Hi resolution audio and extended treble response!

[Frank Dernie]

So that means half of our speakers cannot theoretically produce hi res ! When I look at the response of many of them, many stops or have a steep roll off after 20khz! So those according to Sonys logic are not hi res capable !

It is certainly the case that pretty well none of the speakers on sale can reproduce the bandwidth of “high res” even if we could hear it, and a music distributor would be totally bonkers to make available a recording with even the full 16-bit dynamic range, never mind more since 99.99% of people who listen to music for enjoyment neither have a system which could reproduce it nor a room in which it could be enjoyed or headphones which wouldn’t damage their hearing.

The one thing important to note in terms of 2 samples being enough to accurately code the waveform, this applies to a frequency limited signal. So sampling at 44.1 kHz theoretically accurately codes everything up to 22.05kHz but only if the signal is filtered such that there isn’t anything at a higher frequency than that, if the frequency being sampled has not been filtered the theorem is not valid.

I guess that is why 44.1 is OK it leaves margin for real world filters without encroaching on 20kHz.

 

[Piere]

I don't know the context of that Sony picture but high resolution is not a matter of sample rate alone, but also bit depth and noise floor. And what when that surface is dusty with various kinds of distortion. Oversampling at higher sample rates is mainly done to implement properly anti-aliasing filters at and above 20 kHz. IMHO there is not something such as "Theoretical High-Res".

 

[dogmamann]

It is the first one (But up to a bit below half the sample rate - so around 90Khz for the 192kHz sample rate). But - Hi Res means delivering frequencies higher than the human ear can hear. It is basically pointless.

the name is what confuses me; ”resolution”!!
Instead they could have called it, extended response or something like that!

 

[Blumlein 88]

the name is what confuses me; ”resolution”!!
Instead they could have called it, extended response or something like that!

Exactly! Hi-res is about marketing. The idea more samples per time and extended response meant deeper details for us to hear. What is true is that higher sample rates have more extended frequency response, and that is it. Unfortunately various wrong-headed myths about what is wrong with CD and how to fix it go back more than 30 years. So people offer these other things like 24 bit, DSD, 192 khz and more promising what by design none of it can deliver.

The resolution bit was one of those bad analogies. Resolution like in pictures like in megapixels. Yet there is not a correct version of that in audio. If there is one, the closest would be bit depth. And at least upon the playback end, 16 bit is more than enough.

 

[DavidMcRoy]

My ears are not "hi res" capable.

My first point about my experience with equipment and files carrying the HiRes Audio sticker: I've jumped through the hoops required to get the 24/96 and higher figures to show up on the front panel display of some DACs, but I'm pretty sure my ears have never been exposed to program content with frequencies significantly higher than about 20kHz due to limitations in my speakers, headphones and IEMs. Beyond that, I'm reasonably certain that I can't even hear 20kHz anymore.

Second, where is the content (files) with a frequency response which exceeds 20kHz, if that is what is required? The vast majority of content appears to have been sourced from lesser recordings.

Third, it is my understanding that increasing sampling rates extends the bandwidth of the frequencies of interests, but does nothing to improve the reconstruction of any of the frequencies below half the sampling frequency.

Now, even assuming I can find a "genuine" HiRes file, play it on a DAC, amplifier and speakers with ultra-audible frequency response, what is the math that predicts that my brain "might" be able to discern some difference, let alone improvement in the sound? Could a younger listener with better high frequency hearing than I, yet still limited to 20kHz hear a difference? Is there something to do with "micro dynamics" or some such regarding dynamic range or "dynamics resolution" that's at play here intrinsic to the sampling rates and bit depths used?

Color me confused. I'm not in a position to deny benefits exist to at least some listeners, I just don't understand how it's possible. Indeed, some individuals do seem to be able to detect at least some "difference" in a statistically significant way, Amir coming to mind.

 

[antcollinet]

My first point about my experience with equipment and files carrying the HiRes Audio sticker: I've jumped through the hoops required to get the 24/96 and higher figures to show up on the front panel display of some DACs, but I'm pretty sure my ears have never been exposed to program content with frequencies significantly higher than about 20kHz due to limitations in my speakers, headphones and IEMs. Beyond that, I'm reasonably certain that I can't even hear 20kHz anymore.

Second, where is the content (files) with a frequency response which exceeds 20kHz, if that is what is required? The vast majority of content appears to have been sourced from lesser recordings.

Third, it is my understanding that increasing sampling rates extends the bandwidth of the frequencies of interests, but does nothing to improve the reconstruction of any of the frequencies below half the sampling frequency.

