Vintage JBL 4825 - Need Help Please - Dump Find needs restoration

[Darren Grayshon]

Hi,

I found these little puppies at the dump on Saturday.

I'd no idea what they were BUT they had the potential to fit into a system i've always wanted to build.

Turns out they are JBL 4825's

So, as you can tell, i'm very new to this and need some help.

Stripped them down. The driver cones move freely and both match 2206H. the horns are present but condition is unknown..

So, i quess the questions i have are:

- are they worth having
- are they worth saving
- how on earth do i power them
- how do i test if the horns work
- Does anyone have any idea at all about them
- do i need a sub
- the brown wire, should it be attached?

Guess typical questions perhaps.

I fell in love with them the second i saw them

Any advice would be great

Darren

[JeffW]

They have nice components, but I doubt the wiring is stock. Literature seems to suggest these were external crossover only, with Canon connectors to daisy chain them. Looks like somebody has added something to them, hard to say.

http://www.jblpro.com/pub/obsolete/4825.pdf

The horn/driver is basically the same as the 4430/4435 uses I think, so there's that.

[Ed Zeppeli]

Nice find! If you want to use those cabinets you'll probably need a sub. The top end, as mentioned, was used in the 4430/4435 studio monitors. With a bit of effort on your part you could build some nice clones.

If you want to test the high frequency and horn you can run a sweep from about 1k Hz up and listen for noise.

Good luck,

Warren

[mech986]

They have nice components, but I doubt the wiring is stock. Literature seems to suggest these were external crossover only, with Canon connectors to daisy chain them. Looks like somebody has added something to them, hard to say.

http://www.jblpro.com/pub/obsolete/4825.pdf

The horn/driver is basically the same as the 4430/4435 uses I think, so there's that.

Horn is a bit different in the fact they added two vents for tuning the box, but those can easily be blocked off from the front. Important to check the driver for good OEM JBL diaphragms as the speakers looked messed with wiring wise, so anything could be there. The 2206 is a very nice midrange type driver though so adding a 2235 bottom might prove very tasty with the right crossover.

[robmuso]

Hi,

You are so lucky to find those speakers. They have the top of the line vintage components and are worth heaps.
I recently paid $400 australian dollars just for 2 of those horn flares.
I've been studying the JBL model 4627ap (P stands for Passive), as I want to build a pair for my keyboard monitors on stage.

Try downloading the document below and you'll find the boxes are so similar if not the same.
So there's a crossover network circuit ready to build if that's what you need.

The circuit shows 2 different circuits that apply to different models of this box.

Biamp
&
Passive

You'll find that the wiring for the biamp circuit would be the same as the wiring in your boxes.

Could I ask one favour from you please?

Could you please measure the following and let me know the results?

length of the ports on the horn flare
inside diameter of the ports on the horn flare

Both ports should be the same or similar.

Good luck

Thanks

Rob

www.jblproservice.com/pdf/SR-Series/SR4726A.pdf

[robmuso]

Sorry,

That model was the JBL SR 4726a (wrong model)

Try this

www.jblproservice.com/pdf/Sound%20Power%204700%20Series/4726A.pdf

Good luck

Rob











Hi,

I found these little puppies at the dump on Saturday.

I'd no idea what they were BUT they had the potential to fit into a system i've always wanted to build.

Turns out they are JBL 4825's

So, as you can tell, i'm very new to this and need some help.

Stripped them down. The driver cones move freely and both match 2206H. the horns are present but condition is unknown..

So, i quess the questions i have are:

- are they worth having
- are they worth saving
- how on earth do i power them
- how do i test if the horns work
- Does anyone have any idea at all about them
- do i need a sub
- the brown wire, should it be attached?

Guess typical questions perhaps.

I fell in love with them the second i saw them

Any advice would be great

Darren