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...

MEASUREMENTS: A Look at Linux Audio (ALSA, PulseAudio)

What is that you ask? Well, it is the slowest computer in my house :-). It's a "vintage" HP Mini 110 from circa 2009. I decided recently to stick Linux on there just to see how well it ran... Here's the System Information:

As you see, I've got Ubuntu 14.04 LTS (updates current as of Sept 2015) loaded up on the old machine which has been sitting around unused for a few years. It's one of the early Intel Atom N270 CPU's (32-bit, single-core hyperthreading, 1.6GHz), 2GB DDR2 RAM. Slow 16GB SSD as the main drive. Whole OS loaded up on the tiny storage, no problem. Linux runs fine on the machine but it's obviously not fast, but works for light web surfing, E-mail, word processing... Now, how about for audio?

MUSINGS: Meditations on the limitations of hearing & listening.

For today's MUSINGS, let us take a few moments to think about our sense of hearing. Though the auditory system is not as complex as the visual architecture, the extensive interconnections and association areas they intersect with of course provides us with an altogether unique experience integrating emotions and memories. The "drug of choice" for us audiophiles is in the auditory domain. The music we hear adds to the quality of life, and in so doing, satisfies at least to some extent a sense of meaning to our existence. Much of this is a mystery which perhaps in time with the development of neuroscience, secrets may be unlocked... But even if these remain impenetrable mysteries, there is of course no denying the value and truth to human subjectivity. That joy and meaning is wholly ours alone, it is our right as sentient beings to own and cherish.

As humans, we also recognize that we are limited in every conceivable dimension and sensory modality. We cannot smell as well as dogs, we cannot see as well as cats, we cannot hear as acutely as bats, our proprioceptive abilities pale in comparison to even more primitive primates swinging in the trees... Over the years, I have posted on the importance of being aware of these limitations so as to be insightful about our abilities especially when making claims about what is heard or not heard. For example, I think it's useful to try something like the Philips Golden Ear Challenge as a way to evaluate our own hearing acuity. Having an appreciation of dynamic limits also helps us appreciate the importance of sound levels and silence in the listening environment. Knowing the limits as a human being helps us to understand the importance (or unimportance!) of developments like high-resolution audio and what we should expect.

MEASUREMENTS: Light Harmonic Geek Out V2

I know some folks have been awaiting the results for the Light Harmonic Geek Out V2. As you know, I have already provided a bit of a preview a few weeks back so no need to say much more I think. Generally my feelings about this device have not changes over the weeks... The 3D printed plastic smell has completely dissipated by now. It does sound great and I must say, going into the measurements, the impression was that this is some of the best sound I have heard from these little USB devices! Remember, this is a $235US unit I got as an "early bird" off the Indegogo promotion.

Let's see if the measurements are consistent with some of my early subjective impressions.

MEASUREMENTS: PonoPlayer and DSD Playback

Hey guys, just a quickie posting here for mid-week...

I was looking over the measurements over the last few months and realized I neglected to post results of the PonoPlayer doing DSD64 and DSD128 playback! So, instead of the data just sitting on my hard drive, I thought I might as well throw it out here for reference.

I don't believe I have seen anyone measure results of DSD playback with the PonoPlayer. I suspect a reason for this is that DSD was an "add-on" firmware upgrade released after the major magazines got a hold of these units for review. But then again, how often do you see measurements of DSD output quality?! I'm guessing that DSD playback was a "checklist" feature that some people wanted or it looked good for the company to support. Of course DSD is an acceptable input data format for the ESS SABRE9018K2M DAC chip (as it is with essentially all high quality DACs these days). DSD has been enabled as of firmware 1.0.5 back in February. For my tests, I'm using 1.0.6 from the May 2015 update.

MEASUREMENTS: ASUS Xonar Essence One MKI with DSD upgrade kit. (Part I: EEPROM)

Ahhhh... The ASUS Essence One! Even though looking back, compared to others I have listened to or measured, this DAC had its various imperfections, it has been my constant companion on the computer workstation. Through it, I have listened to hundreds of hours of music, edited my share of audio, evaluated pairs of headphones, and run various "experiments". Like an old friend, you get to learn (and at times even appreciate) the quirks. To this day, it remains my "workhorse" DAC. Why, you might ask?

