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View Full Version : SR4726a vs SR4726X, filter upgrade worth it?



sebackman
02-22-2013, 10:12 AM
Dear all,

I'm restoring a pair of original JBL SR4726a speakers (2226G + 2447/2381). I took a look at the filters in the JBL tech sheet and compared them to the newer SR4726X. They are completely different!


The older SR4726a has a 4ohm woofer and the older topology with resistor based CD compensation and the newer SR4726X has an 8 ohm woofer and a much cleaner filter topology.

I happen to have 4, 8 and 16 ohm 2226's available so I wonder if someone on this fantastic forum would know if the difference between the filters in the older "a" version and "X" revision would make it worth to build new filters and swap the 2226G's for 2226H's.
All the best
//RoB

subwoof
02-22-2013, 05:23 PM
look close...the horns and drivers are different too...

sebackman
02-22-2013, 10:04 PM
Hi Subwoof

They look pretty identical to me, except for "G" to "H" swap and filter. What am I missing. Please advise

http://www.jblproservice.com/pdf/SR-Series/SR4726A.pdf
http://www.jblproservice.com/pdf/SR-X%20Series/SR4726X.pdf


All the best
RoB

subwoof
02-23-2013, 07:56 AM
was thinking the change from 4726 to 4726A...too many versions to remember.

when you change the LF impedance the LF network components have to change - this usually means a small tweak in the HF section (esp the gain structure) and whatever design "upgrades" JBL has incorporated over that timeframe ( notably the use of speakons ).

if you have an older linear type amp ( and are running it passive ) then go with the 4ohm woofs.
if it's a newer digital power supply type then it doesn't matter.

sub

sebackman
02-23-2013, 09:17 AM
Hi

I was not aware that there was a SR4726 with no "A" or "X".... Sorry.

What is in that box? 2446/2382? -Cant find the techsheet.

However, the filters in the "A" and "X" are very different and the question still stands, is there any sonic gains from adopting the newer filter topology in the "SR4726X" while also changing to 2226H woofers. The woofers should sound the same so it is really about the Hi-pass filter and the CD horn compensation.

The drivers and the horns are the same and any sensitivity differences between the 2226G and the 2226H must have been factored in by JBL from the beginning.

I would have to build new filters but the component values are available in the tech sheet and the filters are rather simple with few components.

-And I do have a good pair of 2226Hs to swap in for the2226Gs

In short, do the SR4726X sound better/more HiFi than the SR4726A?

Do these boxes need a tweeter for HiFi usage, like a 2405 on top?

Thank you

//RoB

sebackman
03-04-2013, 12:53 PM
Hello,

No one with experience of the older style SR filters compared to the newer version??

At least there are fewer components in the newer filter :-)

Anyone??

All the best
//RoB