who makes a 13.5µf capacitor?

[brad347]

If I decided to recap by L-65A Jubals, who makes a 13.5µf cap? Most makers on Parts Express seem to jump from 12.0 to 15.0. Any ideas?

[grumpy]

put two standard value caps in parallel, in place of the original.
the values sum (e.g, 12uF + 1.5uF).

[brad347]

put two standard value caps in parallel, in place of the original.
the values sum (e.g, 12uF + 1.5uF).

duh. :banghead:

thanks! :)

[just4kinks]

The reason the caps jump in value is because the tolerance is low -- probably 10%. 1.2x and 1.5x are standard multipliers for 10% tolerance components.

12uF could be anywhere from 10.8uF to 13.2uF.
15uF could be anywhere from 13.5uF to 16.5uF.

It would be pointless to produce a 10% 13.5uF cap, because its range would overlap with its neighbors. Sorry if this explanation doesn't make sense, here's a link that goes into more detail. It's written for resistors, but the same thing applies to capacitors:

http://www.pc-control.co.uk/resistor-eia.htm

If you really want a 13.5uF cap, you should find someone who stocks them in a higher tolerance. If you don't care about the precision, just choose the next closest value, or sum two smaller caps like Grumpy said.

[speakerdave]

use two 6.8's very common

[Don C]

Try Newark or Digi-Key.
http://www.newark.com/30M8915/non-stocked/product.us0?sku=cornell-dubilier-unl9w13p5k-f&_requestid=23130

[readswift]

hey, ive been thru this recently ( upgrading the stock 4430 to MKP) very good deal here on the sweden EVOX-RIFA caps:
http://stores.ebay.com/AudioTek-Shop_Capacitors_W0QQcolZ4QQdirZ1QQfsubZ102552010QQ ftidZ2QQtZkm

im still lookin for 0.01 bypass caps, I can source some audionote teflon for basically free though.

[Gary L]

The Altec 19 XOs used a 21uF cap but I can only find replacments in 20 or 22uF.

I think either is close enough but am not the expert here by a long shot.

My question goes more to back in the day, is it possible Altec decided upon the 21uF simply because that was what they had available at that time?

Gary

[readswift]

hi , you can just wire caps in parallel, like 3x 6.8 + 0.47 would be pretty close IMHO, though watch out for tolerance readings, the EVOX ones I shown are within 5% of their given micro farad value . Paralleled caps have lower ESR (resistance) value than a single one, now this is where my knowledge stops, what ESR these old mylar / polyester caps had. Parallel MKP is obviously the cheap way, boutique large values are waay overpriced imho.

[jcrobso]

This is some what of a common practice in better XOs.
In general you would 10% of the total capacitance in a smaller cap in parallel with the larger one.
Large value caps are layers of metal rolled up to get the desired value the can be some inductive loss at high frequencies, buy putting a smaller cap to bypass the bigger one this can reduce the inductive effect. John

[mini]

This is some what of a common practice in better XOs.
In general you would 10% of the total capacitance in a smaller cap in parallel with the larger one.
Large value caps are layers of metal rolled up to get the desired value the can be some inductive loss at high frequencies, buy putting a smaller cap to bypass the bigger one this can reduce the inductive effect. John

.. what in the end could make a funny unintended high-Q Inductance/Capacitance-resonator. I would like to insinuate that common audio knowledge may be quite missleading when it comes to electrical engineering.

As far as I know salable film capacitors rated from 0,1mu up to 220mu will behave near to ideal with audiofrequencies, R.dc << 0,1Ohm, L.ser << 1mikroHenry, nonlinearities (if any) well below 0,01%.

BTW: I personally don't understand why JBL as a reputable sort of institution came to the idea to "bias" film capacitors ... .

Best Regards

[4313B]

BTW: I personally don't understand why JBL as a reputable sort of institution came to the idea to "bias" film capacitors ...Ed Meitner mentioned it to Greg and Greg tried it. He was stunned at the results. I was skeptical but tried it as well. I was quite impressed at the results. Insinuating that Greg is disreputable only serves to make me cranky. I can tell you one thing for certain, Greg is really sick and tired of discussing it at this point. Did I stress the sick and tired part enough? Do what you want with your gear and he'll do what he wants with his and that includes his loudspeaker designs at JBL. I can also tell you that I don't have time to screw around and if I thought I could save time by not biasing my capacitors I'd be all over it. Hopefully that helps you understand? :)

If not you can read through the links found in this link:

Biased Capacitors aka Charge Coupled Capacitors (http://audioheritage.org/vbulletin/showpost.php?p=32732&postcount=6)



This thread was done at post number two.

[mini]

... read through the links found in this link:

Biased Capacitors aka Charge Coupled Capacitors (http://audioheritage.org/vbulletin/showpost.php?p=32732&postcount=6)

This thread was done at post number two.


O/k, I've had read the related pages before. For honest! I really thought it over and over again. But from these pages there is absolutely no evidence for a benefit from biased film capacitors. It seems to be an excessive speculation. The analogy to amplifier topology (class A vs. B) is rather a persuation than an explanation.

If there was an effect as stated a stunning simple measurent would disclose it: the distortion at lower levels would both increase tremendously by absolute amount and not at least its spectrum would give a signature that can't be overlooked even at diminishing levels. You may measure anything directly at the caps as to avoid contamination by the acoustics.
But - You just guess it right, the opposite is true: even with very poor electrolytic caps the lower the level the lower the distortions go. With film types You won't see any crossover (sic!) distorsions no matter how far You go down close to thermodynamic limits of random noise (-130dB). Consequently the pages omit any graphs on that topic or even a simple single number. In spite of this application area would be very very revolutionary!

edit: think of capacitors in microphones, mixing consoles, nearly anywhere in audio. Much lower levels (charge wise), relative more crossover, more distortion, less pleasing right from the start?

To believe in what the paper says does mean to believe that there is the fabulous something that can't be measured but only heard. The most the more it should be hidden by surrounding circumstances. In so far everybody is free to find his own luck. My hearing ain't impressive - that for the affinity to louder speakers? - but I'm happy.

With posting #x ("some inductive loss at high frequencies") the thread reiterated common wisdom in that capacitors where mythical gremlins which one hardly can get under control. Surely they'll break out again, when the next disbelief is on its way: "Does it sound really right?"

I felt free to give the advice to think all that urban ledgends over. You won't challenge that electrical engineering grounds on rational arguments. If so, why not use terms as "inductance" etc as they are intended? Namely as quantities that can be calculated with. Give it a try. There is no use in all that talking without a basic understanding of proportions. What is of paramount importance and what can be omited simply due to its diminishing numbers?

No offense! ;)

edit 2: This reading would tell the story to the end (I hope so) => http://www.aes.org/e-lib/browse.cfm?elib=5175

[speakerdave]

I think your desire for measurement confirmation of a technical idea is certainly acceptable, but your assumption that a phenomenon does not exist unless you can measure it is not.

My question is--have you aurally compared charge-coupled vs. non charge-coupled versions of the same speaker? If you have not done this, those who have are far more informed on this question than you are, no matter how much electrical engineering you know. Your theoretical objection to someone else's experience is just absurd.

David


O/k, I've had read the related pages before. For honest! I really thought it over and over again. But from these pages there is absolutley no evidence for a benefit through biased film capacitors. It seems to be an excessive speculation. The analogy to amplifier topology (class A vs. B) is rather a persuation than an explanation.

If there was an effect as stated a stunning simple measurent would disclose it: the distortion at lower levels would both increase tremendously by absolute amount and not at least its spectrum would give a signature that can't be overlooked even at diminishing levels. You may measure them directly at the caps as to avoid contamination by the acoustics.
But - You just guess it right, the opposite is true: even with very poor electrolytic caps the lower the level the lower the distortions go. With film types You won't see any crossover (sic!) distorsions no matter how far You go down close to thermodynamic limits of random noise (-130dB). Consequently the pages omit any graphs on that topic or even a simple single number. In spite of this application area being very very revolutionary!

To believe in what the paper says does mean to believe that there is the fabulous something that can't be measured but only heard. In so far everybody is free to find his own luck. My hearing ain't impressive - that for the affinity to louder speakers? - but I'm happy.

With posting #x ("some inductive loss at high frequencies") the thread reiterated common wisdom in that capacitors where mythical gremlins which one hardly can get under control. Surely they'll break out again, when the next disbelief is on its way: "Does it sound really right?"

I felt free to give the advice to think all that urban ledgends over. You won't challenge that electrical engineering grounds on rational arguments. If so, why not use terms as "inductance" etc as they are intended? Namely as quantities that can be calculated with. Give it a try. There is no use in all that talking without a basic understanding of proportions. What is of paramount importance and what can be omited simply due to its diminishing numbers?

No offense! ;)

[4313B]

I would pass your concerns on to Greg but he honestly doesn't care. Seriously. He just doesn't. He's heard it all before and he has far bigger fish to fry.

More importantly, it really doesn't have anything to do with you unless you are having a problem with your JBL loudspeaker systems and you suspect your biased capacitors are at fault.

I really don't know what else to tell you. It's a deadend discussion.

[mini]

... have you aurally compared charge-coupled vs. non charge-coupled versions of the same speaker?... Your theoretical objection to someone else's experience is just absurd.

David

I simply don't think so. I really appreceate that You find my considerations worth a comment in spite of being offended by bad English in the first place. Thank You.

As not to bother You further on I would like to steer Your attention towards this. You might have droped it for being mentioned as an edit to he original post of mine:

http://www.aes.org/e-lib/browse.cfm?elib=5175

The abstract should be a teaser regarding any objection in both directions. People who won't read this fail to show a deeper interest in that topic. Yes, 20$ is a lotta money. But what is this compared to time/money spendings for unessential alterations? All that situations You are doing confirmations, comparing and reviewing some delicate updates to audio urban legends may prove to have been a lost lifetime. You could have heard music, ain't that so?

You have to decide by yourselves, that's for sure. I'm not keen to argue with anybody as my skills to do so in a foreign language won't fit. From my education a more objectivistic attitude is the most convinient for me. I'm such a slacker ...

[4313B]

I'm such a slacker ... It's a deadend discussion.

JBL isn't going to recall all their loudspeaker systems just because you think you know something...

[speakerdave]

. . . . in spite of being offended by bad English in the first place. . . .

I hope I did not suggest I had any problem with your English--I certainly did not experience any. Possibly I've misunderstood something.

By now you are probably getting the feeling that
:tribe:

To speak in terms of cultural stereotypes, this may be nothing more than a difference between the European affinity to theory and the American affinity to pragmatic solutions. We are inclined to do what seems to work; the explanation can follow later.

In any case, we are a random collection of people who appreciate (mostly the old parts of) the Lansing Heritage in speaker art; we are not a forum for calling out current JBL engineers to defend their designs. In fact, we get a little touchy about that, because we like them and want them to continue to befriend us.

David

[speakerdave]

. . . . From my education a more objectivistic attitude is the most convinient for me. I'm such a slacker ...

To denigrate something you have not examined yourself is neither objective nor scientific.

[boputnam]

mini...

The fact that something is not measureable does not make it a myth. Not everything experienced by the human ear (or eye) is directly measureable - not in the way we perceive it.

Your post, above, answers your own question. Yes, JBL is a reputable company. And, in addition to their pioneering engineering, JBL conduct extensive "blind" listening tests, where various manner of cabinets are compared and contrasted, behind a screen, shifted into "listening position", mechanically. JBL does this to ensure that they have created a wonderful sounding speaker cabinet.

Skepticism on this is easy - as 4313B posted (#12, above), certainly the folks at JBL were. Well, JBL has done blind testing, using charge-coupled and non charge-coupled networks and in-spite of what you say the results should be, in-fact there is a noticable improvement and so it became "JBL".

You should try the idea, yourself, or at-the-least, stop arguing that it cannot be so. With that closed-minded approach, you'll never discover anything...

[Beowulf57]

I simply don't think so. I really appreceate that You find my considerations worth a comment in spite of being offended by bad English in the first place. Thank You.



I'm not keen to argue with anybody as my skills to do so in a foreign language won't fit.

This issue has nothing whatsoever to do with language skills. It has to do with the spirit of the contentions, i.e., the zeitgeist on the two sides is not the same.

[Hoerninger]

... the zeitgeist ...
Nice word :) , but it has to do with the ever inherent problem, is someone open to a new unexpected idea or not.
The fine thing for children is they have no "theorie" and they are free in their perception.
And even in science the experiment is the prove of any theorie.
____________
Peter

[mini]

mini...
You should try the idea, yourself, or at-the-least, stop arguing that it cannot be so. With that closed-minded approach, you'll never discover anything...

No - that simple.

[mini]

Insulting people who won't pay $20 to read an unqualified article is just a straw man argument ...

Sorry, I see feelings go high on that topic. I didn't aim to give the insultant >agent provocateur< within a dedicated JBL clique.

The article shouldn't be blamed for just being a reading suggested by me. If You degrade anything against Your personal hearing sensations - connected to aural esthesia - then truely there is no sense in arguing about differences in 'zeitgeist' U.S. vs. European.

I developed a simple method to estimate the amount of the effect claimed by JBL and others regarding capacitor bias. It's very easy and I reiterate that. The lower the signal level the more pronounced the effect should appear. But fortunately for us interested in highest fidelity the forementioned effect neither can be seen in graphs nor can it be heard by to many people. Including me.

Furthermore from a technical point of view the effect claimed would have been quite astounding. Again I stay being a happy nitwit. What I know about electrical engineering is by far enough and right, there's little room left for spectacular audio borne lore. In so far I'm "closed minded" as somebody named me.

O/k, that's me. Nobody is hold to agree. Didn't want to bother You (to much).

So long!

[1audiohack]

One of my friends that knew Richard C Heyser told me he used to say somthing to the effect of,, We tend to measure what we know how to measure, because we can.

Here is a quote from the paper he was working on at the end of his life.

"Perhaps more than any other discipline, audio engineering involves not only purely objective characterization but also subjective interpretations. It is the listening experience, that personal and most private sensation, which is the intended result of our labors in audio engineering. No technical measurement, however glorified with mathematics, can escape that fact."

