5.1 Headphones Surround

Paul Horner’s KS campaign is coming to a close. They timer on his page is now counting down in hours rather than days. He and I are very pleased that he was able to get the support of 45 backers and achieve his funding goal. I talked to Paul the other day about his project and told him I would post an update and work up a stretch goal if we reach $2000. I added that to his page this afternoon. You can check it out by clicking here.

The incentive offered if the $2000 level is reached is a version of the project prepared for “headphone surround”, which is one of the latest technologies being used with headphones. It allows headphones listeners to hear virtual 5.1 playback using a standard set of headphones. I’ve been investigating this new technology for a few years and can tell you that it’s pretty amazing.

Humans can perceive sound from all directions. Just because we only have two ears doesn’t mean that stereophonic sound is the limit of our hearing sense. Sounds from above, behind and even below can be heard and processed by our brains. The new formats being used in current movies are examples of an increased interest in height information. DTS:X, Auro 3D and Dolby Atmos extend traditional 5.1 or 7.1 surround sound to include height information. The post houses and theaters have added speakers to the ceiling and developed technologies that let movies mixers use the added dimension. If you haven’t had a chance to experience a move with height channels, treat yourself and find a Dolby Atmos or Auro 3D equipped theater.

And these new technologies are not limited to movie theaters. Dolby and their hardware partners are providing Atmos systems for home theaters too. There are speakers with upward facing drivers in addition to the forward facing drivers. I read about a Yamaha sound bar that claims to be able to direct sounds to the ceiling with some clever digital processing.

There are a few companies that have attempted to deliver immersive or surround mixes via headphones, which tops the list of most popular audio accessories. The goal is to provide motion picture soundtracks and immersive computer game audio to individual users through headphones. There’s not a lot a music being produced or remixed in 5.1 surround, so the trend has not yet caught the attention of the music industry. But they should be paying attention. Headphone surround is very cool.

The best system currently available has been around for a few years. It’s called a Smyth “Room Realizer” and it reproduces the sound of an actual listening environment using a standard pair of headphones. Obviously, the better the headphones they better the experience. If you buy one of their boxes, it comes with an entry pair of Stax headphones that produces a very convincing spatial image.

The Smyth approach is unique among companies working in this area. They require that each purchaser visit a desirable space to have their ears and devices “calibrated”. A customer visits a studio like mine and has their ears measured using sweep tones played sequentially in each of the 5.1 speakers. This is done while you look forward and to the left and right. An IR sensor detects the position of your head and an individual filter profile is created in the box. Everyone has his or her own personal filter profile.

When a surround track is input to the Room Realizer, the personal filter processes the sounds in the “virtual” speakers to match the real speakers where you were measured. It’s very convincing. In fact, I was blown away.

So Paul Horner’s album exists as a 5.1 surround mix. If his campaign reaches $2000, every backer will receive a set of files prepared using my profile done in my studio. Despite the fact that the processing doesn’t match you exact outer ear, the results are very impressive.

To be continued….


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.

3 thoughts on “5.1 Headphones Surround

  • Hi Mark, Thanks for this post. I am quite interested in the surround headphone experience. I have noticed that there are a number of approaches today for emulating surround in headphones. Each approach is somewhat different. In the late 80’s Yamaha produced DSP multi-channel playback hardware to emulate a number of well known musical venues around the world. Yamaha’s electronic audio emulation was of the environment. Near the end of 90’s, DVD-Audio and SACD came up with surround recordings that were original, not simulated as in DSP. Recently the benefit of surround for headphone listening is coming to the fore. You have been touting the experience of the Smyth Room Realizer A8 system which produces surround for earphones. The Smyth system calibrates a person’s individual hearing with microphones placed in their ears and measures them with
    a specific set of speakers, in a particular room setting. Three things are emulated: an individual’s hearing, an actual set of speakers, and specific room acoustics. Certainly a need trick! Another kind of surround emulation for earphones by Fong Audio is through PC software. Measurements of particular speakers in actual rooms (or studios) drive the software. In Fong’s approach he leaves out the personal ear calibration that the Smyth system includes. Are the gains in using personal ear calibration only slight in nature or are they signifcantly noticeable and worth the $3,000US premium on the Smyth system. (I am Canadian and with the currency conversion rates at present I would have to pay out approximately $4,000 Cdn for the Smyth Room Realizer.)
    Mark, I hope you can shed some further light on the incentives and disincentives for the various headphone surround systems out there. Thanks for your great audio/music commentaries. Jack.

    • Admin

      Fong’s “process” is the same as Smyth with a generic filter set. The difference between a generic filter and your own personalized filter set is immense. It you want the real deal, the Smyth is the only way to go. I’ll be writing more about these systems.

      • I’m also very interested in this technology as setting up a proper 5.1 room for me will prove to be very difficult given my space constraints and the geometry involved.


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