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In an older thread in this forum, I was asked to compare the HDtracks 24/96 downloads for Led Zeppelin I, II, III remasters vs the same remastered on CD.
My Led Zeppelin I, II, III 2014 Deluxe Remastered CDs arrived and I promptly 'ripped' them to my Mac music server (lossless uncompressed AIFF files) and compared a few tracks against the 24-bit/96-KHz 'hi-res' downloads.
I was expecting a big difference in sound quality between them but that wasn't the case. The remastered CDs sound very good in my opinion, much better than the old original CDs from a couple decades ago. I do not own these on vinyl.
I had to listen closely to hear any differences between the CD rips and the hi-res downloads. On some tracks I heard a very slight fuller sound and more ambiance in the 24/96 downloads, which were slightly 'thinner' sounding from the CDs. But the difference was small and only noticeable with frequent A/B switching and focusing hard to hear the difference. I would play the CD track for maybe 20 seconds then play the same 'hi-res' track for 20 seconds.
This reinforces the thought that the source mastering process is more important than the difference between CD resolution and large "hi-res" files. Sure, there's a difference but it isn't always huge. In this case, I can honestly enjoy either the CD or the 24/96 files equally.
Mac Mini > iTunes & Audirvana Plus > Luxman DA-06 DAC > Rogue Cronus Magnum Integrated > Tannoy Definition D500 Speakers
Follow Ups:
Something's not right. I thought it could be the software used for creating the plot, but inmate rrob saw the same blip using different software. So we all suspected something in the music file causing the 28KHz blip.
But here I have more blips at 28KHz in totally different unrelated albums. The only common denominator I can think of is that they both came from HDtracks.
Led Zeppelin I 24/96 Download, track 01 "Good Times Bad Times"
60 Seconds sampled from the beginning of the track
The Doors L.A. Woman 24/96, track 05 "L.A. Woman"
60 Seconds sampled from the beginning of the track
This is weird. Here's an album track that I digitized myself at 24/96 using the HRT LineStreamer several months ago. No 28KHz blip like the HDtracks downloads of Led Zep and The Doors. Not sure what's going on here. Anyone have any ideas?
Velvet Underground home digitized from LP at 24/96, track 01 "Sunday Morning"
I just looked at a spectrum analysis of a commercial DVDA made from an analog tape master (LA4 Just Friends). Spike at 28.8 khz there as well. I am beginning to wonder if it isn't an artifact from the A to D process - or perhaps an artifact from noise reduction.
kerkula
Could there be code embedded in the 28kHz signal? Have you looked at the 28kHz signal in the time domain? Does it spell out HDTracks in some code every so often? Or is Jimmy really dead?
We need a like button on here.
True. But if it is a watermark, when e.g. HDTracks sees a file somewhere it shouldn't be, and runs it through their "decoder ring", it would easily spit out the answer.
They've gotta be doing something more than just putting "headers" into these files, too easily removed. Heck, they could encode an indirect link to the purchaser (somehow), which would make complete sense. But also not *at all* easy to do AFAIK and not affect playback, but there are probably encoding tricks and I sure wouldn't know of them. There have been much more theoretically complicated processes used to safeguard stuff (e.g. I know you remember the old one of laser-burning a hole in a FD in a uniquely encoded position).
I now suspect the tape machine(s) being used for playback and/or possibly record. I found another recording, Waltz for Debbie, that has the same 28 kHz blip.The mastering engineer for that transfer, Paul Stubblebine, might be able to shed light on this situation.
But note, I highly recommended the album in question and never looked at spectra at the time. :-)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Are there tape machines in existence using signals in the 28kHz range, such as one might expect to find in a typical switching power supply? I figured all tape machines are so old they probably all use old school rectified, filtered, transformer isolated 60Hz supplies.
I'd be more inclined to suspect the digitizing machinery.
It's not uncommon to find PC power supplies switching in the 25KHz range but there's no set rule and it depends on the design. Switching power supplies can have a switching frequency upwards of 1-MHz.
