|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
50.159.77.150
In Reply to: RE: Spectrum Plot for CD rip and 24/96 download - pics posted by AbeCollins on July 11, 2014 at 18:55:36
Hmm. If there3 was no D to A and A to D in the process it must be built into the file. That does not speak well for wherever it came from.
Follow Ups:
Now you have me wondering if I should check a couple more files from the same album, and maybe some other albums too. Of course that blip gets filtered by the DAC and is beyond hearing range even before any filters.
" Of course that blip gets filtered by the DAC and is beyond hearing range even before any filters."
The 28 kHz spike had better not be filtered by that DAC. The DAC is running at a 96 kHz sampling rate and should be reproducing information up to about 48 kHz. There might be a slight roll-off at 28 kHz, but it shouldn't be much.
Unless your analog amplification (including that in the DAC) has zero intermodulation distortion the 28 kHz is going to beat with harmonics of the audio and produce combination tones that may be audible. This would account for "hearing" effects of a sine wave that might be otherwise inaudible. (There are similar non-linear effects in one's ear and even in the air. The amount of intermodulation depends on the SPLs involved.). Variations in equipment, listening levels and listeners' hearing can account for different effects from this spurious tone.
It's quite possible that different tracks might not have the same spurious tone, particularly if they were originally recorded on different dates. (The tone might have been an artifact of the original recording, or the mastering engineers might have used different processes to make dissimilar recordings sound similar and one of the processes might have generated the artifact.)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
"Unless your analog amplification (including that in the DAC) has zero intermodulation distortion the 28 kHz is going to beat with harmonics of the audio and produce combination tones that may be audible. "
This is true but on top of that is the question about what damage to the desired signal this signals presence had in the recording gear. Certainly there is some level of damage that is built in to the recording already that can never be recovered even with perfect playback gear.
Without more details, we don't know the source of the problem. The key thing is to understand whether it was on the original tapes or not. These are historical artifacts and are what they are. But if there is no signal on the original then there is little excuse for adding it in the remastering. If the remastering engineers were first rate, they are probably aware of the situation. I would be surprised if the original masters had 28 kHz noise on them, but not if it was at 15.7 kHz. The masters were made before switching power supplies came into use.
It is also possible that residual (harmonics of) the bias oscillator beat with the sampling rate used. If they produced such a loud artifact this indicates something wrong with the digitization process.
If the original digitization of the archive tapes doesn't have the artifact then one can only conclude that the remastering people were incompetent. But we don't know. They probably do if the engineers were first rate.
But note, some of the engineers working on remastering of historic classical music albums are definitely not first rate. This is obvious by listening to the product. I would be suspicious if the masters were captured at 96/24 instead of 192/24, as it indicates that the engineers did not have audiophile pretensions.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: