Saturday, 13 January 2018
DEMO: Dunkirk - Resolution difference between 1080P Blu-Ray and 4K/2160P UHD Blu-Ray (It's CES 2018 also!)
A friend who works in the world of video production saw my post a few weeks back about "4K, Dunkirk and 70mm IMAX" sent me some segments of Dunkirk from the recently released UHD Blu-Ray set so I could have a look at the differences between 4K compared to standard 1080P Blu-Ray. Remember as discussed a few weeks back, this movie was filmed to a large extent with 70mm IMAX (65mm/15perf) gear, we know the VFX rendering was done using >4K with a true 4K digital intermediate. It represents the "pinnacle" of analogue film technology mixed with the best of today's digital effects and processing. I highly doubt we'll see much more of this level of literal "film-making" over the years. As such it's a nice "benchmark" for comparisons.
Saturday, 6 January 2018
|For the 2016 edition, go here.|
For years we've been worried about the "dreaded jitter". However, we know that these days, with asynchronous interfaces like USB and ethernet, there's nothing to be concerned of. Sure, we can see jitter anomalies with old S/PDIF, but I doubt anyone should purposely not use the interface for fear of audible issues assuming otherwise decent gear. For years and still to this day, various "practitioners" of audiophilia hang on to beliefs around cables of all sorts; assuming normal hook-ups with decent quality cabling (and even with poor quality cables), we are typically hard pressed to find evidence of audible differences.
Then we have beliefs that bit-perfect streamers sound different, really? We also hear of esoterica like folks who think lossless file formats sound different, seriously? How about the folks who think that computer OS's make a difference, or software players sound markedly different (assuming it's all bitperfect of course and sent to the same DAC)...
Feel free to browse this blog for discussions and thoughts around countless other audiophile items of faith. Today, let's address the audiophile "myth" that has gained prominence among those trying to sell things and those that advertise said "things" over the last few years.
As per the title, today, let's explore this "myth" of the detested ringing with digital filtering and audio playback since I've been posting a bit of a series on this topic over the last little while.
Monday, 1 January 2018
Today's post is a bit of a continuation from last time's look at the different types of upsampling antialiasing playback filters using my Raspberry Pi 3 "Touch", piCorePlayer and SoX. As you can see from that discussion, across the audiophile equipment spectrum, manufacturers utilize all kinds of digital filter settings in their gear. Each company ends up choosing compromises between how much frequency roll-off, how much aliasing, how much temporal/phasic anomaly each would accept. And of course no matter what a company chooses, there are ways of advertising the decision as "good"; whether it be on the basis of frequency spectral accuracy, temporal accuracy, or just claims from pure subjectivity - "it just sounds better"!
The end goal of audiophilia is a bit like the modern interpretation of Goldilocks (and the Three Bears)... We're all trying to figure out for ourselves what is "just right" as we wade through the commercial and mainstream audiophile literature, unofficial blogs and forums, mix-and-match speakers with amplifiers, try out different accessories perhaps, and the like. So too it seems with digital filters and all the variants attached to the DACs we buy.
Remember that the only reason we're even talking about this is because of that 44.1kHz (and to a lesser degree 48kHz) samplerate such that the Nyquist frequency is at 22.05kHz; relatively close to the usual 20kHz upper limit of hearing acuity that the younger ones among us might be able to perceive. This is literally the only reason for all the hand wringing and millions of spilt keystrokes over the years around filtering by audiophiles (the few who still obsess over this...)
These days, we essentially have 2 major options for filter "types" among the DACs out there... Linear phase (the default for most mainstream DACs, Chord) or Minimum phase (Apple, MQA, Pono) - pick your "poison" :-). Of course within each phasic variety we have different levels of steepness and allowance for aliasing. We intuitively know that due to the biological phenomenon of auditory masking, maximum phase (where the group delay is pushed forward so "pre-ringing" is accentuated) is not desirable. But is there another choice?
Yes, there is of course... We can try to figure out a "just right" state with intermediate phase settings. Accepting that maybe there's some value to ensuring that pre-ringing isn't an issue even with some of the worst audio recordings out there, while maintaining awesome frequency and temporal accuracy - let me show you my choice for the filter that I listen to daily with the Pi 3 streamer...
Saturday, 23 December 2017
HOWTO / MUSINGS: Playing with Digital Filtering - Impulse Responses and Frequency Effects resembling Chord, Old-Skool Meridian, MQA, NOS...
|Remember folks... With antialiasing filtering applied to digital playback, there are no gross "stairsteps" in the oversampled/upsampled analogue output. Regardless of what you might see from misleading audio ads trying to pigeon-hole "digital". The exception being non-oversampling DACs that specifically choose to go down the stair-step path.|
One of the nice features of piCorePlayer is that it allows easy control of upsampling by using SoX; in the "Advanced" settings is the ability to pass along instructions to control the digital filtering used. Combined with a good DAC that accepts high sample rate PCM, we can try listening for ourselves and gain an appreciation of the differences that digital filtering make. The cool part of this is that it allows us to "emulate" the kinds of filters used in the audiophile world.
