Do current Wilson speakers have "Pistonic" drivers?

[Kal Rubinson]

In the absence of proper measures and data we associate stiffness with its consequence - that most of the time is just "slow bass" ...

That subjective association is not universal. I would think that 'In the absence of proper measures and data we associate lack of stiffness with its consequence - that most of the time is just "slow bass" ...' Stiff=tight=quick. Floppy=limp=slow. YMMV.

 

[ddk]

Sorry David, it is well known in the wider Audio world that pistonic refers to a driver that has no inadvertent flexing...at least within its pass band. It has absolutely nothing to do with fast or slow sound.

If this is the pet name you give for slow bass then so be it but don’t try to foist it on the people of this forum. I doubt anyone else here has slow bass in mind when someone calls a driver pistonic.

I normally think you offer a lot of sound advice and experience and I agree with your overall audio philosophy but wrangling over this term with a usage way out in left field is one of the silliest things I have seen from you on WBF.

I haven’t had anything to do with the so called wider audio community for at least three decades if ever and for all that time the term pistonic always had a negative connotation as understood within my circles which I clearly stated from the start. We have a common understanding of the term “pistonic” the difference is the context, the one we’ve used it in for a lot longer than vandersteen’s paper which seems to be yours. You say I’m foisting something new on the forum so be it no different than the term “natural” that people argued about. Let me foist another one, Pistonic references have been made to drivers in even bigger and wider communities than high end for decades including the car and HT circles, their context is the amount of so called air moved by a driver, go ahead and wrangle with them too.

There’s no concensus even understanding simple terms like slow and fast in your wider audio community, Pistonic is just a descriptor used to reference movement of a cone and certainly context isn’t as narrow as you’re making it out to be.

david

 

[microstrip]

That subjective association is not universal. I would think that 'In the absence of proper measures and data we associate lack of stiffness with its consequence - that most of the time is just "slow bass" ...' Stiff=tight=quick. Floppy=limp=slow. YMMV.

Surely - we will never have universal agreement concerning subjective nomenclature. But IMHO the main fault is not with the subjective people - it is with the objective people who do not do their work, most of the time failing to correlate their technically perfect data with subjective data. Bass in stereo reproduction is an extremely complex affair, contrary to what most people think.

 

[Kal Rubinson]

Surely - we will never have universal agreement concerning subjective nomenclature.

This is important because it becomes difficult to have a discussion if we cannot agree on nomenclature,

 

[morricab]

We can not escape from the reality that people associate piston with the macroscopic world - and here David has a point. Our general view of "flexing" is related with what we view and feel with our senses, so we associate it with stiff cones. However stiffness depends on frequencies being considered and effectively we are poor judges of it. In the absence of proper measures and data we associate stiffness with its consequence - that most of the time is just "slow bass" ...

Surely my discourse would be different in the WBF "Measurements " section"!

Stiffness associated with “slow bass”?? Only if the driver is high mass to gain stiffness. Btw. Doped paper is quite stiff and relatively low mass...this a preferred choice for high sensitivity woofers. Carbon fiber based and foam core drivers are also light , stiff and if used properly not slow at all.

Stiffness in and of itself is just one desirable trait and and when done with structure rather than mass is more often than not yielding a fast sounding bass.

 

[microstrip]

Stiffness associated with “slow bass”?? Only if the driver is high mass to gain stiffness. Btw. Doped paper is quite stiff and relatively low mass...this a preferred choice for high sensitivity woofers. Carbon fiber based and foam core drivers are also light , stiff and if used properly not slow at all.

Stiffness in and of itself is just one desirable trait and and when done with structure rather than mass is more often than not yielding a fast sounding bass.

Many times. As you say many people associate stffness witth heavy cones and slow reaction. Do you have access to reliable breakdown measurements of doped paper cone speakers? And sometimes doped cones are quite heavy - the materials used to stiff the paper are really heavy.

