Jbl 4312 mk2 info ?

[Philip moses]

I have picked up a pair of jbl 4312mk2.

Finding it difficult to get any info, etc on tnese.

When made, any good, etc?

Thanks for any info.

 

[hjames]

I have picked up a pair of jbl 4312mk2.

Finding it difficult to get any info, etc on these.

When made, any good, etc?

Thanks for any info.

Of course, since they are JBL speakers - JBL made them ...

Google is your friend - the reviews I found indicate they are generally pretty popular.
JBL 3-way monitor style speakers. Kind of a large bookshelf style.

Looks like the Lansing forum folks provided an answer yesterday -
http://www.audioheritage.org/vbulletin/showthread.php?41500-Jbl-4312mk2

And Earl provided a link to the tech sheet for that speaker -
https://manuals.harman.com/JBL/HOM/Technical Sheet/4312-4312BMkII ts.pdf

That tech sheet has 7/01 stamped on the right corner, so presume the Mk2s were made around 2001. (The original 4312 dates back to the late 80s)

That sheet lists the driver models and has a lot of info - save/print a copy for your records.

 

[ic-racer]

Can you post pictures of the cabinet, drivers and crossover for identification?

 

[Philip moses]

Thanks for the replies.

Unfortunately there are very few user views on this model.
There is no information regarding date of production.

Yes, i posted on 2 other sites, with no informative replies as yet.
It seems these are quite rare in the us and uk.

 

[savatage1973]

They appear to be very similar to the original 4312 series, but not the A or B series, since those used paper cone tweeters. They are more similar to the later 4312C which used the 035ti tweeter (ti indicating Ti dome, rather than paper cone), but the MKII use a Ti tweeter (the 052ti) which was a later Ti dome tweeter found in the 44xx series of speakers, so basically an upgraded version of the later 4312 series.

The mid and woofer drivers are the same as the 4312C. Earlier versions of the 4312 series used the 2213 woofer (Alnico magnet) where the 4312C used the 2213H woofer (Ferrite magnet)--heavier in weight and higher power handling, but otherwise comparable in appearance and performance--JBL lists them as "interchangeable".

I would guess the build date to be somewhere in the 2000's (probably early 2000's), based on when the other models were discontinued. From the Service manuals that I was able to look up, the D, E, and MkII 4312's were not a US market offering, that may be why it is harder to get specific info on them.

 

[hjames]

Thanks for the replies.

Unfortunately there are very few user views on this model.
There is no information regarding date of production.

Yes, i posted on 2 other sites, with no informative replies as yet.
It seems these are quite rare in the us and uk.

Do understand that JBL was based near Northridge California, and during the Northridge earthquake of 1994
a lot of their data archives that had just sort of grown since the 40s were destroyed.
That, plus there was a lot of corporate downsizing after they were bought by Harman Industries,
and a lot of offshoring resulted as well.
Plus, the more recent sale of Harman to Samsung.

There is not the history of records we might hope for from a company of that reputation.

(I am not a JBL employee - but I bought my first JBL L-36 Decade speakers new in 1976,
and got a lot more gung ho with different models after 2000).

I'm based near Wash, DC - folks on the west coast probably know much more.

 

[Philip moses]

Thank you.
Very helpful.

I wanted more info in case i wanted to upgrade the crosdovers in tne future.
Unless i can read Japanese i doubt i’ll find a known tried upgrade om tne web.

Thanks again.
They arrive in an hour, so happy days.

They appear to be very similar to the original 4312 series, but not the A or B series, since those used paper cone tweeters. They are more similar to the later 4312C which used the 035ti tweeter (ti indicating Ti dome, rather than paper cone), but the MKII use a Ti tweeter (the 052ti) which was a later Ti dome tweeter found in the 44xx series of speakers, so basically an upgraded version of the later 4312 series.

