JBL LE14C Maintenance over time

[academia50]

I would like to upload pictures and tell the story of my speakers that are giving great music after almost 40 years of manufactured. JBL Congratulations!



Before long ....

[academia50]

The first change of foam wings (the first series of this speaker wore rubber fabric wing, yellow) after use was about 10 years, I had to splice a section of 2 inches or so to reduce the total diameter 15-14 inches.


http://img809.imageshack.us/img809/3603/7h8c.jpg (http://imageshack.us/photo/my-images/809/7h8c.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


The foam is supposed acoustically behaves better, but not last as long as the fabric, they need not likely replacement ....


http://img819.imageshack.us/img819/5131/j7qv.jpg (http://imageshack.us/photo/my-images/819/j7qv.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)






Sorry my english !! Traductor on line help for me !! :D

Regards friends ! :)

[academia50]

These wings adapted performed well for many years, until almost the end of 2011.

He arrived when a new replacement, the first step, and then cut off the entire wing, and remove all traces of old glue.

http://img832.imageshack.us/img832/8785/y8am.jpg (http://imageshack.us/photo/my-images/832/y8am.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img801.imageshack.us/img801/1581/wrve.jpg (http://imageshack.us/photo/my-images/801/wrve.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


http://img843.imageshack.us/img843/5077/2gxl.jpg (http://imageshack.us/photo/my-images/843/2gxl.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


Continue, regards !

:)

[academia50]

Remove the old glue requires patience and recommend working with mask and in ventilated, the MEK (methyl ethyl ketone) is very volatile and can cause dizziness, etc.

http://img600.imageshack.us/img600/2550/2m7s.jpg (http://imageshack.us/photo/my-images/600/2m7s.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


http://img594.imageshack.us/img594/5678/zpqz.jpg (http://imageshack.us/photo/my-images/594/zpqz.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)





http://img268.imageshack.us/img268/9073/8zva.jpg (http://imageshack.us/photo/my-images/268/8zva.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


simple tools reptidas sometimes soaks the surface to take off, until the glue is clear, after shaves and cleans gently until no traces of it. This is very important because the cone has a rough treatment at the rear should not discard. Be careful there, do not abuse with the liquid.



http://img689.imageshack.us/img689/8567/tryq.jpg (http://imageshack.us/photo/my-images/689/tryq.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Clean front cone




http://img21.imageshack.us/img21/4651/0wzi.jpg (http://imageshack.us/photo/my-images/21/0wzi.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)



parte trasera limpia también, ya podemos instalar el ala nueva

http://img854.imageshack.us/img854/9444/hbjk.jpg (http://imageshack.us/photo/my-images/854/hbjk.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

The repair kit, very complete, wing, glue, adjust and test disc, and instructions.

http://img259.imageshack.us/img259/6536/e973.jpg (http://imageshack.us/photo/my-images/259/e973.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


http://img198.imageshack.us/img198/6117/7pwz.jpg (http://imageshack.us/photo/my-images/198/7pwz.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img853.imageshack.us/img853/253/4u8i.jpg (http://imageshack.us/photo/my-images/853/4u8i.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

Much attention when using the cd, I consider important some considerations about ...

[academia50]

30 hertz to slightly higher volume in an outdoor speaker (there is no limit to the excursion of the cone that gives the enclosure speaker) a volume just head over this frequency may cause the voice coil out of your work area , hit in the gap, it proves the wing if not the glue is dry, especially the containment ring itself we have not yet ...:(
The manufacturer of the kit provides the CD with the intention of proving that there is no friction between the coil and the gap, but just to that, so I hardly noticed it moves freely, turn off the amp and get on with the job. Remember first set to minimum volume. This is a very sensitive speaker (91 db ..... 5 meters with 1 watt!! Think db/1w/1m equals 96), very suitable for tube amps "low power" and its displacement is limited because it has a large area cone. No need to travel far, the opposite of the current speakers 6.5-inch cones and long routes (Xmax), developed for existing solid state amplifiers, where the cheapest are the extra watts and the hardest part is getting realism in reproduction ......
The manufacturer of the kit indicates that in the event that the coil rubbing the gap, as the glue is slow setting, the cone can move slightly sideways to remove it, however I see it unlikely if the spider is healthy, because it is responsible for maintaining the coil axis.:D

[academia50]

El ala nueva tiene la medida exacta,:applaud: decido colocarla por detrás del cono , como en el driver original. :)




http://img689.imageshack.us/img689/9382/974i.jpg (http://imageshack.us/photo/my-images/689/974i.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

I sorry .......:o:



The new wing has the exact size,:applaud: I decided to place it behind the cone, as in the original driver.:)

I say this because I have seen many arrangements in which as a matter of ease, - it is easier to join two smooth surfaces - place a new foam wing over the cone, which does not seem right.

I think this because although in his early JBL LE-14C did well (see photo), the widespread use of foam wings, all stuck in the factory behind. What is the difference?