Richard was the scientist that brought Time Delay Spectrometry into the audio world. His day job was at JPL.

[boputnam]

Sorry, I see feelings go high on that topic. I didn't aim to give the insultant >agent provocateur< within a dedicated JBL clique.Apologies, accepted. Thanks. But not just to/for us - to JBL, of course.


I developed a simple method to estimate the amount of the effect claimed by JBL and others regarding capacitor bias. You are making the point of speakerdave. And now we discover your entire argument was not supported by any measurements, but solely by estimations. Yikes. You really must find another place to posit your dreams...


O/k, that's me. Nobody is hold to agree. Didn't want to bother You (to much). Yeah, and that's the whole reason for this place. Share some ideas, share some observations and grow the experience. To insult the referential manufacturer is a terrible approach - particularly on estimations.


So long!Bye. :wave:

[mini]

One of my friends that knew ... ... somebody ...

In my opinion the trouble starts when people try to relate their very subjective hearing experience to technical details of the infamous audio chain. In an overwhelming proportion subjectivists in internet forums have to admit at best a sketchy knowledge of technology or physiology / psychology of cognition. Your citation can't be paralled to what is discussed here.

Back to topic? The claim that "bypassing" a capacitor would lower ESR and/or lower parasitic inductance is proven to be wrong by calculation and measurement. As You see nothing of the above is related to perception. This for the conclusion: bypass => lower ESR/L => better sound is interupted and - faulty, ain't that so? If it still "sounds better", what imagination is that for?

[mini]

... but solely by estimations.

Bye. :wave:

Sir,

By quantum mechanics it is not impossible that a broken cup will reassemble itself. But a sloppy estimation shows quickly that this shouldn't happen to often.

I gave You a hint on how to estimate the amount of the effect by hearing. What are the circumstances in which the effect would be most prominent? How does the effect develop with some selective experimental settings? What is the proportion of the effect - if any - to other perceptable irregularities? If it is not measurable as some say, how can we be sure to come to the right conclusions (bias => better sound) by experimental hearing?

Second to that I gave a link to a paper published by the Audio Engineering Society (AES) that is dedicated to that topic. The abstract abbreviates the result.

Am I asked to leave the board now?

[speakerdave]

. . . . Am I asked to leave the board now?

No. But, further discussion on this seems pointless, because neither side is listening to the other.

[hjames]

Sir,

By quantum mechanics it is not impossible that a broken cup will reassemble itself. But a sloppy estimation shows quickly that this shouldn't happen to often.

Should I leave the forum now?

JBL engineers do NOT frequent this forum, and they have no need for your arguments. Its their technology, and it pleases many buyers of their speakers. Your arguments to the contrary will not change that.
Thus, your arguments are pointless.

When intrigued, many folks here have installed bypass capacitors. They like the results and have encouraged others. Your arguments will not change their feelings about the value of those additions.

When your arguments do not change those facts, they are just beating a dead horse. Why do you persist in hammering those points over and over again? :biting: It has gotten old, it is not amusing, and I am heading to bed.

Perhaps its time for YOU to retire as well ...

[CauYem]

Mini,

I ran simulations on those charge coupled Xovers & found that the input impedance on all of them screwed up badly compared to the non-charge coupled network. It varies all over places.

Electrically, it doesn't improve anything but seems to introduce distortion by being a tough load to drive for an amplifier. It definitely effects the sound wave, but I don't know how. To some listeners, it might be an improvement.

Here is the L300 Network (Charge coupled vs. regular):
Top Graph: Charge-Coupled network: Red (LF), Green (Mid), and Black (HF)
Bottom Graph: Charge-Coupled Network: Blue (Input Z)

[Zilch]

Bypassing, it's hysteresis; biasing, zero-crossing. If the linked article is relevant, I am at a loss to appreciate in what respect.

THIS, however, is amusing:

http://forums.klipsch.com/forums/t/99466.aspx?PageIndex=1


I ran simulations on those charge coupled Xovers & found that the input impedance on all of them screwed up badly compared to the non-charge coupled network. It varies all over places.Now, WHO among us would have both standard and CC versions of the same crossover to actually measure, or several different ones, perhaps? :hmm:

WT or CLIO? :p

[1audiohack]

Don't leave, we can agree to dissagree, right?



Second to that I gave a link to a paper published by the Audio Engineering Society (AES) that is dedicated to that topic. The abstract abbreviates the result.



The "somebody" I referred to was president elect of the AES, an active member of the AES for almost 30 years, and at various times held all of the elected positions of the Los Angeles Section of the AES.

The "friend" I refer to is the "Chair of the acoustics department" and a professor of acoustics at a real university. Also the author of several chapters in the Hand Book for Sound Engineers, 2008. Sorry, no names.

