haysonics said:
My point is that CD with 96db "theoretical" dynamic range sounds compressed compared to the 144db "theoretical" dynamic range of DVD-A.
1. 144dB is impossible at this point in time. Thermal noise sets in at approximately 120dB in best-case scenarios in present equipment.
2. 120dB is impossible to use -- room noisefloor(35dB for a very quiet room away from traffic or HVAC noises is the baseline) +120dB is starting at 155dB. Wow. Impossible unless you have set up a huge P.A. concert array in your living room! Then, if used it would cause hearing damage, quickly! Even the 96dB range of CD can not be used in home playback under any normal circumstance.....96+35dB(noisefloor): 131dB!
3. 75dB
[1] is the optimum minimum signal to noise ratio for transparent audio playback with speakers.
4. Most recordings use a fraction of the dynamic range available with the CD format! Performa statsitical analysis on sections of tracks using Cool Edit or some other capable audio program, you will find that most pop music, for example, may use 20-25dB average of total range, staying in a 10dB envelope most of the time! Even Jazz is commonly forced into such ranges today by the record companies. Uncompressed classical, btw, may use around 80-85 dB of actual range typically on a very dynamic work.
5. The music is does NOT have to be compressed just by changing from 24 bit to 16 bit space. The conversion retains the same relative amplitude levels of the data. If more than 16 bits were actually used in the first place -- this would not be usable anyways -- refer to no. 2. Changing to 16bit space would do one thing: raise the noisefloor..... that's all, unless you specifically utilize a dynamic compression filter/process. Actually, most CDs with quiet spots will have noise.... due to the original recording(s), not the CD format.
I think the sound of bass on DVD-A/SACD is similar to a good pressing of a record. I think DVD-A and an audiophile pressing of a record are on an equal par.
If DVD-A and SACD are on par with a phono record -- this is a sad state of technology. Phonograph transfers are not accurate, have poor noise performance excepting very special conditions, ritualistic cleaning and handeling procedures. The phono pressing and playback process, on the best turntablels/cartridges produces THD
[2] within human audible thresholds! True, you may not recognize it as discrete distortion, but it is present and has an audible effect due to it's magnitude!
But I think CD sounds different. I speculate this is because of a decreased dynamic range compared to these other formats.
Speculation, indeed! This is not supported by any credible research or data.
However, some have performed objective listening tests. For example, this example done in a studio, using analog masterape to a ADC-->DAC process at 16 bits and double-blind tested:
http://www.pcavtech.com/abx/abx_digi.htm
-Chris
[1]
Signal-to-Noise Ratio Requirement for Digital Transmission Systems
Spikofski, Gerhard
AES Preprint: 2196
[2]
Just Detectable Distortion Levels
James Moire, F.I.E.E.
Wireless World, Feb. 1981, Pages 32-34 and 38