The first is that according to the form and material of the wing, this strength will place voice coil exactly in the middle of its travel.
The cone will move from that position forward or back, according to the polarity of the alternating signal received by the voice coil.
The second and no less important, is that the foam repair ahead immediately denotes aesthetic difference with original speaker says: Hello, I'm fixed, I'm not ORIGINAL

http://img855.imageshack.us/img855/1070/q417.jpg (http://imageshack.us/photo/my-images/855/q417.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Finished, the shroud is very important, a strong attachment helps the wing and the basket





http://img69.imageshack.us/img69/1529/9ev0.jpg (http://imageshack.us/photo/my-images/69/9ev0.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Back (the most difficult, but eventually the foam is tailored to roughness) :D



http://img834.imageshack.us/img834/3963/bqq0.jpg (http://imageshack.us/photo/my-images/834/bqq0.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Finished work, but ........
:o:


http://img40.imageshack.us/img40/7425/qsuo.jpg (http://imageshack.us/photo/my-images/40/qsuo.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

:( Look very ugly!

http://img839.imageshack.us/img839/2682/ujlf.jpg (http://imageshack.us/photo/my-images/839/ujlf.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

The masking tape used in the first repair (when I had to adjust from 15 to 14 inches) glue residue left on the white cone.
The overall look is a dirty old yellow..........
:crying:


must return the original color ....... and if I paint ?
:eek:


Of course !!

:bouncy:

[academia50]

A forista painted his Tannoy speakers with varnish .....:(
He should have used the famous 2329 for marine use, so imagine it would sound good, varnish and English speakers ....:D


We must take into account not fundamentally alter the weight (mass) of the cone, because it alters the sound coloration, and modifies the parameters Thiell and Small ... terrible mistake!
:banghead:

So I had to find a product with covering power, soft and form a film that is as light as possible.
I do not know if anyone ever used it, but I found this:

CHINA INK WHITE :)

http://img580.imageshack.us/img580/5862/pog7.jpg (http://imageshack.us/photo/my-images/580/pog7.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

I used brush, apply two coats immediately dried with a hair dryer on low speed. This will avoid any deformation of the cone, unlikely to happen with this cone JBL 14 " which has a special treatment, but please keep it in mind if you choose to do so for example in a black cardboard cone.



http://img33.imageshack.us/img33/8365/b5lr.jpg (http://imageshack.us/photo/my-images/33/b5lr.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)



I like how it turned out, looks new!:):p:bouncy:


http://img844.imageshack.us/img844/1598/tbqb.jpg (http://imageshack.us/photo/my-images/844/tbqb.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

The next step was to upgrade the xover ......

To be continued ....:yes:

[thrash099]

The next step was to upgrade the xover ......

To be continued ....:yes:

hi academia, i have a pair of le14c's as well so i am looking forward to seeing your progress especially with the crossover :applaud:

[academia50]

Hi Trash099, thank you for your encouragement to continue with the thread, but I thought since I have a LE14C in use ....:D

The xover was updated only with the original capacitor change new "audiophile grade". I left the original coil with iron core (these have magnetic saturation, the theory, but the iron helps to achieve a smaller size, although in theory it is better air core coils, the required value was too large) I wanted accommodate all back into the original xover box. I also would have liked to change by borneras "modern"

Upload more material tomorrow


Regards

[academia50]

Friends :

Upload photos and a brief story.
The theme of the capacitors arouses much controversy. I personally agree that there are important differences between one audible and one bad quality very sophisticated. But the best audiophile grade capacitor does not improve audio system mediocre. Even to not notice differences if you do not have good equipment. My amplifier is Prima Luna Dialogue Two, after many years I came to the valves and I am very happy to have done this (for me) significant investment. HES + valves is a revival of the great epochs of the audio. Luckily I did not let go of the LE-14C, I was about to sell when all Solid State amps sounded bad, very bad. Especially at higher volumes. The distortion specified in the literature of the vast majority of the amplifiers is not a valid reference when listening to sound good. Of course there are some honorable exceptions, but with much higher costs to a humble and well built valve kit with quality components. (Eg upgrade Dynaco ST-70)
In the near future I hope to build new cabinets, (Troels Gravesen design, DTQWII) 150 liters and current production speakers, this coaxial JBL is in a box of 85 liters. Luckily I have high WAF and room 35 m2 .... Good upload some pictures of the xover upgrade, not in order, perhaps, a thousand apologies, gladly clarify any point.

Regards

[academia50]

I get the order


http://img827.imageshack.us/img827/6117/1jq9.jpg (http://imageshack.us/photo/my-images/827/1jq9.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

Price line quality Clarity Cap ESA, there are good references for these capacitors. Some are much higher, they say, but very expensive too.

http://img12.imageshack.us/img12/6343/lra2.jpg (http://imageshack.us/photo/my-images/12/lra2.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

To achieve lower cost, put two in parallel. They also say that it is not best to achieve "the" sound, but the difference adding surcharges to freight and Argentina is important. I do not know if it is so, well ....


http://img94.imageshack.us/img94/3148/sbx1.jpg (http://imageshack.us/photo/my-images/94/sbx1.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

The network circuit is very simple, the full frequency range goes to mid-twofeer :o: (this achieves excellent integration into the medium-high range with the tweeter:bouncy:), and the tweeter is protected by a high-pass capacitor/choke-coil is ours. The wire resistor attenuates the treble level. At my age, is always full ....:D


http://img812.imageshack.us/img812/3245/ntkg.jpg (http://imageshack.us/photo/my-images/812/ntkg.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)




( click on the pictures enlarges the size (http://imageshack.us/photo/my-images/841/7mra.jpg/))

[academia50]

2000 HERTZ is the crossover frequency, excellent SPL, 80 db to 4.6 meters .......! :)

It is equivalent (at the time I did the calculation, I think it corecto) to 96 dB/1 w/1 meter ! :applaud:

http://img833.imageshack.us/img833/2240/4tsg.jpg (http://imageshack.us/photo/my-images/833/4tsg.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

The original capacitor and coil detached. Epoxy failed or incompatible with cast aluminum?

