Re: Why bother with lossy encoding?

Roger,

There is, at least theoretically, a way to increase the bandwidth above 
the original Nyquist limit. That is something similar to a series of 
psychoacoustic enhancer effects such as the aural exciter, which applies 
low level distortion to the high frequency content of the signal, thus 
creating spectral components well above the original spectral limit. 
This signal is added to the original signal in small doses.

I haven't tested this idea. It works fine when the target frequencies 
are in the range 10 kHz - 20 kHz, but I don't know how it would work 
above 20 kHz, or even if it would make any audible difference. Most 
people cannot hear anything above 18 kHz)

The addition of purely random high frequency noise may be a less 
controlled version of this procedure.

Regards,

Federico


On 15/03/2017 11:59, Roger wrote:
>> On Wed, Mar 15, 2017 at 10:30:58AM +0000, Steve the Fiddle wrote:
>> Just a quick technical point: Increasing the sample rate of
>> ("upsampling") a recording, does not and can not improved the quality
>> of the encoded sound. Once the sound has been recorded in digital
> Exactly correct.
>
> This is why I tried increasing sampling, while adding noise and augmenting
> frequencies.  (eg. ALSA LP effect filter.)  In essence, in an attempt to trick
> the ear.  Gives a neat "neato" effect, but really nothing more.
>
> Once the recording is at 16-bits 44100Hz or less, not much more one can do with
> it.  Some day, I'll have to buy some 24-bit 48000Hz Mozart, and perform a
> side-by-side comparison.  As well as compare tape/LP medias, but I just figured
> at this point, I'll still be stuck with 16-bit 44100Hz recordings due to higher
> costs of the 24-bit 48000Hz media and the preference for portable digital media
> over non-portability and shortened life span of tape/LP medias.
>
> Hence, just be content with what one has!
>
>
>
>
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