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What does "Dynamic" Mean To You?

Playing music at 85dB average with 15-20dB peaks, which is more dynamic?

  • Other Definition: Dynamic means lively/high volume/not the difference between loud and soft sounds.

    Votes: 0 0.0%

  • Total voters
    33

khrisr

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A car’s acceleration is much more perceptible than its top speed usually … especially when top speed is attained rarely or for very short durations. So is it (similarly) the rate at which a stereo can go from quite to loud and back the primary factor that contributes to “dynamism”?
 

RayDunzl

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So is it (similarly) the rate at which a stereo can go from quite to loud and back the primary factor that contributes to “dynamism”?

It does that every cycle of a waveform, in fact, goes from full forward to full reverse loud...

But we don't sense that.

We sense some kind of average of those moves over some time period.
 

DVDdoug

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What words do the letters in "LUFS" stand for?
Is your Google broken? :p

Loudness Units Full Scale. "Full scale" is the 0dB reference, and this is a digital level and a digital reference. Of course the actual acoustic loudness (dB SPL = sound pressure level) depends on the volume control and the size of your amplifier & speakers, etc .

LUFS takes into account the fact that low-frequency and high-frequency sounds aren't perceived as loud as mid-frequency sounds, and that short-duration sounds are not perceived as loud as long-duration sounds.

Similarly, dBFS is decibels full scale, which is the digital level relative to the "digital maximum".* That's why digital dB levels are negative. dBFS just looks at the digital amplitude without regard to how loud it's going to sound.

With SPL, 0dB is approximately the quietest sound that can be heard so SPL levels are normally positive. Most SPL measurements are "A-weighted" which takes frequency into account, similar to LUFS. Although there is usually no calibration between SPL and LUFS (or dBFS) there is a direct correlation and if you reduce the digital level by 3dB, the SPL level will drop by 3dB, etc. (assuming everything is linear and the amplifier isn't being driven into distortion).


*0dBFS is the highest you can "count" with a given number of bits. The numbers in a 24-bit file are bigger than the numbers in an 8-bit file, but everything is automatically scaled to match the DAC when it's played so a 24-bit file isn't louder. With floating-point audio 0dB is equal to 1.0, so you can obviously go way over 0dB (but your your DAC is still limited to 0dB).
 
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Wes

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a range is one thing, but the speed from point x to y within that range is something else

anyway, I prefer Dymaxion speakers
 

pseudoid

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The question in my mind is whether there is a weighting factor for DR thru-out (or via a sweep of) the whole audio spectrum.
Like we all know that an "8 Ohm" Load (of speaker) specification is but a static rule-of-thumb and speaks nothing of its impedance thru about this audio spectrum.
 

thefsb

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Even choice 3 doesn't do it for me because dynamic clearly does include all those markings from p through mf to f etc.

This is dynamic (music starts at 53, forum software reset youtube URL to start at 0)


This is less dynamic

 

thefsb

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But seriously, there's a lot in audiophile terminology I don't understand and this is one of them. I cannot hear a dynamic amp or speakers or playback system. I can hear dynamics in music. And iiuc dynamic music sounds dynamic on a system that can play full-range, loud with modest distortion and less dynamic on a system with some limitations.
 

khrisr

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It does that every cycle of a waveform, in fact, goes from full forward to full reverse loud...

But we don't sense that.

We sense some kind of average of those moves over some time period.

Right … I got you. I guess I was thinking more in terms of power delivery (?) If an amplifier has a finite headroom does that also mean it can run out of gas much sooner when a sudden demand is made of it thereby introducing an audible reduction in “dynamics”? Sorry I don’t remember much from my electrical eng degree.

I had upgraded recently after having the same set of speakers for about 10 yrs. Nothing else changed but I recall one distinct quality difference I heard was things like the onset of a drum roll or snare hit or guitar strum sounded “quicker” and “more powerful”. I was thinking maybe the speakers are better designed/stiffer cones/stronger magnets/voice coil or whatever that is resulting in the cones moving with more “acceleration” thereby reproducing dynamics with more fidelity.

I guess an interesting experiment would be to hook up a mic and record a guitar string and speaker cone simultaneously using a laser or whatever … would the waveforms match up perfectly? Or would the cone start lagging in some sections? Assuming of course there is a constant time delay in the signal chain that can be ignored.
 

RayDunzl

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I guess an interesting experiment would be to hook up a mic and record a guitar string and speaker cone simultaneously using a laser or whatever … would the waveforms match up perfectly?

No, but I might assign the amplifier as "least at fault" when they don't.

Experiment:

Record the sound and observe the waveform.

Record the recorded signal being played back by the electronics and observe the waveform (expect a very close match),

Record the playback through the speakers of the recorded signal with a microphone in the air and observe the waveform (expect a loose to unrecognizable match).

Time align, and compare all three and mull the result.
 

pseudoid

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...So is it (similarly) the rate at which a stereo can go from quite to loud and back the primary factor that contributes to “dynamism”?
I am thinking not. The rate (that I think you speak of) is more like a "Slew Rate" spec or "Time Delay" (or "Rise Time") spec... that 'rate' may even be referred to as "Attack Time"... These are 'response' times; with units of voltage-over-time (V/uS) and usually specify how quickly an incoming signal can reach its peak at the output; due to a variety of input output criteria, which never results in an 'instantaneous response' from the circuitry (passive and/or active designs). Not that such fantastic transient response times are always desirable.
 

Wes

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Electrostatic speakers sound dynamic to me
 

pseudoid

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I think what it really means is that the 130dB speaker has an additional +15dB (MORE) headROOM in case of an 1812 Overture BOOM!
 

Lambda

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"Can't Tell: Anything capable of 105dB peaks without compression/distortion is equally dynamic."
Only if the peak playbak level is lower then 105dB. and 105dB is not that mush in terms of dBA.
So a Louder system can have more dynamic because it can play louder over the noise floor or the threshold of hearing.

Equal_loudness_no_caption.svg
 
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