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Where does one go for an education on charge coupled crossovers?
What theory describes the benefits?
I want to start with a replacement project for my 3106's. A very simple crossover indeed.
I saw Zilch respond to one post on 3105's with "Build one your for $25, charge coupled for $10 more."
Cool, where do I start?
Thank you!
Read this thread:
http://www.audioheritage.org/vbullet...ead.php?t=3555
Focus on post #6.
Also, rather than retyping Ian's list, look at his post here with linked references back to these forums:
http://www.diyaudio.com/forums/showt...threadid=87885
Thanks T.D.
That Gregory Timbers is one smart cookie!
Those three pages explain it perfectly.
Off to the electonics store, again.:D
Ed Meitner passed the idea on to Greg and Greg incorporated the idea into his statement systems. This is one of two topics that should have stayed in the private forums due to it causing unnecessary fretting and confusion. :)Quote:
Originally Posted by 1audiohack
What confusion? It is the act of taking any XO, removing the original caps and replacing them with Solen polyproplyene caps of twice the size and always in pairs. Then connecting the positive side of a 9v alkaline battery to the common point of all pairs.Quote:
Originally Posted by 4313B
The result is a far superior set of speakers. The amount of money spent on CC networks, I spent about $150/ea to build completely new XOs, is well worth it.
Yep! My point exactly! :yes:Quote:
Originally Posted by MJC
The amount of posting it generated though was pretty funny to some I guess.
some cc networks in progress
- You forgot the 2 to 5 meg isolation resistor .Quote:
Originally Posted by MJC
- FWIW, these batteries do represent fairly low impedance paths back to ground within the crossover circuit.
- If one omits this resistor / one then creates a lowpass circuit with an F3 determined by the cap values being used , as well as the working impedance for that portion of the circuit .
- The "cat getting out of the bag" preceeded the "May Forum" by a good nine months, if that's what you're referring to .Quote:
Originally Posted by 4313B
- Once Don McR posted those first links to Harmans' tech papers ( just previous to this current forum I believe ), questions started to be asked ( with all the attendant fretting following in due course )
- & Yes, this sort of stuff has definately kept me amused for the last 4 1/2 years .
:)
It just made me cranky. A few others I'd rather not see cranky too. Oh well. :pQuote:
Originally Posted by Earl K
They look as good as they sound ,and worth every penny IMHO. They move 30 year components into the 21st century. :applaud:
GT, 4313b , Guido , and the Aussie guru Ian The true masters of the black art. They dont charge enough considering the years of experience it takes to
build these things.
Rich
Yes, as a matter of fact I did, how silly of me.:banghead:Quote:
Originally Posted by Earl K
Um.. You forgot to mention them? Or you forgot to use them?Quote:
Originally Posted by MJC
Nice.Quote:
Originally Posted by 4313B
:)
I used 'em, just forgot to mention them in that post.Quote:
Originally Posted by 4313B
Having the full applied 9v going straight to the caps, don't think I'd want that:eek:
Well, I would have to agree. I most recently finished six months with 4355's and I am sufficiently impressed with the results.Quote:
Originally Posted by richluvsound
G.T. started all this way back when he modified a few pairs for some friends with 250Ti's. He did it the hard way and just modified the existing networks and we discussed that complete nightmare at length.
The goal has been to make them as painless as possible to bolt in place of the stock networks as well as to make them reasonably easy to ship. A top board goes in place to protect the caps and coils.
Nice work/layout.Quote:
A top board goes in place to protect the caps and coils.
...figured that's what the standoffs were for. Plexiglass? or are these intended
for internal cab use? -grumpy
The manual of a modern JBL speaker (guess which ;) ) at Harman shows charge coupling as well.
There are some patents which show ways of obtaining the DC voltage from the AC signal. I have found
1. KOSS Electronics Inc., Milwaukee - patent 3,632,903
2. American Technology Corporation, San Diego - patent 6,628,791 B1
3. American Technology Corporation, San Diego - patent 7,158,646 B2
obtained by http://www.pat2pdf.org/.
The ATC patents are nearly the same, for me Figure 9 has been most inspiring:
Stabilizing to ca. 3 V (1,1 W at 8 Ohm) and triblication.