Forgive me for learning at the feet of fools.

The truth is there are things and phenomenon we do not yet know how to measure and or measure adequately. Some times you just have to listen, and enjoy.

Back on subject?!? Who does make a 13.5uF capacitor? Only how to achieve the desired value has been answered.

[boputnam]

I gave You a hint on how to estimate the amount of the effect by hearing. I haven't those means, and really don't have an opinion in this topic. I am merely trying to re-assemble some decorum here.


Am I asked to leave the board now?I replied to your good-bye. It was your idea.


I ran simulations on those charge coupled Xovers & found that the input impedance on all of them screwed up badly compared to the non-charge coupled network. It varies all over places.Can you please provide a key to your plots? What is which...?


Don't leave, we can agree to dissagree, right?
Back on subject?!? Who does make a 13.5uF capacitor? Only how to achieve the desired value has been answered.:rotfl: Oh, yeah - where were we...?

[mini]

citation: "Perhaps more than any other discipline, audio engineering involves not only purely objective characterization but also subjective interpretations. It is the listening experience, that personal and most private sensation, which is the intended result of our labors in audio engineering. No technical measurement, however glorified with mathematics, can escape that fact."



Forgive me for learning at the feet of fools.

The truth is there are things and phenomenon we do not yet know how to measure and or measure adequately. Some times you just have to listen, and enjoy.

Back on subject?!? Who does make a 13.5uF capacitor? Only how to achieve the desired value has been answered.

If I should I would insist that the given citation of the somebody a buddy of Yours knew once shouldn't be used right here. Of cause and literaly audio is for hearing and not measuring. That's the basic message of the citation and that is it.

But if somebody (again) tries to improve things - on that the citation is deaf-mute - it would help to know a thing or two about regular engineering. Thankfully CauYem stepped ahead and showed his results. You should discuss the topic as a new thread if You dare.

From here it seems to be a question of belief and denomination. That's not mine. For now it seems to much of a hassle to involve myself to biasing caps. My rough estimation, based on firm grounds, own engineering skills didn't motivate me to much.

[Zilch]

Back on subject?!? Who does make a 13.5uF capacitor? Only how to achieve the desired value has been answered.Not Solen, apparently:

http://www.solen.ca/pub/cms_nf_catalogue_niveau3.php?niveau1=1&niveau2=3

Is this helpful? ;)

[mini]

You simply order two 27 uF capacitors, bias them and viola, you have 13.5 uF.

Ahhh! ;)

[Ian Mackenzie]

Its a proven concept as a far as the JBL house sounds goes with Solen fast caps .

[mini]

This forum pisses them off. One mentioned very nearly having a coronary after reading some of the horseshit posted here. Who in their right mind needs that crap in their life? ... The arguments such as posted by mini and "CauYem" only serve to illicit negative reactions to this website from the very people I would prefer to interact with. It's absurd.

Both, mine and CauYem argumentations are based on engineering, solid knowledge, intelligence as CauYem is concerned and a honest eagerness for truth. If anybody dislikes that so far that he undergoes a heart attack, sad me, as it is for sure not intended.

"Zilch" gave this link: http://forums.klipsch.com/forums/t/9...px?PageIndex=1 (http://forums.klipsch.com/forums/t/9...px?PageIndex=1)

I took the time to read it. There is so much wrong with those fotos, not to mention the other stuff - I gave it up. Please stop flaming too. We two have already found a synthesis of savvy calculations and sheer hearing:
"You simply order two 27 uF capacitors, bias them and viola, you have 13.5 uF."

'Hope You get the irony ... should be fun, o/k? :)


Thanks a lot

[Mr. Widget]

...but I'd suggest that you don't let the door hit you in the face on your way out troll. :wave:Let's try to be a bit more civil...

I am not asking you to like the poster or what he posts, but let's condemn theories and not people.


Widget

[Mr. Widget]

...should be fun, o/k? :)

"Accusations are occasionally made that objectivists can't hear, and conversely that subjectivists hear things that aren't there. This being the entertainment industry, I hope everyone is having a good time." -Nelson Pass

It doesn't sound like you are having fun... maybe you should spend your energy proving how high priced speaker cable is a rip off... or the other side of that coin if you prefer...

As for JBL using charge coupled crossovers in many of their better speakers and a number of DIYers using it here, while I have no personal experience with these networks, I do know that many people who have had hands on practical experience with these networks have all been happy with the results. No one has implemented this design topology and then decided it was inferior sounding to a more conventional network.

Anyone who has spent any real time in audio has learned that while many measurements can be made, there are always unanswered questions and our ability to fully objectively study these systems is still not entirely up to the task and more than that, experts can have differing points of view. Audio isn't unique... take a look at the economy. You can have a handful of economic Nobelaureates all disagree on the best tack ahead.