I doubt that the old tape machines used switching power supplies. I was thinking it could be the tape bias frequency but I believe those were up around 400KHz.
No rule for sure but it makes passing emissions easier to keep frequencies down.
Unlikely to be digitizing machinery at least not in the Waltz for Debbie. That used the Pacific Microsonics ADC. It's unlikely that such a highly regarded device would have spuria that are 40 dB greater than spuria on my $150 juli@ sound card.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
I didn't see many details but am wondering what type of power supplies that Pacific Microsonics device uses. Undoubtedly it meets it's quoted specs but the question becomes how does any analog gear connected to it react to any emissions it may produce? especially old school analog gear which in it's day didn't require much immunity to perform well.
Abe as an example here is about a 20 second peak hold capture of my Asus Essence STX line input hooked up to my turntable and through my powered down phono preamps. I'm using Oscillometer free version to do the capture. I leave the preamps turned off during my noise hunts so as not to obscure the problems with preamp electronic noise.You can see my own setups noise imperfections quite clearly as I seem to have a similar spike at around 25kHz and what is likely to be it's second harmonic at around 50kHz. I'm pretty sure this is caused by my PC power supply but haven't had time to really figure it out. Since this gain is about what I'd use to capture and my particular noise problem is pretty small I might not worry about it so much considering the spike peak itself is somewhere around -115dB.
Edit: By the way in case you can't see the text this is with 2^14 points averaging and Blackman Harris window and with all weighting filtering shut off.
Second edit: I found it interesting that at 1:15 AM this morning my measurements with what I bellieve to be the same setting look quite different . Please see below. Perhaps theere is a power quality difference that explains it. It leads me to want to try some line filters. I don't believe I've noticed a drastic change like this before. Again only difference seems to be time. Notice how much lower than the apparent noise floor is with respect to the picture above. The noise spikes seem to be more or less the same but some new ones have been uncovered. such as at 1kHz which was buried in the noise before. Odd. Definitely going to need to dig into this effect deeper.
Edits: 07/12/14 07/12/14 07/12/14 07/14/14
Probably noise in the analog hardware used to make the original A to D rip. This is right in the frequency range where you might expect to find some switching noise from a typical power supply like you'd find in a PC for example. Though switchers are everywhere these days.
Would you say this is kin to upsampling, which I am not necessarily a huge fan of for minimal improvements. I would really be on board with these "hi-rez" files if they started out that way and not some native 24/48 recording.
Jim Tavegia
SATA cable to make the difference more dramatic?
All the best!
JE
I've compared the new 24/96 Zep I files to a mid-2000's CD rip (which had the left/right channels reversed, so I switched them) and a mid-1970's LP in very good condition (I'm the original owner).
I think the new 24/96 files sound a little better than the LP and the LP sounds a little better than the CD rip.
I will not be buying any other Zep files (except maybe Zep IV because my LP is trashed from playing Stairway to Heaven backwards, or too many times) because there was not a big enough improvement to justify the cost. Besides, I'm mostly into jazz now and rarely get into a Zep mode.
Abe - Thanks for your post. I'm a 99% classical listener, so I don't know those recordings you used for evaluation, and although I agree with the general thrust of your listening observations, it would be interesting to know if there is any musical signal above 20KHz on the selections you heard. Have you tried generating any spectrographs to see if there's any musical signal (or noise bands or whatever) up in the (inaudible, I know) range above 20KHz where the 24/96 files might have at least a visual advantage?
Led Zeppelin II, Track 09 "Bring it On Home", 60-sec segment Spectrum Plot
CD Rip 16/44
Download 24/96
Not sure what the anomaly is just above 28KHz
Led Zep 2 vinvyl, Bring It On Home, rockin part near the end, Atlantic SD19127, ST-A-691672WW-REPL from the deadwax among other things. System listed in inmate systems. You can see 60kHz spike at about `-105dB peak which I've presumed to be an artifact of my crappy little walwarts feeding my dual Cambridge 651p's.The interesting thing to note is a complete apparent lack of the 28KHz spike. As I was watching the thing bounce as it sampled. It seemed apparent there is signal bouncing to the music clear up to the 50KHz range. You may also find it interesting to note that I saw no 28KHz anywhere in the signal while I listened and was taking samples of various parts of the song, even during the quiet part there was no 28KHz.
