Response to an impulse of a driver

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Hello !

Just a straight question
Is there any TS parameter of a driver that can be related to its behaviour in the impulse response test ?
For behaviour I intend rise time and settling time
Maybe the Qts ?
Lately I have been intrigued by fast reacting drivers and I am eager to learn something
I read for instance that electrostatics and ribbon are exceptionally fast transducers

Thank you very much indeed
Kind regards,
gino
 
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T/S parameter tell you about how the system decays.
Nothing about rise time.

Thanks a lot for your kind and helpful reply
Which TS parameter tells us about the decay ?
I understand that the only way to know the driver rise time is to measure it.
Is that correct ?

I would like to explain a little my curiosity
I listened some days ago to a pair of quad ESL 63 electrostatics
To make it short I have never heard a better performance in the midrange from a speaker
Then I asked to someone who knows them
It seems that at least one of the reason of this unbelievable performance is due to the fact that the moving mass of the driver is very low and this makes the driver extremely fast reacting to any kind of impulse
Given that the driver in the ESL63 is particular I am looking for a dinamic driver that could approach that kind of performance
To eliminate any other problem I intend to use an active crossover
In this way I can drive the driver directly with nothing in between except a cable

I was amazed during a movie to listen to sound effects that seem almost the real thing.
When someone knocked at a door on the left I looked at my door
I do not think a sound can be more real than this
Very very impressive

You might ask, why do not take a pair then ?
Mostly because they do no fit my room ... they are so big
But if space was not a problem I think that I woudl try to find a pair, adding maybe a bass unit per side

Thanks a lot and kind regards,
Gino
 
Which bit tells about the decay?
Does it take into account the difference in decay between active and passive crossovers which may be preceding the driver or the difference in damping factor between amps?

Thanks a lot for your reply
Well from some point I have to start
and I said to myself, why not to start from the driver ? selecting it on the basis that its mechanical properties ?
I want a "fast" driver
It is the only way, leaving aside for the moment of the remaining, to get a good response to transient
If the driver is not fast enough you cannot make it faster
Then I would like to skip on the crossover
I intend to use active multiamplification and high damping factor amps (I have them) to drive the drivers
I am looking for an electrostatic performance but with dinamic driver
I imagine that these kidn of drivers should have low moving mass and high power magnet

Maybe I am mistaking but tehre should be at least a qualitative relation between the Qts and the rise time in the impulse response test
I still haven't found what I am looking for (U2)
For me that English is not my first language songs are always a good help
I Can't Get those quad esl 63 Out Of My Mind
Never heard something of more real ... never
Of course they have their limits .. but within them .. they must be heard

Kind regards,
gino
 
Which bit tells about the decay?
Does it take into account the difference in decay between active and passive crossovers which may be preceding the driver or the difference in damping factor between amps?


Qts. Drives have 2nd order high pass characteristics. Qts<0.5 means that for a positive pulse the decay will undershoot zero and then decay to zero exponentially from below. For Qts>0.5 the decay will be a damped sine function (ringing). The amplitude and length of the sine decay will depend on Qts. High Qts yields higher amplitude and linger ringing.

This has no connection to the crossover.

Rise time depends on the high frequency cut off of the driver (or crossover). But none of these have much connection with what is typically referred to as a fast driver. Being fast is a subjective term and if you ask a dozen people what it means you will probably get a dozen different answers.
 
Isn't decay related rather to Qtc, the system value rather than the driver?

Diaphragm mass in a Quad is reportedly 3 milligrams, they are about 0.7x1 meter in size, so the air load mass on the diaphragm is around 8*0.5^3*1.2/3=0.4kg , or 400 grams, about the weight of 3 to 4 12" woofers.... So it isn't mass...

The sound of quads might be due to any number of things:
lack of box colorations
Large area radiator having low excursion so less modulation distortion
Dipole radiation pattern excites the room differently

Fast is a subjective term, and it doesn't correlate with any known measurement. One person will say a certain speaker is fast and another who uses the word will not. In my experience, it seems that the word fast is used to talk about speakers that don't have much bass, sometimes apologetically, as in: "it doesn't have much bass, but it is fast..."
 
