Parametric eq over 20kHz

Hi,
Hope you are all well and keeping safe.

On the parametric equalizer, in the DSP section, I would like to have the ability to see the spectrum from 0 up to 100KHz. Many of us have speakers that range above the 20kHz and we may want to apply changes in this area of the spectrum.
Many thanks
Filipe De Melo Cunha

While it is possible that your speakers can output something above 20kHz, it is extremely unlikely that you (or a typical microphone) can hear it. Does not seem that the benefits are worth the effort to implement it. (How old are you, btw?)

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Kal,

I appreciate your comment…you could have said he is wasting his time! Which he is…

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Due to the Nyquist frequency of human hearing the typical wave file of 44.1 is considered to be lossless and containing everything the human is capable of hearing, maxing out at 20 khz and then an extra 2.05 to act as an ultrasonic noise filter in the digital domain to remove artifacts in the audible band.

So unless you are playing 88,96, 176, 192 or higher khz bitrate tracks, the DAC itself will only be replicating frequencies between 1hz and 20khz with potential electrical circuit coloration variation.

Even with higher bit rate tracks which have ultrasonic information that is not noise, you cannot hear that information nor feel it… So if you are trying facilitate audio laboratory testing conditions and have speakers, like my genelecs which go to 36khz, you would need to have parametric EQ affect the ultrasonic band - but the effects at which point would be more of noise shaping which would actually distort the audible band since Roon itself as far as i am aware would not properly dither any of the ultrasonic information through it’s processing domain where the EQ takes place.

In other and not so many words, what you are looking for is futile - and if you are a lab seeking test settings, you shouldn’t be using roon.

Hi All,

Think in HIFI the saying sais, to be has true to the source has it can be.

Weather or not hearing music after 20kHz, the fact is that many analogue sources don’t have a top end limitation at 20kHz, and may play above that. On the the digital domain, I would think this limitation would be related with the data acquisition points being set to a minimum frequency of 44kHz (2x22KHz) for a CD type recording.

Higher aquisitions rates will:

  1. add more information with in the audible band
  2. increase the top end limitation above 20kHz

I understand may HD files are not native HD, therefore may not have information after 20KHz, and we could debate pros and cons on that and not go anywhere.

I am not saying it is an easy task to do, but if the recording has material after 20kHz, Roon should be outputting that information to the Roon endpoint., and the Roon endpoint should be able to pass that to the DAC. If I them decide to apply a low pass filter (ex: at 20KHz) that would be up to me/user to decide.

Please increase the frequency response of Roon and on the DSP. Many high end amplifiers/speakers are able to play well above 20kHz.

Many thanks

Filipe de Melo Cunha

That is incorrect. Increasing sampling rate only captures higher frequencies. A rate of 44.1kHz fully captures everything under 20kHz.

The “frequency response of Roon” is already whatever is in the digital signal including the extended bandwidth with higher sampling rates. You can effectively low-pass them with downsampling, if you wish.

Hey Kal,

You completely mis-addressed your reply…you meant to address Filipe Cunha, but you replied to me. It seems many people here do not understand audio response frequencies versus resolution…

Hi all,

The media (CDs, file being played, SACD CD, etc…) will have a variable frequency response and is dependent on a lot of factores (like: instruments, vocals, mastering, recoding location etc…). has many of you said before Humans can hear from 20Hz till 20kHz, but the fact is many HiFi systems can reproduce sounds above this range. If we look a at frequency response of a SACD or a native High Res Audio file we can see that there is material (music/sound) above 20KHz.

This extra information (Higer than 20KHz) is commonly known to bring the airiness and environment aspect of the recording.

Given that the HIFI systems can reproduce above 20KHz and In my view the DSP Should also not be limited to 20KHz other wise you can’t manage the frequencies at does ranges.

Many thanks

Filipe

Not if one cannot hear it. very few can.

Not ‘commonly’ in practice. Mixing desk PEQ controls to boost ‘air’ work from 8-14kHz. If there was anything to boost they would be designed to go a lot higher.

In what way do you want to “manage” the frequencies that you cannot possibly hear anyway?
How would this enhance your listening experience?

If I may be so bold as to introduce this paper: There's life above 20 kilohertz! A survey of musical instrument spectra to 102.4 kHz

There is, in fact, musical energy above 20kHz… And all musical energy interacts with the human body in the room as well as the other musical energy in the common human audio range… More to this than meets the ear/brain…

Could it be that “feeling” of more air is just that, a feeling…

Oohashi and his colleagues recorded gamelan to a bandwidth of 60 kHz, and played back the recording to listeners through a speaker system with an extra tweeter for the range above 26 kHz. This tweeter was driven by its own amplifier, and the 26 kHz electronic crossover before the amplifier used steep filters. The experimenters found that the listeners’ EEGs and their subjective ratings of the sound quality were affected by whether this “ultra-tweeter” was on or off, even though the listeners explicitly denied that the reproduced sound was affected by the ultra-tweeter, and also denied, when presented with the ultrasonics alone, that any sound at all was being played.

Interesting.

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I’m not sure exactly how high frequencies interact with the body, considering that the acoustic impedance of the body is orders of magnitude higher than that of the air, causing most of the energy to be reflected back into the air. It may have a massaging effect, although I doubt it is strong enough.

Quite a strange study. The next time I’m subjected to a recording of brass instruments at 113dB I’ll think about what it is I’m missing out on; the health of my hearing probably!
Air attenuates high frequencies with distance much more so than lower audible frequencies.

I certainly wasn’t questioning the presence of musical frequencies > 20Khz and I’m open to the notion that they create some feeling of air for those blessed with hearing that extends to 20k but (to the point of the OP) to be able to “EQ” it?

btw, "At the request of people involved in standards-setting for audio, who wanted this information made available as soon as possible, I published this original paper here, rather than in a professional journal."

Does this mean it’s not a proper peer reviewed scientific paper then?

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Oohashi’s papers are not universally respected. FWIW.

My dog likes this idea

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Can your dog hear a microwave? Stick his head in there and see what he thinks… Seriously… What of the other direction, less than 20Hz… Can not here that either and what about the effects of sound on the human body down low… Seems the same issues… How do you measure and how do you quantify the effects… Really, Maxwell suggests that its all about wavelengths… You can see sunlight and you can feel the sun on your skin… You can hear approximately 20Hz to 20kHz… Do you really think that you can not sense, not necessarily with your ears, beyond that?