Same conditions as my other screen capture post. 24bit 192kHz sampling, 2^14 points averaging, Blackman Harris 4 window, no weighting blah blah blah same stuff
Edits: 07/13/14 07/13/14 07/13/14
My Led Zep II is the 2014 reissue, Atlantic. The Ponty album is also Atlantic. However, I also found it on an A & M recently reissued by QRP.
It is not a constant tone. I can move through the file .328 seconds at a time.
.328 seconds later
.328 seconds later
.328 seconds later
.328 seconds later
.328 seconds later
To me it seems apparent it must not have been on the original since it isn't in my vinyl that I can see. Of course I only have one pressing of many, not even considered the best pressing by aficionados.
Does exist on various digital remasters in yours and Abes possession.
Signs point to it likely being an artifact of one or more digitization processes whether intended or not.
I'm going with not as the most likely answer but there are always the tin hat theories.
Same bump in first 60 seconds of 24/96 recording from vinyl.
You sampled the first 60-secs of the track. I actually started 30-sec into the track, then grabbed the 60-secs after that.
I think that blip is probably throughout the recording.
"I think that blip is probably throughout the recording."
I agree. The first 1 min 45 seconds is relatively quiet, as is the last 30 seconds. The bump appears in all the samples I took from those periods. It gets covered up during the loud portion of the song.
However, I didn't hear anything I would attribute to that 28.7k bump. Led Zep I and II both sound great, better than the CDs I had. I also attribute the improvement to the mastering. Just got III yesterday. Haven't listened yet.
I have no idea what that 28KHz anomaly might be. It's strange that it exists in a number of 24/96 tracks not only on one album but at least a couple unrelated ones from different artists. I viewed this on a Led Zeppelin album and also on The Doors, both from HDtracks. It would be interesting to see if the blips exist on downloads from other vendors.
I hope someone figures it out. We're all just guessing at this point. Bizarre.
My Led Zeppelin is on vinyl that I recorded at 24/96.
I also found the same blip on other vinyl I've recorded. Not all but a few, leading me to believe it's not added by my equipment.
One was a 1979 recording by Jean-Luc Ponty that I purchased the year it was released.
That is just plain weird. Wonder where that 28KHz blip originates.
That's too bad. I wonder if the problem is with the original analog masters. Hope not, since then there'd still be hope someone could do a noise free high res rip.
Hey, I'm fine with the blip. I just don't look at the graph while listening to the track. It sounds quite good IMHO. ;-)
I am one of those customers you hate to get I guess. Back ~ christmas '06 I IIRC I took my first "1080p" tv back after I discovered it only upconverted to 1080p and couldn't take and display 1080p source material. 1080p printed all over the box. That's why I bought it and how the sleazball sales dude sold it to me. I didn't figure it out until I got it home and couldn't get my new at the time PS3 to send it anything but 720p. I probably can't see the difference from my seat with the screen size that fits in here. It is the principle of the thing that bugs me.
Edits: 07/12/14
So those 28kHz blips (@ -100dB on the scale, IIRC -72dB on Abe's) are hurting your listening experience? I guess you also sleep during the day and I really don't know how you're reading this forum, but your typing is excellent considering. :)
Edits: 07/12/14
That noise is a symptom of something wrong. It should not be there. Without understanding the root cause it is impossible to say whether there is a sonic problem. I have transferred a bunch of old master tapes and it's been my usual experience that ones with funny noise peaks on them don't sound as good as clean ones. Usually, filtering out the noise peaks makes things somewhat better. But the best recordings don't start out or gain these unwanted artifacts.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
The peak is -60dB down compared to what is in the 0-1kHz rangeso it is questionable whether one can hear it. There are both masking effects and ear sensitivity going against audibility. Given the age of most audiophiles (or Jimmy Page), the odds are further reduced. I agree it would be more satisfying to know that this noise pollution was not there, but that would be listening with one's brain, not one's ears.
