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The importance of fast and uniform temporal decays over the whole audio frequency band

tuga

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Interesting paper on the importance of fast and uniform temporal decays over the whole audio frequency band:

http://usir.salford.ac.uk/id/eprint/9450/1/ICSV12_Proceedings_2005.pdf

Measurement of sound quality for critical listening
Fazenda, BM, Holland, KR and Newell, PR

Abstract

For the critical assessment of music recordings the uniformity of the pressure amplitude response with respect to frequency has robustly been defended as one of the principals of prime importance for any electro-acoustic monitoring system. This has been particularly so in the appraisal of the room responses, where non-linear factors such as intermodulation distortions do not apply. However, despite the traditional emphasis being placed on the even distribution of modal and diffuse energy, recent investigations have begun to indicate that the uniformity of the modal decay rate is far more important than has previously been appreciated in terms of the definition of accurate and revealing monitoring acoustics.

Parallel work on loudspeaker systems has also been tending to lead to similar conclusions. Modulation transfer function related experiments have begun to demonstrate how the effects of temporal response smearing can significantly reduce the ability of any room/loudspeaker system to convey to the ears of the listeners the complex details within musical recordings. Measurements in real control rooms, and work on the subjective perception of room modes based on binaural room simulations, have now begun to highlight the importance of fast and uniform temporal decays over the whole audio frequency band where monitoring accuracy is a prime requirement. Studies on factors such as modal distribution and decay rates have revealed perception biases that indicate their relative importance in defining perceptually accurate monitoring conditions.

The emerging trend is that to achieve such conditions, the temporal response of electro- acoustic systems must be considered at all times, and the all-pervading pre-eminence of the pressure amplitude response may have to be compromised.
 

sq225917

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Loads of great papers come out of the Salford audio labs. They did the measurements on my final year degree project loudspeaker build, 25 years ago, geez I'm getting old.
 

Pogre

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Fast and even decay times are often cited as a big chunk of the reason so many people prefer RAAL ribbon tweeters.
 

Bjorn

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Interesting paper on the importance of fast and uniform temporal decays over the whole audio frequency band:

http://usir.salford.ac.uk/id/eprint/9450/1/ICSV12_Proceedings_2005.pdf

Measurement of sound quality for critical listening
Fazenda, BM, Holland, KR and Newell, PR

Abstract

For the critical assessment of music recordings the uniformity of the pressure amplitude response with respect to frequency has robustly been defended as one of the principals of prime importance for any electro-acoustic monitoring system. This has been particularly so in the appraisal of the room responses, where non-linear factors such as intermodulation distortions do not apply. However, despite the traditional emphasis being placed on the even distribution of modal and diffuse energy, recent investigations have begun to indicate that the uniformity of the modal decay rate is far more important than has previously been appreciated in terms of the definition of accurate and revealing monitoring acoustics.

Parallel work on loudspeaker systems has also been tending to lead to similar conclusions. Modulation transfer function related experiments have begun to demonstrate how the effects of temporal response smearing can significantly reduce the ability of any room/loudspeaker system to convey to the ears of the listeners the complex details within musical recordings. Measurements in real control rooms, and work on the subjective perception of room modes based on binaural room simulations, have now begun to highlight the importance of fast and uniform temporal decays over the whole audio frequency band where monitoring accuracy is a prime requirement. Studies on factors such as modal distribution and decay rates have revealed perception biases that indicate their relative importance in defining perceptually accurate monitoring conditions.

The emerging trend is that to achieve such conditions, the temporal response of electro- acoustic systems must be considered at all times, and the all-pervading pre-eminence of the pressure amplitude response may have to be compromised.
Yes. It's been said for decades within the small room acoustic community that the time domain is the most important factor to focus on. The frequency response follows the time domain though. And also something many audiophiles that have treated the lows extensively have discovered and where EQ simply can't achieve the same audible result.

You can actually treat certain resonances and if it only effects the time domain great and with very little improvement in the amplitude, it will still be very audible and with the experience that the problem has been solved despite that level is still too high.

It's interesting if the research is also backing up audible lower decay in speakers/transducers. Something many audiophiles have experienced for years.
 
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tuga

tuga

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It's interesting if the research is also backing up audible lower decay in speakers/transducers. Something many audiophiles have experienced for years.

Particularly given how little significance is given to group delay here in ASR.
 

TurtlePaul

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Does this mean they dont like the slot loaded design of the Genelec Ones?
 

Bjorn

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Does this mean they dont like the slot loaded design of the Genelec Ones?
It's difficult to draw conclusions. We also know that commercial speakers with bass reflex generally have too small enclosures and too small ports in order to make them smaller. This compromise of size becomes an audible problem as well. Lower extension will also lead to more room modes and resonances.
 
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tuga

tuga

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Does this mean they dont like the slot loaded design of the Genelec Ones?

From anecdotal experience I have preference for sealed enclosures but bass reflex enclosures tuned to around 30Hz or below seem to have no detrimental effects to my ears (maybe because there's not much content at such frequencies in the types of music I listen to).
 

DVDdoug

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File me under "highly skeptical". But I don't claim to have golden ears...

Of course you can artificially foul-up the timing or mis-align drivers in a speaker. But usually with speakers the big issue is phase shift which can result in cancellation at the crossover frequency where the waves mix, rather than "time delay" problems. (I have read that there were delay issues in early huge theater speakers where the high-frequency horn driver was several feet back from the woofer.)

Most instruments naturally ring and decay, and room acoustics add a lot of "smearing" and "random" delays. Concert halls are intentionally built for reverb.

...And when I occasionally "clean-up" digitized vinyl it's sometimes very-hard to hear when a "click" is happening (relative to the music). Often the biggest problem is "finding" the click when it doesn't obviously stand-out in the waveform.
 

theREALdotnet

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Thanks for refreshing this thread. Unfortunately, the link to the paper doesn’t seem to work anymore. Does anyone have one that works?
 
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tuga

tuga

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Thanks for refreshing this thread. Unfortunately, the link to the paper doesn’t seem to work anymore. Does anyone have one that works?
I've uploaded the paper (attached).
 

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  • Fazenda_Sound-Quality-Critical-Listening.pdf
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theREALdotnet

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Curvature

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Did anyone posting in this thread actually read the paper? It certainly doesn't support this statement:
importance of fast and uniform temporal decays over the whole audio frequency band
 
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