:(


http://img46.imageshack.us/img46/1606/s4o2.jpg (http://imageshack.us/photo/my-images/46/s4o2.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img12.imageshack.us/img12/6894/dz1c.jpg (http://imageshack.us/photo/my-images/12/dz1c.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img197.imageshack.us/img197/5456/t65q.jpg (http://imageshack.us/photo/my-images/197/t65q.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

I favor a combination of both, aluminum forms an oxide film over the years that can cause shedding, well, see you again in 30 years if the silicone rubber is better ....:crying:

http://img571.imageshack.us/img571/5994/0gv7.jpg (http://imageshack.us/photo/my-images/571/0gv7.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


Measuring capacity of the new Clarity, are 3% tolerance, obviously less is better.



http://img16.imageshack.us/img16/5207/6fi4.jpg (http://imageshack.us/photo/my-images/16/6fi4.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[thrash099]

what value are the original capacitors academia? I'm a complete novice when it comes to all this! might rewire the crossover and replace the original capacitor as well….

[academia50]

HI,

The original value as shown in the circuit and the photos is 6.0 microfarads. The iron core coil is 0.5 millihenries, I repeat that perhaps air core from inside the box-xover .....

Here you can buy both and are the best.

http://www.jantzen-audio.com/

Regards
Academia50

[academia50]

Measuring capacity of the new Clarity, are 3% tolerance, obviously less is better.







I meant that less tolerance (%) is better, the ideal is 6.0 microfarads accurate, but as you see in the measurements are values ​​in my case within 3%.

It is so important to good sound as accurate a value, yes it is the quality of the capacitor.

[academia50]

http://img835.imageshack.us/img835/872/tw0x.jpg (http://imageshack.us/photo/my-images/835/tw0x.jpg/)






Uploaded with ImageShack.us (http://imageshack.us)






http://img689.imageshack.us/img689/4169/3ik2.jpg (http://imageshack.us/photo/my-images/689/3ik2.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)








http://img28.imageshack.us/img28/7341/x0vw.jpg (http://imageshack.us/photo/my-images/28/x0vw.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Previous photos:
The type of cable connectors speaker was pressure, and special cables to be very heavy can damage them, so with a steel wire solves the problema.También sure the cable tying the crossover rheostat, can use a seal plastic if you want it is best presented.

[academia50]

The back cover was set with rivets "pop", are deleted and placed metal screws.



http://img841.imageshack.us/img841/5974/5xcg.jpg (http://imageshack.us/photo/my-images/841/5xcg.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)




http://img842.imageshack.us/img842/9168/51lk.jpg (http://imageshack.us/photo/my-images/842/51lk.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


http://img40.imageshack.us/img40/1495/ivfc.jpg (http://imageshack.us/photo/my-images/40/ivfc.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Do not forget to put the rubber seal .....



http://img198.imageshack.us/img198/8366/vznz.jpg (http://imageshack.us/photo/my-images/198/vznz.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Soon, new board speaker, and fine tuning of the tuning of the box.

[thrash099]

looking good academia - i have now started giving mine an overhaul, i have painted the inside of the cabinet with bitumen paint…..59538

[academia50]

Hello trash099 !


Important size box, that's very good! The LE14 C is well adapted to several liters, this promoted the JBL, but, if we are strong and deep low, it is clear that a petty cash fund has its limitations.


http://img196.imageshack.us/img196/5391/oy8t.jpg (http://imageshack.us/photo/my-images/196/oy8t.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)



I have not used bituminous paint, but it is good to reduce resonances.
I fabricate the box according to the plane of the original kit, structural rigidity is achieved with internal reinforcements and was used as an absorbent glass veil.
We'll add some absorbent material? Is very important, above all internal except front ....

[academia50]

JBL planes (Commercially known as cabinet C-53)


http://img6.imageshack.us/img6/2552/mamh.jpg (http://imageshack.us/photo/my-images/6/mamh.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)



http://img812.imageshack.us/img812/945/b9i8.jpg (http://imageshack.us/photo/my-images/812/b9i8.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Other pics


http://img29.imageshack.us/img29/9435/e2ua.jpg (http://imageshack.us/photo/my-images/29/e2ua.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


http://img153.imageshack.us/img153/8250/vh8l.jpg (http://imageshack.us/photo/my-images/153/vh8l.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[thrash099]

hi academia - finally opened up the crossover box… here is what i found. there is no value of the capacitor printed on it so I'm not sure what it is. will have to get a tech to test it i suppose. The markings are the same as yours so i assume its the same but better to be sure.

59569

[academia50]

Hi trash099.