Now, even assuming I can find a "genuine" HiRes file, play it on a DAC, amplifier and speakers with ultra-audible frequency response, what is the math that predicts that my brain "might" be able to discern some difference, let alone improvement in the sound? Could a younger listener with better high frequency hearing than I, yet still limited to 20kHz hear a difference? Is there something to do with "micro dynamics" or some such regarding dynamic range or "dynamics resolution" that's at play here intrinsic to the sampling rates and bit depths used?

Color me confused. I'm not in a position to deny benefits exist to at least some listeners, I just don't understand how it's possible. Indeed, some individuals do seem to be able to detect at least some "difference" in a statistically significant way, Amir coming to mind.

Amir was able to detect the noise floor of 16 bit audio by significantly turning up the volume in a silent part (or fade out part) of the music listened to. In other words, by playing a bit of a trick. This had nothing to do with increased sample rates, and had he left the volume at that level for the normal music, he'd probably have damaged his hearing - so while he was technically able to detect the difference between 16 bits and a higher bit depth - it was an unrealistic scenario for real music listening.

When I asked, he stated even this would not be possible with just a couple of bits more (say 18-20 bits)

All your doubts are founded. There is no evidence that frequency content reaching the ears above the level those ears can detect have any effect on the perception of music. No-one has been able to prove in a blinded test of any sort, that ultra sonic sound is in any way detectable by the listener.

It makes sense - the way the ear works, it is the ear limiting the freqencies we can hear. Signals outside our audio bandwidth are simply not sent to the brain - there is nothing to detect.

 

[Mnyb]

Funny that the marketing focus around sample rate when bit depth is actually within our hearing ability ,at least theoretically ? In practice not so much , but the noise floor is there.
But there is literally no hearing of ultrasonic for us .

it can even be worse it can theoretically modulate in our tweeters , some do extend a bit above 20k say 25-30k with a nasty resonance somewhere >>20k .
Or interact with output transformers of tube amps ? possibly ? Or other untested effects of ultrasonic input into our amplification chain .
Seems reasonable with some slow filter above 20-30k for all content ?

Also there are some confusion about some hires content that might contain the ultrasonic noiseshaping noise from DSD processes either from faulty conversion to 24/192 or software flaws in the playback chain. This would be filtered by a normal SACD player ,the standard for SACD specifies some filtering of ultrasound thats not always implemented correctly .

In general i think DC and ultrasound should be removed by our playback equipment . All kinds off mistakes are possible there are CD's with DC offset . And there are rarely bats or dogs in the studio to monitor the ultrasound and help the producers I've always wondered how to mix and produce stuff you cant hear ? You need a dog assistant I think ?

Edit. I speculate sometimes the problems hirez may cause can make it audible ? But different is always better for the audiophile

 

[antcollinet]

And there are rarely bats or dogs in the studio to monitor the ultrasound and help the producers I've always wondered how to mix and produce stuff you cant hear ? You need a dog assistant I think ?

That is an excellent point I hadn't thought of until now.

 

[dogmamann]

That is an excellent point I hadn't thought of until now.

As per the claim, when higher resolution is enabled it improves soundstage depth and imaging. May be they looked upon that overal perceived quality. I don’t know if any of these are right as I cannot make out a valid difference. Somehow the hi res sounds tad smoother but I won’t underestimate the placebo here.

 

[antcollinet]

As per the claim, when higher resolution is enabled it improves soundstage depth and imaging. May be they looked upon that overal perceived quality. I don’t know if any of these are right as I cannot make out a valid difference. Somehow the hi res sounds tad smoother but I won’t underestimate the placebo here.

The claim remains just that (and a pretty dubious one at that) until someone, somewhere provides valid evidence that supports it. So far, no-one has.

 

[AnalogSteph]

I am still slightly amused by the fact that 24/44 counts as "Ultra HD" in Amazon Music land. In light of our human limits as discussed above, that's actually not very far off...

 

[AdamG]

A follow on question. Does it make sense that by sending inaudible content to our speakers, and assuming that our speaker tweeters and our amplification are capable of reproducing this sound (only Bats and Dogs can hear). That we could be doing several unintentional things to our speakers transducers and amplifiers.

1. Causing them to work harder and experience additional wear and tear on content we can not hear or enjoy ?
2. Placing additional audio load on the tweeters and amplifiers that could be reducing the transducers/Amps ability, even if in a minuscule amount, to fully reproduce content we can hear? To reduce its dynamic range and capacity ?
3. Causing the transducer/Amp to work trying to reproduce, again sounds we can not hear, but enough activity as to cause a heat load on the transducer/Amp ? Resulting in increased cumulative heat operational environment ? For no benefit.
4. Is it therefore possible, that playing content that contains sound above human hearing capabilities we are wasting electrical energy, accelerating heat load related degradation, which will eventually leads to early failure mode of the tweeter and/or the Amplifier ?