A quick experiment: upsampling the 16/44.1 to 16/96 or 24/96 and listen whether this upsampled file gets to sound as good as the "orginal" 24/96 remastering. As you pointed out earlier,one benefit of higher sampling frequency files is to move reconstruction filters to much higher frequencies than what is otherwise possible with 44.1kHz. Nothing to do with the actual file content.
One caveat: we do not know how much high frequencies these hires remasters contains because the posted spectra have been averaged over 60 seconds. As otherssuggested, it would be more informative to see spectrogram to see if there are times at which there is much more high frequency content in the high res file than in the CD file. It is not like Bonham never hit the cymbals!
Normally, I use a 65K FFT for spectrum averaging. But my software allows other sizes as well, plus different windows. (Soundforge 10). I also have iZotope RX and this includes a spectrum plot of time (X) vs. Frequency (Y) vs. intensity (Z, i.e. color). The size of the temporal resolution can be adjusted but there is the inescapable tradeoff of time resolution vs. frequency resolution.
With these spectrum plots it is very easy to see high frequency noise and to distinguish it from high frequency musical sounds. In addition, one can edit the spectral plots to easily remove unwanted noises, even to the point of removing notes out of a chord or removing guitar string squeaks.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Unlikely your software will allow to do a FFT with 60*96,000 points. There's a bunch of averaging going on that's a function on how the analysis is setup (number of points in the window, window overlap,...) The loss of frequency resolution that comes with shorter windows does not matter since energy gets summed up in each frequency band. A delta f of 1Hz or of 10Hz will still tell the story of whether there's significant energy at higher frequencies.
It looks like you posted in the wrong place.
I agree that it's unlikely that Abe Collin's FFT averages over 60 seconds. Possible, but not likely. I know that my FFT averages over 65K points with my usual settings and this corresponds to about 2/3 of a second at 96 kHz. The points in the window are weighed with the central points counting more according to a formula that smooths out the plot. I generally use a Blackman-Harris window.
There are a lot of other issues involved with interpreting FFT plots, such as "FFT gain" which is a measure of how the noise floor varies in FFT plots according to the window size and window type. If Abe wanted to, he could calibrate his FFT gain by creating a test file with a 28 kHz tone and adjust the level of this tone to where the FFT shows it at the point on the suspect download file. A little knowledge can be a dangerous thing, but I'm confident that Abe Collins knows enough to figure these things out, if he hasn't already done so.
BTW, I have other software that I use that uses 8 million points. I've used this to do convolution by transferring to the frequency domain and multiplying. In addition, my player routinely does convolution at 2.8 MHz sampling rate with a time period of about 1 second (over 2,000,000 samples). I presume the software uses FFTs, to avoid the necessity of more than 10^14 multiplications per second using a simple time domain approach, which even if my hardware could do would run up a huge electric bill.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
between Abe's and rrob's samples. It probably accounts for the spike level difference between the two if it is indeed the same spike.
Since my system can sustain a plus 120dB sound at my listening seat per my metering, those would be pretty loud to nearby dogs assuming my system actually responds to them directly and I actually chose to listen at that level. It could happen since it is Zeppelin after all. :)I think my biggest concern is the wasted effort and resources in the system trying to reproduce something that isn't part of the intended program. It will always be damaging at some level, but obviously hard to quantify without some appropriate test gear what level that damage is.
Rational or not I'd spend money yo ensure it isn't there in the first place. It's just bad form to have a -72dB spike in 24/96 files presumably coming at a cost premium.
Edits: 07/12/14 07/12/14
Yeah, I know where you're coming from, but I bet there are bigger battles to fry :) re the recordings' other "failings". (If there are any, besides that they should be from an analog source on LPs, or 192/24-32 etc. etc.)
I wonder if the noises are artifacts from the original masters' tape devices, or from something previously recorded on the tape and poorly erased (it apparently sometimes happened back then). I have no idea.