The capacitor value determines the crossover frequency and acts as a lock to protect low frequencies to the tweeter. Apparently in the first LE-14C was 1200 Hertz (1.2 kHz) - (see brochure) and then changed to 2000 hertz (2 kHz). I do not know the exact reason for this may be several, perhaps due to the factory change the fabric wing (yellow) by the foam. (The latter helps improve Fs - lower - but unfortunately they degrade. Apply liquid silicone helps to prolong its life. Might also change the value of the capacitor according to the volume of the box, what type of wing has a speaker and how many liters is the enclosure? Or just by a decision of "listening to conscience", remember that there were no computers and very common to adjust to "hear" (acoustic specialists, of course)
The liter calculated by multiplying width x height x depth. (Internal measures)
Anyway, I tend to believe that is 6 microfarads to have the same part number 10296 ....:)

[academia50]

:( The oil is surfacing to the surface, deserves a good replacement .....:D




http://img12.imageshack.us/img12/1889/2kv0.jpg (http://imageshack.us/photo/my-images/12/2kv0.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[thrash099]

The cone has been replaced with a paper one and the wing is foam so it's not original - the paper cone would be lighter (advantage or disadvantage???). The external dimensions of the cabinet are approximately 500mm X 600mm X 700mm so I assume the internal volume is about 200L. I don't have the technical expertise or equipment to measure all these variables so I will replace the caps with a 6uf one and play around with the stuffing....

[academia50]

:crying: :(

Well, that changes absolutely everything ....... paper cone can be thick, thin, with a built-fiber treatment, etc, etc ..... You could upload a picture of the driver only?


A cone not original always a disadvantage.....

[thrash099]

Crap :)... I will upload a picture of drivers this afternoon. The original cone material was too damaged to repair so they were replaced with I think fairly light weight paper cones... I'm not sure how this affected the sound as I never heard the original drivers.

[thrash099]

Here is the re-coned driver….

59586

[academia50]

Trash099 :

It looks well done the work . Obviously , Thiele Small parameters are not the same, but if the coil is the original and the tweeter, too much will not change the final sound. I think it will work well for a hearing "shocking" - especially bass - but with out exquisite details (this also depends on the rest of the audio system)
I see you have changed the dust-cup by one not original, (that alters the total mechanical resistance, along with the aircraft and the spider that is hard to see from the front) cone also do not seem to be the original, has less stretch marks , (could be one of the first models, it is rare to find 14 inches, usually all replacement cones are 15) I need not pay too much in audiophile capacitors, I would leave those if a measurement yields a value close (+ / - 5%) to the original, and do not differ more than that percentage not together.
Always work better than a non-polarized electrolytic unknown brand or similar.

For the garden, good drinks and pretty girls is perfect !:p



http://en.wikipedia.org/wiki/Thiele/Small (http://en.wikipedia.org/wiki/Thiele/Small)

[thrash099]

Only thing changed is cone, foam surround and the area around the tweeter (spider?)... Coil is original and tweeter us original... Cone was 15" and cut down (carefully!) to 14"....

[academia50]

Right, that's spider the other speaker used as guardalpolvo in this repair. Two have corrugations, but obviously not offer the same strength ..
In your case, we have two spider, instead of a spider and an overall original.Trash099 speaker, who has done the work? You?

Here we see the voice coil with spider respective


http://img689.imageshack.us/img689/3905/f8wq.jpg (http://imageshack.us/photo/my-images/689/f8wq.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

More brochures


http://img825.imageshack.us/img825/3458/9h2b.jpg (http://imageshack.us/photo/my-images/825/9h2b.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)


Comments on the crossover slope and capacitors employees


http://img594.imageshack.us/img594/599/jmct.jpg (http://imageshack.us/photo/my-images/594/jmct.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[thrash099]

no i did not do the work - a guy in oz who built quite highly regarded guitar amps did the work…. it will be very interesting to hear these speakers after all the work i will do on the cabinets. i plan on replacing the internal stuffing with acoustic insulation (50mm) on all panels (but not baffle) and maybe even cut out odd shapes of the insulation to stick to the walls as well to help break up reflections. i think this will be the most significant upgrade even more than replacing the caps in the crossover network……

[academia50]

Hi trash099 :


I agree not much progress in improving the xover as long as there is not much away correpsondiente value of 6.0 microfarads. Easy to check with a tester that has capacitance meter.
Also I think proper acoustic treatment planned for inside the enclosure.

As observations, I think it would be interesting to measure a parameter T / S which has been modified in the bass cone, the resonant frequency (Fs) and redesign the tuning tube according to the result. This directly influences the quality of the bass.

And a comment:

The maximum power LE14C be taken as 35 Watts (real - RMS) which is what supports the tweeter.
I use with higher power amplifiers (75 watts / channel) but indoors and never in volumes "deafening".
Please do not take seriously what I said listen loud "in the garden" would be very dangerous for tweeters, not the midrange/bass cone - , voice coil 4 inchs it does support higher power.

Regards :)

[academia50]

Back in 1978 I built the boxes for the JBL LE14C following the verbatim form of measures and armed with internal bracing, plywood panels and all gluing.
The only change was the design grid for web, but I thought was a nice aesthetically, I wanted to finish the job quickly and listen to boxes with the anxiety associated with my first job with high quality speakers and prestige. So were made simpler.
Argentina marks of those years had already passed through my hands, Ucoa, Audifiel, Leea, etc. .. The latter with designs copied from Altec Lansing expired patents the years 40/50.


