One way to make expensive speaker cables!

[serengetiplains]

Carlmart, I think I'm winning the argument. Hang in!

[Steve Eddy]

Originally posted by serengetiplains
But what of actually crossing the zero line? Is there some bump of energy required to opposite-polarise or for that matter to polarise from an initial non-polar state?

Well, unless you're dealing with an electret, there's no net polarization to depolarize that I can see. And sure, it would require energy to polarize from a non-polarized state.

But by the same token, it would also require energy even if the dielectric were polarized. Far as I'm aware, the electric field from the signal adds to and subtracts from the field used to polarize the dielectric so the dielectric's polarization still changes due to the signal. And that change also requires energy.

Yes, which, in a transformer, avoids hysteresis loss.

In exchange for increased distortion and reduced level handling.

Perhaps dielectrics experience something analogous to remanence.

From what I've gathered, they don't seem to under what would be typical conditions for audio use. I know the various polarizing mechanisms (space charge, molecular dipoles, ionic dipoles and electric dipoles) have different relaxation times, but under conditions we're talking about here, I'm not aware of anything that would be akin to remnance.

Perhaps our resident Polyester Posthole Digger can shed some light on this.

se

[Steve Eddy]

Originally posted by serengetiplains
It proves Absolutely Nothing, Steve. What *could* you be thinking?

That's Abso!utely, dude!

se

P.S. I was always amused with HP's copyright notice which said that "NOT ONE WORD of the Abso!ute Sound may be copied etc. etc. without permission etc. etc."

I'd always wanted to take out an ad in Stereophile that just said:

"The^*" in huge letters.

The tiny footnote would read "^*Copied without permission of the Abso!ute Sound."

se

[Steve Eddy]

Originally posted by serengetiplains
Carlmart, I think I'm winning the argument. Hang in!

Refresh my memory. What exactly is the argument?

se

[SY]

But what of actually crossing the zero line? Is there some bump of energy required to opposite-polarise or for that matter to polarise from an initial non-polar state?

No.

Ironically, the biasing takes the signal away from the most linear part of polarization. Not that it makes the slightest bit of difference to the signal...

[carlmart]

Originally posted by kelticwizard

Condenser, (electrostatic), microphones work on a different principle entirely than dynamic microphones. Condenser microphones require polarizing voltage or they do not work.

Dynamic microphones are pretty similar to speakers, and indeed many intercom systems use one element as both speaker and microphone. Did you ever hear of anyone saying, "I ran 10 volts DC thru my Shiva and boy, did the bass ever improve?"* Me neither.

As for active speakers, all that amounts to is including the amplifier in the same enclosure as the speaker-there is no difference in principle at all.

Let me make it clear that I am taking no sides in this debate. I have not heard active cables, nor, truth to tell, even any name brand super cable, so I am neutral. I just wanted to comment on the previous message.

*Note to newbies-do not ever run DC voltage through your speakers. You run the risk of permanent damage to your speaker.

You should have realized that by active speakers in our context I meant electrostatic. You also made a mistake: active speakers are not those with the amp in the same enclosure, but speakers where each driver has a separate amp. Most of the times the amps are separate from the drivers, not together.

And of course dynamic mics are different from condensers. Dynamics generate their own, very low voltage when they are excited by sound waves, which is amplified by the mic preamps. Condenser mics use a diaphragm which is polarized with a small voltage (a few volts, in spite of most using 48v), which makes it more sensitive and generates larger signals.

So please let's stop this comparison with mics or speakers and concentrate on active cables. In my opinion they deserve some looking into, but this may not be shared by others.

Or are we going into a lazy stage?...

I better go see my files so I can put some real info in this matter.


Carlos

[moamps]

Originally posted by carlmart
Condenser mics use a diaphragm which is polarized with a small voltage (a few volts, in spite of most using 48v), which makes it more sensitive and generates larger signals.