Anyway, one of the best know light foam core drivers is the KEF B139, commonly associated with "slow" bass. And curiously it is pistonic up to 800 Hz ...

IMHO there is too much variance and lack of knowledge on this subject to allow a technical debate. And using information from manufacturer or dealer sites will always introduce a strong bias!

 

[DaveC]

Stiffness associated with “slow bass”?? Only if the driver is high mass to gain stiffness. Btw. Doped paper is quite stiff and relatively low mass...this a preferred choice for high sensitivity woofers. Carbon fiber based and foam core drivers are also light , stiff and if used properly not slow at all.

Stiffness in and of itself is just one desirable trait and and when done with structure rather than mass is more often than not yielding a fast sounding bass.

Yup.

And mass really isn't the enemy with low frequency reproduction anyways. At low frequencies the cone isn't moving that fast, relatively, and a lighter cone isn't accelerating any faster than a heavier cone if the motor is sized properly. A lighter cone does not result in faster, snappier, etc. bass! A lighter cone can result in distortions that make the bass sound a bit more bouncy, full or energetic though.

However, distortion does go down as the cone becomes stiffer, especially as the frequency decreases. For subwoofers especially, I'll take a heavier, stiffer cone with a large motor anyday.

As far as "slow" sounding bass, it's also a theory that it's a result of excessive inductance according to Acoustic Elegance and I can see that being the case when the woofer is used into the upper bass/lower midrange regions.


And I don't see any room for interpretation on the definition of "pistonic" when it comes to speaker drivers. It's a word used in science and engineering that has a VERY specific meaning, that of an idealized driver that doesn't flex or break up.

 

[microstrip]

This is important because it becomes difficult to have a discussion if we cannot agree on nomenclature,

More than 90% of our debates are on semantics. Do you expect a thread provocatively named "Do current Wilson speakers have "Pistonic" drivers! to be different?

A nice thing about WBF is that we know each other and most of the time know how to interpret others posts. Otherwise it would be a Babel forum!

 

[morricab]

I haven’t had anything to do with the so called wider audio community for at least three decades if ever and for all that time the term pistonic always had a negative connotation as understood within my circles which I clearly stated from the start. We have a common understanding of the term “pistonic” the difference is the context, the one we’ve used it in for a lot longer than vandersteen’s paper which seems to be yours. You say I’m foisting something new on the forum so be it no different than the term “natural” that people argued about. Let me foist another one, Pistonic references have been made to drivers in even bigger and wider communities than high end for decades including the car and HT circles, their context is the amount of so called air moved by a driver, go ahead and wrangle with them too.

There’s no concensus even understanding simple terms like slow and fast in your wider audio community, Pistonic is just a descriptor used to reference movement of a cone and certainly context isn’t as narrow as you’re making it out to be.

david

David, there are papers on the subject dating back at least to the mid-1970s! It has been considered a highly desirable characteristic for a driver since probably much longer than that for driver designers. You should be very aware of this given your interest in historical audio. I found a Japanese AES paper by A. Matsuda describing a honeycomb driver in 1978!and specifically using the term pistonic motion.

Given that you seem unaware of the orthodox usage of the term is A) surprising and B) suggests you should widen your circle.

 

[morricab]

More than 90% of our debates are on semantics. Do you expect a thread provocatively named "Do current Wilson speakers have "Pistonic" drivers! to be different?

A nice thing about WBF is that we know each other and most of the time know how to interpret others posts. Otherwise it would be a Babel forum! [/QUOT
90% of your posts are on semantics ...

 

[morricab]

More than 90% of our debates are on semantics. Do you expect a thread provocatively named "Do current Wilson speakers have "Pistonic" drivers! to be different?

A nice thing about WBF is that we know each other and most of the time know how to interpret others posts. Otherwise it would be a Babel forum!

90% of your posts are on semantics...

