MEASUREMENTS: Apple iPad Air 2 - Audio Output Quality

Although for the most part, I am a Windows and Android guy, I do have a little collection of Apple devices here at home. Despite taking a look at the MacBook's CoreAudio upsampling, measured the iPhone 6 when it came out, and explored various MacBook laptops over the years, I realized that I had missed out on one of the most important "line" of products from Apple - the iPad.

Last year, I needed to run an app for work that was only available on the iPad so I got one of these Air 2's. As a reminder, the iPad Air 2 is currently (early 2016) one of the latest versions of the iPad line (there are of course the parallel Mini and new Pro models). It was announced back in October 2014 and is considered the "sixth generation" iPad tablet. The model I have here is the 64GB gold-color version, Wi-Fi only, with newest iOS 9.2.1 installed. The screen is gorgeous with the "Retina" resolution of 2048x1536, nice and bright with great contrast. CPU is the Apple A8X (1.5GHz tri-core), 2GB DDR3 RAM internally. Physically, nice and thin with the standard 9.7" screen - great for surfing and media content consumption.

MEASUREMENTS: MQA (Master Quality Authenticated) Observations and The Big Picture...

I. Preamble:

As expected, MQA articles are popping up at the usual audiophile sites. So far, what has been disseminated to the public about the technology remains rather nebulous beyond the basic core ideas. Probably the best technical descriptions come from John Atkinson's article back in Dec 2014. It focuses on the "encapsulation" process of reconstructing high-frequency content. Then there's the Robert Harley articles from May/June 2015 where there seems to be more attention paid to supposedly important time-domain factors and MQA's role (alas, the PDF link I referenced in this post got taken down!).

Since CES2016, I see that articles continue to focus on subjective experience, and there's a chorus of testimony about the greatness of MQA (see here, here, here...). Notice the vacuousness of interviews like this. Testimony is fine and is what it is. I'm sure the MQA folks are smart... And I'm sure Mr. Stuart is a great guy... Yes, clearly Mr. McGrath can show off some well recorded material... But it was perhaps surprising how there remains so little spoken further about what the algorithm is doing or even better yet, providing technical clarification on simple questions. In sum, there's little to suggest that the science makes sense in the way it's supposed to make the music sound "much" better despite vague claims like how research in neuroscience is supposed to support the benefits of this technology (Meridian/MQA, care to reveal which neuroscience papers you're talking about?!).

MEASUREMENTS: Stealth Releases of Good Remastering in Hi-Res Audio... (Alanis Morissette!)

The other day, a reader suggested that I check out the recent 2015 HDTracks remastered Alanis Morissette albums. I must admit that I'm not a big fan of Alanis (my sister was more into her albums), but back in the day, did enjoy the 2004 album So-Called Chaos. As I revisit the album again this past week, I was reminded of how poorly the original CD was mastered as witnessed below:

MUSINGS: 1st Week 2016, CES 2016, and Christmas Toys!

 

The first week of 2016 was quite busy in terms of getting back to work and the news feed... Let's just shoot the breeze and talk about a few things this for this post...

1. It has been fun reading about CES 2016. I've been monitoring the articles on The Verge. Mainstream broad coverage is good to see the trends heading our way. Overall, it looks like the push towards 4K TV continues with HDR being the buzz (audio industry should make note and try for some higher dynamic range, please).

Among the new VR products and Internet Of Things (hmmm... Not sure if I really want a Smart Fridge), the main audio news that so far has made it to the mainstream is the re-release of the Technics SL-1200 turntable. Clearly, at the asking price of US$4000, the "Grand Class" SL-1200G(AE) is not going to be heading to your local dance club spinning DJ vinyl any time soon! Clearly this is targeted at the affluent audiophile class. As you may know, I've been spinning LP with my Technics SL-1200 M3D for the last year and a half. The machine is built like a tank and I very much expect it to last a lifetime. If indeed the new SL-1200 street price ends up being even close to $4000, I suspect it's not going to make a dent in the used market at all!

I suspect that when vinyl gets elevated to the realm of a luxury item like the Technics, plus a ridiculous association by Sony that their PS-HX500 turntable is anything deserving of  "Hi-Res" status suggests that the vinyl awakening is in full swing and in the midst of being over hyped in the eyes of the general public (articles like this showing up already). The association with vinyl and high-resolution in the mainstream is particularly disturbing and at some point will trigger a backlash against the BS. As I have said before, there is a "cool" factor to vinyl because of it's material properties (physically tangible, size of artwork - great for talk shows when the host wants to show the album cover) and psychological retro coolness triggering nostalgia. But the idea of associating sound quality in the sense of "high-resolution fidelity" is clearly wrong - and the mainstream knows it. They just have to listen to a typical turntable playing a typical LP. Please Sony, don't do this and set yourself up for more ridicule.

