Last few quarters there have been many great opinion-article pieces in HifiNews.
In the August publication again quite a few, but the one I am posting about here relates to how can one be sure that you purchase 24bit recording and it is not converted.
This is an interesting subject and one that has had quite a bit of chatter over at Hydrogenaudio, but for me Keith Howard seems to capture a beautiful way of identifying whether it has been converted.
Basically Keith developed some software that uses probability density function (PDF) when looking at the music signal.
Normally this would look like a hill or bump, but when the music is converted to 24-bits it is then flat.
Keith tested this also by asynch upsampling 1st which will mask any bit conversion, however using the PDF solution again it was clear that the music was converted from 16bit to 24bit (while not flat it has minimal number of raised sample values).
The good news is that the small selection of 24-bit recordings he checked were actual and not bit conversion, but the question is will this become a future problem with some jumping on the bandwagon and converting not just the sampling rate but also to 24 bits.
However the risk for such sellers is that it can be easily checked it seems.
For further info look to August Hifinews and Keith Howard's Opinion page.
Cheers
Orb
In the August publication again quite a few, but the one I am posting about here relates to how can one be sure that you purchase 24bit recording and it is not converted.
This is an interesting subject and one that has had quite a bit of chatter over at Hydrogenaudio, but for me Keith Howard seems to capture a beautiful way of identifying whether it has been converted.
Basically Keith developed some software that uses probability density function (PDF) when looking at the music signal.
Normally this would look like a hill or bump, but when the music is converted to 24-bits it is then flat.
Keith tested this also by asynch upsampling 1st which will mask any bit conversion, however using the PDF solution again it was clear that the music was converted from 16bit to 24bit (while not flat it has minimal number of raised sample values).
The good news is that the small selection of 24-bit recordings he checked were actual and not bit conversion, but the question is will this become a future problem with some jumping on the bandwagon and converting not just the sampling rate but also to 24 bits.
However the risk for such sellers is that it can be easily checked it seems.
For further info look to August Hifinews and Keith Howard's Opinion page.
Cheers
Orb
