Well folks, it has been a busy last number of weeks around here since I returned from the overseas work trip. No time to play with much audio or tech stuff as a result until earlier this week.
Today I want to just discuss/show a couple of things...
Consider the phrase "multidimensional audio". In today's world, I think if anyone were to use that phrase, one would be thinking about multichannel and surround sound as "multidimensional". Instead, that graphic above is taken from this article - "Multidimensional Audio" (1979) by Henning Møller of B&K.
It's a thoughtful article that harkens from a time when analogue audio was king, years before the availability of even 1Mbit (~128KB) memory on a chip, and a handful of years before digital audio took over (first CDs released in 1982). Reading a paragraph like this from the article:
"Nevertheless there is often open warfare between the "subjective people" and the "objective people". People that really have been listening intensively for years often say that measurements are absolutely useless because they judge from the few old-fashioned measurements they might know. And often the so-called objective engineers say that, for instance, reviewers are crazy because they judge contrary to the measurements."Suggests that in audio discussions on some forums, evidently nothing has changed in the last 40 years :-)!
While these measurement/objective dimensions are still relevant these days, when reading the article, what is of course notable compared to 1979 is the testing technology itself. Today, we audio enthusiasts have at our disposal software (often freely available like Room EQ Wizard) that will give us many of the parameters listed above quite easily with resolutions unattainable in 1979 (certainly not at home!). Computing resources and hardware devices like high quality ADCs and decent measurement microphones, can be purchased without huge expense.
Ultimately, what is most important from the Møller article is the underlying concept of bridging the subjectivist-objectivist divide by embracing all the dimensions of audio within reason. His use of the "apodization" concept beyond the technical definition to suggest:
The "truth" is always somewhere in between. Therefore the practical version of Apodization is to find the optimum compromise between the sharp extremes by smoothing things out.seems appropriate. There is no need to hold on to "sharp extremes" of pure objectivism nor pure subjectivism. After all, "hi-fi" 2-channel sound reproduction is itself a compromise; a simulacrum of actual acoustic events in actual acoustic spaces which we cannot fully capture with 100% accuracy nor of course reproduce with exact fidelity. At best, we hope that each piece of the reproduction chain can do its part in producing the "local" objective intent such that as a whole, the "global" effect of the system represents subjectively "good sound".
Since this article tries to marry both objectivity and subjectivity, let's add one more "dimension". Let's add the dimension of the subjective listener:
7. High fidelity perceptual ability.
This is important because ultimately sound quality is only as "good" as the ability of the listener to perceive and judge such a thing. This dimension can to some extent by objectively understood as well because we can measure the hearing ability of the "subject" him/herself. The listener is the ultimate arbiter of "good sound" but we know that just like all human traits, there is a normal curve to human abilities - not all listeners are equal or desire the same thing. And I think it's just as likely that not all human beings can nor care to appreciate high-fidelity sound.
While we can calibrate measurement devices like microphones, ADCs, and oscilloscopes, the human "subject" is much more complex with all kinds of perceptual and psychological strengths and weaknesses we can never truly know, nor IMO fully trust when it comes to what is said or believed no matter how sincere. At best, we can measure hearing acuity and listeners can be trained, perhaps "certifying" them as capable listeners (like taking a test such as this old "Philips Golden Ears Challenge").
For me, the contention comes when I see supposedly "authoritative" reviews based only on subjective listening, especially when all the other objective dimensions tell us that the product more than likely cannot perform as the subjective reviewer claims! Classic examples of this are the countless cable reviews of remarkably expensive products (here's a recent example - remarkable!). The result of a purely subjective review can only be as good as the reviewing "instrument", the abilities and conditions of the person writing the observations if objective results cannot be used to converge on the same conclusion. We only hope that the reviewer has considered and accounted for questions such as:
- With what other gear was the review based on?
- How were the listening room conditions?
- How long did one listen?
- Was listening done alone or in the company of others and what opinions were added if so?
- What music was used? Was it music one liked? Was the mastering good?
- How was the listener's mood state during the sessions?
- Was there stress with looming deadlines or other life events?
- What is the hearing acuity at the time of the auditions (tinnitus, sinus conditions, recent loud noise exposure, presbycusis)?
- Were "substances" involved at some point in the audition to modify perceptions and mental state? :-)
- Did the physical appearance of the gear or price tag affect the listening impressions?
- What history does the listener have with the manufacturer, representatives, or previous products? Can the reviewer honestly state that relationships, perks, and financial support did not play a part in the product's perceived performance?