Fortunately, as the wise Nelson Pass has said, this is for entertainment... so enjoy it and try not to piss people off. Your naysaying comments are not a particularly good way to make friends here. If you personally find it hard to believe that these systems might work and you must shout about it publicly, why not go to the Klipsch Forum and tell them how bad JBLs sound based on your theories... I am sure you'll get a warmer reception there.


Widget

[Beowulf57]

THE UNTENABLE ARGUMENT

"My adversary's argument
is not alone malevolent
but ignorant to boot.
He hasn't even got the sense
to state his so-called evidence
in terms I can refute."

PIET HEIN

[CauYem]

Both, mine and CauYem argumentations are based on engineering, solid knowledge, intelligence as CauYem is concerned and a honest eagerness for truth. If anybody dislikes that so far that he undergoes a heart attack, sad me, as it is for sure not intended.

"Zilch" gave this link: http://forums.klipsch.com/forums/t/9...px?PageIndex=1 (http://forums.klipsch.com/forums/t/9...px?PageIndex=1)

I took the time to read it. There is so much wrong with those fotos, not to mention the other stuff - I gave it up. Please stop flaming too. We two have already found a synthesis of savvy calculations and sheer hearing:
"You simply order two 27 uF capacitors, bias them and viola, you have 13.5 uF."

'Hope You get the irony ... should be fun, o/k? :)


Thanks a lot
We're all enjoy the sound reproduction of JBL. I'm a owner of different JBL models & enjoy them all. I'm in the process of building some more of them for my own enjoyment. I know this is a touchy subject! I'm not here to bash JBL or to insult the "JBL GOD" or create animosity, but want to point out my observation for a long time with all the speaker manufactures (not only JBL).

To many JBL experts here in this forum, I believe that you have also checked out the performance of JBL networks by using SPICE or any simulation programs and measured using RTA. None of the JBL passive networks are eletrically sound. None of them has flat input impedance, which prevent distortion electrically.

The design of JBL network is fundamentally not correct by connecting all the filters to the input. The summation of impedance at the crossover point screwed up badly when they do this. There is a technique to design a network when connect them tohether, it maintains the same level of impedance.

Obviously, engineers at JBL have been trying to improve their product by trying many different ways to sell their products. To me, some of them are "snake oil", but compare to marketing ploys from other audio & cable manufactures, JBL is still a honorable company. With modern technologies & more known techniques used in space & military systems, I think we can improve the networks, thus our enjoyment.

Off the subject a bit: ALK Engineering (Albert Kaplenberger) has dethrowned all Klipsch networks & sell his own products to replace Klipsch's. He's doing well & also well known for his networks. Klipsch is moing forward to the new designs, but not JBL yet!

Attached is one of my simple design (N=3) to repalce the JBL L300 networks above. I design it for my own use. All component used are standard values (not the 13.5 uF, which starts this thread):

[Ian Mackenzie]

Its obvious that a little bit of knowledge is dangerous thing.

[Mr. Widget]

I know this is a touchy subject! I don't believe it was prior to this thread... though I may have missed something.



The design of JBL network is fundamentally not correct by connecting all the filters to the input. The summation of impedance at the crossover point screwed up badly when they do this. There is a technique to design a network when connect them tohether, it maintains the same level of impedance.I certainly agree that the JBLs of the '70s and earlier including many popular models like the L200, L300 and others had some pretty unfortunate crossovers, but they are simply vintage speakers... if you want a very high quality, accurate representative of what today's designs can be, look elsewhere... that said some of the JBL designs from the '80s through today sound quite good regardless of any theoretical deficiencies.

I have no doubt that a redesign of the N300 network could yield a "better" speaker, but it will still be a system with many compromises just like a Klipschorn with one of Al's updated networks... these older systems do have some fairly severe issues that a better network simply will not "fix". My personal opinion is that I prefer to keep these old systems all original and buy or create new systems if accuracy, imaging, and low distortion are the goals.



Obviously, engineers at JBL have been trying to improve their product by trying many different ways to sell their products.The engineers have made remarkable progress designing new systems that are significantly better than their older counterparts, however you seem to be confusing marketing with engineering... the marketing folks come up with slogans and market driven challenges for the engineers... the engineers do not try to sell speakers, they try to make them the best that they can within the physical and economic restraints that are placed on them.

As for snake oil? Other than using Monster Cable in some of their earlier product that may have even been directed by the marketing dept., I am quite certain that the engineers do not use BS as a design objective... they add batteries and double up capacitor part counts because they hear an improvement.

The bottom line is, does it sound better? I don't think meeting a theoretical benchmark is at all relevant. If the final product sounds better by adding a slight phase angle corruption so be it.


