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Is there an audible difference between HD and CD quality? - Page 3

post #31 of 43
Quote:
Originally Posted by miceblue View Post

Interesting explanations! So if stereo sounds unnatural, how do binaural recordings fit in there since they are stereo per se, but the recording technique makes it sound more three-dimensional?

Binaural is a very special case.  Two microphones, ideally in either real ears or an artificial head with simulated ears, is used to record all information that a real human set of ears would.  Then the recordings are played back on headphones, usually open, on ear.  One of the more developed and refined processes is called Holophonics by Hugo Zuccarelli.  The 3D effect can be startling, encompassing directionality from everywhere around the head (download the holophonics demo, you'll see what I mean -- http://www.holophonic.ch/archivio/testaudio/Cereni%20-%20Holophonic.mp3), or somewhat mild, but in any case there's no good way to play that recording on a set of speakers.  The stereo effects are very lack-luster on anything but headphones, and completely collapses on speakers.  

 

Quote:

Originally Posted by miceblue View Post

Mmk that's good to know then. I'm not sure what artifacts sound like though. They can produce sound above 20 kHz?

Artifacts are undesired by-products.  They should not be audible in a good system.  Yes, high rate systems can produce signals above 20KHz.

 

 

Quote:

Originally Posted by miceblue View Post

I don't even know what oversampling is; is it the same as up-sampling? 

 

Kinda, the goal is to up the sampling frequency so the reconstruction filters don't have to be quite as severe.

Quote:

Originally Posted by miceblue View Post

 If 24-bit is only really advantageous for post-processing, then why do "normal people" buy such music and don't use DSPs?

Some people have to have what they believe is "the best", even if the best is imaginary.  Do the comparisons for yourself, then if you still really want to shop for high-rate files, see if you can find any you want that are confirmed to be 24/88, 24/96 or 24/192 all the way from the original master to your files.  If you can't confirm the file's heritage, you may want to hold off.  

 

I hate it when people post stuff they aren't sure about, so I'm not posting a link for this, but I recall hearing that AIX Records produces both high-rate and surround recordings, and if I recall, they produce the surround recordings in both audience and band perspectives.  Sorry if I'm wrong, just can't find it on their site quickly, perhaps someone with more time to dig can correct me.

post #32 of 43
Quote:
Originally Posted by jaddie View Post
Kinda, the goal is to up the sampling frequency so the reconstruction filters don't have to be quite as severe.

 

The requirements on the overall filter response do not actually change, it is only easier to implement a digital filter with a very fast roll-off than an analog one. In other words, the advantage is that the analog filters do not need to be as severe.

 

Oversampling vs. upsampling in the context of DACs is usually audiophile terminology to differentiate between using a typical modern oversampling DAC chip only, and upsampling the signal first with an external DSP chip (or even software) and then feeding it to the - possibly old style non-oversampling - DAC. However, upsampling will not magically avoid the trade-offs involved in designing a reconstruction filter. On the other hand, it allows for more control over the filtering. But the filters built into a decent oversampling DAC chip are generally good enough to be transparent at 44.1 kHz anyway, so the "upsampling" approach basically just adds more complexity and cost without real audible benefits (which is not unusual for audiophile products).


Edited by stv014 - 5/26/13 at 3:21am
post #33 of 43
Quote:

Originally Posted by miceblue View Post

 

Mmk that's good to know then. I'm not sure what artifacts sound like though.

 

They are not supposed to be audible at 44.1 kHz with good filtering (which is not that hard to achieve), that is the point. The differences (ringing etc.) between the filters can be audible at low sample rates like 22.05 or 11.025 kHz.

post #34 of 43

I generally love technological progression but with music, too many variables and bottlenecks exist in the production or post process that would have contributed to a much larger difference than HD vs CD formats. 

 

I would rather buy some nicely produced CDs than some lousy HD files.  I've learned to only consider purchasing HD version for an album that has excellent reviews on its production.  Even tho I've HD daps I really ain't a believer.  Good music always trump good format.

post #35 of 43
Quote:
Originally Posted by stv014 View Post

 

The requirements on the overall filter response do not actually change, it is only easier to implement a digital filter with a very fast roll-off than an analog one. In other words, the advantage is that the analog filters do not need to be as severe.

Thanks for fixing my poorly written statement...I over-simplified.  What I meant is this:

http://www.analog.com/static/imported-files/tutorials/MT-017.pdf

post #36 of 43
On the subject of HD vs CD quality, can anyone explain these?

QKO1P0L.png

There's clearly nothing about 40kHz here, or on any of the other tracks from this album. Why is this a 192kHz file? Is there any benefit to it, or is it simply paying more for literally zero benefit over a 96kHz track?

GFgQGY6.png

Similar situation here - very little above 40kHz. But what is up with those high energy bands across the track? Shouldn't those be filtered out?

QCB5plA.png

Isn't a -20dB spike that goes on for about 20 seconds potentially damaging to your equipment? Same thing is happening here around 30kHz as well, and above that it's just noise. (clearly sourced from DSD)

A high energy band around 18-20kHz, or around 30kHz seems to be common in a lot of "HD" tracks. It just seems like all you're paying for is more interference/noise in most cases?

If my hearing only extends to 18kHz (which is very quiet) shouldn't I be filtering out everything above that?
Edited by StudioSound - 5/26/13 at 12:10pm
post #37 of 43
Thread Starter 
Yeah I'm wondering how to interpret 24/192 or 24/96 music too. What is all of the 'blue stuff' in the spectrograms? Noise? Some of my music also has the 'random high frequency line' in the spectrum as well.
post #38 of 43

narrow, constant flat high frequency lines are probably "spurs" - spurious tones that are coming from something in the system - not the music


Edited by jcx - 5/26/13 at 2:02pm
post #39 of 43
Thread Starter 

I sent an e-mail inquiry to a vendor that sells digital HD music and the respondent replied:

 

Quote:
Thank you for your question. We receive the most up to date masters from our record label partners. Each record label has their own recording/mastering process when it comes to high res. We are not a record company. We don't do anything to music provided to us by record companies. If something needs to be change or revised it is sent back to label for the process to be taken care of. We are just a retailer. We don't downsample or upsample. 
 
Whenever possible we try to provide as much information as possible about the mastering process that is giving to us by the labels. 
 
Older recordings when remastered may present qualities that originally were unnoticeable when first released or in previous formats. We only hope that our label partners have taken note of that. When it is an issue we do our best to have them correct it.
 
In general with regards to our hi-res content, we DO test them in-house as well as by an independent 3rd party, at various time points within each track in the album. What we look for is a gradual rolloff in frequencies up to the appropriate point for 96/24, 192/24, etc, and reject anything with an obvious brickwall cutoff. Note that depending on where in a track a sample is taken, the rolloff may be at a slightly different frequency, which is natural with dynamic music.
 
I hope this information is helpful.
post #40 of 43
Quote:
Originally Posted by miceblue View Post

I sent an e-mail inquiry to a vendor that sells digital HD music and the respondent replied:
Meh. Sounds quite familiar
post #41 of 43
Thread Starter 

Sorry to bring this thread up again, but what exactly is the point of having a studio master and a CD master? i.e. why not just have a studio master down-sampled to 16/44.1 and burned to a CD?

post #42 of 43

I do purchase the occasional HD album for kicks but I don't seriously expect it to be any better than a Redbook album.

29.gif

post #43 of 43

What you're effectively paying for is the sometimes less destructive mastering. That's it.

 

(Other times it's the same mastering, sometimes even just 44.1/16 resampled (!), ...)


Edited by xnor - 10/3/13 at 12:15pm
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