The dimensions of the tube box tuned to 85 liters are:
4 inch diameter by 3 inches deep.
A friend "very knowledgeable" recommended me to lengthen the tube to achieve low with a little more "punch".
Willing to see if the sound would achieve my liking, I did some hearing tests once assembled the boxes, with various lengths of tubes, and indeed, the bass changed, "beat" a little more.
For my musical tastes at the time - mostly rock, Deep Purple, Pink Floyd, Led Zeppelin, Yes, etc. - I thought it was great advice and so enjoyed until a few months ago from them. With alternating periods with other brands, JBL sound always seemed more transparent and real, that's why I kept until today.
It was love at first sight .....
Continue, my apologies, I use the translator and a bit slow writing, but what a great help! :applaud:

[thrash099]

I had one of the capacitors measured and it was 6.3uf....I am replacing with jantzen superior z capacitors... I have put new binding posts and will be lining the cabinets with a good quality acoustic stuffing. I mainly listen to rock as well and think that the le14c are good for this type of music. I am using a redgum amp (australian brand) which drives them well I think, but it would be nice to hear them with a tube amp :)

[academia50]

This is the amp you have?




http://www.stereomojo.com/REDGUM RGi120ENR Integrated Amplifier Review.htm/REDGUMRGi120ENRIntegratedAmplifierReview.htm



155 watts rms per channel are enough to achieve more than 100 db in a closed environment of household size.
But there is risk of damage if you decide to try "how strong is heard" :D , remember my comments about the JBL-LE20 tweeter. (In the coaxial design has good efficiency, being within the large cone, it acts as a horn, you do not need great power, but is good to have more (favors listening to recordings with good dynamic range)
Here you can read about it:
http://www.troelsgravesen.dk/JBL_LE20-25.htm

I currently use the JBL LE14C a Prima Luna tubes of 38 Watts/ channel in push pull .
I will read the whole article, I like the design! :)

Trash099, what's your name?
I am Rolando, Rolo for my friends

[thrash099]

Hi Rolo, my name is Matt.....
the amplifier I have is this one -
http://www.digitalaudioreview.net/2011/01/redgum-sonofagum-5500-integrated-amplifier/
Its a good review of it that will give you an idea about how it performs :)

[academia50]

Hi Rolo, my name is Matt.....
the amplifier I have is this one -
http://www.digitalaudioreview.net/2011/01/redgum-sonofagum-5500-integrated-amplifier/
Its a good review of it that will give you an idea about how it performs :)



" When cross-referenced against the REDGUM amplifier range proper, the Sonofa’GUM 5500 sports a 180VA toroidal transformer (similar to that of the RGi120). “The SG-5500 is rated at 55WRMS into 8 ohms, it is chunkier than the RGi35 (35+35WRMS) but it could be described as not being as poised as the RGi35 due to the SG-5500 using a conventional power supply. (In the REDGUM range, its own UltraFlex power supply is certainly not a conventional design and so the greater Transient Power available uncovers the musical magic so often left hidden on a disc by other designs.)”, Gerber added. "

Hi, Matt, I think that is the right power for LE14C enjoy! :applaud:

We hope your comments when you finish the work of the boxes.

A friend lost contact which went to live in Australia, I was amazed with the country.


But it does a lot of this, at that time there were kangaroos everywhere yet ....


:)

Regards

Rolo

[thrash099]

Hi rolo,
the red gum drives them easily, it does not take a lot of power to get them singing…. this is what i am lining the boxes with- http://www.acoustica.com.au/echosoft.html
i am using the 50mm. i may also cut out odd shaped pieces to glue randomly inside to help prevent reflections. i will post some pics shortly. i ended up getting some jantzen superior z caps (after your recommendation) which i may have to mount outside the crossover box as they are a little large.

59700

im in sydney so not many kangaroos :)

regards,
Matt.

[academia50]

Hummmmm ......:o:


It is not suitable material for cushioning ......


Must absorb but no cancel the sound, just can read the opinion of a specialist Jantzen here:


http://www.troelsgravesen.dk/JA8008_DTQWT.htm
You can see the photo of what you need

" If you want to source damping materials locally, please do not ask where to buy and what materials are suitable. I have not been able to find e.g. felt material at the usual diy speaker suppliers around the world. 10-12 mm polyester foam can be used, but pay attention to the physical properties of damping materials, some are not specifically meant to absorb sound, rather absorb vibrations from panels, etc. Do not use damping materials having a smooth outer surface like damping sheets for cars, etc. These will reflect sound and are not suitable.
"

The capacitors look very good! :)

Regards Matt


Rolo

[thrash099]

these are not smooth on surface or for damping - they are like dense polyester fibreglass so i hope will be suitable :) i suppose i will find out when i power them up!
59703

i know of people who have used this successfully for room treatments (bass traps) so i assume it would be good for cabinets as they are just like little rooms!

