Power draw by frequency: what am I missing?

P

PENG

Audioholic Slumlord
I agree. But Verdinut has asserted that we need to take dynamic range into account when determining peak amp performance. So that question would be at him or someone who supports his assertion.
I don't think he anticipated that you would set a spl level limit. He may be thinking that someone may just set the volume to where they typically do when listening to their favorite CDs and expect to hear the spl level they typically hear. In such cases, it wouldn't hurt for them to allow extra headroom for the occasional encounter with tracks that have very high dynamics and they may want to raise the volume a few notches higher to allow for the quieter passages, such as the opening of the 1812 overture.

So I suspect he may be thinking about something along the line of the Telarc 1812 CD warning in the booklet:

"Warning! The cannons of the Telarc Digital "1812" are recorded at a very high level. Lower levels are recommended for initial playback until a sfe level can be determined for your equipment."

or the general Telarc warning for their digital recordings:

"Telarc Digital CDs, especially those containing substantially wide dynamic range, will present an extraordinary challenge to all stereo systems. Certain components--even the finest--may have problems with the most demanding passages. Damage could result to speakers or other components if the musical program is played back at excessively high levels."

The last sentence is stating the obvious, they seem to want to brag about their CD's substantially wide dynamic range in the name of warning, but I am sure they also gave "sales/$" in mind at the same time.

Someone like yourself can ignore such warning because you are already keen on imposing a limit yourself. Some audiophiles may opt to get another 3 to 6 dB more amplifier headroom than others, thinking that it will give them some safe margin in the event that they forgot to lower the volume by a few notches.
 
P

PENG

Audioholic Slumlord
Let's imagine that the 1-2 octaves in question did consume 30% of the overall power consumption. That would lower the ability of the amp at that moment by, what? 1-2db?
Just for you, I search and found of of the measurements I made, playing the Hobbit's dragon attack at the opening.

It was about 36% difference between large and XO = 80 Hz, at volume -20, Audyssey dynamic EQ off, based on Vpk X I. That's about 1.52 dB. I also measured one of my Patricia Barber's and the difference was more than 50% on track 1 "Code cool".

If someone has a good 110 W AVR and want to add a 150 W power amp we may caution that the difference is less than 2 dB. In that sense, it is not significant, but imo it is significant enough for me to say TLSG's comment (quoted below) seemed a little on the extreme side, or not, but just too general.

So a sub does not actually off load much power from a receiver, very little in fact.
 
Irvrobinson

Irvrobinson

Audioholic Spartan
I don't think he anticipated that you would set a spl level limit. He may be thinking that someone may just set the volume to where they typically do when listening to their favorite CDs and expect to hear the spl level they typically hear. In such cases, it wouldn't hurt for them to allow extra headroom for the occasional encounter with tracks that have very high dynamics and they may want to raise the volume a few notches higher to allow for the quieter passages, such as the opening of the 1812 overture.

So I suspect he may be thinking about something along the line of the Telarc 1812 CD warning in the booklet:

"Warning! The cannons of the Telarc Digital "1812" are recorded at a very high level. Lower levels are recommended for initial playback until a sfe level can be determined for your equipment."

or the general Telarc warning for their digital recordings:

"Telarc Digital CDs, especially those containing substantially wide dynamic range, will present an extraordinary challenge to all stereo systems. Certain components--even the finest--may have problems with the most demanding passages. Damage could result to speakers or other components if the musical program is played back at excessively high levels."

The last sentence is stating the obvious, they seem to want to brag about their CD's substantially wide dynamic range in the name of warning, but I am sure they also gave "sales/$" in mind at the same time.

Someone like yourself can ignore such warning because you are already keen on imposing a limit yourself. Some audiophiles may opt to get another 3 to 6 dB more amplifier headroom than others, thinking that it will give them some safe margin in the event that they forgot to lower the volume by a few notches.
Those warnings on Telarc CDs were originally written in the 1980s when LPs and cassettes were the norm. Telarc also put warnings on their LPs about tracking and dynamic range. Telarc was something of a pioneer in the digital realm, using the old Soundstream 50KHz recording system before most others, which I think made potential digital dynamic range part of their marketing. I always thought it was mostly bravado, but hearsay abounded back then of blown tweeters with the 1812 Overture recording, which led to discussions about amp clipping being the root cause, and other speculative analyses. Besides the 1812 Overture, which is an outlier, Telarc recordings have never struck me as being any more dangerous to drivers than other digital recordings (and I own most of the original Telarc "classic" series catalog, with the exception of the Cincinnati Pops CDs; I own only a few of those).
 
