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Peter Larsen
 
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Default Should I Re-cone a JBL L-65 Woofer ??

GregS wrote:

Digital media? I remember digital ready! But its hard to find
woofers with square wire.


They are digital ready, remember the classic JBL voice coil design!

joke, poor, don't want nobody to believe this, therefore this UNML-tag

What is needed is biwiring, so that there can be a set of wires for the
0's and one for the 1's so that they do not get mixed up. Much clarity
is lost on non-digital ready setups because of this issue, addressing it
also enhances the sale of loudspeaker cable and boosts copper price by
increassing the demand.

/joke, poor, don't want nobody to believe this, therefore this
UNML-tag

The jubal played very loud. I'm sure they can handle "digital"
media. They were a bit bright, I thought at the time, so I
didn't spend the $800 or so to buy a set. I was really impressed
by the look and advertising sheet, but not the sound.


As is they have in-built loudness, so they *are* digital ready*! - what
I would want to do if I owned a pair would be modding the x-over to make
bass and midrange meet in agreement and to eq the midrange unit in its
upper range. I think it has an upwards tilt in its response and that
getting it flatter and lowering output of the 2405 a couple of dB would
help remarkably in making the system more "mainstream" as in violins
sounding like made of wood.

To get back to the topic, what is likely needed will be new surrounds
for the bass units, third party spareparts may do very well. The bass
unit was not in the pro equipment line, I wonder whether original recone
kits are at all available, if not, then do not rush into a full recone.
Replacing with a modern JBL 12" may be possible, it will be costly, it
will alter the sound and necessitate at least a bass reflex retuning,
possibly also a cross-over mod, just fixing the darn foam surround if
torn is a much more attractive strategy in my 2-second view of this.

greg



Kind regards

Peter Larsen


--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************
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jakdedert
 
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Default Should I Re-cone a JBL L-65 Woofer ??

Peter Larsen wrote:
GregS wrote:


Digital media? I remember digital ready! But its hard to find
woofers with square wire.



They are digital ready, remember the classic JBL voice coil design!

joke, poor, don't want nobody to believe this, therefore this UNML-tag

What is needed is biwiring, so that there can be a set of wires for the
0's and one for the 1's so that they do not get mixed up. Much clarity
is lost on non-digital ready setups because of this issue, addressing it
also enhances the sale of loudspeaker cable and boosts copper price by
increassing the demand.

/joke, poor, don't want nobody to believe this, therefore this
UNML-tag


The jubal played very loud. I'm sure they can handle "digital"
media. They were a bit bright, I thought at the time, so I
didn't spend the $800 or so to buy a set. I was really impressed
by the look and advertising sheet, but not the sound.



As is they have in-built loudness, so they *are* digital ready*! - what
I would want to do if I owned a pair would be modding the x-over to make
bass and midrange meet in agreement and to eq the midrange unit in its
upper range. I think it has an upwards tilt in its response and that
getting it flatter and lowering output of the 2405 a couple of dB would
help remarkably in making the system more "mainstream" as in violins
sounding like made of wood.

To get back to the topic, what is likely needed will be new surrounds
for the bass units, third party spareparts may do very well. The bass
unit was not in the pro equipment line, I wonder whether original recone
kits are at all available, if not, then do not rush into a full recone.
Replacing with a modern JBL 12" may be possible, it will be costly, it
will alter the sound and necessitate at least a bass reflex retuning,
possibly also a cross-over mod, just fixing the darn foam surround if
torn is a much more attractive strategy in my 2-second view of this.


Damn, Peter. Where have you been? All the potential fixes, including
most of the above, were addressed in this forum last week. The OP took
my advice (seconded by others here) and purchased replacements off Ebay.

Case closed.

jak

greg




Kind regards

Peter Larsen


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Peter Larsen
 
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Default Should I Re-cone a JBL L-65 Woofer ??

jakdedert wrote:

Damn, Peter. Where have you been?


Working mostly.

All the potential fixes, including most of the above,
were addressed in this forum last week.


Thanks.

The OP took my advice (seconded by others here) and purchased
replacements off Ebay.


Aha.

Case closed.