I guess it would be worthwhile to check out the original LPs and speculate after that, but probably any 28kHz if it could even be on there would be ground away by now on mine, and I always took/take good care and used half-decent carts even when I was a teenager.
Vinyl made from 24/96 master??
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
According to the Analog Planet article, they were 24/96 masters.
My recording of the vinyl was made at 24/96.
"Not sure what the anomaly is just above 28KHz"
Try running the scan again with no source playing. If the 28kHz is still there it's likely to be some em noise from some supporting hardware. Just above audio frequencies are a very popular frequency for the various types of switchers found in most computers these days. They put them there to keep the magnetics from audibly vibrating, however that does not mean this energy will be harmless to your sound.
There was no playback equipment involved, just the static audio files read into Audacity.
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.
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
Try looking at spectrum plots at several points in time. That will tell you what is related to the music and what is related to noise. This is most easily done with a spectral plot that shows frequency vs. time vs amplitude (X, Y, Z), but it can be done with an ordinary spectrum plot by selecting different points in the file.
The artifact at 28 kHz seems rather loud. More common is 15.7 kHz signal from video monitors, etc... Some converters have noise peaks due to charge pumps, etc., but these are at much lower levels. Were I doing this remastering, I would have noticed this noise and tried to figure out and eliminate its cause. Something was not right somewhere. If it was on the original master tapes the best results might have been to leave it in, or might have been to filter it out. (This would require subjective listening.) If it's in the remastering analog chain then something is seriously broken. Probably a bad sign. But remember if you buy recordings you are looking for good music and good sound, not measurements. :-)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Thanks Tony.
By no means perfect but the 60-second sample included some dynamic variations and transitions from relatively quiet to loud. Captured using the freebie Audacity editor.
There is musical signal on some of my classical recordings above 50 kHz. On recordings derived from magnetic tape usually there is not much above 25 kHz.Even when there is no musical information above the noise floor above 20 kHz there is still a difference with higher sampling rates. The problem with the lower sampling rates is not so much the missing frequencies, it's the effect of the filters needed for sample rate conversion and/or the artifacts created when these filters are omitted or compromised. I would not say these effects are game changing. They are subtle. I have transferred and remastered dozens of cassette tapes and even here there is often a noticeable downgrade in sound quality when an 88/24 "studio master" is down sampled to 44/16 for release on CD.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Edits: 07/11/14
""This reinforces the thought that the source mastering process is more important than the difference between CD resolution and large "hi-res" files."
Completely Agree. If the mastering process is poor, why would you want more bits of 'Bad Sound'.
Cut-Throat
Do all of that again only this time using a highly modified Windows PC and see if you get the same results. ;-)
Mastering quality is certainly critical for any recording. I also downloaded II since I remember when it came out. My "system" at the time consisted of a Norelco Carrycorder 150 cassette deck at age 12. :)
My only caution is that this is still a fairly compressed multi-miked recording with little real ambience. I'm anything but a classical snob (call it 10-15% of playlist), but I'd really like to use a better recording for evaluation.
The week before last, business took me to Chicagoland and I had the chance to connect with fellow inmate Brian Walsh. His TT was having issues, so we listened exclusively to his superb server listening to a wide range of content. I sat back with closed eyes and enjoyed the experience. There were several times when the quality was exceptional (yeah, classical stuff) and when I looked at the display, it was consistently DSD or hi rez PCM.
I understand. However, the requested evaluation was specifically for the three albums mentioned, at 24/96 (downloaded) vs the CD rips uncompressed. In this case, the differences were very minor.
do such comparisons - my hats off to you!
My comments were to temper those of others who think that even the very best recordings can be fully captured in 16/44. That assessment does not support my experience. :)
..my experience is the same. The Led Zep catalog was captured to 24/192, and mastered in 96/24. If they had started at 44.1 the end product would have been far inferior.
"...but I'd really like to use a better recording for evaluation."
It is called Rock N Roll dude. There is nothing to evaluate. Just trip.
