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Smyth Research Realiser A16, Product Review

Jazzfan | Published on 9/23/2020
Smyth Realiser

The Worlds Most Advanced 3D Headphone Processor


  • Best 2-channel/multi-channel 3D virtualization available
  • Personalized capture/reproduction of actual measured speakers and environments
  • New feature upgrades available via firmware updates


  • Expect a steep operational learning curve
  • The user interface is less than optimal
  • The small display panel is challenging to read from a distance
  • Optimum performance can only be achieved by taking personal measurements
  • The unit must be returned to the UK for service/repair


Since I began this hobby in the mid-70s, I always preferred the three-dimensional holographic presentation of a good stereo sound system. Today well-recorded music on the best two-channel systems can transport the listener to live performances and convincingly project performers across a life-sized soundstage. Systems capable of this level of performance tend to be large and beyond the means of many audiophiles, including myself. So, I was intrigued when I read John Atkinson’s 2011 article about the Realiser A8.


“After the listener has the sound field produced by his system at the entrance to his ear canals analyzed with tiny probe microphones, the Realiser synthesizes that soundfield with STAX electrostatic headphones. The effect is though the listener was not using headphones but listening to his system; and unlike conventional headphone listening, the perceived sound is outside the head and if the listener turns his head, the sound remains centered.”

I’ve used headphones in the past, but I never cared for the in-your-head presentation commonly found with headphones. While the headphones experience can be immersive, in my experience, two properly positioned speakers present a more natural and realistic soundstage. Could the Realiser and a pair of STAX headphones accurately mimic the sound of a two-channel system? The year was 2011, and I was determined to find out.

I purchased an A8 and a pair of STAX SR-009 “earspeakers”. I had been a satisfied A8 owner until the used unit I bought failed after four years. When I learned that an improved Realiser was in the works, I knew I had to have one. Finally, after a three-year wait, I took delivery of the new Realiser A16, which is the subject of this review.

Many Realiser owners use the A16 primarily to watch movies and replicate real-world multi-channel Home Theater (HT) systems with headphones. I use the A16 mostly for music, so this review is heavily biased from a two-channel listener’s perspective.


In August of 2016, Smyth Research LLC initiated a Kickstarter campaign to produce the next generation Realiser, the A16. Towards the end of 2019, the first A16 units began shipping, and I received my A16 in November of 2019.

What is the Realiser A16?

Smyth Research describes the Realiser as a real-time 3D audio processor for headphones. However, this description does not begin to describe the capabilities of the A16. The Realiser is a first of its kind audio device that offers personalized surround sound capture and virtual surround sound playback for two listeners via headphones.

What does this mean?

The most important keyword in this description is “personalized”, which for the Realiser translates to what you “hear” is what you get. The Realiser is the first virtual surround playback device that uses measurements taken directly from an individual’s ear to generate a believably natural virtual stereo and multi-channel soundfield.

Because the listener’s measurements are taken in the room with test tones played back by the speakers, the Realiser can capture the room’s acoustic signature (good or bad) along with the speakers’ sound. The end result of the measurement process is a Personalized Room Impulse Response (PRIR) file used during audio playback to faithfully recreate each speaker’s sound playing back in the room. In addition to frequency response, soundstage and imaging characteristics are also captured by the measurement process. Combined with headtracking hardware and software unique to the Realiser, real-time active sound localization with headphones is a reality with the A16.


  • Realistic two-channel audio reproduction
  • Immersive 3D Home Theater experience
  • Immersive 3D VR/Gaming experience
  • Immersive 3D audio creation/production

For a brief introduction to the capabilities of the Realiser, watch this short video 5+-minute video.

Do you believe in magic?

“Any sufficiently advanced technology is indistinguishable from magic.”

Arthur C. Clark

Mr. Clark’s words are true of technology in general but especially true for the A16. The two features that differentiate the A16 from all other 3D headphone emulation products are 1) the ability to individually customize each listener’s experience with a “personalized” measurement and 2) the introduction of headtracking technology, which fixes the entire virtual soundfield in space, even if the listener rotates their head. With headtracking, the listening experience becomes more believable because the soundfield is solidly fixed in space, as in the real world, vs. a soundfield that moves with your head as with conventional headphone listening. Combine these two features with a DSP based virtual surround sound processor for multi-channel audio playback, and you have the magic that is the Realiser A16.