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JerryLove

JerryLove

Audioholic Samurai
First attempt to Google on dynamic range, music genre and frequency spectrum resulted in the following article that @JerryLove and @Verdinut may be interested in reading.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4753356/
That is a cool chart, but it discusses the difference between the average and the peak. Something with a higher average but the same peak will look lower on that chart. Something with a lower average and the same peak will look higher on that chart.

It doesn't really tell you how much power you need for those peaks.
 
JerryLove

JerryLove

Audioholic Samurai
I don't think he anticipated that you would set a spl level limit. He may be thinking that someone may just set the volume to where they typically do when listening to their favorite CDs and expect to hear the spl level they typically hear. In such cases, it wouldn't hurt for them to allow extra headroom for the occasional encounter with tracks that have very high dynamics and they may want to raise the volume a few notches higher to allow for the quieter passages, such as the opening of the 1812 overture.
The "hurt" in this case may be permanent hearing loss.

The last sentence is stating the obvious, they seem to want to brag about their CD's substantially wide dynamic range in the name of warning, but I am sure they also gave "sales/$" in mind at the same time.
Yes. That means that, when you turn up the volume so those quiet bits aren't so quiet, the loud bits will break your ears.

The RedBook dynamic range is fixed. That is to say, it's the same on their CD as on anyone else's. But I suspect they had more low-volume content, which would inspire people to turn up their volume (the opposite of what you've suggested in your first paragraph) meaning that when the peaks did hit, you had them louder than usual.

Someone like yourself can ignore such warning because you are already keen on imposing a limit yourself. Some audiophiles may opt to get another 3 to 6 dB more amplifier headroom than others, thinking that it will give them some safe margin in the event that they forgot to lower the volume by a few notches.
I'm not sure what you are talking about here.

I've asserted that, removing sounds between 40 and 80hz *doesn't* give you 6db of extra power to work with. Do you have some proof that it does?

Why would you suddenly be interested in louder peaks just because the lows are lower?
 
Irvrobinson

Irvrobinson

Audioholic Spartan
The RedBook dynamic range is fixed. That is to say, it's the same on their CD as on anyone else's. But I suspect they had more low-volume content, which would inspire people to turn up their volume (the opposite of what you've suggested in your first paragraph) meaning that when the peaks did hit, you had them louder than usual.
This is the challenge with some CDs, in that they use more of the CD's 96db dynamic range. The Telarc 1812 Overture CD does start out with rather quiet passages as compared to most CDs, even classical ones, to "reserve" (if I may use that term) headroom within the CD's dynamic range for the cannon shots and bells. So, yes, IMO some people were turning up the volume on their initial listening session for this CD, only to find that the loudest passages overloaded one thing or another in their system.

The notion that Telarc CDs (or anyone else's ) are "louder" than competitive CDs is, of course, nonsense. Many pop music CDs are mastered with average loudness in the data words nearly at the CD limit, but their dynamic range is only a few decibels. And this phenomenon leads to the recording industry bullshit story about "inter-sample overs", which is nothing more than lack of overload processing capability in some DACs.
 
P

PENG

Audioholic Slumlord
The "hurt" in this case may be permanent hearing loss.


Yes. That means that, when you turn up the volume so those quiet bits aren't so quiet, the loud bits will break your ears.

The RedBook dynamic range is fixed. That is to say, it's the same on their CD as on anyone else's. But I suspect they had more low-volume content, which would inspire people to turn up their volume (the opposite of what you've suggested in your first paragraph) meaning that when the peaks did hit, you had them louder than usual.


I'm not sure what you are talking about here.

I've asserted that, removing sounds between 40 and 80hz *doesn't* give you 6db of extra power to work with. Do you have some proof that it does?

Why would you suddenly be interested in louder peaks just because the lows are lower?
I like to get as much headroom as I can afford but that's just me being crazy. I have never said anything about removing 40 and 80 Hz would give 6 dB to work with, no idea why you bring that up. I thought we were generally in agreement on the topics discussed. I also agree with irv and Verdinut, the only remarks I disagree with was TLSG's mainly because I thought it seemed like a blanket statement and I might have misunderstood him too.
 
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JerryLove

JerryLove

Audioholic Samurai
I like to get as much headroom as I can afford but that's just me being crazy. I have never said anything about removing 40 and 80 Hz would give 6 dB to work with, no idea why you bring that up. I thought we were generally in agreement on the topics discussed. I also agree with irv and Verdinut, the only remarks I disagree with was TLSG's mainly because I thought it seemed like a blanket statement and I might have misunderstood him too.
When you said "Some audiophiles may opt to get another 3 to 6 dB more amplifier headroom than others "

That seemed to be a reference to "You were referring to the possibility of 30% of the amplifier's power being drawn by the low frequencies on some peaks, but the possibility is close to more than 75% being drawn for the lows in some recordings which represents more than 6dB. "

My apologies for misunderstanding your intent.
 
