Power . How much do we need...

[mep]

Anyone owning electronics with a large warmup period - such as a the Krell KSA250 - knows that when listening cold at live sound levels most times the sound seems too loud, and the tendency is to decrease volume but listening at the same electrical level when the system is hot does not suggest such high levels - only after the neighbors complain you notice it.

I agree it takes awhile for the KSA-250 to come up to temperature. And I mean the kind of temperature where you can stick your mitt over the top of the amp and know it’s hot. This is where the music server comes in handy. I always turn the amp on two hours ahead of my listening session and let it cook with the music server set on random.

 

[microstrip]

Care to explain this a bit ? Not sure I understand ...

Simple - I just used the difference between the sound quality of an amplifier cold or hot to show we perceive loudness differently depending on the quality of sound. If you fix the volume at a loud level with the Krell cold people will find the volume excessive and too loud. However after warmup people will not find it too loud. BTW, when I find that loudness disturbs me or is not pleasant I turn the volume down ...

I choose the warm up effect as it is an experiment with controlled conditions.

I could have picked others. Spaciousness and envelopment of the sound also strongly disturb our perception of sound level.

 

[microstrip]

I agree it takes awhile for the KSA-250 to come up to temperature. And I mean the kind of temperature where you can stick your mitt over the top of the amp and know it’s hot. This is where the music server comes in handy. I always turn the amp on two hours ahead of my listening session and let it cook with the music server set on random.

Could you try to describe the main differences between cold and "cooking" sound?

 

[Phelonious Ponk]

Somewhere in this world there is an old man tucked away in an asylum who has access to the internet and he takes great delight in writing things that are pure nonsense and passing them off as psychobabble science. He knows damn well the laws of physics exist, but his shtick is trying to convince others that the laws of physics don’t really apply to audio.

That old man is tucked away right next to another old man whose shtick is pretending to be a 21 year old woman looking for love and having lonely guys fawning over “her.” It’s a toss up to which old man is laughing the hardest at their antics.

. Are you sure there isn't a whole ward full of them, madly typing away all the time?

Tim

 

[Gregadd]

As we can see distortion rises with the power output. I don't have a psychoacoustic study but it is just natural that distorted sounds appear more harsh than undistorted sounds. So if you drive a speaker with a fifty watt amp and that amp is pushed to its' upper power limits then is operating in its higher distortion range. It may be perceived as louder.

 

[Gregadd]

For a higher powered amp we may say that same speaker being driven in the low distortion range. Less distortion giving a cleaner sound. Perhaps giving the perception that it is not playing as loud.

 

[microstrip]

As we can see distortion rises with the power output. I don't have a psychoacoustic study but it is just natural that distorted sounds appear more harsh than undistorted sounds. So if you drive a speaker with a fifty watt amp and that amp is pushed to its' upper power limits then is operating in its higher distortion range. It may be perceived as louder.

Greg,

The way we perceive distortion in sound depends of the spectrum of the distortion and the harmonics relative weight. It can be made sound harsh, as you say , but also full and excessively spacious.
But this maybe one of the reasons why some amplifiers sound louder than others at the same electrical gain.

 

[Gregadd]

Microstrip you are right. You may recall my recent discourse with Tom on pleasing distortion and preferences. Of course when the music sounds "bette"r it does not bother us as much

 

[Phelonious Ponk]

Microstrip you are right. You may recall my recent discourse with Tom on pleasing distortion and preferences. Of course when the music sounds "bette"r it does not bother us as much

It doesn't sound better to me, though YMMV. I think that's the thing that sent me down the path I'm on instead of the euphonic/subjective path. Are the colorations of tubes and analog media more pleasant than a SS amp clipping or a digital source with lots of audible jitter? Yes. But they are still wrong to my ears. That system-generated warmth and spaciousness get in the way of what I'm seeking just as much as harsh SS distortion.

For emphasis: YMMV.

Tim

 

[Gregadd]

Tim we have been down this road so many times we could do it blind folded (or ear plugs). Can we at least agree it sounds different? That would be sufficient for the sake of argument.

 

[DonH50]

Somewhat on-topic, I found this in the latest Audio Advisor catalog, discussing the benefits of Cambridge Audio's "Class XD" technology:

"This system should not be confused with Class AB, which inherently generates greater audible distortion at high levels than pure Class B."

Hmmm...

 

[microstrip]

It doesn't sound better to me, though YMMV. I think that's the thing that sent me down the path I'm on instead of the euphonic/subjective path. Are the colorations of tubes and analog media more pleasant than a SS amp clipping or a digital source with lots of audible jitter? Yes. But they are still wrong to my ears. That system-generated warmth and spaciousness get in the way of what I'm seeking just as much as harsh SS distortion.

For emphasis: YMMV.

