Impressive Technology at AXPONA & Binaural Sound Part 1

It was certainly nice to see returning attendees and meet new faces at the recent AXPONA audio show in Chicago a few weeks ago. As I said in my previous post, it will probably be the last time I assemble a high-resolution, surround demo with my partners Oppo, Benchmark, Emotiva, DH Labs, and JVC. It’s tremendously expensive (and getting more expensive every year), takes a lot of planning, sweat, and time to pull together and for what? I do enjoy sharing my recordings and talking about high-resolution music during the extended sessions in the Lakeshore B ballroom, but I would probably sell more discs if I simply manned the table in front of the room.

It was encouraging that a couple of writers stopped by the room and the sales tables in front of the main demo area. While I guess I would have preferred that Chris Martens of HiFi+, Steve Guttenberg (the Audiophiliac), or Steven Stone of TAS write up their experiences after visiting our 5.1 surround demo, it was nice to see Thomas Mulready of Cool Cleveland rank our room among the best he experienced. Thanks Thomas. And, of course, the attendees that experienced our immersive, surround sound music were treated to something rare — actual high-resolution audio recording delivered through a system capable of exceeding CD fidelity.

Steven Stone, an associate writer at The Absolute Sound, has been popping up more an more in my circle lately. He was kind enough to sit through the YARRA 3DX demonstration I gave at our sales table in Chicago and wrote glowingly that it was, “one of two of the most impressive demonstrations at AXPONA…”. And just this morning, Steven passed along a link to an article by Roger Skoff on Binaural Sound (you can read the entire series of four articles at click here). I’m a fan of binaural recording and actually did a few recordings in this format — including my doctoral dissertation.

Roger is obviously a fan of binaural recordings. He argues that a single microphone for each channel delivered via headphones to our ears delivers a convincing “you-are-there” listening experience. I don’t disagree but there’s more to the story than producing a “sonic documentary” for music consumers. The sound of recorded music is fundamentally different than a live concert experience — and that’s as it should be if you ask me. Binaural recordings succeed to a great degree in delivering immersive 3D audio. All you have to do is search for binaural recordings on YouTube and you’ll be able to get your hair cut, hear David Chesky walk through a large NYC Cathedral, or listen to a nature preserve in full surround. I made a lot of nature recordings during the week that I had a Sennheiser KU-81U “Fritz” binaural head 30 years ago. It works.

But there’s a downside to binaurally recorded tracks as well — the loss of presence. The sense that you are close to a sound is lost when a single microphone is placed some distance away from the sound source. It turns out that there’s a very clever way to rectify this critical flaw in binaural albums. Take a well-recorded surround track (5.1 or 7.1 or 11.4) and “binauralize” it using software.

To be continued…


As readers and supporters of this site, I would like to ask you to help in bringing awareness to an innovative product that a close friend of mine is developing that makes use of binaural sound projection. I’ll get into more details over the next few posts, but the YARRA 3DX speaker array that he’s about to launch on Kckstarter is a remarkable technology and worthy of support. Imagine the immersive, “you-are-there”, quality of binaural with the intimacy of commercial tracks without the need for headphones and you’ll start to understand the revolutionary nature of this product. We need to develop a healthy email list prior to our launch. If you or someone you know is interested in a smart sound bar (and subwoofer) that can deliver immersive, 5.1 surround sound for games, music, home theater and more for less than $500 (with an opportunity to get up to 50% off during the campaign), then please visit the site and sign up. We promise never to spam you or distribute the list. I really think they’re on to something truly disruptive. Again please visit, YARRA 3DX.


Mark Waldrep, aka Dr. AIX, has been producing and engineering music for over 40 years. He learned electronics as a teenager from his HAM radio father while learning to play the guitar. Mark received the first doctorate in music composition from UCLA in 1986 for a "binaural" electronic music composition. Other advanced degrees include an MS in computer science, an MFA/MA in music, BM in music and a BA in art. As an engineer and producer, Mark has worked on projects for the Rolling Stones, 311, Tool, KISS, Blink 182, Blues Traveler, Britney Spears, the San Francisco Symphony, The Dover Quartet, Willie Nelson, Paul Williams, The Allman Brothers, Bad Company and many more. Dr. Waldrep has been an innovator when it comes to multimedia and music. He created the first enhanced CDs in the 90s, the first DVD-Videos released in the U.S., the first web-connected DVD, the first DVD-Audio title, the first music Blu-ray disc and the first 3D Music Album. Additionally, he launched the first High Definition Music Download site in 2007 called iTrax.com. A frequency speaker at audio events, author of numerous articles, Dr. Waldrep is currently writing a book on the production and reproduction of high-end music called, "High-End Audio: A Practical Guide to Production and Playback". The book should be completed in the fall of 2013.

14 thoughts on “Impressive Technology at AXPONA & Binaural Sound Part 1

  • I am enjoying 5.1 audio and am a convertee I do wonder if there is limited enthusiasm for this media
    As long as you have lots of slam with good explosions that is all that appears to be necessary
    I have a linn Exakt 5.1 system and it really is amazing and you can really hear so much more from the sound track of movies which you would never hear at the cinema and realise the immense effort many of the sound engineers have put in
    Looking forward to the book\
    Thanks Neale

  • Please reference the AES papers that underpin the acoustics behind the “Yarra 3D” technology. Sincerity alone used to be enough to have me throwing cash at innovations in audio, but I have learned my lessons.

