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View Full Version : JBL 4313 vs 4313B crossover differences?



bolero
04-16-2017, 09:02 AM
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

bolero
04-16-2017, 10:09 AM
aha: after searching some more on this forum, I did find a post specifically related to this

http://www.audioheritage.org/vbulletin/showthread.php?248-L-112-as-oppossed-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!!

Malefoda
04-18-2017, 12:08 PM
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.