The mid and woofer drivers are the same as the 4312C. Earlier versions of the 4312 series used the 2213 woofer (Alnico magnet) where the 4312C used the 2213H woofer (Ferrite magnet)--heavier in weight and higher power handling, but otherwise comparable in appearance and performance--JBL lists them as "interchangeable".

I would guess the build date to be somewhere in the 2000's (probably early 2000's), based on when the other models were discontinued. From the Service manuals that I was able to look up, the D, E, and MkII 4312's were not a US market offering, that may be why it is harder to get specific info on them.

 

[Philip moses]

Thanks for the info.

I actually bought these on impulse as i love the L26 i have.
I’m in the process of doing tne Gravesen crossover upgrade.
Just waiting for Jantzen parts to arrive.

Do understand that JBL was based near Northridge California, and during the Northridge earthquake of 1994
a lot of their data archives that had just sort of grown since the 40s were destroyed.
That, plus there was a lot of corporate downsizing after they were bought by Harman Industries,
and a lot of offshoring resulted as well.
Plus, the more recent sale of Harman to Samsung.

There is not the history of records we might hope for from a company of that reputation.

(I am not a JBL employee - but I bought my first JBL L-36 speakers new in 1976,
and got a lot more gung ho with different models after 2000).

I'm based near Wash, DC - folks on the west coast probably know much more.

 

[savatage1973]

I wanted more info in case i wanted to upgrade the crosdovers in tne future.

Listen to them first. They are not all that old that they necessarily "need" a XO rebuild. As far as mods, you may want to look up info on the 4312C and some of the 44xx series that used the 052ti tweeter. Some people don't like the "brightness" of Ti dome tweeters, but I don't mind it at all, and they can usually be "tamed" with the L-pads (to your taste)--but then again, I love the ribbon/quasi-ribbon tweeters in my Infinity's, Maneplanar's and Apogee's--YMMV.

The big thing that most people try to change in JBL's of that era and design is the "upper bass bump" inherent to the XO design and woofer drivers of the L100 and 43xx 3-way series (all using the same or similar mid driver, and either the 123a, 2213, or 2213H woofers). I like the "extension" of the Ti tweeters, far better than the "roll-off" you get with paper cone tweeters--but, again, that is just me.

 

[litefootdan]

I did the Gravesen complete upgrade on with a pair of L36's I had and cannot be happier. It was night and day for me. It took decent speakers to completely satisfying speakers.

 

[Philip moses]

Excellent.
You’re the first person i have found to have done tne Gravesen mods to similar speaker.
Definately looking firward to tne upgrade.

Thanks.

I did the Gravesen complete upgrade on with a pair of L36's I had and cannot be happier. It was night and day for me. It took decent speakers to completely satisfying speakers.

 

[Philip moses]

I had a listen to the 4312mk2 today as they arrived this afternoon.

Very impressed.
A very big clear sound and on firsr impression i like tnem a lot.
And rhey look stunning.

 

[Philip moses]

One question....
Where is rhe best room positioning for the 4312 range?
How far from walls etc?

Thanks.

 

[litefootdan]

Room placement is probably going to be a case by case deal. I did a quick and dirty search with "2 channel speaker placement guide" and this was the first link I was presented with.

https://www.aperionaudio.com/blogs/aperion-audio-blog/2-channel-stereo-speaker-placement

About Gravesen's upgrade (regarding the 3-way L26/L36), it is uncanny how well the speakers sound. I am deficient in my right ear, so I don't get stereo imaging well, nor do I get pin point placement in specific recordings... but I do get congestion and phase smearing very well. Somehow the work he did with those drivers really cleared them up. They are very, very satisfying to listen to now. Normally I listen to single driver speakers or sometimes single driver with a tweeter up top for sparkle. But those 3-ways really deliver. I don't know if Gravesen did a reworking of the 4312 mk2 crossover, but if he did it is bound to be fantastic. I have a pair of stock 4312a's and they just sit as the sweetness of the L36 is so nice.