____________
Peter
Hmmm..Someone's been busy. Nice work.:bouncy:
l'll bet that lot took a month of Sunday's to get it to that stage.:)
Ti Dome..I've long since stopped talking about this topic;).....controlling the random noise floor coming through the Inbox was just too much hard work...particularly when the guy says he only wants to spent $10 or porn is navy watch. ..bring out the violin....:blah:.
You guys just need to try it (CC).
For stock vintage owners its a step in the right direction .
Ian
:)4313B you have reminded me of a lttle bit of history, in case anyone is interested.
Ed Meitner is a true audio pioneer. I first met him in the early eighties when he was at Amber Electrodesign working with Wayne Jones. They had moved from making the Olive automated mixing consoles to new, radically better analog-based distortion analyser designs. Leading edge stuff back then, I still have one here and it performs like new.
I think the PC controlled Audio Precison product came in just after that and took over most of the market.
I had an opportunity to audition the prototypes of what was to become the Museatex line of electronics in the future at Ed's home. Ed also had just invented a novel way to interface MM phono catrtidges using them as a current, rather than a voltage, source.
I actually have a couple of DIY versions of this MM design that are still in use here today. They have remarkably low noise and very good sonic performance.
The first time I personally encountered CC caps was in a Ward Beck broadcast distribution amplifier from the late seventies. The design used tantalum coupling capacitors in the interests of saving PCB space and they featured DC biasing. The biasing was likely as a result of their inherent poor sonic performance in audio circuits. FWIW, a good example of this would be the Revox A77 which is full of tantalums. An A77 with better caps takes it to a new level of performance.
This would predate the famous Jung/Marsh arcticles in Audio by quite a bit of time.
I hope this isn't too OT.
I don't think it is. Thanks for the post Chas. :)Quote:
Originally Posted by Chas
http://www.emmlabs.com/html/about/ed.html
Just curious, are there people who make these charge coupled X-Overs for others in audioland?
Sounds interesting for my L-65's. Mark
OK, months ago I was looking at the network for the 4344MkII as it lines up with a project of mine, and was puzzled by the 9v battery.:blink:
My intent to build a CC 3106 is because I currently use them between my 2404's and 2425's on 2344's. I know what the 3106 sounds like, and as simple as they are it looks like a good place to test.
So let me see if I understand the theory behind this, the sign wave delivered from the amplifier is at its highest potential when the voicecoil is close to its peak, the point of least acoustical output. When the voicecoil accelerates back toward center, it is at maximum velocity and acoustical output as it passes thru center, at wich point the amplifier is currently at its lowest potential (pun intended) to control the coil motion. It is at this point the voltage crosses the zero line and the capacitor creates a step as it copes with changing polarity.
In short, at the point of maximum acoustical output the capacitor has the best chance to make itself heard.
So if I have it right, charge coupled caps for me.
I looked high and low for a thread on this subject as charge coupled crossovers, not capacitors, oops.
The 4344MkII scematic shows the 2.2m series resistor, I cought that, I just didn't understand the charged cap theory.
As for the quote"should have stayed in the private forums", what the hell is that all about?!?
I've said before, with out information sharing, we would still be hunting animals with sharp sticks.
Thank you for sharing.
Applying a 9v charge, thru high resistance(6 meg ohm), to the common point of two series caps keeps the audio signal from crossing the dielectric zero point of the caps, thus eliminating the phase shift.Quote:
Originally Posted by 1audiohack
Right. Thats what I got out of it.
Thank you.:)
Hi,
I dont think this is a dead topic at all. Why should this be a private topic? I am starting to sound storm-ish here, but there are plenty of people interested in this topic.
Quote:
Originally Posted by 4313B
Welcome back 4313B ! Didn't recognize your new name and avatar, but I reconize your charge coupled 250TI networks every time I hear them :).
Glad to see you around these parts again...
jblnut
:bouncy:wow,
thats alot of deleted text. i thought this was a free country? :bouncy:
Do not confuse freedom of speech with the right to bar trolls ...
Buy your own server and You Too can have a free country ...
until the spammers try and take it from your cold hard fingers
Quote:
Originally Posted by spwal
I'm Currently making a CC crossover for my L65's. I'll let you know how it turns out.
