Speakerplans.com Homepage
Forum Home Forum Home > General > General Forum
  New Posts New Posts RSS Feed - JBL 4828
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

JBL 4828

 Post Reply Post Reply
Author
Message
angrykid View Drop Down
Registered User
Registered User
Avatar

Joined: 03 December 2009
Location: Rickmansworth
Status: Offline
Points: 216
Post Options Post Options   Thanks (0) Thanks(0)   Quote angrykid Quote  Post ReplyReply Direct Link To This Post Topic: JBL 4828
    Posted: 24 October 2010 at 9:48pm

Has anybody got a passive crossover for a JBL 4828 or a wireing diagram for the PCB? I know it's prob a long shott as their either non existant or like rocking horse shit!

Cheers Smile
Back to Top
jbl_man View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 12 January 2005
Location: London.
Status: Offline
Points: 11121
Post Options Post Options   Thanks (0) Thanks(0)   Quote jbl_man Quote  Post ReplyReply Direct Link To This Post Posted: 24 October 2010 at 9:56pm
Ben,here is the spec of the cabinet..it crosses over at 800hz,so you could allways subsitute it for a similar passive xover.,as i dont think you will ever find an original.
 
Be seeing you.
Back to Top
_djk_ View Drop Down
Old Croc
Old Croc


Joined: 23 November 2004
Location: United States
Status: Offline
Points: 6002
Post Options Post Options   Thanks (0) Thanks(0)   Quote _djk_ Quote  Post ReplyReply Direct Link To This Post Posted: 25 October 2010 at 3:01am
" Ben,here is the spec of the cabinet..it crosses over at 800hz,so you could allways subsitute it for a similar passive xover.,as i dont think you will ever find an original."

It is a very special crossover, a standard crossover will not work well.

http://www.jblproservice.com/pdf/SR-Series/SR4722A.pdf

You should either use the SR4722A crossover, or what I used, a 4435 high-pass and a custom low-pass.

http://www.jblproservice.com/pdf/Studio%20Monitor%20Series/4435LR.pdf

IIRC, I used the low-pass from this:

http://www.jblproservice.com/pdf/SR-X%20Series/SR4722X.pdf


djk
Back to Top
_djk_ View Drop Down
Old Croc
Old Croc


Joined: 23 November 2004
Location: United States
Status: Offline
Points: 6002
Post Options Post Options   Thanks (0) Thanks(0)   Quote _djk_ Quote  Post ReplyReply Direct Link To This Post Posted: 31 October 2010 at 4:43am
djk
Back to Top
angrykid View Drop Down
Registered User
Registered User
Avatar

Joined: 03 December 2009
Location: Rickmansworth
Status: Offline
Points: 216
Post Options Post Options   Thanks (0) Thanks(0)   Quote angrykid Quote  Post ReplyReply Direct Link To This Post Posted: 31 October 2010 at 6:27pm
Clap top job, i'll get my iron out!
Back to Top
_djk_ View Drop Down
Old Croc
Old Croc


Joined: 23 November 2004
Location: United States
Status: Offline
Points: 6002
Post Options Post Options   Thanks (0) Thanks(0)   Quote _djk_ Quote  Post ReplyReply Direct Link To This Post Posted: 01 November 2010 at 12:20am
Obviously, if you don't also need the bi-amp capability you could omit some parts (the switches and the 20µF+0.1µF cap).

You don't need the 0.1µF in parallel with the 2x12F in the woofer circuit. The other 0.1µF caps are for the best audiophile performance, good polypropylene caps (without the 0.1µF bypass) may be good enough for PA use.

You might be able to eliminate the upper of the two pads, I had to run it wide open to get the high end flat to 16Khz. On the other hand, you may want the capability to roll-off the high end a bit. The lower pad is the midrange level.

-----------------------------------------------------------

Mine were killer for hi-fi with an 18" sub below 100hz. Worked well for small DJ jobs too.


Edited by _djk_ - 01 November 2010 at 12:23am
djk
Back to Top
Riley Casey View Drop Down
New Member
New Member


Joined: 17 January 2014
Location: MD
Status: Offline
Points: 1
Post Options Post Options   Thanks (0) Thanks(0)   Quote Riley Casey Quote  Post ReplyReply Direct Link To This Post Posted: 20 November 2023 at 2:00am
I hope no one used the 800 hz suggestion in building passive crossovers for 4828s. The horn won't load the driver below 1khz. The SR4722 also uses a smaller version of the Dolly horn and a different ( cheaper ) HF driver and needs to crossover even higher. A search for a JBL 4726 will get you a schematic for a crossover that is the closest match you're likely to get for the 4828 and crosses over at about 1k6 hz. I'd post the schematic but the forum isn't giving me the option for images. The studio monitor 4430 crossover is very hifi but crosses over at 1khz to give the 15" woofer some chance of meeting the HF horn but I wouldn't want to drive a 1" compression driver very hard at that low a frequency and its a bit dubious if the low pass filter would be a good match for the 12" 2204H or 2206H  woofer in the 4828 ( depending on when it was made) Another caveat in using the 4430 crossover schematic is that the HF driver in the 4430 is an 8 ohm 2426J while the driver in a 4828 is a 16 ohm J version.

In my experience JBL tends to build passive crossovers for live sound speakers with driver survivability as the first consideration and performance second. I've been bi-amping the 4828s at 1300 hz for for years with good results both in my living room and for use as stage monitors. 

Zombie threads R us


Edited by Riley Casey - 20 November 2023 at 2:15am
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.109 seconds.