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[boputnam]

THE UNTENABLE ARGUMENT

"My adversary's argument
is not alone malevolent
but ignorant to boot.
He hasn't even got the sense
to state his so-called evidence
in terms I can refute."

PIET HEINBrilliant post. Painfully, I expect "mini" will ignore it's depth of sense...

I feel compelled to remind, "mini", the tone (and arrogance) of one's posts, by themselves, distinguishes the poster (by that, I mean you, "mini").

Frankly, at this point, you are making no point and only further discrediting yourself. If you truly believe your position - which as you admit is based upon "estimations" - you should make some real "blind" experiments. We look forward to your report. Until then, your continued repetitive posting here is merely Internet masturbation - er, that's just my opinion. Your "15-minutes of fame" has expired...

[CauYem]

.

The bottom line is, does it sound better? I don't think meeting a theoretical benchmark is at all relevant. If the final product sounds better by adding a slight phase angle corruption so be it.

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Without the engineers, who coined the term like "charge-coupled", "phase enhanced matrix", "ding dongs"..., marketing has no clue to advertise/marketing the products.

IT'S ALL ELECTRICAL before the energy interact with the magnet to produce sound. Many experts on this forum posted all kind of graphs, chart s & techniques trying to make the response flat across the band electrically, and now it became irrelevant! :blink:

I do believe it's all relative when it comes to audio listening, especially when we're loosing our hearing ability when we get older. It will sound better if we eliminate some uncertainties by producing a clean signal without distortion/coloration to translate the same sound as it was recorded. Of course, this does not cover personal taste!

[Mr. Widget]

Without the engineers, who coined the term like "charge-coupled", "phase enhanced matrix", "ding dongs"..., marketing has no clue to advertise/marketing the products.I have no idea who makes up these terms... or what motivates them... here is the only Google entry I could find for "phase enhanced matrix"

Where do you make these terms up and what is your motivation?


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[Mr. Widget]

Many experts on this forum posted all kind of graphs, chart s & techniques trying to make the response flat across the band electrically, and now it became irrelevant! :blink:Experts on this forum? I think that term may be over used, but in any case, I used to believe that a ruler flat frequency response was tremendously important... I have learned that it is but one component in the chain required to create a wonderful sounding loudspeaker... it can and should be ignored when achieving that goal interferes with the sound. The bottom line is that no one has yet discovered how to measure our perception of sound. Frequency response is a very significant measurement but it simply doesn't tell the whole story and neither do any of the other measurements that we frequently see... the interaction between your electrical impulses, the electro mechanical audio and speaker system, the air in our listening rooms including the rooms, and our electromechanical transducers in our heads is simply too complex.

It's time to go enjoy the holiday with family and friends... I hope you are too.
Happy Thanksgiving!


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[Zilch]

IT'S ALL ELECTRICAL before the energy interact with the magnet to produce sound. Many experts on this forum posted all kind of graphs, charts & techniques trying to make the response flat across the band electrically, and now it became irrelevant! :blink:Well, no, the objective is to have the ACOUSTIC RESPONSE be flat, generally. The electrical transfer function must compensate for characteristics inherent in the drivers themselves to accomplish that, and thus, is typically not itself flat.

I believe we'd all agree that minimum impedance variation is also desirable from the standpoint of having the system be "friendly" to various types of amps, but within limits, leveling it, as with conjugates, for example, is somewhat of an academic endeavor.... :yes:

[Ian Mackenzie]

If the source is not a perfect voltage source it won't be.

The phase angle of the impediance is also important.

In any case the subjective performance without imprediance smoothing is often better depending on the drivers and the amp involved.

[4313B]

I don't believe it was prior to this thread... though I may have missed something.You did... see my post #16 (http://audioheritage.org/vbulletin/showpost.php?p=229470&postcount=16) above.

There have been several waves of "people" who've whined and cried about the network biasing and diaphragm dusting. The diaphragm dusting was put to bed once and for all. The network biasing is an even simpler concept that doesn't require any more explanation than has already been given in document links and post after post after post on the subject.

As was said a couple months ago, you either do it or you don't, nobody else cares... so for one or two people to pop out of the woodwork to post negative comments with respect to the practice and insinuate that something sinister is going on at JBL, something disreputable, is ludicrous. Rather than my getting upset over it I should have simply laughed about it like others did. The network biasing is done for a reason and that's the end of it. Either do it or don't do it. I really do need to start laughing at these doofs instead of letting them get to me. :yes:

Experts on this forum?There were two and they both left years ago.

[Chas]

I really do need to start laughing at these doofs instead of letting them get to me. :yes:

Maybe it's because you're a little biased yourself! :D (Pun intended)

[4313B]

Maybe it's because you're a little biased yourself! :D (Pun intended)Admittedly.