Perhaps not surprising is the lack of talk about "High Resolution Audio" in the mainstream (discounting the audiophile press where they are limited to this stuff). Unlike last year with awards handed to MQA and hype around the new Walkmans and Pono, I'm guessing things have gotten pretty quiet this past year in terms of actual sales. (As I noted a few weeks back, it's not surprising when the current crop of music labelled as high-resolution is nothing but the same recycled mixes/masterings not truly deserving of larger digital 'containers'.)

MEASUREMENTS: ASUS Xonar Essence One DSD Upgrade (Part II: NJR MUSES 02 "Audio Opamp Rolling")

As you may recall, a few months back, I posted on the ASUS Xonar Essence One and the DSD Upgrade Kit. That post was only Part I because the kit not only included an upgraded firmware EEPROM to allow DSD64 playback, but there were a couple of New Japan Radio MUSES 02 opamps in there to use as well. New Japan Radio seems insistent on marketing this MUSES brand of opamps for audiophile applications and certainly the price tag is consistent with the audio "high end" - we're talking US$45 per stereo "flagship" opamp (MUSES 01 and 02)! As a result, there are quite a number of fakes out there especially on eBay so make sure you get these chips from a reputable dealer if you're in the market.

On a side note, it's interesting that companies these days are using "replaceable opamps" as part of the feature set of devices like motherboards; even motherboard manufacturers like Gigabyte are in the act of selling opamp kits!

When it comes to the old ASUS Xonar Essence One, I figure why not perform a few measurements and see if replacing the LM4562NA opamps (US$2.00 a piece) I had in there with these expensive MUSES 02's made a difference; the company claims that there's a "Profound Musicality" benefit with the MUSES. As a reminder, I had put in the LM4562NA opamps a few years ago. The stock Essence One uses NE5532 (<US$1.00) so my results may not be the same as someone going from stock configuration to these MUSES 02's. Remember that "opamp rolling" is not uncommonly discussed on message forums. And there have been some excellent write-ups in the past. Like high-end cables, there are those who swear by the improvements they hear but looking around, I have not seen anyone publish objective results from a DAC despite all kinds of testimony.

Note that there are different positions I could place these MUSES in but basically settled on the Low Pass Filter (LPF) stage which potentially could benefit all audio outputs. (In diagram below: 3A - for RCA output only, 3B - XLRs, 4 - headphones only.) I really did not have any great desire to pull out and reseat various opamps to try different configurations so just plugged them into place and closed my DAC, running measurements before and after the surgical procedure.

So here they are situated on the PCB:

MUSINGS: The Wisdom of Simplicity [RE: Hi-Res Audio]? And a Happy New Year!

Life is really simple, but we insist on making it complicated.
--- Confucius

Everything should be made as simple as possible, but not simpler.

--- Albert Einstein (apocryphal?)

Only the simplest can accommodate the most complex.
--- Juni Kimura, 47 Labs / Sakura Systems :-)

Let us ponder a few moments on the first "As We See It" column for 2016 in Stereophile. Humorously titled "To the Simple, Everything Appears Simple".

After reading it, I was thinking, what was this article about anyway? An admonition (based on some other Facebook comment) about the perils of blind testing? Another caution to listeners that A/B testing involves the activation of analytical brain networks rather than those we use to appreciate art? Yet another attempt to impress/convince readers that music in a high-resolution container is significant for the home listener (like comments and articles about the virtues of Pono and high-res on-the-go)? A fair warning about jumping to conclusions without considering nuances or alternatively an attempt at instilling fear, uncertainty, and doubt in what should be rather obvious observations?

As we sit here at the end of 2015, I remind readers that "high-resolution" audio has been with us now for a rather long time! Many of us interested in technology and the "cutting edge" have likely been listening, perhaps testing, and evaluating >44kHz and >16-bit audio for the last 15 years. We have seen technologies like SACD and DVD-A essentially come and either gone or linger in some state of stagnation. We have witnessed the promise of a better-than-CD but CD-compatible "format" like HDCD come and go. I suspect many of us bought "music DVD's" encoded in 24/96 or 24/48, stereo, and multichannel years ago to get access to that promise of high resolution and listen for ourselves to satisfy our own curiosity - way before the Hi-Res Audio branding hype or inflated expectations from "evangelists" like Neil Young or the corporate push (eg. Sony).