P

PENG

Audioholic Slumlord
When you said "Some audiophiles may opt to get another 3 to 6 dB more amplifier headroom than others "

That seemed to be a reference to "You were referring to the possibility of 30% of the amplifier's power being drawn by the low frequencies on some peaks, but the possibility is close to more than 75% being drawn for the lows in some recordings which represents more than 6dB. "

My apologies for misunderstanding your intent.
Oh no, it was unrelated. Sorry about the confusion. Again, everything you and irv posted I could have said something similar myself. I still think you might have misunderstood Verdinut's point. Irv's last post help clear the point I, and I suspect Verdinut too, tried to make.

Happy New Year to you all.
 
mtrycrafts

mtrycrafts

Audioholic Slumlord
...

It looks like the 20 dB peak THX requirement for movies would work for music as well. One of my 1812 CD has 18 dB, Symphony fantastic 20 dB. I scanned more than 30 pages and only saw 20 and 21 dB a few times, all orchestral classical. There were some non classical ones with high numbers too.
One question about that THX 20 dB peak. From where? Average sound level that would be 85 dB and 105 db at peak as that is the THX and accepted target for recording audio for movies. I don't think that is the dynamic range amount.
And, even that 85 dB average is loud in homes.
 
mtrycrafts

mtrycrafts

Audioholic Slumlord
...

I agree. But Verdinut has asserted that we need to take dynamic range into account when determining peak amp performance. So that question would be at him or someone who supports his assertion.
Couldn't help myself. ;)
Peak is peak. It only applies if you want that peak well above 105 dB, very low sensitive speaker or a very large space.
More power will not help hearing the soft passages, the low side of DR. :) As per your example, to take advantage of a DR of say 80 and 105 dB peak, you need a room with a noise floor of 25 unless you ride the volume control to hear that signal above the noise floor.
So, as you indicate, power need depends on peak spl desired, speaker sensitivity of the bands you want.
Perhaps my subs are not sensitive enough and needs all that power to feel those cannon blasts that, by the way blew out surrounding windows when Telrac made that recording.
 
P

PENG

Audioholic Slumlord
One question about that THX 20 dB peak. From where? Average sound level that would be 85 dB and 105 db at peak as that is the THX and accepted target for recording audio for movies. I don't think that is the dynamic range amount.
And, even that 85 dB average is loud in homes.
As you stated, the THX 20 dB peak is the headroom required on top of the 85 dB reference level. According to THX:

https://www.thx.com/blog/questions/what-is-the-reference-level/
  • Experience Studio Clarity: THX Certified Receivers reproduce studio Reference Level, 85dB SPL with 20dB of headroom.
Whereas, Dynamic range for music, per Wiki:

https://en.wikipedia.org/wiki/Dynamic_range

Music[edit]
In music, dynamic range is the difference between the quietest and loudest volume of an instrument, part or piece of music.[38] In modern recording, this range is often limited through dynamic range compression, which allows for louder volume, but can make the recording sound less exciting or live.[39]

The term dynamic range may be confusing in music because it has two conflicting definitions, particularly in the understanding of the loudness war phenomenon.[40][41] Dynamic range may refer to micro-dynamics,[42][43][44] related to crest factor,[45][46] whereas the European Broadcasting Union, in EBU3342 Loudness Range, defines dynamic range as the difference between the quietest and loudest volume, a matter of macro-dynamics.[40][41][47][48][49][50]

The dynamic range of music as normally perceived in a concert hall does not exceed 80 dB, and human speech is normally perceived over a range of about 40 dB.[28]:4
 
Verdinut

Verdinut

Audioholic Ninja
Oh no, it was unrelated. Sorry about the confusion. Again, everything you and irv posted I could have said something similar myself. I still think you might have misunderstood Verdinut's point. Irv's last post help clear the point I, and I suspect Verdinut too, tried to make.

Happy New Year to you all.

Happy New Year to you all with a good health which is the most precious asset.
 
lovinthehd

lovinthehd

Audioholic Jedi
Here is a good article on dynamic range of various CD formats (CD, DVD-A, SACD).

Surprisingly, the DVD-A disc has more dynamic range than the SACD! :)

http://sound.whsites.net/cd-sacd-dvda.htm
Love the little bit of wisdom at the end: Anyway, one should not take too much notice of "how many" said this or that. What is important is how things really are, not how many people believe this or that. Deciding truths by voting is seldom a good way. It can only show what people believe. Some peoples' beliefs might of course be right, but too often correct information and relevant listening experiences drowns in common misconceptions, preconceived notions and the media background noise
 
P

PENG

Audioholic Slumlord
That is a cool chart, but it discusses the difference between the average and the peak. Something with a higher average but the same peak will look lower on that chart. Something with a lower average and the same peak will look higher on that chart.