I listened some days ago to a pair of quad ESL 63 electrostatics
To make it short I have never heard a better performance in the midrange from a speaker
I was amazed during a movie to listen to sound effects that seem almost the real thing.
When someone knocked at a door on the left I looked at my door
I do not think a sound can be more real than this
Very very impressive
Did you ever listen to other dipoles of some decent quality? Could it be that it is not the quality of the driver but the working principle, which made that impression?
 
I think big dipole is part of it - Magnapan has a similar sound.
But those ESLs with the right amp are just amazing.

Hello !
I did some search about the speakers that amazed me so much
And found this

Stereophile: Quad ESL-63 loudspeaker

First of all I am everything but an expert but just look at the impulse, step and square wave response
I would like to ask, are these normal results or are quite exceptional ?
Surely the absence of a crossover is part of the result
I remeber to have seen how a square wave was modified after passing through a crossover network


Regarding the quality of the amp ... well my friend has a revox b150, a good old integrated but nothing spectacular or particularly exotic
I have the feeling that ANY amp of reasonable quality can have similar results

The performance on the square test is similar to that of an amp instead of that of a speaker
I think that this text is exceptionally severe for ANY loudspeaker
Unfortunately very very uncommon
Surely as anything in real life these speakers have limits ( I think a limited max SPL with low distortion and also limited bandwidth)
But within these limits ... well I am here to get opinion

I will try to answer all of your extremely kind and valuable reply
Kind regards,

gino
 
Did you ever listen to other dipoles of some decent quality?
Could it be that it is not the quality of the driver but the working principle, which made that impression?

Good evening !
I listened some years ago to a Magnepan .. do not remember the model
I had a very positive impression
To be more precise, what impressed me most of the ESL63 was the midband
Voices were just ... perfect
I can't think of a more realistic reproduction of human voices
The bass ... well I felt something was indeed missing
About your question maybe the Magnepan can give a similar performance
Better in the bass ... but the midband on the ESL63

Maybe some ribbon drivers ... or something like the Infinity Emit ???
They seem pretty similar to an electrostatic
They could have a similar performance ???

Kind regards,
gino
 
I remember reading an old interview with someone from Quad before the IAG buyout. Going from memory but I believe they randomly pull samples from the line and compare them with a reference model by placing them face to face and playing opposing square waves. The idea is if they cancel out then the speaker is up to tolerance.

Linkwitz seems to claim that the reason ESLs and Planars are so sensitive to the room is due to a rippled off axis FR.

http://www.linkwitzlab.com/images/graphics/polar1.gif
 
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Qts. ...
High Qts yields higher amplitude and linger ringing

Thank you very much again
I suspected this but I was not sure

This has no connection to the crossover

I will try to eliminate the crossover. or using and active one or finding a mid that can work without it
Like the Morel MW166 in the Eggleston Works
I think that inductors in particular are detrimental
Maybe a square wave test could give evidence of this
Unfortunately I have no lab equipment to perform tests

Rise time depends on the high frequency cut off of the driver (or crossover).
But none of these have much connection with what is typically referred to as a fast driver.
Being fast is a subjective term and if you ask a dozen people what it means you will probably get a dozen different answers.

I think I understand
If I look at the impulse response of a woofer and that of a tweeter I can see that the tweeter is faster than the woofer because, obviously, the rise time of the tweeter is lower than that of the woofer
I understand that it is impossibile to get a woofer behaving like a tweeter
But among woofers do they present the same rise time ???
I have the feeling that low Qts woofers have a lower rise time of that of high Qts woofers
As a consequence Low Qts woofers follows the impulse better They reproduce more faithfully the original test signal
For me this is enough for saying that they are indeed better :)

But I have another doubt/question
Let's take two woofers with the same Qts but different moving mass
Which of the two will have a better impulse response ?:rolleyes:
I do not really know ...

