Any player output up to 50Khz signals?

[audiobomber]

The meaning of 24/192kHz or 24/96kHz does not reflect the frequency the file can process up to. I can have a 24/96kHz file that only plays music with a range of 20Hz to 20kHz. What the 96 or 192kHz meant in sampling rate is which how many times your Digital Analog Converter (DAC) or compresser is processing the file per second. If I record a live performance right now, the analog signal is processed and compressed into a digital signal (imagine a smooth curve turned into a multitude of stairs replicating a similar shape). The number of "steps" processed per second is the sampling rate. It has asolutely nothing to do with the audio frequency that you are hearing.

That is not correct. There is a definite correlation between PCM sample rate and frequency, called the Nyquist Theorem. In order for a digital ADC or DAC to correctly reproduce a frequency, the sampling rate must be 2X the frequency. In other words, a device with 44.1kHz sample rate can reproduce any frequency up to 22.05kHz, a device capable of 192kHz sample rate can reproduce any frequency up to 96kHz.

Personally I don't believe that frequencies higher than 20kHz have any effect on a human listener. A tweeter or headphone playing a signal higher than 20kHz is not audible IMO, but the fact that the driver can play this high means it is fast to react, and this may be a benefit in playing audible frequencies cleanly. I do believe that oversampling is beneficial, i.e. transcoding CD quality to a higher frequency, as it allows for a more gradual aliasing filter. I prefer to do this in exact multiples of the original signal to avoid interpolation. For CD (44kHz), I use 2X (88.2kHz), 176.4kHz (4X), or DSD (64X, 128X, etc).

 

[Alvadora]

That is not correct. There is a definite correlation between PCM sample rate and frequency, called the Nyquist Theorem. In order for a digital ADC or DAC to correctly reproduce a frequency, the sampling rate must be 2X the frequency. In other words, a device with 44.1kHz sample rate can reproduce any frequency up to 22.05kHz, a device capable of 192kHz sample rate can reproduce any frequency up to 96kHz.

Personally I don't believe that frequencies higher than 20kHz have any effect on a human listener. A tweeter or headphone playing a signal higher than 20kHz is not audible IMO, but the fact that the driver can play this high means it is fast to react, and this may be a benefit in playing audible frequencies cleanly. I do believe that oversampling is beneficial, i.e. transcoding CD quality to a higher frequency, as it allows for a more gradual aliasing filter. I prefer to do this in exact multiples of the original signal to avoid interpolation. For CD (44kHz), I use 2X (88.2kHz), 176.4kHz (4X), or DSD (64X, 128X, etc).

I definitely agree on that but I think that afreekindazone is misunderstanding the numbers presented in the typical 16 or 24bit-depth along with the sampling rate frequency both of which (96 or 192kHz) is way more than it is needed to provide a good conversion from a digital signal to analog.

 

[audiobomber]

Player specs only write down what frequency files (FLAC, etc) it can process and they do not tell you the output frequencies. Would be nice if people write down those really measuered frequencies at the output. Sorry I am sometimes so in the details.....

As I said above, a DAC will process frequencies up to 1/2 of the sample rate.

Wondering: is it known if there are any amplifier able to process such high frequenties?

Amps don't process, they merely amplify the signal. The frequency range they can amplify is normally stated as the bandwidth. Most can do 50kHz easily, some can amplify signals up to the Megahertz range.

 

[audiobomber]

I definitely agree on that but I think that afreekindazone is misunderstanding the numbers presented in the typical 16 or 24bit-depth along with the sampling rate frequency both of which (96 or 192kHz) is way more than it is needed to provide a good conversion from a digital signal to analog.

Bit depth has nothing to do with frequency response.

Audiophiles have complained that 16 bits is insufficient for audio ever since the advent of CD. Each bit represents 6dB of signal, so 16 bits is 6x16 = 96dB SNR, which seems like it should be enough for listening. DSD is the equivalent of 20 bits in PCM. I believe that the quality of the recording far outweighs the importance of 16 vs. 24 bits or sample rates beyond 44.1kHz.

 

[castleofargh]

I saw this headphone and the specs:
AK T5P generation 2, it's frequency range is from 5 Hz to 50 KHz.

Higher frequenties should have some influence in our brain, as our sub conscious brain processes a lot more than we hear / see, etc.

Player specs only write down what frequency files (FLAC, etc) it can process and they do not tell you the output frequencies. Would be nice if people write down those really measuered frequencies at the output. Sorry I am sometimes so in the details......

Wondering: is it known if there are any amplifier able to process such high frequenties?

to answer your question: when you play a file that has a given sample rate, the actual sound will go up to about half that value(it has to, Nyquist proved that much). so to approach 50kHz, you'd need to start with files at 24/96 and above. then the DAC or amp may also limit the maximum frequency on their own accord(for stability or whatever), but you can find amps with very wide range without much issue. when they put in their specs that the FR is stable +/- a few dB within a frequency range, you can be confident that the amp can at the very least go that high. and such information is often available.

now the caveats:
- headphone specs that mention ludicrous frequencies like 50kHz are usually marketing crap. if you've ever looked at frequency response graphs for headphones, you know that they are not keeping anything flat even in the audible range. so whatever method they use to get that number, it's in no way the same thing as a DAC or amp giving a frequency range and a tight tolerance(maybe +/-1dB or 2 or 3). such specs certify that the device keeps the response within that tolerance in the entire specified range. on the other hand, that 5Hz to 50Khz spec for the headphone, what does it mean? that they got a sound at 50kHz regardless of how rolled off it was? do they stick to a tolerance and if so what is it? you'll notice that headphone manufacturers playing the uber frequency range game usually "forget" to specify anything about what that frequency range actually means.

- humans have human ears(usually). most of the known effects of ultrasounds(skin, eyes, etc) require intensities that we're not getting with headphones(at least if you care for your ears). and beside children, it's relatively rare to have someone actually perceive a 22kHz signal with his ears at reasonable listening level. and forget about 50kHz.

- because humans have mixed/mastered the albums by ears, even if you end up with a fairly loud signal in the ultrasounds on the track, it can be tricky to know if it's music content, what was done to it, how much is just noise and distortions pilling up, etc. so if our playback rig can provide relatively accurate ultrasounds, I'm one to wonder if we should even try, or if we'd actually benefit from filtering all that out ourselves? but that's just me.

 

[Alvadora]

Bit depth has nothing to do with frequency response.

Audiophiles have complained that 16 bits is insufficient for audio ever since the advent of CD. Each bit represents 6dB of signal, so 16 bits is 6x16 = 96dB SNR, which seems like it should be enough for listening. DSD is the equivalent of 20 bits in PCM. I believe that the quality of the recording far outweighs the importance of 16 vs. 24 bits or sample rates beyond 44.1kHz.

I know all this and the differences. You really do not need to tell me. If you bothered to read the earlier messages, I’m just trying to correct afreekindazone’s misconception