I agree with Møller that a broad set of objective measurements will correlate with subjectively "good sound". I've heard it asked whether a deaf engineer is capable of making good sounding gear based just on measurements. IMO, of course this can happen! After decades of research and generations of consumer audio, it would be an absolute failure of science and engineering if it were otherwise! The unfortunate part would be that without being able to listen, the engineer would ultimately not be able to verify the design and use the adjective "good" in a global, subjective fashion.
As I've said before, I think having a "more objective" bias when it comes to equipment reviews and methodology simply makes sense as providing much more information to the reader. In a related way, when was the last time you dug up your favorite subjective reviewer's articles from 1979 and found the described sound quality impressions confidently applicable in 2018?
While the subjective reviewer with all his/her complexities could be long gone from the audiophile scene, improvements in objective audio fidelity can be appreciated across time documented by the value and relevance of objective facts.
(By the way, remember that Dolby TrueHD, which is the lossless compression audio format typically used for these Atmos soundtracks is actually Meridian Lossless Packing [MLP] which Bob Stuart helped create, like MQA... See... I'm not biased against Stuart - only when there's reason to show that the technology is poor!)
Here's my audio / home theater room as of mid-November 2018:
Notice I've added a couple of rear height channels situated on top of my vinyl collection (there's also my old Onkyo receiver, Sony laser disc player, and Playstation 1 up there).
Since my Yamaha RX-V781 receiver (if buying these days, I'd consider the current Yamaha AVENTAGE RX-A1070 model) is capable of decoding 2 height/ceiling Atmos or DTS:X channels, and I had a couple of old Energy C100 bookshelf speakers hanging around, why not employ them to improve my surround sound system?
So I bought some generic 14G speaker wires, 8 of these Hudson Hi-Fi 1.25" hemisphere silicone footers:
And found inexpensive yoga foam bricks of the appropriate height to prop the speakers up to the calculated ~32° I needed for them to be angled at. The reflections off the ceiling would be directed just in front of those seated on the sofa. Here's a side view of the rigged Atmos speaker:
|Note the two pairs of hemisphere footers stuck on at the base and upper-mid of the speaker to prevent slippage off the foam brick.|
Notice I've set them as overhead "Presence" speakers (instead of typical ceiling bounce speakers which I believe incorporates Dolby's HRTF). While I am doing some "ceiling bounce" with those speakers, they are physically placed higher up unlike the "Atmos Enabled" speakers like these where an up-firing drive unit is mounted just on top of the speaker cabinet slightly higher than ear-level (typically with only a 20° angulation forward). My speakers are set up as "Small" speakers with crossover at 120Hz. Some have recommended for reduced localization to increase the crossover frequency to 200Hz; something I'll try later. I have flat, smooth (not stucco or otherwise uneven), and reasonably reflective 8' ceilings which is exactly the type of conditions recommended for "bouncing" the sound.
Ideally, one should be going with the same speaker manufacturer and line of speakers for tonal matching. Notice that I have a pair of Paradigm Signature S8's powered by my Emotiva monoblock amps. The Paradigm Signature C3 center channel, Studio 80v3's in the rear are powered by the receiver. Now we add the 10-year old Energy C100 speaker pair to the receiver amp. The Energy sounds similar in tonality to the rear Paradigm Studio 80's. Perhaps not surprising since both are Canadian companies using research from the National Research Council and are not far apart in age.
No doubt my kind of arrangement isn't exactly what Dolby calls for with an Atmos 5.1.2 set-up:
|Official Dolby Atmos 5.1.2 configuration.|
So how does it sound?
Pretty decent, actually :-).
The height and angulation worked quite well. Seated at the "sweet spot" on the sofa, when playing pink noise, the sounds from the "presence" speakers do appear like they're coming from directly overhead rather than behind when watching the screen. Atmos demo material (can be downloaded here) as well as some DTS:X demos (here) sound good showing off the extra dimensionality. I also checked out a few of my UHD Blu-Ray movies with Dolby TrueHD Atmos soundtracks: the start of Mad Max: Fury Road when Max hears the voices "worming their way into the black matter of my brain", the gory yet funny start of Deadpool 2 with contributions from Dolly Parton and Enya, and the fantastic overall surround mix for John Wick Chapter 2 come to mind.
Consumers like to debate format wars but as far as I can tell, there's no such war between TrueHD/Atmos and DTS:X at this point (nor needs be!). Both are capable of lossless, high resolution, object-based audio. Most good receivers these days support both. What we can say is that DTS:X has provisions to be more speaker placement agnostic and the Multi Dimensional Audio (MDA) format supposedly is open and royalty-free. Ultimately I guess we'll see which of the two is supported by the most studios and have the most number of shows released for the home consumer.