Light Dependant Resistor
03-04-2015, 18:35
Many forum members would be aware of the perceived difference between 14 bit CD players introduced in the early 1980's
and progression marching forward where 16 bit started to sound better. Players using the Philips TDA1541 are still sought
after which were 16 bit capable. Moving further forward 20 bit then became available, and more recently 24 bit.
Comparing 16 bit to 24 bit I doubt if there would be disagreement which sounds better. But you would be interested to know
the recording industry was generally always behind in capability of capturing dynamic range.
The more bits = dynamic range improvement.
(1) "resolution - When an analog signal is digitized, it is represented by a finite number of discrete voltage levels. The resolution is the number of discrete levels that are used to represent the signal. To more accurately replicate the analog signal, the resolution must be increased. Resolution is usually defined in bits. Using converters with higher resolutions will reduce the quantization error"
The recording industry principally was built around 1 device - the reel to reel recorder it served purpose from
the late 1920's until today where it is and will continue to be used. http://en.wikipedia.org/wiki/Reel-to-reel_audio_tape_recording
Modern day high speed reel to reel recorders are capable of 55db which is just 8.8 bits, and with companding
a process of preserving dynamic range used widely in the form of Dolby and DBX improvement that can increase the dynamic range to 80db ie 13 bits is achieved.
Dolby which is also a compander preferences certain frequencies, whereas DBX applies companding to all frequencies, both
are companders.
Preserving dynamic range is directly related to the quality the recording can provide, and to audiophiles
who love music and sound reproduction a real goal to understand and appreciate.
If you have been doing your sums the CD player specification has always tried to stay ahead of what the recording
industry was up to, and if you have been really been paying attention the modern day CD player has now fallen behind
what the recording industry is capable of.
So what changed to go to 24 bit ? The digital recorder. which is 24 bit capable.
But back a few steps, if we recognize the ability of a 16 bit recorder it can with companding
provide 20 bit dynamic range.
Does Digital recording have limitations YES they unlike analog recorders overload very sharply
Analog recorders similarly do overload when presented with too much dynamic range however
start gently converting that overload to increased harmonic distortion. So the recording engineer
must be aware of the digital mediums sharp overload, and guess what they have to do? Yes
reduce level that instantly translates to less bits.
The answer is to once again use companding to preserve dynamic range.
How does this translate to your home hi fi , well to accept companding as
a understood method to preserve dynamic range and to explore what it can do
would be a good start, as it is unlikely CD players will be available with yet higher
bit capability.
DBX have already explored further improvement and their Type 4 white paper (2) is essential reading
as it opens up new capability for Analog to digital conversion and the reverse which is
Digital to Analog conversion, inviting similar to the virtues of analog tape overload a
digital overload region where conversion does not suffer sharp cutoff.
(1) http://www.maximintegrated.com/en/design/tools/calculators/product-design/data-conversion.cfm#ENOB
(2)ftp://ftp.dbxpro.com/pub/pdfs/WhitePapers/Type%20IV.pdf
and progression marching forward where 16 bit started to sound better. Players using the Philips TDA1541 are still sought
after which were 16 bit capable. Moving further forward 20 bit then became available, and more recently 24 bit.
Comparing 16 bit to 24 bit I doubt if there would be disagreement which sounds better. But you would be interested to know
the recording industry was generally always behind in capability of capturing dynamic range.
The more bits = dynamic range improvement.
(1) "resolution - When an analog signal is digitized, it is represented by a finite number of discrete voltage levels. The resolution is the number of discrete levels that are used to represent the signal. To more accurately replicate the analog signal, the resolution must be increased. Resolution is usually defined in bits. Using converters with higher resolutions will reduce the quantization error"
The recording industry principally was built around 1 device - the reel to reel recorder it served purpose from
the late 1920's until today where it is and will continue to be used. http://en.wikipedia.org/wiki/Reel-to-reel_audio_tape_recording
Modern day high speed reel to reel recorders are capable of 55db which is just 8.8 bits, and with companding
a process of preserving dynamic range used widely in the form of Dolby and DBX improvement that can increase the dynamic range to 80db ie 13 bits is achieved.
Dolby which is also a compander preferences certain frequencies, whereas DBX applies companding to all frequencies, both
are companders.
Preserving dynamic range is directly related to the quality the recording can provide, and to audiophiles
who love music and sound reproduction a real goal to understand and appreciate.
If you have been doing your sums the CD player specification has always tried to stay ahead of what the recording
industry was up to, and if you have been really been paying attention the modern day CD player has now fallen behind
what the recording industry is capable of.
So what changed to go to 24 bit ? The digital recorder. which is 24 bit capable.
But back a few steps, if we recognize the ability of a 16 bit recorder it can with companding
provide 20 bit dynamic range.
Does Digital recording have limitations YES they unlike analog recorders overload very sharply
Analog recorders similarly do overload when presented with too much dynamic range however
start gently converting that overload to increased harmonic distortion. So the recording engineer
must be aware of the digital mediums sharp overload, and guess what they have to do? Yes
reduce level that instantly translates to less bits.
The answer is to once again use companding to preserve dynamic range.
How does this translate to your home hi fi , well to accept companding as
a understood method to preserve dynamic range and to explore what it can do
would be a good start, as it is unlikely CD players will be available with yet higher
bit capability.
DBX have already explored further improvement and their Type 4 white paper (2) is essential reading
as it opens up new capability for Analog to digital conversion and the reverse which is
Digital to Analog conversion, inviting similar to the virtues of analog tape overload a
digital overload region where conversion does not suffer sharp cutoff.
(1) http://www.maximintegrated.com/en/design/tools/calculators/product-design/data-conversion.cfm#ENOB
(2)ftp://ftp.dbxpro.com/pub/pdfs/WhitePapers/Type%20IV.pdf