What other possible negative or unwanted effects could be caused by this inaudible sound ?

 

[HarmonicTHD]

A follow on question. Does it make sense that by sending inaudible content to our speakers, and assuming that our speaker tweeters and our amplification are capable of reproducing this sound (only Bats and Dogs can hear). That we could be doing several unintentional things to our speakers transducers and amplifiers.

1. Causing them to work harder and experience additional wear and tear on content we can not hear or enjoy ?
2. Placing additional audio load on the tweeters and amplifiers that could be reducing the transducers/Amps ability, even if in a minuscule amount, to fully reproduce content we can hear? To reduce its dynamic range and capacity ?
3. Causing the transducer/Amp to work trying to reproduce, again sounds we can not hear, but enough activity as to cause a heat load on the transducer/Amp ? Resulting in increased cumulative heat operational environment ? For no benefit.
4. Is it therefore possible, that playing content that contains sound above human hearing capabilities we are wasting electrical energy, accelerating heat load related degradation, which will eventually leads to early failure mode of the tweeter and/or the Amplifier ?

What other possible negative or unwanted effects could be caused by this inaudible sound ?

I am not an expert here so please correct me. To your question: assuming it would, wouldn’t it show up in the Klippel tests eg compression tests here from Erin KEF Ref 1? Or does Klippel send a perfect signal which ends exactly at 20kHz?
And yet the Ref 1 is perfect at 20kHz at 102dB SPL. Plus Music has rarely that much power at 20kHz (provided the amp does not clip, but that is a different problem).

 

[Blumlein 88]

The range of bat hearing is 20khz on the low end and 200 khz on the high end. One decade instead of 3 decades like us humans.

So bat speakers from high end makers might have a huge 1/2inch (13 mm) woofer.

 

[AdamG]

Klippel tests eg compression tests here from Erin KEF Ref 1? Or does Klippel send a perfect signal which ends exactly at 20kHz?

Iirc, it does show up and typically because we know humans can’t hear this frequency of sound the data is mostly disregarded. In the Audibility context anyway.

 

[AdamG]

The range of bat hearing is 20khz on the low end and 200 khz on the high end. One decade instead of 3 decades like us humans.

So bat speakers from high end makers might have a huge 1/2inch (13 mm) woofer.

Now you have me wondering what kind of Speaker the Batman prefers?

 

[kemmler3D]

The takeaway here is that "hi res" tends to be more of a marketing term than a technical one.

In general, it's used any time either sampling rate or bit depth is higher than 44.1/16.

The marketing implication is that there is "more" to the sound, either in detail, frequency extension, etc. The truth is, be that as it may, you will basically never hear a difference.

 

[kemmler3D]

, when higher resolution is enabled it improves soundstage depth and imaging.

That's basically a fictional claim.

Is it therefore possible, that playing content that contains sound above human hearing capabilities we are wasting electrical energy, accelerating heat load related degradation, which will eventually leads to early failure mode of the tweeter and/or the Amplifier ?

The higher in frequency you go, the less power needed to reproduce the signal, so ultrasonic content will tend to use very very low wattage if it's there at all. In theory it can cause intermodulation or other undesirable effects, but burning up the amp or tweeter is a minor concern at most.

 

[HarmonicTHD]

Iirc, it does show up and typically because we know humans can’t hear this frequency of sound the data is mostly disregarded. In the Audibility context anyway.

Where does it show in the Klippel test? Please I am genuinely curious.

I didn’t see it in the compression test at least the non linearity is probably less than 0.1dB at 20kHz.

I also had a look at distortion at 96db SPL. Yes distortion increases but the chart only goes to 10KHz. And probably still at non audible levels considering also MunsonFletcher.

Thanks. Appreciate it.

Full results here. Just serving as an example. Pick any other speaker if needed.

KEF Reference 1 META Bookshelf Speaker Review by Erin's Audio Corner

Parting / Random Thoughts (of Erin) As stated in the Foreword, this written review is purposely a cliff’s notes version. No order; just some random notes from my listening. For details about the performance (objectively and subjectively) please watch the YouTube video. But a few notes: All...

www.audiosciencereview.com

And sure. I for sure can not hear 20k anymore, so overall I think it is a non starter.

 

[HarmonicTHD]

Now you have me wondering what kind of Speaker the Batman prefers?

Probably Medical Ultrasonic Transducer ;-). You can also use it to check your kidney stones ;-)