PHILIPS RED BOOK

[BentonF]

Ok, I am confused and not suprisingly so. I have read two different arguments but this not being my line of work nor what i was trained in, i'm having some difficulty grasping this being a 'layman'.
My speakers are 8200kilowatts and have a peak SPL of 12oish dB.
The amplifiers Heliox class-D have a S/N ratio rated around this figure too.
The DACs and ADCs onboard are rated at this approximate figure.
A classical concert at say the BArbican or other purpose built venue will have a dynamic range from 0 to 123ish PEAK (as per the table above).
The sound meter in the living room where i listen to music measures ambient noise peaking at 30dB using a meter, does that mean that even with the most carefully recorded and mastered music (i mostly listen to classical), i will not be able to hear the benefits of high res 24/96 because i have a 30dB noise floor to contend with or can i hear the quieter bits of music in a performance below/into this noise floor?

 

[RayDunzl]

My speakers are 8200kilowatts

Wow.

That's 8,199.30kW more than I have. (700W at 4 Ohms)

The sound meter in the living room where i listen to music measures ambient noise peaking at 30dB using a meter, does that mean that even with the most carefully recorded and mastered music (i mostly listen to classical), i will not be able to hear the benefits of high res 24/96 because i have a 30dB noise floor to contend with or can i hear the quieter bits of music in a performance below/into this noise floor?

24 bits gives a theoretical 144dB range. 144dB is jet engine loud. The active flight deck of an aircraft carrier is in that range.

Good luck.

 

[RayDunzl]

A classical concert at say the BArbican or other purpose built venue will have a dynamic range from 0 to 123ish PEAK (as per the table above).

No, not 0dB... It will have a dynamic range from 30~40dBA (background noise level of the players, audience, HVAC, harp pedals, page turning, etc) to 123dB.

Turn it up loud (unbearably loud at the loudest parts) and in the quietest parts you may notice it.

 

[RayDunzl]

A classical concert at say the BArbican

https://www.barbican.org.uk/sites/d... Visitor Management Plan_Revised Dec 2016.pdf

"Garden Room
Amplified music is only permitted up to 95dB (as per our licence agreement with Environmental Health) due to the proximity of residents. A decibel limiting device is installed to ensure all musicians and DJs comply with this regulation. The noise limiter cuts off power to speakers when the sound levels in the room reach 95dB. If the device is activated or “tripped” once, the Centre Manager will be called to reset the device. If the device is tripped a second time the function continues without the use of amplified music"

... still looking

 

[BentonF]

No, not 0dB... It will have a dynamic range from 30~40dBA (background noise level of the players, audience, HVAC, harp pedals, page turning, etc) to 123dB.

Turn it up loud (unbearably loud at the loudest parts) and in the quietest parts you may notice it.

1.
Apologies, I meant 8.2kilowatts not 8200kw. Does a dynamic range reduction from high resolution to RBCD mean that you have to turn the volume up to max to hear the quieter bits or do you also loose both the quietest bit and the loudest bits simultaneously with a reduction in dynamic range?

2.
Amir, forgive me could you summarise what you’re saying please? Are you saying that you agree with the others here that high resolution isn’t of value unless you have a super quiet room and a revealing system but if you’re an average Joe like me with a baseline noise in my living room of 30dB stick with RBCD?

3.
Amir and others, what do you make of this please?

https://xiph.org/~xiphmont/demo/neil-young.html

Versus

 

[RayDunzl]

Does a dynamic range reduction from high resolution to RBCD mean that you have to turn the volume up to max to hear the quieter bits or do you also loose both the quietest bit and the loudest bits simultaneously with a reduction in dynamic range?

If you play a CD, and the "full scale" signal registers 100dB SPL in your room, and then you play the same piece of music from a 24 bit source, you'll still only get 100dB in your room.

To my initial surprise, when I first investigated 24 bit, practically speaking, it seems that the extra 8 MSB bits (48dB) expand the resolution of the smallest sound (one LSB in 16bit becomes divided into 256 parts), instead of expanding the range of the highest level sounds. Maybe it improves the quantization levels in the rest of the range, but that's a tough call as to whether it can be heard or not.

I somehow thought that the extra 8 bits would show up "on top" of the existing 16, instead of just adding detail (so to speak) within the existing range.

 

[RayDunzl]

Here's my room noise level, as best as I can measure it. 3:00PM

The 12oHz is mainly the ceiling fan, on its lowest setting. I only notice it was there if I turn it off. Barely audible, not distracting.

If I overlay one of the Room Noise Recommendations, it seems to fall within the NCB20 range... or at least be within the "good enough" range.

Assuming a comfortably loudish 100dB SPL for peak listening, the noise level of 24bit digital would be at -44dB. 10 of those 24 bits might be wasted in "room noise", if I'm thinking about it correctly. the first 2 or 3 bits of CD would be at the noise threashold.

 

[DonH56]

The "top" is dictated by things like the input sensitivity of your amplifier and is relatively constant at around 1~2 Vrms for consumer components. Providing an output of 256 Vrms is not useful in the real world, so the "extra" bits get added to the "bottom".

That is not how I think of dynamic range but perhaps make sense for the sake of argument?

 

[RayDunzl]

Maybe what I meant to say, I was surprised when 24bit recording had no additional headroom when compared to the similar 16 bit commercial recording.

 

[DonH56]

IME (limited) where the extra headroom matters is in the recording, mixing, and mastering process. In the end 24 bits adds dynamic range but "headroom" is relative to your system and that is driven by consumer levels and what your system can do. If it plays at 100 dB now, will it play at 150 dB or so if you push up from 16 bits to 24 bits? Would you want it to (OK, I wouldn't don't know about anybody else). Just not practical...