Kind regards,:D
gino
 
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Just another question
Talking of response of a driver to a square wave test
The response of a conventional driver (cone or dome shaped) is very different from that of a planar, ribbon, electrostatic ?
I understand that the square wave does not exist in nature
Nevertheless I think it is a good way to assess the dinamic properties of a driver
I cannot forget that test result on Stereophile review of the ESL 63
Kind regards,
gino
 
First of all I am everything but an expert but just look at the impulse, step and square wave response
I would like to ask, are these normal results or are quite exceptional ?

This loudspeaker measures quite a bit better than the quads and though not shown, it will pass a square wave. It won't sound like a quad. Stereophile: Vandersteen Audio 3A loudspeaker

Here's another: http://stereophile.com/floorloudspeakers/492thiel/index.html

Most loudspeakers with crossovers will not pass a square wave. It doesn't matter because your ear is not sensitive to waveshapes...
 
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Most loudspeakers with crossovers will not pass a square wave. It doesn't matter because your ear is not sensitive to waveshapes...

Probably depends where you put the wave. I think if you get it an octave away from the filter you have a shot but if it's anywhere near the filter (doesn't matter if it's phase linear) it will change it to more of a sine wave before it even hits the driver.
 
This loudspeaker measures quite a bit better than the quads and though not shown, it will pass a square wave. It won't sound like a quad. Stereophile: Vandersteen Audio 3A loudspeaker
Here's another: Stereophile: Thiel CS2 2 loudspeaker

Good evening !
I know the Brans mentioned. Very high quality Brands indeed
But my final intention is to use an active crossover
Presently my interest is more on transducers than on a complete speakers
I will ask another question hereunder

Most loudspeakers with crossovers will not pass a square wave.
It doesn't matter because your ear is not sensitive to waveshapes...

I am not arguing this. I am not talking about what we heard
Let's say for a moment that the ear is not a perfect measuring tool
A square wave is a wave that does not exist in nature
Nevertheless it is extremely difficult to reproduce
In fact a crossover network modifies it
We have seen that a quad can reproduce it
If I take a single drive, a cone midwoofer, can this kind of driver reproduce (of course in its bandwidth) a square wave ?
Can other drivers like planar or ribbon reproduce it ?

I mean to test everything you have to take it to its limits
Another question
From what I understand most crossover networks do not pass the SWT (Square Wave Test)
An amplifier, I think, will pass the SWT
Will an electronic crossover pass a SWT ?
I do not know, I am just asking

If a component pass a SWT for me is a superior component
Indipendently by the fact that the SW exists or not in nature, or by the fact that I do not hear a SW

I have the opinion that in general the EAR is overestimated
No one argue that a eye is inferior to a microscope to see small things or a telescope to see distant things
Ear is limited by nature.
I would not rely on my ear to evaluate a speaker
I am confident in appropriate measurements, like SWT, distortion measurements and so on

By the way I ask mostly for curiosity anyway
Regards,

gino
 
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Will an electronic crossover pass a SWT ?

Some can come very close.

But you will get much more argument then agreement about this subject. it's what we call in English "A Can of Worms".

My experience is that if you choose the right cone midrange and get the crossover right, you can get very close to that ESL sound for a lot less cost and in a smaller size. Not easy, but it can be done.
 
Some can come very close.
But you will get much more argument then agreement about this subject.

Very very interesting. Thank you very much for your kind and valuable reply

it's what we call in English "A Can of Worms"

just think that someone here in Italy eat cheese with them inside
we also use to elect them as our representatives in the Parliament
This just for saying that we are used to worms.
Better .. we like them

My experience is that if you choose the right cone midrange and get the crossover right, you can get very close to that ESL sound for a lot less cost and in a smaller size.
Not easy, but it can be done.

That's what I hoped to hear, difficult but not impossible
And above all for a lot less cost and in a smaller size :eek:

Thank you very much indeed for your very kind and helpful reply
Kind regards,
gino
 
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