I enjoy Rihanna, too but would not use her recordings as a gauge for judging the capability of hi-rez recordings. Some stuff I listen to is available only in MP3 so I just enjoy the music. :)
Just giving you the bizness...heheh...
Actually the new Robin Thick album does not sound bad...
I was one of the guys who was interested in the comparo.
Hi Abe,
I've done similar tests with digital copies of vinyl. My Alesis Masterlink can record at 24/96 or 16/44, or several other resolutions in-between. I do not hear any difference between a 16/44 Redbook copy and a 24/96 copy of the same vinyl record from the same turntable front-end. In my opinion, 16/44 is quite sufficient to capture everything vinyl has to offer although I now archive all my LPs at 24/96 just because I have the playback capability and because most other people feel that higher resolution digital is better than Redbook. I can't hear the difference, though.
Best regards,
John Elison
In using either of my Tascam DR-2ds at 2496 and my DR-07 which is redbook, I can hear a difference of my needledrops at 2496. It is not huge or night and day difference, but I sense a smoother presentation. I would have to admit that the differences in DAC's between the two unit could be the issue and that the DR-07 could not be as good, but the redbook recordings I make with it sound very good to my old ears. I have been impressed by these very affordable units. I have also had others say that the Sony PCM-M10 is also an excellent SDHC card 2496 recorder.
Jim Tavegia
For a valid comparison, you need to use the same DAC for both sample rates.
"For a valid comparison, you need to use the same DAC for both sample rates."
You are absolutely correct. I have studied this matter in quite a bit of detail and have some more observations that may be useful to anyone interested in doing serious qualification of the various digital formats.
One also needs to examine the digital files and compare the (RMS) level of the two files, to verify that the levels are the same.(1) In addition, it would be a good idea to measure the DAC with test tones at both sampling rates to ensure that the DAC has identical gain when running at the two formats involved. The file measurement can be done using an audio editor such as Audacity. The editor can also generate test tones in different formats. A voltmeter can be used to measure the DACs gain while playing test tones at the different formats. For valid comparison, one must have levels matched to at least 0.1 dB, better 0.05 dB.
There is still a remaining issue, namely the identical DAC is running different DSP at the two speeds. So in the end one can not know whether differences one hears are due to artifacts of the DAC or the format. In addition, if one does not hear differences one can not tell anything, since the lack of differences could be a function of the original recording, the mastering, limitations in other system components or even the listener's lack of training, attention or hearing.
I have done tests starting with a very high quality 176/24 file and downsamping to 44/16 using the 64 bit iZotope SRC and the iZotope Mbit+ dither algorithm. I then use the same tools to upsample back to 176/24 format. This takes the DAC out of the comparison to the extent possible. In addition, because the iZotope SRC allows control over various downsampling and dither parameters, I was able to train myself as to the tradeoffs involved, i.e. better learn to hear just what the limitations of the 44/16 format are for acoustic orchestral music. However, even in this case, I am still stuck with inability to distinguish limitations of the software and the settings it supports and that I chose vs. limitations of the format itself. In addition, there is a nagging doubt that any differences that I hear might not be real sonic differences encoded in the file, but different artifacts created by the DAC and rest of my playback chain. (One example of an artifact that magnifies a tiny difference to a larger difference would be low level non-linearity in a ladder DAC or variation in noise level due to DC offset in a sigma-delta DAC.)
(1) There are various reasons why the two formats might have been released at different levels, even if the 44/16 CD was made directly off the 96/24 digital master by digital conversion.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Thanks for taking one for the team and buying these in both formats.
I'm not surprised by your results. I've read many reviews of 24/96 downloads where they are described as being 'different' from the cd version, but not necessarily better. And this is even the case when the album was recorded in 24/96.
I think the music business has had us all chasing our tails for a long time.
I wish they would just concentrate on making better sounding recordings. But that takes care. And talent. And money. Easier to come up with a new format and charge more money.
"The problem with quotes from the internet is that many of them just are just made up."