 

[microstrip]

(...) I found a Japanese AES paper by A. Matsuda describing a honeycomb driver in 1978!(...)

As far as I remember the honeycomb driver with pistonic behavior was already referred in the late 50's.

 

[ddk]

David, there are papers on the subject dating back at least to the mid-1970s! It has been considered a highly desirable characteristic for a driver since probably much longer than that for driver designers. You should be very aware of this given your interest in historical audio. I found a Japanese AES paper by A. Matsuda describing a honeycomb driver in 1978!and specifically using the term pistonic motion.

Given that you seem unaware of the orthodox usage of the term is A) surprising and B) suggests you should widen your circle.

This is getting ridiculous, pistonic generally refers to an in & out motion wether used in scientific or sexual terms. Fine with me if you want to idealize it but explain that to a partner who prefers a grind !

david

Edit- PS. My context from the beginning was about the sonic attributes of certain woofers and bass performance of those drivers. Vandersteen's testing is at much higher frequencies to show that his drivers have better performance than an unknown conventional paper cone at certain frequencies, how does that disqualify other context?

david

 

[microstrip]

90% of your posts are on semantics...

Nice to know you are carrying the statistics of the area of my posts - WBF only refers the total number. But I think your statistics is wrong.

But yes, we should be able to interpret other members posts and nomenclature if we want to contribute to the subject being debated. Both Kal and David have a lot to contribute on this subject, if we are interested in learning from them we should "translate" their posts.

 

[morricab]

This is getting ridiculous, pistonic generally refers to an in & out motion wether used in scientific or sexual terms. Fine with me if you want to idealize it but explain that to a partner who prefers a grind !

david

Edit- PS. My context from the beginning was about the sonic attributes of certain woofers and bass performance of those drivers. Vandersteen's testing is at much higher frequencies to show that his drivers have better performance than an unknown conventional paper cone at certain frequencies, how does that disqualify other context?

david

Sorry David, more silliness from you. Like Kal, I too am out .

 

[morricab]

Nice to know you are carrying the statistics of the area of my posts - WBF only refers the total number. But I think your statistics is wrong.

But yes, we should be able to interpret other members posts and nomenclature if we want to contribute to the subject being debated. Both Kal and David have a lot to contribute on this subject, if we are interested in learning from them we should "translate" their posts.

When clear definitions of terms exist (as in the case of pistonic motion of drivers) then it would be helpful if everyone used them then interpretation would be unnecessary. It is unhelpful when Somone jumps i with a highly insular definition that is totslly something other than the well understood definition.

 

[ddk]

Sorry David, more silliness from you. Like Kal, I too am out .

Fine with me if you don't think that pistonic is used in only one context isn't silly.

When clear definitions of terms exist (as in the case of pistonic motion of drivers) then it would be helpful if everyone used them then interpretation would be unnecessary. It is unhelpful when Somone jumps i with a highly insular definition that is totslly something other than the well understood definition.

My definition of "pistonic" isn't insular it's the same as the handful of people on this thread, we have a difference in context.

david

 

[Folsom]

David, is your definition not a more tongue'n'cheek comment than some kind of official technical term? Like how people will snicker when they hear a certain word that is contrary to their circle? (not audio specific)

 

[ddk]

David, is your definition not a more tongue'n'cheek comment than some kind of official technical term? Like how people will snicker when they hear a certain word that is contrary to their circle? (not audio specific)

Aside from sexual remarks it really wasn’t meant to be tounge’n’cheeck, within our vintage groups when a woofer sounds mechanical we call it pistonic because you hear the back & forth travel of the cone as delayed reaction to part of the signal in contrast to the rest of the speakers. Nothing to do with breakup or distortion just speed and length of travel vs very light paper woofers with very limited travel that shimmer and react in real time.

Here’s pistonic used in technical terms in context of driver air displacement, nothing to what Kal and Morricab are fixated with.

https://www.ht-audio.com/pages/SpeakerBasics.html

david