[Toom]

No, the human ear on the other hand is far from perfect.

 
While I am as far from a religious creationist as it gets, the popularity of One Direction must surely be a sucker punch to the theory of evolution. 

 

[KeithEmo]

  Using real time high resolution resampling software, based off interpolation algorithms that create the waves perfectly when compared to the sampled waves.
 
If the DAC uses a simple linear resampling, the created waves look like steps on a staircase, while in high resolution, they are curved lines. 
 
The step things create alaising, and harmonic distortions, due to the fragmented movement of the driver. They also have other problems. 
 
Example down.
 
You can come to my place for more details.
 
 
This is how sampled waves look like in computer, 1Khz, 10khz and 16 khz, created with free software audacity
 

 
 
 
 
This is how they look after resampling using a high resolution resampling algorithm:

 
 
In real life, waves must always be curved lines, and never have straight lines or corners.. It sounds much better with high resolution capable DACs.
 
Just try hqplayer. My algorithm is optimized differently, trying to do a different thing.

 
Fortunately, while very dramatic, that scary story just isn't true (at least not for real world properly designed "audio DACs"). Whether you're talking about the "steps" caused by the sampling itself, and which are present at the output of a basic ladder DAC, or about the distortion and aliased information added by an oversampling process, both are (or should be) ENTIRELY REMOVED by the reconstruction filter in the DAC (and a reconstruction filter to do just that is part of the design of any PROPERLY designed DAC). True, if I use linear interpolation to upsample, the resulting waveform will contain lots of extra high-frequency information. However, once the reconstruction filter is applied to remove that information, what remains will be a very nice smooth signal, and one that is very close to a higher-sample-rate version of the original.
 
The only way you're going to see all sorts of stairsteps and aliasing is if you're using some sort of "NOS filterless DAC" - which simply omits the proper filtering. (Some of those omit the filtering, but they aren't truly "filterless" anyway; they're just counting on the limited frequency response of your other components to do the filtering, which leads to the sorts of problems you described, and is sort of hit and miss - since your speakers weren't designed as a reconstruction filter).
 
Most DAC chips include one "correct" oversampling filter, although some offer you a choice between several, and many allow you to bypass the internal filter and design and use your own. The nice thing about software like HQPlayer is that it allows you to choose between several different filters without altering the hardware. However, the down-side is that you're still going through the oversampling process and reconstruction filters in your DAC itself, in addition to the oversampling and filtering performed by the software, unless you design one specifically intended to be used with external filtering and upsampling. (Your DAC will still need to have a reconstruction filter on its output, but it can be a much simpler one, designed to work with the oversampling filters provided by the software.)
 
Looking at the pictures in a program like Audacity is really not very useful. The only ACTUAL information involved is the little dots that represent the individual samples; whether the software you're using renders the line it uses to connect those dots as a jagged line, or as a smooth curve, is determined solely by the graphics and rendering algorithms they use to create the screen picture. (When you play that signal, the data points will be sent to the DAC, and it's the hardware in the DAC that will be "connecting the dots" - so what you see on screen is simply the program's "idea" about what that result will be. )
 
 

 

[upstateguy]

  I see you guys have been very busy feeding our resident troll.

 
It must be "LOVE YOUR TROLL WEEK" or something because they just can't leave him alone.

 
Now Guys, ask yourselves this:

1. Where would this thread be without our troll?
2. Wouldn't you say that the troll is responsible for generating and stimulating, more posts than anyone else?
3. Isn't that why you guys keep answering him?
4. What would you do if he went away?
5. So, admit it, don't y'all really want the troll to stay here and continue doing what he does?

 

[Steve Eddy]

Just want to introduce two words to the ultrasonics discussion. Intermodulation Distortion.

se

 

[lamode]

Just want to introduce two words to the ultrasonics discussion. Intermodulation Distortion.

se

you're a few pages too late

 

[Dobrescu George]

 
you're a few pages too late

Intermodulation distortion. 
 
I had thought about that. But i thought that if it was meaningfull for what you can hear, the microphone should had already picked up on it.

 

[StanD]

  Intermodulation distortion. 
 
I had thought about that. But i thought that if it was meaningfull for what you can hear, the microphone should had already picked up on it.

Intermodulation Distortion is not in the air to be picked up by the microphone, it is generated within the the audio chain. Hint, the word distortion.

 

[upstateguy]

Just want to introduce two words to the ultrasonics discussion. Intermodulation Distortion.

se

wondering what the frequency response is of the mike that's recording all this ultrasonic stuff?
 

 

[StanD]

 
wondering what the frequency response is of the mike that's recording all this ultrasonic stuff?
 
 

You can find mics that exceed the high frequency limits of us meat popsicles, however, I don't see what value it can possibly contribute unless one is an ultrasonic troll.

 

[Dobrescu George]

  You can find mics that exceed the high frequency limits of us meat popsicles, however, I don't see what value it can possibly contribute unless one is an ultrasonic troll.

i read a lot on bands recording nowdays with ultrasonic mics so that they will sound more naturally. 
 
The ultrasonics look like noise in spectrographs, but there is a book which concluded that it could affect what we hear. 
 
I will look deeper into the matter, but for the moment i install a perfect low pass filter, nothing over 25Khz will ever get over my things, because at the moment i consider ultrasonics more harmfull than benefical.
 
I might change this later, if i fiind to be wrong, but with the knowledge of the moment, this is how i consider it to be fair. Headphone drivers hurt temelves by trying to reproduce ultrasonics, it could destroy headphones, or normal sounds that one should hear.

 

[upstateguy]

 

 
wondering what the frequency response is of the mike that's recording all this ultrasonic stuff?
 
 

You can find mics that exceed the high frequency limits of us meat popsicles, however, I don't see what value it can possibly contribute unless one is an ultrasonic troll.

I assume the mics we're referring to are recording studio mics.  So I'm wondering why they would be calibrated to pick up stuff beyond human hearing?  If that's the case how did this ultrasonic stuff come end up on a recording?  Never mind the filtering that might be done during mastering.

 

[StanD]

 
I assume the mics we're referring to are recording studio mics.  So I'm wondering why they would be calibrated to pick up stuff beyond human hearing?  If that's the case how did this ultrasonic stuff come end up on a recording?  Never mind the filtering that might be done during mastering.

I can sum it up in a common acronym, BS. 

 

[Dobrescu George]

 
I assume the mics we're referring to are recording studio mics.  So I'm wondering why they would be calibrated to pick up stuff beyond human hearing?  If that's the case how did this ultrasonic stuff come end up on a recording?  Never mind the filtering that might be done during mastering.

there are lots of albums with ultrasonics. I had my hands on one few days ago, it sounded, very very good. But i do not think that it had anything to do with the ultrasonics, i manually filtered the ultrasonic data out, and it still sounded very good.

 

[StanD]

  there are lots of albums with ultrasonics. I had my hands on one few days ago, it sounded, very very good. But i do not think that it had anything to do with the ultrasonics, i manually filtered the ultrasonic data out, and it still sounded very good.

So you've learned something, firsthand.

 

[upstateguy]

 

 
I assume the mics we're referring to are recording studio mics.  So I'm wondering why they would be calibrated to pick up stuff beyond human hearing?  If that's the case how did this ultrasonic stuff come end up on a recording?  Never mind the filtering that might be done during mastering.

I can sum it up in a common acronym, BS. 

what is the frequency range of the ultrasonics we're talking about?