Because it has 2 nice big volume knobs. One for speaker output, the other for the headphones... Simple as that :-).

If you look back at my measurements and review of this DAC back in 2013, you'll see that I generally liked it. With my perspective today, though I believe much can be improved (everything from channel/volume control balance [apparently fixed with later Essence One MKII edition which also incorporates the DSD feature], J-Test could look better, noise floor cleaner, etc...), it was the hyped up "symmetric upsampling" that was perhaps the most bizarre let-down. Imagine a digital filter that acted as a brick wall at 15kHz! Certainly made the DAC sound "mellow", but in a bad, inaccurate way...

Despite rumours of a fix to the firmware, nothing happened after I reported this anomaly. Until late 2014 by the looks of it. And I wasn't aware of this until this past month...

MEASUREMENTS: Sound Room Update, Digital Room Correction (DRC) and JRiver DSP Studio...

Many years ago, back in 1992 to be precise - the year Windows 3.1 was introduced, when the typical PC was running below 33MHz, and Mortal Kombat 1 was hot in the arcades - I vaguely remember reading this article from Stereophile and filed it in my memory banks as something from science fiction for another day (I heard my first MP3 compressed song soon after and thought it was amazing given the data compression!). In it, Peter W. Mitchell reportedly "heard the future" and was clearly impressed by the technical wizardry of what a "Digital Signal Processor" could accomplish. The power of the digital room correction was described as "mind-boggling". If you haven't thought much about digital room correction, I would highly recommend reading that article in its entirety and consider whether the arguments make sense to you. I don't recall reading anything further about AudioSoft or whether Snell eventually created this cartridge-based "black box" audio correction system, but as we fast forward to 2015, we are living the legacy of what was described.

These days, DSP techniques are commonplace. As digital has long supplanted analogue as the preferred method of encoding our audio and video media with high fidelity, it has all become data that we can examine and modify as we desire depending on the situation. Compress to MP3 for times we don't need highest fidelity? No problem... Resize from 1080P to 720P for the cell phone screen/storage? By all means!

Explicit uses for improving audio quality include audiophile offerings like DEQX and Lyngdorf (including McIntosh MEN-220), some products like the Devialet amps include their "Speaker Active Matching" correction filters, and the home theater crowd have been using Audyssey and the like for years.

It is interesting these days then that DSP room correction is primarily the domain of home theater and AV receivers, rather than high-end audio. In fact, reading certain "high end" audio forums suggest a stigma against DSP techniques to improve the sound of an audio system. Among audiophiles, it's not unusual to see suggestions around listening to tubes, turntables, and vinyl LPs as providing some kind of elevated audiophile experience, but I've ironically experienced the cynicism when you bring up the idea that digital room correction is important if not essential as a very desirable way of improving the high-fidelity experience.

MEASUREMENTS: Samsung Galaxy Note 5 Phone

As you probably know, for me, convenience and practicality are the most important elements of mobile audio. As much as I enjoy the audiophile hobby and achieving high fidelity sound, I think it's important and realistic in acknowledging that consumption of music on-the-go these days is tied in to the ubiquitous "smartphone" many of us carry around. They have become indispensable tools in so many ways that for music lovers and audiophiles to not take them seriously IMO would be denial. I think it's fascinating that audiophile magazines rarely ever mention these devices despite the fact that millions of us use them every day and gain so much enjoyment in the process!

The last phone I got was the Nexus 5 which I measured back in early 2014. As you can see, it doesn't measure too well using the standard test bench but adequate for busy environments. Not inspiring 16/44 performance and it does accept 24-bit audio but can't really perform beyond close to 16-bit dynamic range. It's also limited to standard resolution 44kHz only.

Last year, my wife got the iPhone 6 which I also examined. Up to 24/48, it performed well subjectively and with objective measures. Clearly a step above my Nexus 5 in terms of achieving >16-bit dynamic range. In terms of output impedance, Ken Rockwell measured the iPhone 6+ as 3.18-ohms and the Nexus 5 is probably around an unimpressive 10-15-ohms.

Well, after close to 2 years, here then is my phone upgrade:

Shown in Otter Box case.