[d.phens]

What's the benefit of PRO bias actually?
I know that with higher bias voltage stator spacing can be larger - it's likely I think that the static electricity FORCE pushing / pulling the driver is generally THE SAME for low volume levels.

That means, better dynamics but any other benefits too?
Better bass?

 

[audiomagnate]

I haven't heard the Lambdas in years, but I'd sell my first born before I'd sell my Gammas (maybe just a SLIGHT exaggeration). They are colored compared to more modern cans, and they are sadly lacking in the bass, but I still love them and listen to them every day, unlike most of my other cans.

 

[spritzer]

Quote:

Originally Posted by d.phens /img/forum/go_quote.gif What's the benefit of PRO bias actually? I know that with higher bias voltage stator spacing can be larger - it's likely I think that the static electricity FORCE pushing / pulling the driver is generally THE SAME for low volume levels. That means, better dynamics but any other benefits too? Better bass?

They are more efficient and you can get more bass out of them with the higher bias. You could do the same with a lower bias point and better build quality so the bias isn't the ultimate deciding factor.

 

[d.phens]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif They are more efficient and you can get more bass out of them with the higher bias. You could do the same with a lower bias point and better build quality so the bias isn't the ultimate deciding factor.

I believe you, it's a psychological issue often engaged in advertising:
You know, high bias means Pro and pro means better

Let's say electrostatic potential falls exponentially increasing distance from electrodes.
Then I may say that having an electrode CLOSER means also that most of the playback time electrode is under higher voltage
(considering the distance, higher bias doesn't mean higher electrostatic force pushing the electrode during QUIET passages) and having a push-pull system,
I can even assume that LOW BIAS enables SMALLER ELECTRODE SPACING causing MORE CONTROL FOR LOW VOLUME, better timbre reproduction, improved clarity !
More spacing means more apparent control for larger volume amlitudes but not necessarily in cases the membrane extension isn't that high (quiet music).


All of this is just a speculation still to be proved...

Well then:
HAS ANYONE LISTENED TO NON-PRO AS WELL AS PRO VERSION OF THE SAME HEADPHONE?

Disclaimer:
I'm not a native speaker so you may misunderstand some of the text above

 

[Carl]

The reason Stax changed over to a higher voltage was because Daimler asked for a headphone with a higher signal:noise ratio. Bias voltage has bugger all effect on the musicality of a transducer.

 

[edstrelow]

Quote:

Originally Posted by d.phens /img/forum/go_quote.gif Let's say electrostatic potential falls exponentially increasing distance from electrodes. Then I may say that having an electrode CLOSER means also that most of the playback time electrode is under higher voltage (considering the distance, higher bias doesn't mean higher electrostatic force pushing the electrode during QUIET passages) and having a push-pull system, I can even assume that LOW BIAS enables SMALLER ELECTRODE SPACING causing MORE CONTROL FOR LOW VOLUME, better timbre reproduction, improved clarity ! More spacing means more apparent control for larger volume amlitudes but not necessarily in cases the membrane extension isn't that high (quiet music). All of this is just a speculation still to be proved... Well then: HAS ANYONE LISTENED TO NON-PRO AS WELL AS PRO VERSION OF THE SAME HEADPHONE? Disclaimer: I'm not a native speaker so you may misunderstand some of the text above

I think I understand you quite well. This is very interesting speculation.

I have compared the Sigma Low and High Bias and think you may be on to something, because I feel the high bias phones are somewhat harsher sounding. However they clearly have better dynamics. But even that is not an unalloyed improvement as many people think it is. I have used the dBx dynamic range enhancers (aka compander) and am used to tweaking dynamics in music. You get more oomph and "prat" ( pace, rhythm and timing)with increased dynamics, but you also get less ambience.

Now, depending on your set-up you may find the increased ambience is better for you ears than prat. And if you are right on the harshness issue that is another plus for the low bias set.

I like the low bias Sigma but still mostly listen with the higher bias sets. Yet very time I put the low bias set on, I end up asking myself, why I don't use them more.

 

[cosmopragma]

I dunno, it seems to be oversimplified.
The most smooth sounding and at the same time excelling in the micro- and macrodynamics department electrostats I'm familar with are the current SR-007s, and these are high bias headphones.
In comparison the low bias SR-X MK III are relatively harsh and grainy sounding and overall way less refined.
The SR-X are still interesting headphones and I like them better than any Lambda (and I did own most of them), but this is more due to their unique sound and personal preference.
In technical terms any Lambda is better.

 

[spritzer]

You may here a slight difference between the same driver driven fitted to pro or normal status because Stax changed the ratio of spacer/bias voltage so the driver will behave in a different fashion. How much difference is hard to predict.

Comparing the Sigmas is a bed way because the drivers are vastly different as can be head with the equivalent Lambda models. The SR-Lambda and it's Pro sibling are as close as you can get with out some serious DIY and they don't sound the same. I have converted a SR-X Mk3 driver to pro configuration but didn't spend enough time comparing it so I can't comment since it was more of a test then a complete mod.