Generally recordings will push near (hopefully not beyond) the full-scale limits of the converters to attain the highest dynamic range possible and so with an essentially fixed maximum level the only way to go is to push down. You could drop the average level by e.g. 6 dB and allow 6 dB higher peaks if you add a bit but I am not sure people would understand and accept that they have to turn their volume knob up 6 dB to get the same average volume as before and get that extra 6 dB of upper (louder) dynamic range. And of course then they would need a system that can handle an additional 6 dB (4x the power).

Not sure I am explaining myself clearly...

 

[RayDunzl]

I am not sure people would understand and accept that they have to turn their volume knob up 6 dB to get the same average volume as before and get that extra 6 dB of upper (louder) dynamic range.

I would.

Not sure I am explaining myself clearly...

I get it.

 

[Sal1950]

This talk got me curious as to the lowest noise levels, as I mis-understand the db scale on this.
"In 2015, an anechoic chamber on the campus of Microsoft broke the world record with a measurement of −20.6 dBA"
Look inside Microsoft’s anechoic chamber, officially the quietest place on Earth
https://venturebeat.com/2015/10/01/...amber-officially-the-quietest-place-on-earth/

 

[RayDunzl]

This talk got me curious as to the lowest noise levels, as I mis-understand the db scale on this.

The way I understand it, 0dB SPL represents the sound level at the threshold of what the best human ear can begin to hear, but it isn't the complete absence of vibrations in the air.

Negative dB SPL is just some level of air pressure variation below that level.

 

[Sal1950]

The way I understand it, 0dB SPL represents the sound level at the threshold of what the best human ear can begin to hear,

I finally caught onto the concept, but isn't that purely a guestimation?
How can anyone know the lower limit of the worlds most sensitive human?

 

[Wombat]

I finally caught onto the concept, but isn't that purely a guestimation?
How can anyone know the lower limit of the worlds most sensitive human?

My wife could hear what I was thinking.

 

[fas42]

The complication is that the ear/brain adjusts the dynamic range, depending upon the "quality" of what it's hearing - unfortunately, , the experience of such is always subjective ... always. Obnoxious qualities in the sound, whether reproduction or something live, make it seem louder, but it may have poor apparent dynamic range.

Anyone who gets an audio system to a certain level of competence will note seemingly strange "volume changes", depending upon what the quality is at the moment - the SPLs never ever vary, by the meter; but the apparent volume and/or 'intensity' will alter ... the ear/brain is adjusting, internally. This is why most audio systems never seem real, because the dynamic range adjustments our head is making don't match how our hearing system reacts to live instruments.

 

[DonH56]

Like the loudness curves and 80 Hz subwoofer crossover frequency for localization it is based upon an average of responses from a number of people. Not guesses, but does not mean everyone hits exactly those numbers.

 

[Wombat]

There is a variation around the set norms and then there are hearing disorders:

http://www.hyperacusis.net/what-is-it/4-types-of-sound-sensitivity/

 

[Frank Dernie]

Ok, I am confused and not suprisingly so. I have read two different arguments but this not being my line of work nor what i was trained in, i'm having some difficulty grasping this being a 'layman'.
My speakers are 8200kilowatts and have a peak SPL of 12oish dB.
The amplifiers Heliox class-D have a S/N ratio rated around this figure too.
The DACs and ADCs onboard are rated at this approximate figure.
A classical concert at say the BArbican or other purpose built venue will have a dynamic range from 0 to 123ish PEAK (as per the table above).
The sound meter in the living room where i listen to music measures ambient noise peaking at 30dB using a meter, does that mean that even with the most carefully recorded and mastered music (i mostly listen to classical), i will not be able to hear the benefits of high res 24/96 because i have a 30dB noise floor to contend with or can i hear the quieter bits of music in a performance below/into this noise floor?

IMO the idea that an audio system, for recording or replay, needs a dynamic range of 123dB is moot.
It would only be necessary if you wanted to make a recording of any sound without adjusting the level control, ie record a trickling stream out in the country and then show up at a rock concert with the same recordewr and microphone and wish to record that too without adjusting the input level. Bonkers.
Same listening at home assuming you never touch the volume control, want even the lowest levels on a recording to be audible and are prepared for permanent hearing damage when a loud bit comes along. Equally bonkers in practice.

In reality, if I am recording a trickling stream out in the country, I will be turning up the levels on my recorder and my limiting factor monitoring the levels will be listening for microphone or other noise in the quiet bits, and the dynamic range - from the loudest trickle to the quietest inter-trickle moment will easily be precisely recorded within 16 bits, never mind 24.
Similarly when I bimble out of the country into a rock concert with my trusty recorder and microphone, when the band is warming up I twiddle the level control - probably a long way down and then, when monitoring (theoretically, headphones won't isolate from the racket enough to monitor levels when in the concert itself) I will be making sure I don't clip. Yet again the difference in loudness between to loudest bits of music and the witty between song dialogue will be easily covered by 16 bits of dynamic range, never mind 24.

So in real sound recordings 16 bit is plenty.
24 bit has the theoretical (and pointless IMHO) benefit of recording every sound there is without adjusting volume - but who in the real world would ever think of doing such a thing?

The difference between theory and practice...

 

[Sal1950]

So in real sound recordings 16 bit is plenty.
24 bit has the theoretical (and pointless IMHO) benefit of recording every sound there is without adjusting volume - but who in the real world would ever think of doing such a thing?

The difference between theory and practice..

AMEN