REVIEW: Optimal Audio and Video Reproduction at Home (Vincent Verdult, 2019)

For those reading this blog, I think I've been quite consistent over the years in expressing my views about audio/visual technology. I think my philosophy around the importance of focusing on the objective and being careful with purely subjective evaluation has been clear.

As such, once awhile when I am contacted to consider a new product or asked to provide an opinion, I will of course evaluate through that perspective.

A couple months back, I was contacted by Vincent Verdult to have a look at a book he recently published by Focal Press, succinctly titled Optimal Audio and Video Reproduction at Home, released in 2019. I was sent the 346 page paperback from the publisher, it's also available in hardcover and eBook editions. Let's spend some time with the contents of this book and consider how one might find it helpful especially as an audiophile.

As you can tell from the title, this book is not just about audio. Rather it sets its sights much broader to encompass the full audio-video experience at home - topics include multichannel audio and modern high-definition video.

Verdult's bio tells us that he works as an Information Security Consultant at the Ministry of the Interior and Kingdom Relations in the Netherlands. His background is in systems and control engineering and he developed an interest in audio-visual reproduction over the last 2 decades with his own systems, speaker designs, and acoustic treatments. Clearly, he's approaching this as an author with a scientific background aiming the book at hobbyists who might be keen to understand an engineering perspective. Indeed, the science-based and disciplined approach results in a well-edited, clean layout, high resolution (black and white) illustrations including graphs, charts, room diagrams and even the occasional mathematical formula to demonstrate relationships in the text (don't worry, not too many formulae!).

The paperback edition is printed with a rather small font size (between Calibri 9 and 10 point) so if you want larger text, the eBook edition may be easier for some; not sure if the hardcover edition would be different.

Topics are methodically approached from the perspective of the basic scientific principles and then built up as he discusses the engineering and home implementation. I appreciate this approach and I think many readers will find this foundation very helpful. For example, Chapter 2 "Audio and Video Basics" reaches into a discussion of physiology of the eyes and ears; key definitions are presented for luminance, color range, frequency, timbre, loudness, etc. that will be further built upon in later chapters. This makes sense because it is only once one appreciates these basics can the author then address the defining theme of "optimal reproduction" - which happens to be the topic of Chapter 3.

Chapter 4 discusses essential elements of room design which obviously is a complex topic and requires much consideration. The remaining four major chapters are devoted to individual components in the overall AV system - the digital sources (he accurately acknowledges the superiority of modern digital from analogue sources), video equipment, audio equipment, and a very important chapter on room acoustics and recommendations on treatment. Each major chapter is broken down into subtopics which really helps the reader quickly hone in on an area of interest. Want to learn more about amplifiers? Sure, that would be under "Audio Equipment", and there you go, section 7.2 on "Power Amplifiers" - 12 pages on one's possible power requirements, the various classes of amps, and a great section on amplifier measurements and performance characteristics.

Let me identify a few highlights I quite enjoyed reading about in this book...

Section 3.4 - IMO this chapter is mandatory reading for subjectivists just as much as the objectivists! Verdult writes about the important topic of "Sound Quality" and nicely lays out the dimensions of "Timbral Quality" and "Spatial Quality" for how we describe sounds. For each dimension, he breaks it down further, for example, timbre can be refined further into "spectral balance", "clarity", and "dynamics". Then for each of those, discusses how we can describe characteristics such as frequency "fullness", or "transient impact", or "coloration". Likewise, we can think about the spatial dimension and speak about the sense of "localization" and "immersion" we hear in our music. Great stuff that if followed consistently, will no doubt allow one to build up a systematic way to listen and the language to describe what one hears.

Section 4.1 - section on the importance of subwoofer(s) in one's sound system. Detailed rationale of why it's good to use a sub including the potential to improve the clarity of the midrange, and reduction of strain in audio playback. This chapter also nicely continues into 4.2 where Verdult expands on floor plans and room layout in a much more detailed fashion than I have seen before in other books.

By the way, I was inspired enough by the importance of considering the room layout that I mapped out my own room with measured dimensions using the Online Room Planner as a starting point to visualize ways I could optimize the geometry and placement of speakers and furniture. For full disclosure then, this is how my room is laid out and dimensions:

Section 4.2.3 - This is the best description of finding optimal front speakers placement I have ever read. The 5 points he makes on pages 88 and 89 are excellent and should result in fine placement including tips on "toe-in" when followed.

Chapter 5 starts with these thoughts: "Playing a mediocre recording on an excellent sound system won't make it sound better. In fact, it will sound worse." as he proceeds to discuss the topic of "Digital Sources". Bravo. So often we hear certain audiophiles claim that they have achieved a kind of optimal selection of components or set-up where "everything sounds great" - that's literally impossible given how many bad sounding recordings there are out there! If a person believes his sound system can make everything sound good, it's possible that the system has a certain coloration which he likes and this is imparted on every recording; this is obviously not "high fidelity".

Chapter 5 is also interesting because he goes through both video and audio sources and provides an opportunity to compare and contrast important characteristics of a video system with audio characteristics like sample rate, bit depth, signal-to-noise / dynamic range. This book is factually "dense" with deep attention to detail. Topics are up-to-date, for example, discussions on multichannel formats include modern dts:X and Dolby Atmos. For audiophiles, he even spends some time discussing DSD and MQA ("lossy" of course). Likewise, when it comes to video, Verdult discusses 4K, HDR, and 8K resolution is even mentioned (lots of info in Chapter 6 on "Video Equipment" including color space, gamma, deinterlacing, white balance, frame interpolation, etc. familiar to videophiles that I won't go into detail on here).

