Smyth Research Realiser A8 Headphone Surround Simulator

Many have tried, but few have succeeded in simulating a convincing surround soundfield with conventional headphones. Several years ago, I heard a demo of one such system from UK-based Smyth Research, and it really knocked my socks off. That was a prototype, but the technology, known as Smyth Virtual Surround (SVS), is now available in a commercial product called the Realiser A8.

Most headphone-based surround-simulation systems use mathematical algorithms called head-related transfer functions (HRTFs) to describe the effect of sound waves diffracting around a human head from any given direction. The HRTFs are used to alter the amplitude, phase, and delay of an audio signal before it's sent to the headphones, and the listener perceives the sound coming from the desired "direction."

Unfortunately, most of these simulation systems suffer from a couple of drawbacks. For one thing, the HRTFs are generic, based on the average of many individual measurements, which means they are accurate for no one in particular. Also, as a listener turns his or her head, the simulated speaker system turns with it, which sounds quite unnatural. If you were listening to a real surround speaker system, turning your head would change the relative orientation of your ears with respect to the speakers, resulting in plainly audible changes to the sound.

SVS starts by "capturing" the HRTF of a specific individual—i.e., you—listening to a specific set of speakers in a specific room. You put a small microphone in each ear, and a series of test signals are played from the Realiser processor to each speaker. The resulting HRTFs are stored and used to re-create the effect of sounds coming from the modeled speakers in that room as heard by you.

To fully optimize the system, the headphones must also be taken into account. So after the room measurements are taken, you put on the headphones over the mics, and more test tones are played to measure the precise interaction between the headphone cups and the listener's outer ear. The profiles of 64 rooms and 64 headphones can be stored internally, and as many as you want can be stored on removable SD cards.

After the measurements are stored, up to eight channels of analog audio are fed into the Realiser processor, which applies the selected HRTFs (room and headphone) and sends the processed audio to the headphones fitted with a small, rechargeable head-tracking device on the headband. That device sends an IR signal to a set-top receiver, which communicates the listener's orientation to the processor. This information is used to modify the HRTFs in real time so that the virtual speakers appear to remain in place as the listener's head moves.

Smyth wants to make sure that listeners aren't using lousy headphones, so the company sells a complete package with a Stax SRS-2050 MKII electrostatic-headphone system—which includes the cans and a dedicated amplifier—all for $3360. That might seem like a lot to pay for virtual surround in headphones, but the Realiser A8 offers far more than this—it provides the ability to emulate specific rooms and speakers for your ears only. For example, if you had access to an acoustically superior room with a million-dollar surround-sound system, you could perform the setup procedure and essentially take that room and speaker system with you for far less than it would cost to physically replicate them. Kinda makes three grand seem like a bargain, doesn't it?

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Jarod's picture

Upon first look I thought these headphones would be a gimmick but after reading the last few sentences it may be kinda cool

Scott Wilkinson's picture

Jarod, I've heard the system, and it's not only kinda cool, it's really cool!

Kal Rubinson's picture

Yes. The idea seemed so cool to me that I jumped at the chance to try them out.......even though I hate wearing headphones. Have I changed my mind after a couple of weeks with this ingenious device? Review in my "Music in the Round" column in the upcoming Nov ember Stereophile. Kal

Dilbert Zoolander's picture

Don't see where Smyth sells the processor separately. I already own Stax Lambda Pro Signature headphones, so I don't need another set (which is actually inferior to what I have). Another issue. I'd love to try the unit out, but I find the lack of digital inputs baffling. I have PS3 which sends multichannel info via HDMI to Denon AVR. The AVR can output via HDMI or optical. I don't have room for another 8 high-quality cables running in or out of my AVR. Smyth really needs to get into the 21st century here.

Steven Kastner's picture

I am a music surround sound fan from way back. I still have a hundred or so quad reel tapes. I will soon have to sell my 5.1 system that includes Apogee Mini Grands, a Persius LCR and Centaur Minors, because I must move from a house to an apartment. The problem is volume level. I can't listen to music or a movie at full dynamics without having my new neighbors calling the cops. So I've been looking at headphones, which up to now meant no more quad or 5.1 . May be now I can have my cans and eat them too! I was considering Stax and Sennheisers (maybe 650's or 800's). Scott, if I am not crazy about the SR-202's that come with the A8 system, will the surround system work with other types of headphones as well as the SR 202's? Steven

Scott Wilkinson's picture

Dilbert, Symth does sell the processor separately; they simply don't want to encourage people to use it with poor-quality headphones, which yours are obviously not. I agree that the lack of a digital input is baffling, and something I didn't even think of, but I'm certainly going to ask them about it. Thanks for pointing that out! Steven, as I mentioned above, the system will work with other types of headphones. Smyth would prefer you to use good cans, which it sounds like you intend.

Paul Christ's picture

if it is capeble to store the info of a "superior room with a million-dollar surround-sound system", why not store that setting in there right away? That would be a great selling feauture...

Paul Christ's picture

please disregard my previous comment, obviously I did not think it through.

Lorr Kramer's picture

Regarding digital inputs: The decision to go all analogue for the first product was in order to have a single model that was universally connectable, pro and consumer. An S/P-DIF input would require adding core Dolby and DTS decoding for surround tracks, which is of diminishing interest now that there are lossless codecs and uncompressed digital beyond the capabilities of S/P-DIF. Also a majority of our users are pros who work uncompressed, pre-encoding. HDMI for the home user would be nice for the future -- nothing on the schedule yet, though.

Scott Wilkinson's picture

Paul, I see you figured out why they don't sell it with such a profile depends on your ears and headphones. The unit does ship with one profile: the Smyth listening room using Stephen Smyth's ears and the Stax SR-202 headphones. It's not customized to your ears and headphones, but it's included so people can hear something right out of the box.

Lorr Kramer's picture

There is a pre-loaded room file, but no pre-loaded headphone EQ file. You can listen to a room file with no headphone EQ file; and the buyer can easily create his own headphone EQ file right away.

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