-Tim
I have a pair of L300's that I'm considering charge-coupling the crossovers. Analyzing the charge-coupled crossover schematics it seems to me if you remove the battery voltage the crossover reverts to the usual passive unit so an A/B listening comparison should be very easy just by putting a switch in the battery line. Has anyone tried this?
You can build your cc networks and leave the batteries out for a few weeks while you get accustomed to how the new networks sound. Then install the batteries.
Or you can just compare two sets of loudspeakers like a few guys did with their 18Ti's, 120Ti's, and 250Ti's.
Wow this subject has been a lot of fun!
I have ordered the components to build a pair identical to the 3106, the "B" pair, and a "C"pair, charge coupled. Then I will run them against the "A" pair.
The reason for the "B" pair is for control, it would not be objective to test against my old 3106's with their old caps and all. I will also exlude the L-pad with fixed value resistors. I will of course A B C test.
Its probable that small improvements would make themselves more evident in the higher order more complex networks, this is just where I chose to begin this journey.
I just bought a new TEF 25 PRO kit with all the extras for component testing. It is even supposed to be able to measure and display Heyser Spiral plots on capacitors, and inductors. A lot to learn here to get good data! $3500.00 in red pills! Its never gonna be the same from now on.:D
So I hope to be able to measure and post the results, but in the end, its all what ya hear.
Thanks for all the input. Keep up the fight, ha ha.:barf:
Well I'm almost ready to make the plunge to Charge-coupled for my L300's. You guys really think it makes all the difference huh??
I really don't know,,, yet. I doubt it makes ALL the difference, however performance is why I love JBL.
They really are well built hotrods, hence the romance most of us of feel toward them.
Keeping them running, and improving if and what we can is the never ending adventure.:)
JBL has used this charge-coupled technology in many of their TOTL loudspeakers for years now. We have the option to apply this technology to our older loudspeaker systems. It makes for a very nice improvement that many people enjoy.Quote:
Originally Posted by Domino
Back when JBL started using bypass capacitors in many of their systems we applied that technology to our older JBL's and that made for a very nice improvement.
Quote:
Originally Posted by Domino
Domino,
Unfortunately it not that simple. The capacitors will hold their charge and the effect on the dieletric will rermain for a period of time. The same holds for connection of the battery. Allow several days for the effect of the battery.There is information somewhere in the library on "how" it works.
Are you still building these networks?Quote:
Originally Posted by Earl K
No!Quote:
Originally Posted by rbnjr
http://www.audioheritage.org/vbullet...1&d=1194723064
I have never built dc-biased networks for others ( though I do use them and very much appreciate them ) .
The above picture ( that you omitted ) were of some CCed networks that were under construction by LHF member, 4313B.
:)
Ohoooo,Quote:
Originally Posted by Earl K
what a nice picture
ivica
What are those 6 posts on each board? Is that for mounting or for some type of terminal? Thanks.Quote:
Originally Posted by Earl K
Tom
Standoffs, presumably for mounting to a surface (perhaps plexiglas/perspex for show) or to the cab.
Thanks Grumpy. How'd you get that handle? You can't possibly be as grumpy as I am known to be!Quote:
Originally Posted by grumpy
Tom:)
The standoffs are for the boards containing the second half of the networks.
Wow! That's an awesome layout. The epitome of neatness. Makes my crossovers look like a bucket of worms:) Thanks.Quote:
Originally Posted by 4313B
Tom
I thought I would share my build of a CC 3155 network that went into my 4355's. All wiring reverse side. It is neat on that side as well. Entire X-over assembly was mounted to rear of cabinet with standoffs. Schematic and design courtesy of G. Timbers and Giskard.Quote:
Originally Posted by 4313B
Attachment 70189Attachment 70190Attachment 70191Attachment 70192Attachment 70193
Nice! Where do you get those circuit boards?Quote:
Originally Posted by JBLPRO
They green PCB's are available on ebay in various sizes. All the circuit wiring is under each network with the exception of the 2202/2441 1.2 kHz network which is wired on the main board.(largest coil & Caps) It was a logical & organized layout keeping each network separate, easier for troubleshooting as well. Also the coils were attached with cable ties and hot glue to prevent vibration. ALL caps were all hot glued into place as well. I used 1/2" standoffs and necessary hardware to elevate the smaller PCB's on the main board. I can send you some links for the vendors if you like. I did not go over the top with really expensive caps and coils. I used the Solen caps and Jantzen Superes resistors parts because all the correct values were available. In addition because I was using a charge couple design I felt it not necessary to use the very best boutique caps. I could have easily double or tripled the cost if I went in that direction.Quote:
Originally Posted by tjm001
If you ever decide to produce these please put me on the list.. name you price...looks amazing.Quote:
Originally Posted by 4313B
cheers!