 

[d.phens]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif They are more efficient and you can get more bass out of them with the higher bias. You could do the same with a lower bias point and BETTER BUILD QUALITY so the bias isn't the ultimate deciding factor.

How exactly can better build quality improve bass (i.e. what do you call better build quality)?
Electrostatic principle is know to be SIMPLE and not very dependent on 'build quality' - you know that it's not that hard to actually built good sounding electrostats at home.

There's no need for a good enclosure, damping, membrane material is just simple thin polymer...


Does STATOR MATERIAL matter?
Can DAMPING help the bass (I think it would cause the opposite)?

 

[spritzer]

Quote:

Originally Posted by d.phens /img/forum/go_quote.gif How exactly can better build quality improve bass (i.e. what do you call better build quality)? Electrostatic principle is know to be SIMPLE and not very dependent on 'build quality' - you know that it's not that hard to actually built good sounding electrostats at home. There's no need for a good enclosure, damping, membrane material is just simple thin polymer... Does STATOR MATERIAL matter? Can DAMPING help the bass (I think it would cause the opposite)?

The build quality will make or break the design. The enclosure is much more important then the driver but a crappy driver in a good housing isn't going to be good so it is a harmony of those two things.

There is only one real way to get astounding bass out of an ESL and that is to make a big strong panel. Look up the Sound-Lab U1 for a good example. The Stax SR-007 is the best example in the headphone world with the SR-Omega a strong second. A housing that firmly anchors the driver and then transfers all vibrations directly to the head.

Stator material matters of course but it isn't an ultimate deciding factor. I prefer PCB based solutions but the gold plated plated copper mesh of the SR-Omega sounds very nice indeed.

 

[edstrelow]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif The build quality will make or break the design. The enclosure is much more important then the driver but a crappy driver in a good housing isn't going to be good so it is a harmony of those two things.

I ascribe to the belief that at the level of performance of a good electrostatic, everything matters, i.e. just about every thing you can do in design, from materials to trasnsducer thickness, earpads etc. will make a difference to the sound.

I would still like to kniow if anyone thinks that low bias operation has some advantages over high bias.

 

[Duggeh]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif There is only one real way to get astounding bass out of an ESL and that is to make a big strong panel. Look up the Sound-Lab U1 for a good example. The Stax SR-007 is the best example in the headphone world with the SR-Omega a strong second. A housing that firmly anchors the driver and then transfers all vibrations directly to the head.

Each of QUADs refinements on the original ESL63 design with the point source FRED driver has involved a major structural upgrade to the housing. The newest ESL2905 has got a large backstrut exactly for the purpose of making the housing rigid and moving a greater sense of bass down into the floor in the manner you describe. So I am given to understand anyway.

 

[spritzer]

Quote:

Originally Posted by edstrelow /img/forum/go_quote.gif I ascribe to the belief that at the level of performance of a good electrostatic, everything matters, i.e. just about every thing you can do in design, from materials to trasnsducer thickness, earpads etc. will make a difference to the sound. I would still like to kniow if anyone thinks that low bias operation has some advantages over high bias.

It is a package deal, where every part has to be good. It's most obvious on the Stax OEM designs where they took their good drivers and built a bad housing to make them sound worse.

There aren't really any advantages to be had by using low bias but the sound difference is mostly because they are from a different era then the Pro models. Vinyl was the main source so massive bass wasn't a priority but rather euphony ruled the day.

Quote:

Originally Posted by Duggeh /img/forum/go_quote.gif Each of QUADs refinements on the original ESL63 design with the point source FRED driver has involved a major structural upgrade to the housing. The newest ESL2905 has got a large backstrut exactly for the purpose of making the housing rigid and moving a greater sense of bass down into the floor in the manner you describe. So I am given to understand anyway.

That is what they are trying to pull off. It is better then the original design but a side mounted support would work equally well or better. It works wonders with the original ESL.

It's just too bad that Quad doesn't fix the design issues with the ESL63 because the new models are failing in the same way the old ones did. It gives me the felling that there is no designer there that fully understands how to design an ESL. Great speakers but on the third revision you should have worked out some small problems with QC...

 

[Fitz]

Since it's related to the subject at hand, how does the pro bias SR-X/Mk3 compare to the normal bias SR-X/Mk3? Is it just the rarity, or does it actually sound significantly different?

I'm trying to decide if it's worth dropping coin on the pro version after just buying a Sigma and a second Lambda (to compare with/without the fiberglass).

 

[Carl]

Quote:

Originally Posted by Fitz /img/forum/go_quote.gif Since it's related to the subject at hand, how does the pro bias SR-X/Mk3 compare to the normal bias SR-X/Mk3? Is it just the rarity, or does it actually sound significantly different? I'm trying to decide if it's worth dropping coin on the pro version after just buying a Sigma and a second Lambda (to compare with/without the fiberglass).

No one here has heard an actual mk3 Pro. They're just short of unobtainium. A Gamma Pro vs SR-Xmk3 compro is doable though.