18v would be better technically but in this world of dimishing returns, would anyone hear the difference? I think not....Originally Posted by Zilch
Allan.
18v would be better technically but in this world of dimishing returns, would anyone hear the difference? I think not....
Allan.
I seem to have noticed this as well. Initially they sounded a little fuzzy, but snapped into focus. This was during a build on another forum, and when I commented positively, the general reaction was like a 16th century witch hunt! Mostly from people that never tried it, just had a million reasons why it "wouldnt work". I think it does!
Russellc
Charging time is a function of voltage, resistance, and capacitance.
There are several calculators for this including this one: http://www.csgnetwork.com/rctimecalc2.html
To give you an example of charging time, it takes ~27 seconds to charge a 6 MFd capacitor in series with a 1 M Ohm resistor to ~9V using a 9V battery.
"Zobel is as zobel does"
4313B, I for one am grateful for what you have shared with us. I built a few CC and non-CC L200T3 networks to compare when Zilch was doing the Q&D fest. I don't think I'd do a non-CC network for any speaker system that used decent drivers. CC networks do rock, as do so many of the things you have shared.
"Zobel is as zobel does"
Yup. I thought that as well but others may not agree. Some people also beleive that cables need to burn in for a few weeks as well.............
Charge couple the suckers and if it aint better, send me the bill.
Allan.
indeed, many people believe in Magic, as defined by Arthur C Clarke: Any sufficiently evolved technology, meaning, something beyond the understanding of the observer.
Magicians perform ritualistic tasks hoping to achieve their goal without understanding why. Many technicians are essentially magicians as they lack a fundamental understanding of the systems they work on, and instead rely on repeating what they know worked before.
To most people, these computers we use are nothing short of magic, as is their consumer electronics, all they know is they push a button and sounds or pictures appear. As a kid in the 1960s, I had to know how everything worked, took stuff apart to see what made it tick, built Heathkits, read endless books on science and technology. Both my teen kids are perfectly happy to just accept stuff without understanding its inner workings, this saddens me. Admittedly, things like modern HDTV are bogglingly complicated, with layers and layers of nearly incomprehensible technology, all of which must work in perfect unison to deliver that picture into your living room...
http://en.wikipedia.org/wiki/Superposition_theorem
____________This procedure is followed for each source in turn, then the resultant responses are added to determine the true operation of the circuit. The resultant circuit operation is the superposition of the various voltage and current sources.
Peter
True it is simply dc biasing but many would not have thought of that approach to topology.
As to the rest of the discussion its perhap useful to understand exactly how a polarised and non polarised capacitors works and then related that to the application of a Dc potential. Black Gate used to have a very useful explanation of the facts . Try Google. http://en.wikipedia.org/wiki/Capacitor
http://www.elna-america.com/tech_al_principles.php
http://www.technologystudent.com/elec1/capac1.htmhttp://en.wikipedia.org/wiki/Capacitor_(component)
A lot of research as been done recently on voltage (AC signal) induced vibrations within capacitors used in audio crossover applications.
According to the reseach its the voltage not the current that induces the vibrations within the structure and this directly effects sound quality.(Vibrations caused by sound within the enclosure have no effect what so ever according to the research)
Depending on the manner of the windings within the structure a DC voltage potential may help control these vibrations
I agree with charge coupling, but have a implimentation question: Does one need to CC the cap in the woofer zobel? I didnt do that on the one I built and was wondering. CC the zobel cap or not?
russellc
I always thought of a capacitor as an electron hotel where the lobby normally would accomodate the same amount of electrons as the beds, the difference being the electrons in the lobby could not get out the back door and the electrons in the beds could not get out the front. If you pushed an extra electron into the lobby the imballance would push one out of bed where it would wait outside the back until it could get back in. The problem is the halls (the dielectric) act like a spring accumulator causing delay and possibly giving that electron somewhere to hide and him not going outside to do the work he was supposed to, or at least making him late.
All right so I rode the short bus to electronics class.
Quoting from the Handbook for Sound Engineers, Fourth Edition 2008 on dielectric absorption or DA
"Dielectric absorption is a reluctance on the part of the dielectric to give up stored electrons when the capacitor is discharged. If a capacitor is discharged through a resistance and the resistance is removed, the electrons that remained in the dielectric will reconvine on the electrode, causing a voltage to appear across the capacitor. This is also called memory.
When an AC signal, such as sound, with its high rate of attack is impressed across the capacitor, time is required for the capacitor to follow the signal because the free electrons in the dielectric move slowly. The result is compressed signal. The procedure for testing DA calls for a 5 minute capacitor charging time, a 5 second discharge, then a 1 minute open circuit, after which the recovery voltage is read. The percentage of DA is defined as the ratio of recovery to charging voltage time 100" Close quote.
So to mitigate this issue you take a battery and two like capacitors and cram the lobby AND the halls full so when one electron gets pushed in the front door, another gets kicked right out the back and into your tweeter to do the work you intended him to do and back again. Making a more ideal device. CC is a very simple and elegent soulution.
The funny thing (to me) is that even seems to bridge the gulf between "pierce and Hoerninger", on the subject of can it theoretically ever be fully charged and if so how long. 5 time constants is considered 100%, your ears may tell you different.
OK I am off to find a flack jacket, and a bottle of tequila and a straight razor.
I C-C all the caps. If a current is flowing through a cap w/o C-C then it is producing a phase shift.
Living in the Land of the Sun
Thank you for your contribution.
I have never seen a "gulf" between Pierce and me. We only had to clarify our viewpoints, it is from the scientific side for both of us.
First of all I go with Earl K and Allan. They pointed out to try it first and seek an explanation afterwards.
For those who are interested in investigations about distortion in capacitors there are some compiled links :
http://audioheritage.org/vbulletin/s...124#post252124
____________
Peter
ah, yes, Bob Pease. that man is a genius. I miss reading his regular columns in Electronics Design.
A current flowing through a capacitor or inductor will always produce phase shift. Charge coupling will actually double the phase shift up to somewhere near 180 degrees.
Allan.
Wrong, I suggest you go back and do some searches for what Greg Timbers has to say on the matter, and look at the pics of an audio sinewave in a cap w/wo C-C.
When the sinewave crosses the zero dielectric point in a non C-C cap the wave shifts. When C-C the sinewave is above the zero dielectric and continues w/o the shift.
http://www.lansingheritage.org/html/...3-k2-s5500.htm
Last edited by jblsound; 05-20-2009 at 04:35 PM. Reason: add link
Living in the Land of the Sun
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