Was the suggestion to keep or sell the old units rather than discard
them included?

jak



Kind regards

Peter Larsen


--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************
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jakdedert
 
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Default Should I Re-cone a JBL L-65 Woofer ??

Peter Larsen wrote:
jakdedert wrote:


Damn, Peter. Where have you been?



Working mostly.


All the potential fixes, including most of the above,
were addressed in this forum last week.



Thanks.


The OP took my advice (seconded by others here) and purchased
replacements off Ebay.



Aha.


Case closed.



Was the suggestion to keep or sell the old units rather than discard
them included?

Actually, I made one half-hearted offer to buy which was overlooked or
ignored. That's probably for the best, since I'm a little 'speaker
poor' at the moment. I have a pair of K-120's which are surplus; and I
recently purchased a couple of case-lots of NOS Polk replacement drivers....

jak

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Peter Larsen
 
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Default Should I Re-cone a JBL L-65 Woofer ??

jakdedert wrote:

Actually, I made one half-hearted offer to buy which was
overlooked or ignored.


The point I am anxious to get across is that old JBL loudspeaker
chassis's should not be discarded, they can almost always be re-equipped
with matching cones or diaphragms, they are hardly ever trash.

That's probably for the best, since I'm a little 'speaker
poor' at the moment. I have a pair of K-120's which are surplus;


Please stop reminding me, my wallet gets strangely scared and my credit
card hides whenever you mention them, it would be worse even if it were
D123's, and I really ain't no use for them but drooling and putting into
totally useless cabinets and power with a Bang & Olufsen "Dirigent"
valved receiver from 1963. A pair of LE8T's however .... it could be fun
trying the real stuff in place of Corals 8F60 semi-clone of them for
midrange.

jak



Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************


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jakdedert
 
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Default Should I Re-cone a JBL L-65 Woofer ??

Peter Larsen wrote:
snip

Please stop reminding me, my wallet gets strangely scared and my credit
card hides whenever you mention them, it would be worse even if it were
D123's, and I really ain't no use for them but drooling and putting into
totally useless cabinets and power with a Bang & Olufsen "Dirigent"
valved receiver from 1963. A pair of LE8T's however .... it could be fun
trying the real stuff in place of Corals 8F60 semi-clone of them for
midrange.

They actually 'did' sound pretty good in the Pioneer HPM cab's; but
don't get too excited. I bought 'em used over 15 years ago. They've
had a pretty easy life since then, but one was obviously reconed before
I got 'em. The surrounds don't match, and I concerned that one or the
other has a generic voice coil.

I don't have a certified genuine k-120 to compare, so I don't know which
--if indeed either--one is original. They both work well, sound the
same...IIRC, the serial numbers are reasonably close.

There's no doubt of the authenticity of the basket, though. g

In any case, I've got a deal going with a former customer of mine,
who--almost thirty years back--bought a set of HPM-100's, a set of
HPM-40's and a Technics SA 5760 from me.

I found and installed new woofs for the HPM-40's last year. (Hows that
for warranty service? g)

He's willing to trade me the receiver for the k's in order to fix his
100's...until he can find OEM woofs to replace the ones he blew way
back. After that, he's gonna put the JBLs in his bass guitar cabinet.

jak
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Peter Larsen
 
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Default Should I Re-cone a JBL L-65 Woofer ??

jakdedert wrote:

He's willing to trade me the receiver for the k's in order to fix his
100's...until he can find OEM woofs to replace the ones he blew way
back. After that, he's gonna put the JBLs in his bass guitar cabinet.


K120 is a midrange unit, he will risk tearing them if he uses them for
bass, unless of course he wants to use them as "high range" units in a
two-way with an 18".

When I was involved in using them in PA our design was to cross them at
250 Hz 12 dB pr. octave in a 4-way system or to use them in fairly small
closed box type stage monitors, ie. with a similar excursion protection
even if not highpassed. If I were to spec them for anything today my
spec would be that they should be used with a 120 Hz 12 dB/octave
highpass if used at high power.

Guitar use with reduced assumed powerhandling - see my JBL brochure on
http://www.jblheritage.org - is OK, full range bass guitar use is most
definitely in contravention of JBL application note for the K120.

jak



Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************
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