[thrash099]

Mine are done - had to add little more polyfill to the cabinets as they sounded a bit boxy- like the vocals were far away - once I did that they were great.... Except that one seems to have lost treble response so I will check all connections but once that is sorted they will sound great

[thrash099]

As they say the general rule is to check the most obvious thing first- a wire had come loose on the tweeter inside the cabinet.... They now sound great - overall clearer sounding, bass is lower and treble seems to be a bit brighter which is welcome. They sound a bit more lively which is cool, well worth the effort :)

[thrash099]

A photo of the crossover box - I mounted the new caps outside

[academia50]

Congratulations Matt ! I'm glad that the result is to your liking, good job! :applaud:

"Smoke on the Water" (Deep Purple) and enjoy!:bouncy::)

[hoschibill]

Hi :)
It's nice to see that other people loves the LE-14C. I see a lot of nice work here. Wonderful:applaud:! Here's a link to my C53 Libra restoration.

http://www.diy-hifi-forum.eu/forum/showthread.php?t=5882

And a picture of my LE-14C:

59877

BR
Oliver

[academia50]

Hi hoschibil

On treatment with brake fluid (do not share the idea, because if you alter the parameters of the speaker softening the wing, to change the fs, you must also change the tuning of the box (fb) ....) changing the tube tune.
Do not forget that the ideal for balanced sound is that any measure acoustic box as flat as possible.
Moreover, the photo attached does not correspond to the same speaker, the cabinet is not the C-53, is very small .......



Regards

Rolo

[hoschibill]

Hi Rolo :)

On treatment with brake fluid (do not share the idea, because if you alter the parameters of the speaker softening the wing, to change the fs, you must also change the tuning of the box (fb) ....) changing the tube tune.
The treatment with brake fluid are only for collectors who want their speakers in original shape. For those who want to listen to their speakers it is imho better to replace the surrounds with new foam surrounds. Then the speakers have the correct parameters and a sound as close as possible to the original speaker as they were new.

Do not forget that the ideal for balanced sound is that any measure acoustic box as flat as possible.
Yes I know it ;).

Moreover, the photo attached does not correspond to the same speaker, the cabinet is not the C-53, is very small .......
The picture is from my LE14C after restoration. The enclosures are original C53 Libra.

LG
Oliver

[academia50]

Hi Oliver :)


Now I understand, thanks for the explanation, friend

They look great now! Congratulations !

I see you used my method of "painting" exlusiva rejuvenating , and the same wings, good job ! :applaud:

you've changed the original tweeters by any chance?

:confused:

Please attach a picture of the speaker mounted in the cabinet C-53, !
You've built your?



Regards


Rolo

[hoschibill]

Hi Rolo :)
Thanks for your appreciation.

you've changed the original tweeters by any chance?

The tweeters are the original ones. Both tweeters were damaged due overload but both coil windings were intact so I could repair both tweeters.

Please attach a picture of the speaker mounted in the cabinet C-53, !
You've built your?
I will do that when they were restored. The restoration is still in progress. A friend do this for me. New veneer is not my specialty ;).

Have a nice week
Oliver

[academia50]

Back in 1978 I built the boxes for the JBL LE14C following the verbatim form of measures and armed with internal bracing, plywood panels and all gluing.
The only change was the design grid for web, but I thought was a nice aesthetically, I wanted to finish the job quickly and listen to boxes with the anxiety associated with my first job with high quality speakers and prestige. So were made simpler.
Argentina marks of those years had already passed through my hands, Ucoa, Audifiel, Leea, etc. .. The latter with designs copied from Altec Lansing expired patents the years 40/50.
The dimensions of the tube box tuned to 85 liters are:
4 inch diameter by 3 inches deep.
A friend "very knowledgeable" recommended me to lengthen the tube to achieve low with a little more "punch".
Willing to see if the sound would achieve my liking, I did some hearing tests once assembled the boxes, with various lengths of tubes, and indeed, the bass changed, "beat" a little more.
For my musical tastes at the time - mostly rock, Deep Purple, Pink Floyd, Led Zeppelin, Yes, etc. - I thought it was great advice and so enjoyed until a few months ago from them. With alternating periods with other brands, JBL sound always seemed more transparent and real, that's why I kept until today.
It was love at first sight .....
Continue, my apologies, I use the translator and a bit slow writing, but what a great help! :applaud:



I return to the previous thread . My friend did not give me the best advice , I do not know as much as said or imagined ..... ami me the same sound like him.
The tube tuning than a long indicated on the drawings of JBL , acting on the grave so nice, not so deep , but had some punch .... Now , after so many years it occurred to me : And with the exact size recommended by the manufacturer , how to change the sound ?
So get to work . The cardboard tube 96 mm preferred . mm.de diameter and 138 deep, was replaced by a PVC as indicated by JBL , ( see previous flat wire ) or a diameter of 102 mm and 76 mm deep. The change was for the better, and much !
The serious down ( deeper ) , but more surprising , improved media ! Female voices charged a presence and lack of stridency that was not previously .
Here I emphasize two points :
1) I've tried for many years countless acoustic cabinets from the 70's and 80 's, I remember that we were one of the first houses in Buenos Aires audio to have a switching console to instantly be able to compare the sound of different pairs of speakers. Recall that no auditory memory, always difficult to describe the perceived sound, sometimes words are not enough, and often are ridiculously employed .... "Round sound" will sound "envelope" for example? Here there is no deception, the sound is present instantly revealing the strengths and weaknesses of the boxes. So I set up a simple set-top box signal source, two pairs of RCA output and an input. And to put a small switch in monaural signal and thus send exactly the same signal to both channels, left and right. We can use a balance going from left to right, or we can use two similar readers standart CD (44100 Hz 16 Bit) with the same material recorded and selected with the input key.
2) First Realize the modification of a single cabinet, did the tests and it convinced the remarkable improvement, I finished the other.
There was also another improvement I leave for the next thread. Now I upload pictures.
http://www.audioheritage.org/vbulletin/images/icons/icon11.png So, friends do not always give good advice, beyond good intentions.

