My quest for Nyquist

What are some examples of the artifacts that you might hear at 44.1 kHz vs. higher sampling rates?

Essentially, false signal at fractions of the sampled source frequency. In extreme cases you’d get a false “tone”.

But it’s not about 44.1 kHz vs. higher frequencies specifically. It’s about the relationship to frequencies in the source material vs. the sampling rate.

Start with this basic discussion of anti-aliasing filters and you can do more reading from there.

You still have to have content in the source at higher frequencies than the half the sample rate of the ADC actually reaching the ADC for this to happen at all.

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@Torq and @alont really nailed it with the technical considerations when comparing hi-resolution files vs lower sampling rates. Their suggested method of starting with the highest sampling rate file, and then using that source file to make your own lower sampled versions, and then using blind testing like Foobar’s ABX comparator is the only way to be sure you are comparing apples to apples. Trying to make any type of comparisons across different sources like streaming sites or CDs will not be sufficient due to the different masters being used.

To emphasize this point about considering the masters being used, there was a very good reddit post showing examples of how to quantify the quality of a master by using a software called AudioLeak, which uses the method Leq(A) to show a spectrograph of the A-weighted loudness of a track across time. The author of the post does a great job in explaining this more and provides some great examples of what this actually looks like. When considering the same song, different mastered versions can have drastically different qualities in production. From the author’s photo album, here is an example of “New Religion” by Duran Duran:

Original recording (1982):

Remaster (2009):

It is clear that the remaster version is clipped and of shows a much worse dynamic range compared to the original recording. One of the issues with streaming sites as well as digital music stores is that it is sometimes nearly impossible to track down exactly which master version they are providing regardless of how they actually label it on their site. This is another reason that comparing the different streaming sites to each other is so difficult, often times each of the different services is using a slightly different master before doing their lossy conversion.

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It’s probably incredibly difficult for most people to detect these aliased images even if you had a slow roll-off low pass filter - especially in music when you have masking effects in play. If this is a concern, there is a test tone on audiocheck.net that lets you hear how ‘leaky’ your low pass filter is. If you don’t detect any spurious tones before the main sweeping sine tone, then the filter is doing its job.

I wouldn’t argue to the contrary.

I’m simply pointing out that recording at higher sample rates than double the maximum frequency present in the source material is only useful to offset the potential for imaging issues (audible or not) resulting either a) from the lack of a perfect brick-wall filter (i.e. always), or b) when you have insufficient frequency headroom at a lower sample rate to allow a more practical, low-pass/roll-off filter, of a more typical 6-12 dB/octave.

In other words, a higher sample rate will not capture the lower frequency information with any more fidelity than a lower sample rate, provided you have no energy in frequencies above 0.5 fs of that sample rate reaching the quantizer.

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@alont

That makes more sense. Maybe it is that the recording I’m listening to was a better master as some have suggested.

It also sounds (not a pun) that the combinations of master, encoding, playback device, amp/DAC, and headphones are essentially infinite. Add to that the huge variation in hearing capacity and personal taste.

Before you know it, it’s a hobby with a discussion board. Oh, wait. It is.

That would be my guess as well.

I think you are all correct. I’ve been listening to streaming versions of some of the classics for so long, I forgot what CD quality really means. The Miles Davis CD was the “Legacy” edition that was recently remastered.

Now I’m wondering if I need to get a little CD player again, hook it up to a good amp and make myself a critical listening rig.

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I don’t know what CD quality is on Miles’ Kind of Blue. I have vinyl.

Original or remastered?

The other, and far more likely possibility, given the history of Kind of Blue is that the “CD Quality” version you listened used a different mastering to the hi-res version.

I would guess the same. One easy way to control for this @jflores476 would be to convert the hi-res version to 16/44.1 and then see how that sounds. If you’re feeling really adventurous, you could use some ABX testing software to easily compare them side-by-side.

I actually just bought a DSD version of Michael Jackson’s “Thriller”, not because I think I can tell the difference between DSD and Redbook PCM, but because this comes from the SACD mastering of that album which seems to be highly regarded.

In my imaginary dream world, I have access to a music catalog that allows me to pick any mastering of any album and download it at any bit depth and sampling rate.

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Yeah, “recently remastered” is sadly often a bad thing. As a rule of thumb, the older the CD, the better mastered it is. For this reason, I like to buy used CDs from places like Discogs, and also enjoy combing through my local library which often has some rare old CDs on hand.

Now I’m wondering if I need to get a little CD player again, hook it up to a good amp and make myself a critical listening rig.

No need. I rip everything to FLAC immediately and go from there. On-the-go I actually just use high bitrate VBR MP3s made from the FLAC “masters”.

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I think I know where you coming from, but that’s not necessary always true, i.e. Steven Wilson remastered some of YES’s early works; and they sound fantastic to my ears.
The key would be to research and ensure that the new remastered versions uses a good source and that the remastered version is something you enjoy. There are enough remastered versions that just ramp up the loudness and they sound like crap. No reason to re-purchase something like that for your collection.

That’s a fantastic recommendation. Your local library is also a great resource to find new music that you normally wouldn’t listen to. A great way to escape the echo-chambers of Spotify and the like, if you dare to embrace the adventure.

+1 :sunglasses:

What are you ripping from?

Audio CDs; or did you mean what program to use?

@z0rk,

I was wondering about the source. I’m trying to decide about where to purchase and where to store high quality audio.

I’m thinking about a blu ray player through a good DAC and amp as one possible source. The other would be to research and find sources of well mastered music that I can download and store on a drive or the cloud.

I have a large number of CDs but I’m not sure of the mastering behind them.

Still in search of the lost chord…

Well, @jflores476, every good boy deserves favor.

I’ve not made decisions on how to store and serve music. While I have a lot of vinyl that I will keep as vinyl, I do have CDs also. Some were ripped years ago as 320k MP3, then later as Apple Lossless, FLAC or kept as WAVs. I have a Mac Mini that can do OK as a Rip and Store location, but have really thought about unifying things with a dedicated music server. I sort of like the Wyred4Sound music server, but it also appears that this is where Roon can be a boon.

I like things that I can pay for once, not have as a subscription. So this perches me on the horns of a dilemma. And I do nothing.

Someone recommended this site for FLAC purchases…haven’t done so yet but I have it bookmarked. 7digital
looks like ok prices for albums.

Definitely! The recent remaster of Abbey Road is another good example that bucks the trend.

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Gotcha
I’ve converted my entire music library (CDs) to FLAC files. I store them on a NAS and use Volumio for playback.
NAS > DAC > Volumio > Amp

You may want to check out this discussion over here.
Keep in mind that when you download HD audio tracks it’s important to verify that the service used a high quality master for the HD audio file, otherwise you’re just getting upsampled garbage.

It’s best to enjoy what you have. And then as time progresses and new (good) remasters become available you may decide to revisit a couple of albums that are worth the upgrade. At least that’s my philosophy.

Cheers