It doesn't really tell you how much power you need for those peaks.
May be not, but I guess we are looking at, and for, different things. If you look at fig.2, the delta dB SPL vs frequency chart does show there are a lot of high spl contents in the low octaves regardless of the genres except speech.
 
mtrycrafts

mtrycrafts

Audioholic Slumlord
As you stated, the THX 20 dB peak is the headroom required on top of the 85 dB reference level. According to THX:

https://www.thx.com/blog/questions/what-is-the-reference-level/
  • Experience Studio Clarity: THX Certified Receivers reproduce studio Reference Level, 85dB SPL with 20dB of headroom.
Whereas, Dynamic range for music, per Wiki:

https://en.wikipedia.org/wiki/Dynamic_range

Music[edit]
In music, dynamic range is the difference between the quietest and loudest volume of an instrument, part or piece of music.[38] In modern recording, this range is often limited through dynamic range compression, which allows for louder volume, but can make the recording sound less exciting or live.[39]

The term dynamic range may be confusing in music because it has two conflicting definitions, particularly in the understanding of the loudness war phenomenon.[40][41] Dynamic range may refer to micro-dynamics,[42][43][44] related to crest factor,[45][46] whereas the European Broadcasting Union, in EBU3342 Loudness Range, defines dynamic range as the difference between the quietest and loudest volume, a matter of macro-dynamics.[40][41][47][48][49][50]

The dynamic range of music as normally perceived in a concert hall does not exceed 80 dB, and human speech is normally perceived over a range of about 40 dB.[28]:4
It's all settled, thanks. :)
 
JerryLove

JerryLove

Audioholic Samurai
May be not, but I guess we are looking at, and for, different things. If you look at fig.2, the delta dB SPL vs frequency chart does show there are a lot of high spl contents in the low octaves regardless of the genres except speech.
Is that what it says?

What I read is that there is a large difference between average and peak. That could mean high peaks, but it could also mean low averages. Perhaps most of the time there's more sound in the dialog range than in the engine-noise range.

It might also be worth noting that the areas you are referring to are between 200Hz and 500Hz.
 
P

PENG

Audioholic Slumlord
Is that what it says?
Of course not, that's wasn't the purpose of the study. I was searching for data (in response to your post about what google query..) that shows low frequency contents of music of different genre, that happens to be one article that contain such data, that's all.

What I read is that there is a large difference between average and peak. That could mean high peaks, but it could also mean low averages. Perhaps most of the time there's more sound in the dialog range than in the engine-noise range.
May be so, but again, I linked that article only because it happens to contain the frequency contents of music of different genre, that should allow us to see what sort of load we can reasonably expect the subwoofer to take from the main speakers with high pass crossover set to 80 Hz and above.

It might also be worth noting that the areas you are referring to are between 200Hz and 500Hz.
No the area I refer to is below 200 Hz. The article does not specify the exact range other than stating the frequency axis scale is in kHz. If you look at the graphs, you can see Fig.1 shows 0 to 10 kHz, it looks like log scale, and the you can clearly see it shows contents well below 200 Hz.

It actually did mention say something above the range below 200 Hz:

"Speech is only locally surpassed by chamber music in the lowest two frequency bands ([110 Hz to 140 Hz]; [140 Hz to 177 Hz]) and by orchestra and opera in the lowest band."

"lowest band" has to refer to below 110 Hz, I would assume, reasonably.

1546524550448.png


1546525620826.png
 
P

PENG

Audioholic Slumlord
What I read is that there is a large difference between average and peak. That could mean high peaks, but it could also mean low averages. Perhaps most of the time there's more sound in the dialog range than in the engine-noise range.
A very interesting point indeed, but I hope that's not what they meant.

Again, in the introduction, it stated:

Dynamic range refers to the level difference between the highest and lowest-level passages of an audio signal. It does not say anything about "averages", and it did not define "passages" of "an audio signal", but I agree with you that it would indicate some sort of averages, though we can't tell the duration and the where about of such "passages". For it to mean something though, for the purpose of their study, I think it is reasonable to assume those passages would be either the whole song (if a song), or a "movement" if it is a symphony, just for examples.

You seem to be looking for data to provide hints of power requirements whereas I am more interested in the low frequency contents below 80-120 Hz in different music genres. The two are obviously related but not the same.
 
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