http://img62.imageshack.us/img62/1305/cm2p.jpg (http://imageshack.us/photo/my-images/62/cm2p.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img706.imageshack.us/img706/9202/8s98.jpg (http://imageshack.us/photo/my-images/706/8s98.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img30.imageshack.us/img30/807/pa4g.jpg (http://imageshack.us/photo/my-images/30/pa4g.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

Continue ......http://www.audioheritage.org/vbulletin/images/icons/icon14.png

[academia50]

Morephotos

:D



http://img812.imageshack.us/img812/3227/o7j2.jpg (http://imageshack.us/photo/my-images/812/o7j2.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)
http://img854.imageshack.us/img854/8610/msmg.jpg (http://imageshack.us/photo/my-images/854/msmg.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img845.imageshack.us/img845/1256/pkwx.jpg (http://imageshack.us/photo/my-images/845/pkwx.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img801.imageshack.us/img801/6141/yso7.jpg (http://imageshack.us/photo/my-images/801/yso7.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

http://img811.imageshack.us/img811/1008/4cq0.jpg (http://imageshack.us/photo/my-images/811/4cq0.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[academia50]

Well, now I would like to ask ..... the change in sound, bass is understandable because different tube tuning moves the point of maximum SPL at low frequencies.

But why improved midrange???




:eek::eek::eek:

Regards, friends



Rolo

[hoschibill]

Hi Rolo :)
It's done. Here as promised the pictures of my C53 Libra. Since yesterday they live again. Wonderful speakers, magnificent sound, dry bass.

http://www.diy-hifi-forum.eu/forum/picture.php?albumid=792&pictureid=15229http://www.diy-hifi-forum.eu/forum/picture.php?albumid=792&pictureid=15230http://www.diy-hifi-forum.eu/forum/picture.php?albumid=792&pictureid=15231http://www.diy-hifi-forum.eu/forum/picture.php?albumid=792&pictureid=15232

It was a lot of work but it was worth it. It is amazing what these speakers were able to perform 47 years ago.

BR
Oliver

[hoschibill]

Hi Rolo :)
I forgot, your speakers are very nice. How much volume have the enclosure? 3ft³? Wonderful old style.

But why improved midrange???
If you move the tuning of the port to lower frequencies (longer port), the bass is deeper and quieter. If you move the tuning to higher frequencies (shorter port) the bass is less deep and louder. In relation to this, the mids are loud or quiet.

BR
Oliver

[academia50]

Well, now I would like to ask ..... the change in sound, bass is understandable because different tube tuning moves the point of maximum SPL at low frequencies.

But why improved midrange???


Rolo


The answer is to change the length and diameter of the tube, the Fb (tuning frequency of the box) moved below
The Fx, crossover frequency, 12 dB / octave is 2000 hz. Recall that the flat section of the cone is reproducing the mid / bass and tweeter upper mids. (Area surrounding the tweeter, which is flat and has no ripples)


There is an advantage in reproducing average critical frequencies for large cones, see:

http://www.troelsgravesen.dk/HES.htm



Post scriptum

I had a mail from a guy who had just heard a pair of vintage Pioneer speakers, actually the HPM-100. Below to the left:

http://www.troelsgravesen.dk/HES/hpm-100_C copy.gif http://www.troelsgravesen.dk/HES/L100_1.gif

The questions from the writer were these: Why does this speaker provide such a pleasant sound? Why is it so easy to listen to? What does it have that most modern speakers do not have?
Well, I have never heard the HPM-100s, but this speaker is a Japanese clone of the famous JBL L100 Century (http://www.troelsgravesen.dk/JBL_L100.htm) (speaker to the right above). The JBL was a three-way system not having the supertweeters these Pioneers have.
One important thing that may be part of the "pleasant" sound and an "easy to listen to" speaker is probably the fact that a major part of the midrange is handled by a large cone. The JBL 12" bass driver really handles all of the midrange and the Pioneer probably also. Large cones = minor cone movement and reduced distortion. Now, the L100 is (was) not the most respected speaker around when it comes to neutrality, three-dimensionality and a number of other parameters we take for granted these days. The mid had major trouble due to poor filtering but I wouldn't be surprised if Pioneer had made a decent crossover for this speaker - and probably used a middriver not as notoriously difficult as the JBL LE5-2. I guess the system sensitivity is around 90 dB like the JBL L100.


Regards.

Rolo

[academia50]

Hi Rolo :)
I forgot, your speakers are very nice. How much volume have the enclosure? 3ft³? Wonderful old style.

If you move the tuning of the port to lower frequencies (longer port), the bass is deeper and quieter. If you move the tuning to higher frequencies (shorter port) the bass is less deep and louder. In relation to this, the mids are loud or quiet.