-Abraham Lincoln
The Hi-fi rags (you know who I mean) have done a PISS POOR JOB of covering this whole 'hi-rez download compared to redbook' thing.
I guess it is in their interest to keep the hype machine rolling.....
"The problem with quotes from the internet is that many of them just are just made up."
-Abraham Lincoln
"This reinforces the thought that the source mastering process is more important than the difference between CD resolution and large "hi-res" files."
I think that's true. For whatever that's worth... If I have only ONE great sounding CD (and I have quite a few) that means they all 'could' be. BUT... Extra resolution in both domains prolly greatly improves the odds that any given instance will be good as it removes two hard walls. I can't think of a system of any nature that doesn't do better over time if it has some headroom. We just aren't all that great at nailing down thresholds, especially when biological units are involved!
Pragmatic Rick
". If I have only ONE great sounding CD (and I have quite a few) that means they all 'could' be."
No. That does not follow. Some music is more demanding than others. Also, you don't know how much better that great CD could have been. It might have been "out of this world".
Abe is right, though. In general differences in mastering are much greater than differences in format. There is another factor. Those engineers with the highest quality standards are going to be using the highest resolution format, hang the cost and inconvenience. Those using lower resolution mastering equipment do so either because they are in it for a quick buck or because they haven't developed their listening skills to the point where they can hear the quirks of converters operating in various formats.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
"No. That does not follow. Some music is more demanding than others. Also, you don't know how much better that great CD could have been. It might have been "out of this world"."
All true Tony...
But the outer limit, as it were, is essentially limitless. What's maximum?
On the other hand the threshold of acceptability, or satisfaction or something along that line seems clearer: you know it when you're below it or well above it. And I've had too many experiences where I was well below it at live concerts!
Since I am usually above it at home (as I don't listen very much to poor recordings) that's good. Actually I'd love to hear your system as I suspect that I might find it above it also but with better margins than mine, but who knows? We're complex, cranky creatures...
Rick
The maximum possible is a good seat in a great hall, such as Symphony Hall in Boston or the smaller Jordan Hall, also in Boston. More recently, I've heard great sound in the Barre, Vermont Opera House from a set in the center of the front row. In this case, the production was partially staged, with the orchestra at the back of the stage and the set and singers in the front, about 20 feet from where I was sitting. The orchestra was small, appropriate to the Rossini opera.
I have a friend who is an organist and a leader of the Organ Historical Society and have had occasion to hear a number of organs throughout Vermont, including up close and personal. I can tell you that the sound is amazing and not something that my system can come close to reproducing, certainly not when it comes to the pedal notes. Some of these 150+ year old instruments produce truly magnificent sound. I got to wander about the empty churches and try out a variety of listening positions and find the position I liked best for the music being played at the time.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
"I got to wander about the empty churches and try out a variety of listening positions and find the position I liked best for the music being played at the time."
Yea, there you go, optimizing information that usually goes largely uncaptured let alone reproduced well at home. A few months ago I went to our local concert hall which had been redesigned since I went regularly plus we had quite good seats. It was really impressive the choir was on floor to ceiling risers and the orchestra well arrayed in front. The air was just thick with information and we were awash.
I can't imagine how one could capture all of it let alone reproduce it at home. Maybe some binaural scheme with multiple ears whose mix changes when you turn your head at home. Sure isn't gonna happen with two channels and neither is your cheating and finding the best seat in the house PER NUMBER. Yes, that probably does amount to as good as it gets!
Regards, Rick
In my youth I used to sit in Boston's Symphony hall in the cheapest seats in the second balcony. The program came with a map of all the seats in the hall, and I used to mark out all the free seats in the better sections that were still empty at the start of intermission. Then I went down and sat in the expensive sections for the second half of the concert. This usually worked out OK, but once in a while an embarrassing situation happened that required a bit of fast talking on my part and movement to another previously scoped out seat.So I became quite familiar with how the various seats in Symphony Hall sounded and took advantage of this in later years when I was sufficiently affluent to afford whatever seats were available.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Edits: 07/12/14
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