Merry Christmas! 2015 (NYC)

Season's Greetings everyone! As part of my travels, this past week, I spent some time at the "Big Apple"...

As expected, the crowds were enormous this time of year in Manhattan but what wonderful atmosphere to take in! The museums, the shows, the people, the food... Remarkably mild weather too.

MUSINGS / BUILD: HTPC Rebuild... Skylake / 4K (Part II)

Okay, after laying out the foundation in Part I, let's rip open the boxes and get building the new HTPC!

Right... So I'm reusing the old Antec ATX tower case from 2003(!) for this build. It used to house an old Intel Core 2 Quad Q6600 CPU/board you see on the floor there. I put that computer together back in 2007 and it had been in constant use until 2 weeks ago so I really got my money's worth after 8 years! What I'm really impressed by is that there was still one of the early-model 1TB Maxtor HDs in there in good shape. Time to retire this board in any case... Maybe I can still put it to service at some point for my kids.

And here is the new Intel i5-6500/Gigabyte Z170X-Gaming 7 assembled with the CoolerMaster Hyper 212 Evo heatsink (and Corsair DDR4 RAM) living in the old Antec case. Blue SATA connector attached to the ADATA SP600 256GB SSD:

MUSINGS: HTPC Rebuild - time for Intel Skylake and ready for 4K... (Part I)

For many of us, I suspect the image above would be familiar... The 'old' Windows Media Center (WMC) software. Alas, as of this year, with the release of Windows 10, the Media Center functionality has died (although arguably after a long period of being on life support since 2009). Not that I ever used the software much but I do recall the hey-day of when Microsoft was promoting the PC as the center of the home theater hub. In fact one of my early Home Theater PC's (HTPC) was built around a reasonably fast AMD processor and running WMC as a PVR with a TV card installed back in the early 2000's.

Now in the 2010's, functions promised of by the HTPC can be handled by Smart TV's and all those standalone boxes like the AppleTV, Amazon's FireTV, or the myriad of inexpensive devices like this. Perhaps wisely from a revenue perspective, Microsoft has shifted the focus on development of media access through their Xbox One game system (and Sony in their PlayStation 4).

Personally, I still love the idea of a full-functioning HTPC in the media room. A machine that can handle whatever audio and video format I can throw at it (I posted some thoughts back in early 2014). And when not watching a movie or listening to music, something I can turn on and use for software like REW or Acourate, surfing, the occasional game, or computer-based karaoke when friends come over :-). Software for HTPC functions have grown nicely over the years - check out some options here. And for those who insist, there's even a hack to get WMC on a Win 10 install.

MEASUREMENTS: Digital Room Correction with AudioVero's Acourate...

A few months ago, I posted on the use of the free DRC software for audio room correction. I was already very impressed with what the technology is able to accomplish and wanted to explore this even further. In this spirit, I invested in a copy of (((Acourate))) from AudioVero. As I had mentioned previously, there are a number of other software/hardware packages to accomplish a similar task. While I'm sure other packages would do a fine job, as a JRiver user, I wanted to create WAV-based FIR filters like I did previously with DRC which I could import into the convolution DSP and Acourate allows me to do just that without needing to run any other plug-in.

Acourate isn't inexpensive and does cost 286€. However, realize that we are entering rather "specialized" territory and although I suspect many audiophiles know about FIR-based room correction, it's not exactly mainstream (for example, how often do showrooms at audiophile shows utilize room correction DSP?)... Personally, given the amount of potential improvement, we could easily spend 286€ (~$310USD currently) on stuff like fancy cables and other tweaks achieving likely no actual improvement in sound quality.

MEASUREMENTS: Apple Mac OS X ("Yosemite") Software Audio Upsampling

Well... You knew this was coming, right? After looking at Linux, then Windows, what about all the hub bub with Mac OS X? Depending on which forum one visits, there's often talk about Mac's being "better" as audiophile sources than PCs.

As readers here know by now, I think sound quality these days with a decent modern digital interface is primarily a function of the quality of one's DAC. So long as the digital source device is decent (not a high bar to cross by any means!) with bitperfect results and absent of any timeout errors, or extreme noise pollution, it's just fine. And one can verify the quality with objective measurements of course.

The question being asked today is, compared to the software upsampling in Windows and Linux, how well does the Mac OS X software upsampling measure up?

MEASUREMENTS: Windows 10 "Audio Stack" / DirectSound Upsampling

I know, I know... Windows audio mixer sucks... (From the perspective of perfectionist audiophiles.)

But having just done some measurements with Linux and PulseAudio with some of the upsampling algorithms, I wondered just how well the default Windows 10 audio mixer performed as an upsampler...