Chapter 7 - "Audio Equipment". I can see audiophiles spending a good amount of time in this section. Lots of stuff from the basic construction of a speaker driver, to crossovers, to enclosure designs, and frequency response including discussion of off-axis performance. There's a thorough section on power amplifiers (noted above). The section on subwoofers is remarkably detailed and speaks to Verdult's familiarity with subwoofer design - he covers enclosure effects, transient response, SPL calculations, driver excursion vs. diameter vs. SPL, power vs. enclosure volume, just to give you an idea of the knowledge summarized in this section.

In this chapter he even spends a surprising amount of time on cables including some of what I mentioned recently about speaker cables like AWG, resistance, benefit of lower inductance, etc... Not surprisingly, he summarizes:

"You should use decent quality cables, but there is no good reason to spend a lot of money on expensive specialty audio cables with esoteric designs or materials. There is no scientifically sound evidence to support many of the claims that changing a cable would magically change the sound of your system."

Like I said, no-nonsense and scientifically supported positions are found through this book.

While audiophiles do not frequently speak of it, it is important to remember that room acoustics and treatments must be right up there when it comes to "optimal" sound quality. Verdult devotes all of Chapter 8 to this topic. A thorough walk-through including discussion of room dimensions, use of absorption and diffusion devices, an excellent section on subwoofer placement/EQ/integration. I would certainly encourage the use of measurements (eg. REW) to see how your room is performing as you go through this section to better understand and fine-tune your setup.

The book ends with some supplemental material including a Summary chapter of all the key points dispersed through the book. A couple of appendices describing where one can find test signals mentioned in the text, he also lists software worth considering. I am impressed by the bibliography of references (of which there are many, even one referenced to yours truly). References are up to date and includes some recent papers like the Reiss meta-analysis of high-resolution audio mentioned in a previous blog post, a list of relevant SMPTE and ITU-R standards documents for video and audio reproduction, as well as numerous "classic" papers such as those by Toole, Thiele, and Small.

As you can see, this book is very thorough. Having said this, I did notice that it didn't discuss the role of streamers and low-cost single board computers (SBC) like the Raspberry Pi in section 5.3.4 "Computer Audio". These days, SBC's I suspect are very common devices used by many AV enthusiasts instead of laptops and computers in the sound room. Remember that inexpensive SBC-based TV boxes these days also have the ability to play 4K, HDR video and multichannel audio (as discussed here using a TV box and CoreELEC). While dynamic speakers are most common and thoroughly discussed, I did not see a discussion on flat panel speakers, omnidirectionals, and considerations like placement tips for such devices for the sake of completeness. Finally, remember that this is not a book about headphone listening so don't expect discussions about things like headphone amps and the like.

Who is this book for?

It's for anyone who wants to know more about "optimal audio and video reproduction at home" of course! :-)

As you can imagine from my descriptions above, this book covers in detail the audio and video technologies one would want at home for high quality playback/reproduction. It's a book about the technologies involved and the principles of how these things work with practical tips about system layout, "best practice" with set-up, and promotes understanding above all else. No doubt, applying these principles will certainly result in excellent (even if not "optimal"!) sound and video reproduction.

Let me be clear, this is not a "buyers' guide" type book meant for basic audiophiles. Verdult does not make product or brand recommendations. The level of discussion here is significantly higher than one would find in audiophile magazines and typical online resources. Likewise it's not a focused "how-to" like Mitch Barnett's book Accurate Sound Reproduction Using DSP (2016) best suited for those of us using Acourate. I see Verdult's book as a resource for the audiophile and videophile who wants a text that he/she can reference over the years digging into the physics of quality video and audio reproduction building from first principles. The topics discussed here are up-to-date (2020 as I write this) and the principles discussed are foundational to this hobby - IMO this book will stand the test of time with enduring value. This book would make a great gift for the serious AV enthusiast looking for science-based substance.

It's tempting to compare this book with Mark "Dr. AIX" Waldrep's Music And Audio: A User Guide To Better Sound (2018). While both books overlap in many ways (Waldrep's book only focuses on audio of course), we can see the strengths of each author's approach. Verdult approaches the writing from a hardware engineering perspective with great detail and "density" of concepts pertaining to the physics of audio and video fine tuning and set-up at home. Waldrep's background in music production results in his writing focusing more on the consumer products, audio formats, audiophile controversies, discussion on studio techniques, and includes a great selection of sample audio to try (on Blu-Ray disk). They're both technical in nature and for those of you who have followed this blog, Mark's book covers much of what I have written about whereas Verdult's book will open up more ground to consider, I think.

Highly recommended. Thanks Vincent for the opportunity to review the book. No doubt you've devoted a lot of time and energy in creating this content and I can certainly sense the "labour of love" poured into the research and writing!

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Alright guys and gals, remember to enter your listening impressions for the "Is high Harmonic Distortion in music audible?" blind test - you have 1 month left. Remember, in the test I'm applying some rather high distortions to some of the music samples; levels that would be rather unfortunate to see in amplifier measurements for example! As a whole, are music lovers/audiophiles able to hear the difference? We shall see...

Stay calm. Stay healthy everyone as I'm writing here at the time of the COVID-19 "lockdown". Hope you're all enjoying the music with "optimal" high quality reproduction!