Jbl L300 Summit

[Fangio]

you have an idea about the difference between the two woofer (except weight)
136A (Alnico) L300
136H (Ferrite) L300A
i have not find a link ..

Me neither, never seen a direct link to a data sheet for one of them. AFAIK the magnet assembly is the only difference.

Anyway, next level would be the different magnet ingredients.

Note that discussions about alnico vs. ferrite, and their impact on sound can get very passionate here...
Facts to start with:

http://audioheritage.org/vbulletin/showpost.php?p=37039&postcount=1

and the designer on the subject:

http://audioheritage.org/vbulletin/s...2&postcount=29

[BMWCCA]

and the designer on the subject:
http://audioheritage.org/vbulletin/s...2&postcount=29

Great link! Got to love an engineer with a sense of humor about his work!

The old decade woofers (116A and 127A) only had to see an amplifier in the room and they got really nervous.

[richluvsound]

Hi rich

what do you make changes to improve the sound quality of the already very good L300?

Hi mm54,

I looked at all the small things that could be done ie. New insulation, binding post, Fillet all internal joints with a structural adhesive, new gaskets on all components, etc. If they were mine I would remove the old networks service and clean , then pack them away safe and build CC networks - charge coupled. The 2235 is quite easy to find if your not worried about using original 2235 baskets. Jbl-recone kits are still made and there are a few jbl baskets that can be made into 2235 while still maintaining original factory spec.

I use forum member "Guido" for all my re-coning and all things electrical. We're good friends also. However, that friendship was built on mutual respect and trust.
There are people, closer and cheaper,but I have no desire to penny pinch
on any aspect of a speaker project.

The summit was the first JBL I ever heard - but at 18, unless I was going to live a life of crime, I would have to wait a good few years to own a pair. . In my opinion, they sound brilliant and look stunning.

How about some pics of said specimen ?

BTW . WELCOME !


Rich

[mm54]

These Summits were built between 1975-1982 which were arguably JBL’s most innovative and prolific period. These were designed by Greg Timbers, who worked at JBL for over 35 years and is one of the worlds most respected speaker designers.

Ferrite magnets do not demagnitize

is gtimbers the same person ? whaoo

I admire and am impressed
MOULT RESPECT !

[mm54]

I made my new plates (Please do not copy my images)

[mm54]

Our L300's have 2235H's in them, and we love that woofer, very much! It's offers tight, highly detailed bass, and a warm sweet sound that is very natural to our ears. When I say "our" ears, I mean Sweet Bride and myself.

Hi Doc and thank you for your impressions on the L300

you hear a real difference between 136A and 2235H ?
is the range of response is clearer , more nervous ?
Michel

[4313B]

The biggest differences between the 2235H and 2231/136A was the introduction of a progressive suspension and high power voice coil. The progressive suspension was developed to deal with the issue of dynamic offset. At higher output levels, coil motion is no longer centered at the vertical midpoint of the coil gap but can be centered at some point outside of the gap. This greatly increases distortion. The progressive suspension acts to counteract this phenomenon and keep the coil centered. Power handling was increased with these suspension changes and the change to a kapton coil former. The result was that the later 2235H had twice the power handling of its predecessor.

Whether or not anyone can actually hear the improvement can be debated just like anything else. I know Greg could. After a few beers I really don't think it matters.

[Fred Sanford]

^^ Thanks for that...

je

[mm54]

Whether or not anyone can actually hear the improvement can be debated just like anything else. I know Greg could. After a few beers I really don't think it matters.

it's very fair, listen good music with good beer, a real pleasure !!

a person who loves music and beer can not be fundamentally wrong!

[Doc Mark]

Hi Doc and thank you for your impressions on the L300

you hear a real difference between 136A and 2235H ?
is the range of response is clearer , more nervous ?
Michel

Hello, Michel,

The first L300's that I heard had their original woofers in them, and I remember them being simply outstanding!! I've heard several other sets of those wonderful speakers over the intervening hears, and always loved them. But, I have heard other speakers, including some that I have made myself, with the 2235 woofers, and for whatever reason, seem to prefer them. When we got the chance to buy our L300's with 2235 woofers, we were really happy about that, and dearly love our speakers, very, very much! BUT, had they contained their original woofers, rather than the 2235's, I'm sure we would have bought them and enjoyed them, just as they were. But as for the 2235's, I've always thought they were more punchy on the bottom end, less boomy, and more accurate, than the original woofers. For what it's worth.... Take care, and God Bless!

Every Good Wish,
Doc

[mm54]

[mm54]

I connect my L300 tomorrow on my 1801+4401 for a first listening impressions follow ..

[hjames]

Nice pictures!
Thank you for sharing with us!

[mm54]

Nice pictures!
Thank you for sharing with us!

thank you hjames it is a pleasure, what do you think of my new nameplate JBL

it is a big job, but you see the result

[BMWCCA]

what do you think of my new nameplate JBL

I think your little water-mark or trade-mark symbol embedded in your photos is a bit over the top. If . . . IF . . . anyone wanted to copy your photos they still easily could and two seconds in Photoshop would sponge-tool away your mark. What proprietary material are you trying to protect from copying? Your copy of the JBL logo???