Using all that CD has to offer?, What types of music and specific discs use the full bits and freq. Options

[BearcatSandor]

(i'm probably oversimplifying this in my ignorance about it)

Dynamic range of analogue vs digital cannot be compared so easily either - the former can provide subjectively useable dynamic range which exceeds that of its digital equivalent, because it 'fails gracefully' above its rated maximum range, continuing to capture information which, in the digital domain, would have simply been truncated (resulting in a clipped waveform).

You're looking at the wrong end. Where is the noise floor? As a delivery format 16 bits is sufficient in storing this information. With the vast majority of the music out there and especially from the artists referenced in this discussion this can be done with fewer than 16 bits.

This got me wondering what styles of music generally do use the full bandwidth and bit-width available on CDs? The bits provide the dynamic range, yes? So classical would be more likely to take advantage of all 16 bits than rock recordings? What about frequency response? What types of music are likely to span that 18.5hz - 22.5khz range? Electronic? Classical again?

Anyone have an specific discs that utilize all the bandwidth and bits that CD has to offer?

As an aside, i do remember reading a subwoofer shootout in some magazine where they measured some CDs as going down to 16hz. Doesn't that go below the limits of CDs? Were they probably just listening to reflections?

Thanks

[pdq]

AFAIK there is no lower limit to frequencies allowed to be encoded in CD. The digital data can even have a DC offset, which is zero frequency.

[dhromed]

Lots of electronic music trivially uses the entire range. Do you need specific examples of tracks?

[Brand]

This got me wondering what styles of music generally do use the full bandwidth and bit-width available on CDs? The bits provide the dynamic range, yes? So classical would be more likely to take advantage of all 16 bits than rock recordings?

Yes, I'd say classical/opera music, ideally synthetic (computer made), so that you don't have noise at the bottom. Some music that is very quiet and then gradually (so that your ears don't get shocked) escalates to the loudest part, which perhaps also includes an inaudible (low freq) peak, just to steal some more dB. Something like that could perhaps stress the dynamic range to the point of 16bit being audibly worse/different than 24bit.
Of course, IRL such music might not exist and peaks get compressed during production.

What about frequency response? What types of music are likely to span that 18.5hz - 22.5khz range? Electronic? Classical again?

Well, that depends on the specific instruments/sounds used.. could be any genre, really. If you were to intentionally stress test high freqs, it would be the easiest to do it with synthetic sounds.

[knutinh]

Q: What music use all of the bits that CD has to offer?
A: All music use all bits, they are either set to zero or one.

Q: What music use all of the frequency range that CD has to offer?
A: Any music/recording where the instrument output HF energy, high bandwidth microphones are used etc.

Q: What music is most critical for revealing the limitations of the CD format (or closest to doing so)?
A: Now that is a more interesting question. I would stay away from most genres that could be heard on commercial radio.

-k

[db1989]

Q: What music use all of the bits that CD has to offer?
A: All music use all bits, they are either set to zero or one.

Good literal answer, but of course bits in this case means bits’ worth of dynamic range.

[Arnold B. Kruege...]

Dynamic range of analogue vs digital cannot be compared so easily either - the former can provide subjectively useable dynamic range which exceeds that of its digital equivalent, because it 'fails gracefully' above its rated maximum range, continuing to capture information which, in the digital domain, would have simply been truncated (resulting in a clipped waveform).

As seems to be his habit, Jamie has just made a technically incorrect statement. Digital and analog can be compared quite easily. Anything that has been done with soft clipping and perceptually-shaped noise floors in the analog domain can and has been done digitally.

You're looking at the wrong end. Where is the noise floor? As a delivery format 16 bits is sufficient in storing this information. With the vast majority of the music out there and especially from the artists referenced in this discussion this can be done with fewer than 16 bits.

I think that Gerynol is being gentle. 16 bits is overkill, and so is the 22 KHz bandwidth. The actual dynamic range of recordings is generally limited to about 14 bits, unshaped. And approximately 16 KHz bandwidth generally suffices.

This got me wondering what styles of music generally do use the full bandwidth and bit-width available on CDs? The bits provide the dynamic range, yes? So classical would be more likely to take advantage of all 16 bits than rock recordings? What about frequency response? What types of music are likely to span that 18.5hz - 22.5khz range? Electronic? Classical again?

Anyone have an specific discs that utilize all the bandwidth and bits that CD has to offer?

Per the above, very few such discs, if any exist. The analog source (e.g. the microphones, the room, the instruments, etc.) and/or the analog receiver (i.e. the loudspeakers, the ears) generally under perform the CD format.

As an aside, i do remember reading a subwoofer shootout in some magazine where they measured some CDs as going down to 16hz. Doesn't that go below the limits of CDs? Were they probably just listening to reflections?