I assume you are using these for a pair of 4355's? And.... Would you like to use the same components I used or upgrade? When I know that I can PM you with a quote.Quote:
Originally Posted by rbnjr
Thanks for your interest.
mk
I used to build networks for people back in the day when I had time. Those days are long gone. Sorry.Quote:
Originally Posted by rbnjr
actually my speakers are the L300's. I would like to be able to bi-amp them or at least update the crossovers.Quote:
Originally Posted by JBLPRO
forgot that these were for the 4355's.
regards.
Some nice nice work here, absolutely beautiful
But I have never been unable to understand the high count and the many builders (not just here at Lansing Heritage) who use CRIMP type connectors on these otherwise beautiful constructions?
There is no way in hell I'm going to go to those lengths and costs to only turn around and tie it all together with the worse thing that's ever come down the pipe since the 3M Scotchlok..............or these:
http://contentinfo.autozone.com/znet...S8881/image/4/
I ask myself the same thing every time I have to get a standard slotted screwdriver out of the tool box... "What total dumbass would ever design a screw with a single straight slot..."
Fortunately Phillips had his head on straight. (The credited inventor of the Phillips screw was John P. Thompson.)
I have to say that I don't see a problem with the crimp connectors that have the wires soldered in.
I concur, 99.9999% of the time :)Quote:
Originally Posted by 4313B
Nor do IQuote:
Originally Posted by 4313B
;)
"I have to say that I don't see a problem with the crimp connectors that have the wires soldered in"
If used properly, they work well and reliably. The uninsulated variety often can benefit from a bit of solder
as kind of a backup.
Problem is almost no one bothers to use the right tool or match up the wire gauge or cut back the proper
amount of insulator or use decent quality connectors or ...
So in general, I'd advise trying to avoid them unless required (such as interfacing to a driver with spade
lugs as the connector type).
If done right, you'll break the wire before it gets pulled out of the crimp.
Yup. I had a tug of war with the guys at our off road shop with a 10WR vise grip locked on a #10 blue T&B ring end crimped to about six feet of #14 aircraft wire.Quote:
Originally Posted by grumpy
Thats a demo they will never forget. When I say pull test I mean PULL!!!
Barry.
I trim back properly and have the correct tools for the terminals I have used.................Quote:
Originally Posted by grumpy
The main focus of my complaints/dislike for them is related more to corrosion and oxidation than anything else (over the long haul)
Connections that "look" clean and perfectly fine but ain't happenin'................it's never been a strength issue for me, rather a circuit integrity/conductivity one
My other issues (when I really learned to dislike them as a general rule) was back when I was doing a lot of custom audio installs in automobiles
LOTS of problems with faulty connections over time, especially with fly leads, bundles and looms run under carpets
With things using Fastons (like LE25s)? Where I have little if any choice?
Ah well, but I definitely lather up those joints well with DeOxit or similar once they're pushed in place!
I'll solder all the terminations I can until they make it impossible (as it is already almost illegal now! :))
HI,
I wouldn't mind a quote for a set of charge coupled crossovers either for the jbl 4355's or 4345's.
thanks
John
Quote:
Originally Posted by JBLPRO
Hi, I'm planning to order parts from Solen.ca and build this xover for my 4344 (schematic attached) but then I just realize that there is no Low Frequency. Could anyone help explain where I would hook my bass driver to ? Thanks.
The filter you show here is for active only.
You need an electronic crossover and two stereo amplifiers.
