I thought that you were saying that making the horn more structurally sound was important, but I don't see your data as supporting that.
Not much real science there, but then "stored energy" is not a scientific term so I guess that's to be expected. The only way that I know of a system storing energy is in a resonance. But then this statement " That gave an extremely flat frequency response, but also a lot of energy storage. " does not make sense since a flat response means no resonances. For this statement to be true, the time-frequency relationships that have to hold for minimum phase systems would have to be violated. Most speakers are minimum phase systems.
That didn't make sense to me either. If I had to guess, I think the article was miss-quoted. I prefer the term "stored energy" since it helps people connect the dots between a frequency response peak and the cummulative effect in the time domain. It's the stored energy which manifests later in time. Many don't grasp this aspect as evidenced by so many people highly focused achieving a flat on-axis response using passive crossover notch filters or DSP.
Agreed on the lack of scientific data to support the claims and the original explanation may have been misinterpreted by the interviewer.
Personally, I associate stored energy with reduced efficiency (ƞ0)
I guess resonances also negatively affect (system)efficiency.
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Resonance and stored energy are exactly the same thing. I don't think there is any correlation to efficiency. The correlation lies in the the frequency and time domain. A spectral anomaly in the decay plot will have a corresponding impact on the frequency response and vise versa. For me personally, to achieve a flat frequency response I need to look at the time domain aspect.
Here is a quote from Joe D'Appolito in his article "Testing Loudspeakers: Which Measurements Matter, Part 1"
Testing Loudspeakers: Which Measurements Matter, Part 1 | audioXpress
In over 30 years of designing loudspeakers, I have found the following measurements taken as a group provide the strongest predictor of loudspeaker preference available to us today. These measurements are:
• On-axis frequency response
• Impulse response
• Cumulative spectral decay
• Polar response
• Step response
• Impedance
• Efficiency/Sensitivity
• Distortion
• Dynamics"
His take on measurement aligns with my approach as well.
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Thank you, thank you, thank you! Someone who understands the issue.
There is no way to store energy except in a resonance.
Now it is true that two closely coupled resonances can have a fairly flat frequency response and yet still ring out, which looks like it violates this rule, but it doesn't really.
That's correct. I don't make mention of the horn material or it's structural properties. For me as long as it doesn't resonate any more than other sources of resonance then it's structurally sound enough. My brother thinks the stain or the horn material does effect the sound but I think it's his imagination. He's yet to show me any evidence....brotherly quarrel.
How do you measure "dynamics"? 1,2, 3 and 5 are just three different ways of looking at the same thing, (give me 2 and I can derive the other three,) and "distortion" in a loudspeaker has been shown to be insignificant perceptually. I would also question if "impedance" has any real audible effects unless the amps can handle it. But that's an amp issue.
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I think that's his point. His priority for placing it second to frequency response represents his full appreciation for the all that can be derived by this through the Fast Fourier Transform.
For THD I only use it to confirm maximum SPL.
For dynamics I would love the answer to that question as well. My personal opinion on the matter, which is completely unsubstantiated by any literature or white papers that I know of, is that dynamic range is a function of spectral decay. Since dynamic range would be compromised if the noise floor was brought up due to slow spectral decay. This makes dynamic range a function of the frequency spectrum. If this is actually the case, then a speaker may have only 15-25 dB of dynamic range depending on frequency. Which makes me wonder why so many focus so heavily on 100dB+ of dynamic range in electronics or playback format when the speaker is such a limiting factor.
Maybe/likely a sales argument! Like the 70-80's 0.0003% dist figures in amps...
I would be very cautious writting this. Although there are reasons to believe that distortion in loudspeakers can not be perceived because of sound masking effect, i can not find any papers on distortion perception done in mid and/or near field conditions where the influence of the room is quite low.
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I would love to debate the scientific basis for dynamics, but I think that may take us too far astream of the OPs intentions.