As others have correctly pointed out, digital recordings have no perceptually significant limitations in the bass range. The actual inherent LF limit is related to the inverse of the length of the recording. For example, a 1 minute long digital recording has an inherent low frequency limit that is on the order of a wave whose period is one minute.

[pdq]

As an aside, does anyone know the lowest frequency that will be encoded in an mp3? Is that a codec limit or is it implementation dependent?

Edit: I need to know because I will be encoding elephant infrasonic calls.

This post has been edited by pdq: Jun 8 2012, 13:54

[pawelq]

AFAIK there is no lower limit to frequencies allowed to be encoded in CD. The digital data can even have a DC offset, which is zero frequency.

Looking at it in a different way, the maximum length of a CD is 80 minutes, which is 4800 seconds, so you might say that the lower limit of frequency is 1/4800 Hz, which is about 0.00021 Hz



EDIT. I missed that Arnold just said the same thing.

This post has been edited by pawelq: Jun 8 2012, 14:06

[dhromed]

a 1 minute long digital recording has an inherent low frequency limit that is on the order of a wave whose period is one minute.

My math is continually out of shape, but that would be ~0.016Hz, am I correct? Yes.

This post has been edited by dhromed: Jun 8 2012, 14:25

[greynol]

Why aren't we also considering the limitations of the human auditory system?

Concerns about frequency response immediately go right out the window, at least for most adults. Masking pretty well covers the rest.

I believe cases have been made about bit depth dealing with minimum possible noise floor at atmospheric pressure and how the ear responds to increasing loudness.

[Arnold B. Kruege...]

Why aren't we also considering the limitations of the human auditory system?

Concerns about frequency response immediately go right out the window, at least for most adults. Masking pretty well covers the rest.

I believe cases have been made about bit depth dealing with minimum possible noise floor at atmospheric pressure and how the ear responds to increasing loudness.

The threshold of hearing around 4 KHz is about the same as the noise created by Brownian motion of air molecules according to JJ.

But this is very optimistic because the limit to the dynamic range of real world recordings comes from someplace else and is orders of magnitude larger.

This post has been edited by Arnold B. Krueger: Jun 8 2012, 15:27

[Arnold B. Kruege...]

As an aside, does anyone know the lowest frequency that will be encoded in an mp3? Is that a codec limit or is it implementation dependent?

Edit: I need to know because I will be encoding elephant infrasonic calls.

That's going to depend on the encoder designer. If they are inaudible then he should have made them go away. ;-)

[greynol]

Depends on the source material. Some genres fare better than others. My post that started this topic was primarly (solely?) concerned about 44/16 as a delivery format. This isn't to say that this discussion should be contrained to that; afterall, I did mention masking.

Rather, I think the point remains: what audio reveals 44/16 as insufficient in a double-blind test? If something is identified, does it matter to you (read: are you interested in listening to it for pleasure more than once)?

[Arnold B. Kruege...]

Rather, I think the point remains: what audio reveals 44/16 as insufficient in a double-blind test?

I think that our guest has had numerous invitations to step up to that challenge. Have I missed any relevant replies from him on that subject? ;-)

[greynol]

Let's not make this discussion about any particular individual.

[DonP]

As an aside, does anyone know the lowest frequency that will be encoded in an mp3? Is that a codec limit or is it implementation dependent?

Edit: I need to know because I will be encoding elephant infrasonic calls.

That's going to depend on the encoder designer. If they are inaudible then he should have made them go away. ;-)

There isn't so much to be gained by ditching the infrasonic as at the high end, since it's only 20 Hz.
BUT remember that lossy encoders are generally working on an assumption of normal human hearing. Even if the source material is entirely within 20 Hz-20Khz, an mp3 encoding may sound strange to animals with significantly different hearing parameters.

By the same token, we can see a full spectrum of color represented by a mix of the primary colors red, green, and blue, because they match the 3 different color receptors (cones) in our eyes. Birds and insects generally have more different cones so a smooth color image for us would look posterized to them.

[DonP]

Rather, I think the point remains: what audio reveals 44/16 as insufficient in a double-blind test? If something is identified, does it matter to you (read: are you interested in listening to it for pleasure more than once)?

The first post wasn't suggesting that 44/16 was inadequate. It asked what CD/music comes closest to fully utilizing it. (implicitly, in a way that matters)


The closest I have for dynamic range is a taiko drum track (Monochrome from Best of Kodo) with a long crescendo going from very light finger taps (-70 dB peak) to full out wailing (near 0 dB). The first time I played it, I though the CD had ended because a PC running in the room drowned out the first minute or so.

[greynol]

It was in direct reply to the following:

But this is very optimistic because the limit to the dynamic range of real world recordings comes from someplace else and is orders of magnitude larger.

