stock and price considerations. I would rather buy the best choice in each inductor. I am a rookie building crossovers, but have so far taught myself to recap amps, refoam and recone spaekers. If it wasn't for this board, I would be back in the stone ages of know how.

Some might also think why not just buy the 4313B and refurb that? I thought I was getting a budget 4313B set by choosing the A version on the cheap, swapping out the LE-10A woofers for LE-10H's and go. What I really found was this early crossover was not documented in all the 3113 drawings for the A version, and that a crossover recap isn't exactly cheap, but its been an experience builder.

mucho thanks for best choice to anyone, before I warm up the soldering iron.

Don

Regarding the use of bolts through the center of inductors. Any ferrous metal bolts will change the value (increase) of your inductors. I usually use industrial high temp hot glue to attach my inductors, but I have also used brass bolts. Brass hardware will not affect the inductor's performance.

There is nothing wrong with using high quality iron core inductors. Quality iron core inductors use laminated steel and I believe yours are of this type. The steel bolts going through the laminations will likely change the values though and plain steel bolts will saturate more easily than properly designed laminated cores.


Widget

Thanks guys and thanks for this beautiful and intelligent group of HIFI nuts.
Its great to spend time on informative sites like this.
I hope someone else will find use in that odd duck 5 inductor 5 cap early 3113 crossover.
I used my autocad background and drew that up.
I might be able to submit it as a pdf file if needed.

Don in cold Iowa

Quote:

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Originally Posted by bolero

The reason I am asking is I have a 4313B and a 4313 that are paired up. the 4313 is substantially lacking in bass, but the woofer has been reconed by someone. I suspect the recone may be the reason

I do see the driver is different between them. ( LE 10H vs LE 111A )

however from my research so far, JBL says the LE 10H and LE 111A have the same specs

thanks!



http://el34.coolpage.biz/images/filters.jpg

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The LE111A and LE10H, which as the sames specs as LE10H-1 and LE111H, are similar but do have different specs. The LE111A has an Alnico magnet and the LE10H has a ceramic magnet. One possibility for your poor bass performance in the 4313 could be due to the Alnico magnet loosing its magnetism. The change in crossover designs from 4313 to the 4313B was more than likely due to the change from the LE111A to the LE10H. Another possibility could be that the recone kit used was not OEM and the surrounds may not be as supple as the original ones were.

Larry