When you bias a minimal loudspeaker like a 4406 and then have a group of people over of various backgrounds to compare them against stock 4406's and they're all left speechless it becomes readily apparent that it's a worthwhile practice. The response was then and has been since - overwhelming. I agree with Greg, the results are staggering. I respect the people who report back; I value their discourse. Thay have a ton of time and money sunk into their systems and they take it all pretty seriously. They aren't a bunch of keyboard wannabees who are compelled to talk instead of do.

"I don't even bother listening to unbiased networks anymore." - Designer of the Everest II

It isn't for everyone though! Theorists, sloths, and really intelligent people probably shouldn't try this at home. Leave it to the people who actually know what the $@# they are doing please. :)

[mini]

Brilliant post. Painfully, I expect "mini" will ignore it's depth of sense...


Ah, just in the beginning I begged Your pardon for writing bad English. My reading is bad too. The citation is playing with words I don't know. I'm afraid it wouldn't stand a deeper analysis if the clue was told in everyday language. I extrapolate that from German aphorisms that can be quite amusing if one gets the punchline and invests a third thought :D


I feel compelled to remind, "mini", the tone (and arrogance) of one's posts, by themselves, distinguishes the poster (by that, I mean you, "mini").

Again I appologize. I can't give an eloquent talk. I have to express quite directly. It is NEVER been meant as an offence against the boards staff. This includes JBLs corporate identity ...


On the topic of biased c/o I stopped talking for the sake of peace. Most of the dissidents don't appreciate to hear from the others. For me personally the issue is prone to a rough estimation with the well known result. If it's wrong for You nonetheless it may be o/k for me. Be asured that I'm not prattleing. But why should I talk to people that would dislike anything of it? That's no fun then.

For my understanding sheer hearing and in so far a judgment by taste does not replace a comprehensive foundation regarding sciences - soft and hard - related here. At least if it comes to purposive inhancements. Related to this, if a specific technique is to be discussed some basics would be helpful. If it come to my vey subjective personal hearing experiences we could talk about - music ;)

so long

[Robh3606]

I was a bit surprised by this thread. Figured I would just stay out of it as I am biased as well.

Rob:)

[Zilch]

I am both biased and unbiased. Mostly, however, I am simply bypassed.

[Unless it's Solens, of course, in which case, I strive to keep the peace. ;)]

I'm just here to see the cat pics, really. Post more for the Zilchster, please.... :thmbsup:

[4313B]

I was a bit surprised by this thread.Me too. I just don't get why we have to revisit these deadend topics every six months...

[boputnam]

...I am biased as well.:rotfl: Thanks, Rob! That was great...

[Jakob]

:blink:
Please, now when the holidays are coming and all, can't we try to be nice and civil to eachother? I've always treasured this and the old Lansing Heritage forum not only for the expertise held by it's members, but for the lack of attacks on people who disagree with what other see as a proved fact.

I, like many others on this forum, have tried both bypassed and biased networks and come to the conclusion that it works for me. That doesn't mean I would'nt like to hear from people like "mini" who has another view of things. We don't have to be rude just because we disagree.

We are discussing speakers, -don't take it personal, and all opinions should be welcome, how weird they ever seem. Well, at least in my world...

Regards to all!

[4313B]

That doesn't mean I would'nt like to hear from people like "mini" who has another view of things. We don't have to be rude just because we disagree.Publicly discrediting Greg Timbers and insinuating that JBL is dispreputable because they bias networks doesn't fly here.

[Beowulf57]

Good grief Charlie Brown...more polemics? Just by way of clarification, a small bio on Piet Hein. Please note that no criticism whatsoever is intended towards anyone by this post. Note in particular his statement at the end, which also applies to forum discussions:

[Ian Mackenzie]

I found two other speaker manufacturers who bias their crossover capacitors.:)

[Mr. Widget]

That doesn't mean I would'nt like to hear from people like "mini" who has another view of things. We don't have to be rude just because we disagree.I agree completely.

If someone posted that he had built a charge coupled network for his vintage L150 or whatever and compared this network with the stock one and perhaps one using Mundorf or Wondercaps or whatever... I personally would have found that most interesting and certainly worthy of discussion. That said, simply posting theoretical reasons why using this technology should be bad, when thousands of people who have actually listened to and even built them have been quite pleased with them is just not a good idea. A "virtual" exploration isn't necessarily valid and it is going to piss off some people.

I think asking the question, "Could charge coupling be wrong?" is fine, but if you are going to damn CC'd networks you had better have at least tested them in the real world. So many others have. Their conclusions are posted here and elsewhere.


I am pretty sure we have beat this off topic discussion to death.


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[Mr. Widget]

It has been suggested that this thread be closed... I see no point in keeping it open further... the initial questions were dealt with pretty well.

If anyone would like to discuss the side show here take it up in a new thread in an appropriate area or better yet take it up via PMs.


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