Tim

Tim,

Surely, MMMVs. Just read today an interesting comment of Anthony H. Cordesman in TAS219 review of the Sussrros cartridge about the SACD and vinyl versions of a recording

" These discs obviously do not sound the same, but the Sussrros were so uncolored that they showed that the best recordings in both mediums have the same ability to create a deeply involving illusion of a live performance. And here, it is important to remember that you don’t buy recordings and high-end systems to please Descartes. The epistemology of high-end audio is not based on finding the best answer to “what is truth?” It is based on finding the best illusion of the real thing. "

I must say I agree with him.

BTW, I have been considering adding IMHO and YMMV to my signature. But I suppose that any member of WBF knows of that.

 

[amirm]

As we can see distortion rises with the power output. I don't have a psychoacoustic study but it is just natural that distorted sounds appear more harsh than undistorted sounds. So if you drive a speaker with a fifty watt amp and that amp is pushed to its' upper power limits then is operating in its higher distortion range. It may be perceived as louder.

I hope the plot is not lost in all of this . Discussion was started with my scenario of hearing an amplifier hiss. There was no clipping involved in that scenario. The hiss source and level were constant to boot. The notion then that my brain all of a sudden decided to *increase* its levels when played through a less efficient speaker makes no sense based on any perceptual science I know of. Indeed, if such a factor existed, we would never be able to level match equipment in blind testing because our internal volume would do what it wants. Yet we know this to not be true.

 

[microstrip]

I hope the plot is not lost in all of this . Discussion was started with my scenario of hearing an amplifier hiss. There was no clipping involved in that scenario. The hiss source and level were constant to boot. The notion then that my brain all of a sudden decided to *increase* its levels when played through a less efficient speaker makes no sense based on any perceptual science I know of. Indeed, if such a factor existed, we would never be able to level match equipment in blind testing because our internal volume would do what it wants. Yet we know this to not be true.

Amir,
What equipment do you use to match volumes for blind tests of different types of speakers?

 

[amirm]

Tim,
What equipment do you use to match volumes for blind tests of different types of speakers?

You quoted me. Did you mean to be asking me or Tim?

 

[Gregadd]

I hope the plot is not lost in all of this . Discussion was started with my scenario of hearing an amplifier hiss. There was no clipping involved in that scenario. The hiss source and level were constant to boot. The notion then that my brain all of a sudden decided to *increase* its levels when played through a less efficient speaker makes no sense based on any perceptual science I know of. Indeed, if such a factor existed, we would never be able to level match equipment in blind testing because our internal volume would do what it wants. Yet we know this to not be true.

AMIR I'm confused. This thread was started by Frantz. I don't see your comment as a response to my post. Undistorted music may be perceived as less loud than distorted music IME. For example listen to an FM station. The music volume could be fine until it mistunes and startles you. I don't recall saying anything about clipping. Another example would be music form the ice cream truck vs a police siren played at the same level. I would find the siren perception as louder.

 

[fas42]

Frank, it seems that you've made quite a study of audio perception, psychoacoustics and ear/brain interaction. I find the subject very interesting myself. Could you refer me to a source, for example, that talks about apparent volume changing with the quality of sound when the actual sound levels didn't change at all? Specifically, can you refer me to study in which listeners perceived sound with hiss as much "louder" than clean sound? I'm up for a little reading.

Tim

Tim, thanks for putting me on the spot :b! My "understanding" of this area is a combination of my own experiences, deliberating "testing" myself while listening to sound in various situations, and relatively lately, noting various references and more scholarly writings in a number of places over a period of time.

So, did a mad scramble to get something more concrete: in regard to AGC, Automatic Gain, or volume, Control with the ear, there is a lot of material out there, a start could be -- AUTOMATIC GAIN CONTROL IN COCHLEAR MECHANICS: http: www.dicklyon.com/tech/Hearing/AGC_MOH1990-Lyon.pdf

With regard to perceived volume vs. sound quality, a concept that is used is the "roughness" of the sound, gives an excellent impression of what is being focused on, try -- Psychoacoustics Analysis in ArtemiS II: http://www.head-acoustics.de/downloads/eng/application_notes/PsychoacousticAnalysesII_06_11e.pdf
and
The Psychoacoustics of Sound-Quality Evaluation: http://www.zainea.com/fastl.htm

Frank

 

[Steve williams]

that talks about apparent volume changing with the quality of sound when the actual sound levels didn't change at all?

but Frank none of your references as best I can tell address the very question upon which we are all interested as mentioned above

 

[amirm]

AMIR I'm confused. This thread was started by Frantz. I don't see your comment as a response to my post.

The latest discussion started with this comment from Frank regarding psychoacoustics: http://www.whatsbestforum.com/showt...ch-do-we-need...&p=78434&viewfull=1#post78434. Since you used the same phrase, I thought you were backing up his contention.

Undistorted music may be perceived as less loud than distorted music IME. For example listen to an FM station. The music volume could be fine until it mistunes and startles you. I don't recall saying anything about clipping. Another example would be music form the ice cream truck vs a police siren played at the same level. I would find the siren perception as louder.

If I asked you then about the observation regarding FM multipath, would you say it makes FM stations louder or just distorted?

 

[microstrip]

You quoted me. Did you mean to be asking me or Tim?

Apologies, just corrected it. It was addressed to you.