In this post, let's play with some of the parameters and show the kinds of impulse responses and "digital filter composite" graphs we can achieve...
Saturday, 16 December 2017
Merry Christmas everyone! Hope things are going well out there.
As you know, earlier this year, I had a look at the Oppo Sonica DAC including measurements with the "fixed" firmware. Over the last few months, I've actually sold the device to a "more needy" audiophile buddy. Remember, the DAC measured and sounded fantastic, but truth be told, it is to the point where I personally am not able to differentiate the sound quality from my already excellent TEAC UD-501 bought in 2013 and I didn't absolutely "need" any of the new features it provided. Furthermore, as you know from my discussions of digital room correction, sound quality IMO is more a function of other factors than just the DAC accuracy.
Before I parted with the Sonica DAC, I did make a few other measurements out of curiosity. One of the measurements was to have a listen and look at the Bluetooth 4.1 audio playback from my Samsung Note 5 phone to the Sonica.
Saturday, 2 December 2017
Since returning from my Asia trip. I see that new toys for Christmas have now been released including the new Xbox One X (which I mentioned a few months back).
Although it seems like there may be issues that need to be fixed, one nice feature of the Xbox One S and X machines is the ability to play the new Blu-Ray UHD disks which have been available since March 2016. Though there are a number of disks out there now, I suspect the growth has not been spectacular... Not unexpected really since the jump from 2K (1080P) to 4K (2160P) resolution does require the right conditions as laid out previously to be truly appreciated, plus, like music, movies have gone "virtual" with streaming being the primary mechanism of consumption.
For this post, I thought I'd put together a few discussion items about video IMO worth thinking about as we are very much in the era of the 4K videophile!
Saturday, 25 November 2017
|piCorePlayer streaming WavPack-compressed DSD128 (1-bit, 5.6MHz) to TEAC UD-501 from recent nightly version of Logitech Media Server 7.9.1.|
Saturday, 18 November 2017
Many moons ago (back in 2013), I discussed DSD audio. While over the years I've talked about DSD from a a number of different angles (eg. JRiver realtime conversion listening, PCM <--> DSD conversion, conversion 2015, equipment DSD playback measurements like PonoPlayer / TEAC UD-501 / Oppo BDP-105 / Oppo Sonica DAC), concerns from that very first discussion about DSD still irks me these days!
The main issue is simply this: the lack of ability for gear and software to support both tagging and data compression when dealing with DSD. This IMO truly has been a ridiculous state of affairs for so many years! Despite years of cheerleading in the industry and even smaller sales outfits like NativeDSD Music already putting files out there for consumers, the relative inelegance of it all is rather silly.
As usual, I find it rather baffling that the typical mainstream audiophile press remains silent on deficiencies like this. To me, it is issues like these, while perhaps not "sexy" nor provides the press something to market to consumers, that when addressed can actually move the hobby forward. Unlike yet another megabuck product that provides a few minutes of eye-candy at best and affects the few, "infrastructural" changes can affect the many. Yet another example of the myopia of the audiophile press and an inability to muster any leadership in changing the industry and hobby in meaningful ways.
Sunday, 5 November 2017
Greetings from Asia.
Okay with all the recent chatter on MQA, let's take a little break from audio for a bit and talk about something much less controversial :-). In fact, this is downright basic for all the computer overclockers out there...
Remember a few months ago, I upgraded to the AMD Ryzen 7 1700 CPU. As discussed in my previous article, I upgraded to a computer with this processor for workstation purposes, not gaming or anything like that. I've certainly been impressed by the speed already but as one who enjoys tinkering with the machines, I thought it would be fun to try overclocking without sacrificing power efficiency...
Sunday, 22 October 2017
Saturday, 14 October 2017
|Cartoon looks about right and reflective of MQA... From article here.|
Sure, I'll be around to add my two bits and answer questions where I can, but to be honest, I'm a little tired of MQA by this stage and how much of a big deal it isn't, IMO.
Saturday, 7 October 2017
After having gone through the "core" results and subgroup analysis from the MQA Core vs. Hi-Res PCM Blind Test, let's review and post some subjective comments gathered in the survey. This provides an opportunity for us to see how people described what they heard and since we know what the preferences were, put them in the context of whether the descriptions referred to a bias towards the MQA decode or standard PCM...