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Measuring dynamics

ernestcarl

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To be honest I no longer believe that the Wavelet diagram will tell much about the dynamics (or maybe we shall call it transient response?) of a speaker

Well, it's odd that you would say/guess subjective "dynamics" to be directly what "transient response" means... since the wavelet spectrogram plot you had previously used does faithfully show the frequency-time components of your captured/measured impulse response i.e. transient response as measured at a given single point in space -- but, then, you've also selectively heavily biased it to show mainly the time aspect of it all which kind of defeats the purpose it was derived for in the first place. Remember, speaker manufacturers take many, many measurements -- off-axis points included.

Of course, a speaker's directivity performance matters a lot and should not be neglected. As you said so yourself: larger drivers seem more "dynamic" -- ask yourself what is the relationship between driver size and directivity in a given performance space... Well, whatever this notion of speaker dynamics is, I think it is only fair to consider both transient response and directivity as (at the very least) part contributors.
 
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Bjorn

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Some food for thought.
Planar speakers generally have a very narrow dispersion. They also have a large surface area, examplied with the picture below.
setuptips-img.png

Planars are also considered to have very low intermodulation distortion.
Despite of this, they don't really sound like large horn speakers.

Or does B&O Beolab 90 sound more like a horn speaker when the beam width is changed from wide to narrow (120°)? IMO, they don't by any means. While 120° directivity is wider than many horns, it's actually very close to modern JBL waveguides in the horizontal plane.
Or do we get close to how a horn speakers sounds by minimizing early arriving reflections with physical treatment? IMO, we don't.

What about thermal distortion or compression? We know this in area where horns and compression shines and were traditional speakers struggle. However, a horn speaker remains the transient characheristics even at very low levels and with volumes other speaker designs wouldn't have an issue with compression.

I'm not saying these areas have no influence of what makes a horn sound like it does, but I don't think they are the main cause of the "transient" sound. So perhaps it mainly comes down to a fast impulse response and well damped resonances. Where the result is a fast and dynamic presentation of transients.

While we learn to adopt over time, it can actually be difficult in the short run to go from a well designed horn speaker to other designs. They tend immediately to sound borrowing in comparisons with horns. And especially with the traditional "dynamic speaker" design, you experience going from realism to only good hifi at best. Here I find the CBT (constant beamwidth transducer) speaker design with piston drivers to be the closest to horns, despite that the impulse of such a CBT isn't quick.
 
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Keith_W

Keith_W

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Here I find the CBT speaker design with piston drivers to be the closest to horns, despite that the impulse of such a CBT isn't quick.

What is CBT? I only know the other abbreviation, which I can not repeat in a family friendly forum like ASR.
 

fpitas

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after switching to horn mids/treble myself I searched for the answer, but couldn't find it.
It can have 2 reasons:
1) the rise time of the driver; if you get a membrane to vibrate at a certain aplitude, it wont achive this amplitude at the first wave. compression drivers might just be faster getting there?
2) it could be just dispersion related. horns will give you more direct sound and less reflected sound. So the reproduction is less smeared.
My guess is this. Also, since a typical horn is capable of tremendous output, perhaps the ear can tell that there is very little signal compression.
 

Bjorn

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What is CBT? I only know the other abbreviation, which I can not repeat in a family friendly forum like ASR.
Apologies. CBT is short for constant beamwidth transducer. In very short it's line array speaker design where the weaknesses in such an array in regards to summation has been resolved. More info in the links below:

 

puppet

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I think all these new "sub-categories" of the term dynamics are nonsense. These various degrees of the term dynamics are just a part of the type of music one is listening to as well as the individual composers intent and/or style ... nothing to read into here.

I feel that a loudspeakers ability to sound more dynamic than another just comes down to how well it couples to the air around it. Like a trumpet vs a clarinet.
 

gnarly

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I was wondering if there is a measurement that predicts how "dynamic" a speaker would be. Impulse response?
I enjoyed your preamble. Like you, I run multi-way actives where i can fiddle and do what i want. :)


In my strong, but hopefully still humble, opinion.....there is definitely a measurement that predicts how "dynamic" a speaker is....
And it's nothing more than an acoustic transfer function measurement of the speaker, and how it holds up as drive level increases. (speaking anachoically)

Particularly, it's flat frequency response, with flat phase response, with low freq extension.
And that stays fully linear throughout the spectrum with increased SPL for both average and peak levels.
It equals a near perfect impulse response, from low volume thru high.

I really think flat mag and phase is a fundamental audio concept that seems too simple for folks to accept.
For me, when the lights went on, I realized how profound flat mag and phase, that stays linear, is the answer to great dynamics.
And it's not a matter about the audibility of phase...it's more a matter of everything gets right with the sound...whatever it is we think we can or can't hear....
 

dc655321

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I enjoyed your preamble. Like you, I run multi-way actives where i can fiddle and do what i want. :)


In my strong, but hopefully still humble, opinion.....there is definitely a measurement that predicts how "dynamic" a speaker is....
And it's nothing more than an acoustic transfer function measurement of the speaker, and how it holds up as drive level increases. (speaking anachoically)

Particularly, it's flat frequency response, with flat phase response, with low freq extension.
And that stays fully linear throughout the spectrum with increased SPL for both average and peak levels.
It equals a near perfect impulse response, from low volume thru high.

I really think flat mag and phase is a fundamental audio concept that seems too simple for folks to accept.
For me, when the lights went on, I realized how profound flat mag and phase, that stays linear, is the answer to great dynamics.
And it's not a matter about the audibility of phase...it's more a matter of everything gets right with the sound...whatever it is we think we can or can't hear....

Stop making such sensible posts - you're ruining the mysteries! ;)
 
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