    • Grant, I’ll talk to my friend about this. The topic of beam forming is well known is a multiple disciplines. I’ll be posted his white paper on the Yarra3DX site soon. But I can assure you that this works.

  • craig allison

    Steven Stone is a fine fellow. He loves MQA, incidentally.

    • Steven is a very qualified reviewer and I know he knows audio. He and I disagree on DSD and MQA. Oh well.

  • craig allison

    I too am friends w/Roger S. Binaural has been around a long time and has never been adopted as a uniform standard, but it makes for a very fascinating listen if never previously experienced.
    My main hang-up with his “you are there” perception is based on the very fact that it is being generated by headphones.
    Evidently Roger conveniently forgot that music is meant to be felt from the bottom of your feet to the top of your head, the one thing that ‘phones will never do.
    I appreciate the ability to open up the inner fabric of the music program and hear the true ‘conversation’ between musicians that headphones allow better than loudspeakers in many cases.
    But getting anywhere near ‘virtual reality’ w/ little sense of impact is impossible.
    Woodstock w 1/2 million pairs of ‘phones? I think not. All the amazing music of the 60s and 70s was made to be experienced on high-grade loudspeakers, headphones were not even an afterthought.

    • I’m not convinced by headphones either although the Smyth Research “Room Realizer” is amazing. The next step is the technology that I’ve been talking about that delivers accurate sound fields from a sound bar. Beam forming using a small array of speakers AND a subwoofer gives you the binaural “you are there” sensation with the butt kick that you want. Check out the YARRA 3DX page and come to the LAAS in a couple of weeks to have a listen.

  • In your opinion, is good immersive audio (related to surround sound) as successful in its application as good immersive video? About twenty years ago immersive video was demonstrated to me that used projections on four walls (more recently this has been upped to five walls including the ceiling). The effect was, I appeared to be in the middle of the scene, with the rest of the world surrounding me. In one scene fish appeared to swim by my head, and I felt as though I could reach out and touch them. If I moved, the scenes changed to reflect my movement. I was also provided with special gloves containing sensors and transducers (haptic devices) that allowed me to reach out and seemingly touch the fish swimming nearby.

    • I haven’t experienced the kind of immersive visual experience that you describe. But I can tell you that immersive 3D audio is mind blowing when done right. The two together will bring us to the holodeck.

  • Mark, couldn’t you bother to elaborate in an article on how impulse response affects the quality of digital audio? Thanks.

    • I’ll get to it asap.

  • I have to disagree with the theory that binaural sound through headphones works. The first time I read about it I was very excited because it seemed to me that would be the perfect sound system if you didn’t mind wearing headphones. Then I got to the end of the article which said it doesn’t work because the sound appears to be coming from inside your head. And that is because when you turn your head the sound turns with it. That was when I was 14 years old in the early 1960s (I’m dating myself.) Endless experiences confirm this fact, it just doesn’t work. I’ve tried it again for an hour today. The sound appears to be coming from a space just outside one ear, in between my ears, and just outside my other ear. There is no forward, backward, up, or down.

    Advocates claim that the detection of direction of a sound source is based on three factors; the time difference between the arrival of sound between one ear and the other, the loudness difference, and HRTF which is head related transfer function which actually relates to sound diffracting around your head so that the spectral content of one ear is different from the other ear for the same sound not directly in front or behind you. This theory is clearly false and it is easy to prove. Binaural sound played through headphones meets all three criteria yet it doesn’t work. Why doesn’t it work? This was a key to my understanding of acoustics and psychoacoustics. The difference between headphone sound and other sounds is that headphone sounds are two scalars, that is they have no direction relative to your ears. Other sounds are vectors and they do have direction. Every source, every reflection. When you turn your head the vectors don’t move but your relationship to them does. Therefore it is the change in arrival time compared to the change in position of your head which defines direction and it works in all three planes. It is no accident that the organ that senses the position of your head is directly adjacent to your eardrum. The ability to detect the arrival of sound is one of the most important strategies for survival in all higher animals whether they are predator or prey. You will usually hear something before you see it and your instinct is to turn your head in its direction to find out what it is and whether or not to run. Your eyes go to sleep but your hearing doesn’t. How sensitive is it? A change in the time of arrival of 2 to 5 microseconds is sufficient for humans to identify direction of the source.

    Still, there are people determined to find a way to make binaural sound work. IMO it’s a hopeless task.

    • It may not work for you but it brought endless smiles and expressions of amazement to an group of attendees at the LA Audio Show over the past couple of day. In fact, the sound from our binaural setup “blew away” the judges for the Alfie awards last evening. It does work. Yes, the tracking can be an issue — one that the Smyth brothers solved with their patented “room realizer” with tracking system. When I asked the listeners to point in the direction where the sound is coming from when listening to the binauralized 5.1 music, they always smile when I solo the left or right surround channel. They point over their shoulders and can’t believe that they are perceiving a sound from a position where there is no speaker.

      It may not work for you…but it works for many others. It is, after all, how we humans experience the sounds around us.

  • stevenswall

    Is there a binaural demo of this you could link us to, particularly to “prove” that sitting in three different positions, you can hear three different things?

    Just went down the rabbit hole of this blog today, and am tempted to but the soundbar… Pretty skeptical, though based on how anti-snake oil this site is, my fingers are crossed.


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