Hi,
Condenser mics usually have voltage converter inside witch generate ca 60V for plate(s) polarisation. 48V from console has relatively high output resistance (6k8)(also create microphone preamp input impedance) what cause voltage drop on mic's connector around 10-15V. Also, condenser mics have preamp/impedance converter built in.
Back-electret mic is another story.

So please let's stop this comparison with mics or speakers and concentrate on active cables.

My sugestion too.

Regards
Milan

[gmarsh]

From personal experience in the matter, cables indeed can have dielectric effects. In my line of work, we run kilowatts of RF power through coax.

In general, you can model a cable dielectric as a distributed capacitance and a distributed resistance. As the voltage on the cable gets closer to the dielectric breakdown voltage, the resistance term will become smaller. So in effect, cables can "compress" the signal going through them, and for very large signals, that can create distortion.

But unless you're running immense amounts of voltage through the cable, you won't be able to measure this - you have to get *very* close to the dielectric breakdown voltage before you can even measure it, and once you add a few more volts your cable just arced and died. I'm certain your your home stereo equipment isn't at risk of frying its cables, so I doubt you'll be able to hear any dielectric related distortion in your interconnects.

Adding a couple volts of bias to one of these cables won't change the sound, I guarantee. But assuming that dielectric distortion *did* matter (eg, if you made a cable out of MOVs or something) then adding bias would make the distortion asymmetrical. Which won't be good.

And 'zero crossing' in dielectrics doesn't exist. Otherwise the whole RF filter design business wouldn't exist.

[phase_accurate]

Additionally cables will also exhibit microphony when DC biased. Apart from being nasty in certain applications (like audio signal cables) this might probably also be used as some form of sensor.

Regards

Charles

[kelticwizard]

Originally posted by carlmart

You should have realized that by active speakers in our context I meant electrostatic.

Your statement was made in rebuttal to the following post by Steve Eddy:

Originally posted by Steve Eddy: In the case of the condenser microphone, the biasing isn't to make it better, it's to make the thing work in the first place. Cables don't need biasing to work as cables.

In rebuttal, your statment was:

Originally posted by Carlmart: Dynamic microphones don't need any polarizing to work either. Or speakers.

Given these facts, I really don't see how you can say I should have realized that you meant electrostatic speakers. Steve's whole point was that electrostatic microphones were designed to be used with polarizing voltage: without it they cannot possibly work. When you answer that "dynamic speakers don't need any polarizing to work. Or speakers.", what can possibly be the conclusion other than you are referring to the normal, traditional, (electrodynamic), speaker?

And if you were referring to electrostatic speakers, than what electrostatic speaker do you know of that does not need polarizing voltage? Because you were talking about speakers that don't require it.

Originally posted by carlmart

You also made a mistake: active speakers are not those with the amp in the same enclosure, but speakers where each driver has a separate amp. Most of the times the amps are separate from the drivers, not together.

You are incorrect. Perhaps this is a language difference. In the English speaking audio world, the setup described above uses an active crossover. A separate amp is simply understood as being needed in any setup where an electronic, (active), crossover is used.

An active speaker is one where the amp is located in the same enclosure as the speaker. By far the most common example is the active subwoofer, which has it's own amp and crossover in the same box as the driver. Take the amp and crossover out of the box, (cover the hole, of course!), move them over to your stereo rack, buy a longer cable, and you no longer have an active subwoofer. You have a passive subwoofer with it's own electronic crossover/amp.

Let's put it this way. A passive speaker had to be hooked up to a power amp to work, even if that power amp is dedicated to that speaker exclusively. An active speaker can be hooked up to a preamp, CD player, or other line level device. There are some active subs that also have speaker level inputs, but they use only a tiny fraction of the wattage from those speaker cables.


Meridian and other makers make active speakers, (or used to), and the amps were in the box. Theoretically, you can make a multiway active speaker that uses passive crossovers, but it would be hard to imagine anyone wanting to do that.

Originally posted by carlmart
Or are we going into a lazy stage?...

Nope. Just clarifying. And I am not saying that these active cables don't even work. But I felt your statements needed response.