BR
Oliver



Hi Oliver !

I had not seen your answer, and I answered myself ......:D
Correct reasoning, we agree 100%.
Thanks for the pictures.
Congratulations on the new box, I see other JBL speakers there!
You could tell what they are and your impression compared to LE14C ?
Indeed, my boxes are three cubic feet, you can see it in the DIY plans that I attached.
I think the C-53 Libra corresponds to this volume.

Regards

[academia50]

Hi Rolo :)
I forgot, your speakers are very nice. How much volume have the enclosure? 3ft³? Wonderful old style.



:crying::D
Correction, your cabinet is the C-53 Libra, and mine DIY would be 3 cubic feet equivalent commercial JBL model Dorian S-12, bears the same components as the driver LE-14C but not in coaxial mount. The LE-20 tweeter and mid-twofer LE-14A




http://img33.imageshack.us/img33/1726/0bo7.jpg (http://imageshack.us/photo/my-images/33/0bo7.jpg/)


Uploaded with ImageShack.us (http://imageshack.us)

[hoschibill]

Congratulations on the new box
Thank you :)

I see other JBL speakers there!
You could tell what they are and your impression compared to LE14C ?
Man, my english.. ok I try. The other speakers on the pictures are the L-112 and the 4311B. Both seem to have a deeper bass than the C53 but the bass is softer, more boom-bass. The C53 is more precise in the Bass. In the mids the 4311B and the L112 produces a little more distortion than the C53 and womans voices are a little sharp. The C53 is pretty smooth in the mids. I've also measured it. The 4311B and the L112 make K3 distortion in the mids up to 1% at 2,83V input. The C53 less than 0,2%. I think that's amazing for a speaker of 1966. Of these three, the C53 is the best speaker.

Greets
Oliver

[academia50]

Thank you :)

Man, my english.. ok I try. The other speakers on the pictures are the L-112 and the 4311B. Both seem to have a deeper bass than the C53 but the bass is softer, more boom-bass. The C53 is more precise in the Bass. In the mids the 4311B and the L112 produces a little more distortion than the C53 and womans voices are a little sharp. The C53 is pretty smooth in the mids. I've also measured it. The 4311B and the L112 make K3 distortion in the mids up to 1% at 2,83V input. The C53 less than 0,2%. I think that's amazing for a speaker of 1966. Of these three, the C53 is the best speaker.

Greets
Oliver


San Google hilft wirklich, ich Spanisch nach Englisch und Deutsch auf Englisch tu. Sie sind zwei Übersetzungen!. Als ein Experiment, ich befehle diese übersetzt aus dem Spanischen ins Deutsche.


Es ist gut verstanden, und ich bin froh, dass das, was Sie denken, die Mid-Range des LE-14C, zum Glück hielt ich diese herrlichen Lautsprecher so lange!. :applaud:
Alnico-Magnet, Spule und große Zellstoffkonus und Hochtöner mit einem guten Verstärker produziert hervorragende Klang!
In meinem Fall einen Röhrenverstärker mit 35 Watt in Push-Pull.

Ich schicke Ihnen eine große Umarmung Freund! :)

[academia50]

I think that's amazing for a speaker of 1966.



Looks like it was released in 1962..

http://www.lansingheritage.org/images/jbl/catalogs/1962/page08-09.jpg


http://img202.imageshack.us/img202/2087/q8fy7.jpg (http://imageshack.us/photo/my-images/202/q8fy7.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

[hoschibill]

Hi Rolo :)
Google translator is very helpful :D. The LE14C was introduced in 1962, thats right. My LE14C were from 1966, it was the last series marked 16 ohms. In 1967 they were marked 8 ohms. I think the production stopped in 1969. It was the last catalog in which the LE-14C was mentioned.

Greets
Oliver

[academia50]

Hola. He estado ocupado construyendo mis nuevas cajas de bricolaje. con la decepción que veo las fotos de todos mis contribuciones a este hilo ImageShack ha suprimido el servicio gratuito, ya que parece que no es así.


Que no deben hacer. si ofrecen algo gratis, una vez que el período de uso expiró sin costo, debe mantener visible el material proporcionado .. Una vez más, la letra pequeña nos engaña. Una verdadera pena para todos los que han seguido el hilo y también algunos nuevos miembros del foro ..... De todos modos, si desea volver a ver mi querida y noble JBL LE 14C, puede hacerlo aquí :

http://www.diyaudio.com/forums/multi-way/276238-dtqwtii-argentina-7.html

( page 119 )

Ellos siguen trabajando muy bien, pero pronto serán parte de un sistema 5.1, serán los altavoces traseros.
Gracias amigos !




Hi. I've been busy building my new boxes DIY. with disappointment that I see the pictures of all my contributions to this thread ImageShack free service has been deleted, since it seems that it is not.




They should not do. if they offer something for free, once the period of use expired without cost, must be kept visible material provided .. Again, the fine print deceives us. A real shame for all those who have followed the thread and also some new forum members ..... Anyway, if you want to see my dear and noble JBL LE 14 C, you can do so here:


http://www.diyaudio.com/forums/multi...gentina-7.html


(Page 119)


They still work fine, but soon will be part of a 5.1 system will be the rear speakers.
Thanks friends !