what is this 4312 mod?

[Goldjazz]

Just curious on this one. Someone's selling a pair of 4312's they've modded the woofer as shown. I presume they've added large alnico magnets or non magnetic ferrous material to the back? Anyone seen this, does it do anything?

[ivica]

Just curious on this one. Someone's selling a pair of 4312's they've modded the woofer as shown. I presume they've added large alnico magnets or non magnetic ferrous material to the back? Anyone seen this, does it do anything?

Hi,

may be in order to reduce driver magnet magnetic field influence to nearby CRT-TV or monitor.

regards
ivica

[Goldjazz]

I'm pretty sure they were claiming it improves the speakers in some way. I can only think it is to strengthen the magnetic field or optimise it in some way. Perhaps an alternative to recharging the magnets?

Hi,

may be in order to reduce driver magnet magnetic field influence to nearby CRT-TV or monitor.

regards
ivica

[Goldjazz]

So the seller says "Modified woofer via professional mastering studio in Japan"...I'll ask him what he means

[kelossus]

I dont think it would be to recharge the woofer. Like you mentioned I think it would increase the strength of the magnet but I am by no means technically minded so I have no idea.

They are ferrite drivers so they shouldn't be prone to demagnetization. I have seen them on Gumtree for awhile now and am glad you posted them up here as I was wondering what the "mods" are also.

I have owned a pair of 4312a's and I think they are priced relatively high. Much better JBL's to be had for the 1k asking price. The woofer and crossover are the weak link in those speakers. A set of 4411/4412 would embarrass them.

[macaroonie]

Shun Mook ?

[Goldjazz]

Ha just took a look at Shun mook never heard of it before...interesting but they started to lose me a bit with the ebony pendulum that channels mind energy ha.

Shun Mook ?

D

[macaroonie]

Did you check out their prices In the Hi Fi trade Shun Mook was a euphemism for anything inexplicable , weird or plain tweaky.

[Ed Kreamer]

Uh.....There are two John Curls. One would be interesting to talk too, and the other......Uh, not so much

[Wagner]

Uh.....There are two John Curls. One would be interesting to talk too, and the other......Uh, not so much

You can guess which one..........as for "interesting"? I would think that would depend on who you asked

[Ed Kreamer]

It must be the black paint. I have a couple of extra menorah's, I'll paint them and see what happens.

[Wagner]

It must be the black paint. I have a couple of extra menorah's, paint them and see what happens.

We better watch out, John Curl may be lurking around here somewhere

[Goldjazz]

Didn't speak to the guy but perhaps they are "Bucking magnets"

"Bucking magnets mounted on the back of the motor system are used to achieve semi magnetic shielding and/or higher magnetic flux density in the air gap"

http://www.scan-speak.dk/magnets.htm

[Wagner]

Just curious on this one. Someone's selling a pair of 4312's they've modded the woofer as shown. I presume they've added large alnico magnets or non magnetic ferrous material to the back? Anyone seen this, does it do anything?

Familiar
Cannot remember the name of the "technology" for the life of me..................I am searching now
A guy I used to have work done by was an "authorized" installer, so I am working from that
Claimed to be some derivative of submarine technology related to cancellation
A few folks were peddling it during the late '90s..........fairly obscure "tweeker" stuff
That MAY be what's in that photo, what I am trying to dig up was an add on type thing like that.........same as those magic deals that stereofool reviewed once that you glued onto the backs of your speaker cabinets
I will see if I can dig it up

Of course what you have in you photo may also just be some sort of bucking magnet(s)

*Edit/Update: FOUND the mod/product(s) I was thinking bout being associated with my "acquaintance" (charlatan); a totally different line of ware from the magnets thing..............I'll keep digging

[brettMc]

Hi All,

I am a proud owner of a nice pair of JBL 4312a control monitors....and a proud owner of 4408's and 4406's as well. I love all of them but really dig the 4312a's. However I have to say they are harsh and unforgiving. There is an upper-mid or low-high frequency that comes off the woofers that drives me up a wall. I can dial down the midrange and the tweeter and the frequency that bigs me is definitely coming off the large cones. Can anyone tell me why or what I can do about it? One of them was professionally roconed all JBL parts. Everything seems to be in working order. Do I maybe need to replace the capacitors? Is there a known 'diffraction' that comes of them big ridged paper cones? I've had to resort to draping some fabric over the cones to reduce this frequency.

Perhaps someone could suggest a nice tube amp that would play well with these?

I am using a tube-based modwright Oppo as my digital playback source. Emotiva amp.

Any advice would be greatly appreciated.

Thanks,
Brett