You're right though, the OP doesn't assume any genres are inadequate.

With Arny's and your points in mind genres that make use of synthesized samples are going to make greater use of the available dynamic range, though the case can be made that one can increase the dynamic range of natural sounds through DSP.

I can't think of any single genre that can't exceed 22kHz, though.

This post has been edited by greynol: Jun 8 2012, 19:47

[naturfreak]

AFAIK there is no lower limit to frequencies allowed to be encoded in CD. The digital data can even have a DC offset, which is zero frequency.

The Red Book Standard specifies a flat frequency response from 20 to 20000 Hz.
But I guess that the most amplifiers in the signal chain (microphones, mixing consoles...) are not DC-coupled. So there is in fact a lower frequency limit in real recording and audio material on audio-CD.

The threshold of hearing around 4 KHz is about the same as the noise created by Brownian motion of air molecules according to JJ.

According to that source, the sound level auf the Brownian noise caused by the motion of air colecules is at -23 dB of human hearing threshold level.

[knutinh]

For example, a 1 minute long digital recording has an inherent low frequency limit that is on the order of a wave whose period is one minute.

What is the lower frequency limit of a 1-minute-long positive-only pulse? No matter how long you zero-pad it prior to DFT, the 0-th coefficient should be >0?

-k

[BearcatSandor]

I think i might be confusing two things: the intended auditory freq. range and the freq range that the CD can produce that can be measured via equipment.. I have read (somewhere a long time ago) that the reason 44.1 was picked was because that gave you a frequency range of 44.1/2 on either side of the middle. That means up to 22.1lkhz and down to 18.1hz, and there are some people that can hear that range. If a CD (and the system it's playing on) can reproduce frequencies lower than you can hear, you can still appreciate it tactically in some cases which would still mean that the lower frequencies are of value to a listener, though i'd imagine you'd have to turn the system volume up quite a bit.

i was responding to someone saying that most music doesn't cover the dynamic and freq. range of a 16/44.1 let alone 24/96k so i was wondering what music did. It was well answered.

I'll have to check out that Kodo disk. I saw them play live once and that was an awesome experience.

[stephan_g]

I think i might be confusing two things: the intended auditory freq. range and the freq range that the CD can produce that can be measured via equipment.. I have read (somewhere a long time ago) that the reason 44.1 was picked was because that gave you a frequency range of 44.1/2 on either side of the middle. That means up to 22.1lkhz and down to 18.1hz, and there are some people that can hear that range.

Errr... no.

That would be -22.05 to +22.05 kHz, if anything. As mentioned, 0 Hz is neatly included within this range.

(Explaining the concept of negative frequencies would get a little complex (pardon the pun). It has to do with the representation of sine and cosine with complex exponentials.)

I'll have to check out that Kodo disk. I saw them play live once and that was an awesome experience.

For another example, Ravel's Bolero is a classical piece notorious for its dynamic range. That's about 50 dB in the recording I'm looking at here. Very hard to listen to without adjusting the volume at least once, even in quiet surroundings. There still is plenty of detail in the quietest parts that you'll normally miss. And that's on an early-'80s digital recording in this case.

This post has been edited by stephan_g: Jun 9 2012, 00:31

[greynol]

i was responding to someone saying that most music doesn't cover the dynamic and freq. range of a 16/44.1 let alone 24/96k so i was wondering what music did. It was well answered.

If that someone was I (the author of the post you quoted), then you need to go back and look it over again.

FWIW, hearing pure tones between 18.1 kHz and 2X.XX kHz and being able to demonstrate that you can tell that 18kHz and up has been removed from music are two completely different things.

Have a go with the "mustang" clips:
http://web.archive.org/web/20110611011454/...et/samples.html

This post has been edited by greynol: Jun 9 2012, 00:37

[Arnold B. Kruege...]

I think i might be confusing two things: the intended auditory freq. range and the freq range that the CD can produce that can be measured via equipment.. I have read (somewhere a long time ago) that the reason 44.1 was picked was because that gave you a frequency range of 44.1/2 on either side of the middle. That means up to 22.1lkhz and down to 18.1hz, and there are some people that can hear that range. If a CD (and the system it's playing on) can reproduce frequencies lower than you can hear, you can still appreciate it tactically in some cases which would still mean that the lower frequencies are of value to a listener, though i'd imagine you'd have to turn the system volume up quite a bit.

i was responding to someone saying that most music doesn't cover the dynamic and freq. range of a 16/44.1 let alone 24/96k so i was wondering what music did. It was well answered.

I'll have to check out that Kodo disk. I saw them play live once and that was an awesome experience.

There is simply no doubt that the CD format can handle frequencies far lower than 18.1 Hz.