Attachment 73818
DangQuote:
Originally Posted by dang
I made a typo in the network schematic I have posted the corrected diagam in the original thread.
http://www.audioheritage.org/vbullet...BL-4344-Clones
@Odd right, so if I want a it as internal only crossover I'll need another scheme for the low pass. Would this scheme work for the low pass ?Quote:
You need an electronic crossover and two stereo amplifiers.
Attachment 73868
@christo thanks for pointing that out.
btw I live in Australia which makes it so difficult to order parts. I preferred the CC scheme because I can order everything in one go from solen.ca. If anyone knows of any one stop shop to order all the parts to build the 4344 xover please let me know, much appreciated. :bouncy:
Is not as easy to see out of your drawing.
If you only used it passively you will not need switches.
Here's another variant you can look at
Attachment 73881
@Odd thanks. Do you know why +/- is inverted for 2235H/2245H as compared to the rest ?
Crossover is designed so reversed phase provides a flat curve at the crossover point.
More about reversed phase and crossovers;
http://www.audioheritage.org/vbullet...5-clones/page3
https://en.wikipedia.org/wiki/Audio_crossover
If you have the possibility go for active.
They provide better sound.
Steering back towards the beginning of this thread... Ian and others on various other threads have explained the theory and practice of using the charge coupled technique. I'll add another data point.
I have been enjoying my stock DD66000s with their factory charge coupled networks since March of 2012. Recently I thought something was amiss... my speakers were sounding rather honky. The sound was not unlike switching out my highly class A biased amps for a more typical class AB mosfet sort of sound. Not nasty or screechy, but a bit nasal and less transparent than what I have been accustomed to.
:hmm: Then I had an idea... how old are the batteries in my speakers? I popped the grille off and saw the expiration date. March 2015. Well. I guess I got an extra year out of them. :D
I popped in 4 new batteries and almost immediately the sound returned back to that sound I love. Yes Virginia, CC'd networks do work. :bouncy:
Widget
The skills of an attentive listener.Quote:
Originally Posted by Mr. Widget
I wonder how many owners of high-end charge coupled speakers have let their batteries die but didn't know any better. I imagine they either don't notice, get used to it or think they're falling out of love and sell them cheap!
I read this and thought "hmm...been a while since I've looked at the batteries in my 250's networks". So I took a look yesterday and was somewhat appalled that I had missed the window by more than I'd care to admit. Some leakage was evident on 3 of them and one had its post get trapped in the connector when I tried to remove it. OK, note to self...do this annually now.
With 4 fresh batteries the sound is indeed a bit more detailed and there's a better sense of cohesion among all of the drivers. But bliss was short lived. The 044Ti's are on the way to Gordon now for some fresh damping foam. I've done all of the tube and cable voicing I can..it's time to solve the problem for good.
So, the 250's are doing their best vintage speaker emulation now. They are a bit soft on the high end with no tweeters :-).
jblnut
Quote:
<<<SNIP>>>So, the 250's are doing their best vintage speaker emulation now. They are a bit soft on the high end with no tweeters :-).
That's A Good One! ;0
That is because JBL has been very inconsistent and stubborn in adopting the industry standard for polarity, so the red knob is negative and the black knob is positive only for some years of JBL. Use a flashlight battery to test the polarity and switch the knobs accordingly.Quote:
Originally Posted by dang
Old thread, but it seems like I could get the answer here.
All of the schematics I see show the point where the 9V is applied between the caps, but where does the other end of the battery land?
eso
Battery Ground is attached to the minus side of the network.
:)
Thanks, that is implied, but why not just draw it into the schematic?Quote:
Originally Posted by Earl K
So like this? Or doI just need one battery charging both the mid and high filters?
One will get it done.Quote:
Or doI just need one battery charging both the mid and high filters?
Rob:)
Might also look into the later-implemented use of a diode to rectify the audio signal, thus providing the bias voltage with no need for a battery.
:cheers:
Further Charge Coupling question: has anyone tried a mismatched series of caps to get a capacitance value in between standard values?
I.E. on a tweeter 1uF is a standard, so in charge coupling we would use 2 2uF caps in series. Would it work if I used a 4uF and a 2uF in series? The resulting value is not 1.5uF, but it is less than 2...
eso
4.7 and 2.2 are standard values though ;) (if you -wanted- 1.5) ... 1.8 and 2.2 would get you 1.0