MUSINGS: Trust, empirical testing, and evidence in the Audiophile hobby. And the Double Blind Test (DBT) strawman argument.

For this post, let's spend a little bit of time thinking about "levels of evidence" in audiophilia. This is important because it helps determine how we gauge the veracity of the articles we read and how we build confidence as we create our own internal models of the topics covered in this hobby.

Inevitably, if we stick around this hobby of audio gear and products long enough, we'll come across the abbreviation 'DBT' - that dreaded Double Blind Test; that seemingly ultimate methodological scientific "gold standard" in human research to tell us whether an intervention or change in our systems actually resulted in a worthwhile difference.

But do audiophiles actually throw around the comment "You need to do a DBT!" very often? Or insist that "I don't believe that unless a DBT proves it!". The answer is 'NO!'- of course not!

Let's start by zooming out a bit and thinking about the very big picture...

High Frame Rate (HFR) movies: time to overcome resistance? Also, on anachronistic nostalgia. And why I rarely go to movie theaters these days.

This week, indulge me in staying a little longer with discussions on the video theme; since I view audio and video technologies as members of the same family, there will be references and detours made about audio in this post.

Although I think 4K is plenty of spatial resolution already for home use (discussed years ago at the advent of UHD BluRays), there is one obvious way to increase the perceived resolution of video playback - improve the "time domain" performance.

While basically everything about motion picture technology has evolved - aspect ratio changes from 4:3 (silent film) to widescreen, frame sizes (35mm various forms, 65/70mm, various digital sensor sizes), B&W to color, higher effective resolution, transition from analog film to digital - isn't it amazing that the cinematic framerate has remained at a mere 24fps, and commonly 180° shutter rule for motion blurring (more geeky testing here)? Since the dawn of the "sound film" in 1926 - almost exactly a century ago! 

High Frame Rate (HFR) movies - movies that were filmed and projected at more than the "cinematic" 24fps - typically 48fps or 60fps - have been simply uncommon for feature presentations to this point. Perhaps reminiscent of multichannel music which had its starts and misses over the decades (eg. 4.0-channel quad back in the '70s), HFR also had a time in the '70s and early '80s when the company Showscan was trying to achieve higher image quality with 65-70mm film at 60fps. But like quadraphonic audio, the technology of the day wasn't really good enough for practical, economical, trouble-free high-fidelity visual reproduction.

Imagine what kind of physical demands would have been necessary for this. Showscan ran the film at 4.68ft/s or 281ft/minute! Clearly a costly endeavor (estimated $2-3M just for the negatives and processing to make a movie back in the '80s) plus imagine the pounds of film to send out to all the theaters, maintenance needs, plus potential damage to the film after a number of runs. How many showings would have been needed for a decent return on investment?!

No surprise then that full-length films were never released in this format. (Here's an interesting brochure from 1990 of their High Impact Cinema prototype, and their 1987 company prospectus.)

HDMI Musings: high speed cables, data rates, YCbCr color subsampling, Dolby Vision MEL/FEL, optical cables and +5V injection.

Hey folks, for this post, I thought it would be good to dive a little more into the world of AV technologies after discussing the nVidia Shield TV Pro last week. While "classic" audiophile technology (ie. standard hi-fi analog and digital 2-channel stereo without special DSP advancements) has matured nicely already, this isn't quite the case with modern digital video tech. While many (probably most) features have settled, we can see ongoing evolution of the High-Definition Multimedia Interface (HDMI) standard to be mindful of - for example the recent announcement of HDMI 2.2 at CES2025 expanding capabilities well beyond the needs of today.

As usual, it'll take time (years) for this standard to be incorporated into TVs and source devices like GPUs (latest nVidia RTX 5080/5090 are HDMI 2.1b) or something like VR devices being at the forefront of potential generational gains. For more than 20 years, with each significant revision of the HDMI standard, we're seeing doubling of data speed with HDMI 2.2 now aiming at just shy of 100 gigabits-per-second (96Gbps), twice of the 48Gbps bit rate in current HDMI 2.1 products.

This recent update makes HDMI the fastest of all currently-announced consumer Audio-Video connection standards, the one wire that basically does it all - hi-res video (with high dynamic and frame rate), hi-res audio (up to 32 PCM channels at 24/192, with DSD to 8-channel of DSD256), HDCP copy protection, audio return channel, even ethernet (100Mbps).

This level of sophistication (and licensing costs) could make it difficult for small companies with limited R&D capabilities to get in the game with custom designs. This is probably in part why the cottage industry audiophile companies rarely use HDMI other than selling overprices cables (like AudioQuest). Plus frankly, basic 2-channel audio doesn't need the higher technical capabilities anyway (which is basically what Paul McGowan says).

Let's run through a few thoughts about HDMI that might be good to know as general knowledge as tech enthusiasts. I'll provide a few links of interest, touch on tech stuff like color spaces and subsampling, and things you might want to try if you're running longer high-speed HDMI connections and potentially noticing issues.