Why are PRIR measurements vital?

An individual’s hearing is as unique as a fingerprint, which explains why a range of opinions on the sonic characteristics of a piece of equipment can be expressed when auditioned by several individuals. Hearing differences are caused by a variety of factors like age, health, listening abilities. Other physical differences, like the shape of your pinna (Fig. 1), your torso’s shape, the size and shape of your head, and the distance between your ears, all influence how sound is altered before it enters your ears.

All of these factors ultimately affect how an individual perceives sound. The Realiser can capture an individual’s unique physical differences by using small microphones to measure sound as it arrives in one’s ears. In Realiser terminology, this measurement is known as a Personalized Room Impulse Response (PRIR).

In contrast, measurements taken with a dummy head (Fig. 2) are referred to as a Binaural Room Impulse Response (BRIR) measurement.

Figure. 2 – Neumann KU 100 Dummy Head Binaural Stereo Microphone

Both measurements relate to the function more broadly known as the Head-Related Transfer Function (HRTF), which is how we can perceive the direction of sound. As previously mentioned, the PRIR measurement is unique to an individual. PRIRs form the basis of custom filters that the Realiser uses to create individual virtual surround speakers.

Several other companies offer 3D surround products that also take advantage of the HRTF function. Binaural recordings also capture the directional aspects of sound, as demonstrated in this Virtual Barber Shop example. However, these systems use dummy heads to measure and produce directional audio effects, which ultimately are less accurate than those made using an individual’s PRIR measurements taken with the Realiser.

Realiser Exchange

In some cases, the shape of an individual’s pinna is similar enough to another’s so that the PRIR of one individual can be used by someone else who might also achieve similar results. The notion of sharing PRIRs was the genesis for the Realiser Exchange available at the Smyth-Research website. When the exchange site is fully functional, users will have the ability to store, exchange, or purchase PRIR files from other users or services.

PRIR/HPEQ Measurements

Shipped with the A16 are two generalized BRIRs taken from two rooms listed below. Measurements were created using dummy heads:

  • BBC 40 Ch. room w/Neumann KU100 (dummy head only)
  • Surrey University 32 Ch. room w/Cortex-MK.2 (dummy head-and-torso simulator)

Using either of the supplied BRIRs, you can begin using the A16 out of the box without taking a PRIR measurement. However, optimum results from the A16 can only be achieved by taking your own PRIR measurements.

The actual PRIR measurement process is fairly quick and can be completed in a few minutes. However, the measurement setup process of a simple system can take up to an additional 30 minutes. For complex systems, an hour or more may be necessary to complete setup and all measurements.

Step one of the measurement process is to connect the Realiser output channels to the system under measurement. In my case, I created my PRIR files using the Dutch & Dutch 8C. The 8Cs are active speakers that posed a particular challenge because they only accept balanced analog or AES3 digital input via XLR. To connect the Realiser to the 8C, I used a Jensen ISO-MAX transformer to convert the A16 single-ended analog outputs to balanced XLR out.

After connecting all channels, small microphones are positioned in the listener’s ears (Fig. 3). Once the listener is seated in the ideal listening position, the actual measurements can begin. The listener is prompted to turn their head towards three different listening positions Left, Center, and Right as a series of sinusoidal sweeps are sent from the A16 to each speaker. When the sweeps stop, the PRIR measurement phase of the process is complete.

The last measurement step takes a Headphone Equalization (HPEQ) measurement. In this step, headphones are worn by the listener, then a series of test sweeps are played through the headphones. Smyth advises taking an HPEQ immediately following the PRIR measurement to ensure the in-ear microphones have not shifted. Movement of the microphones could negatively affect playback of the virtual image.

During playback, both PRIR and HPEQ measurements are combined using Smyth Virtual Surround (SVS) algorithms to render, in real-time, virtual speakers for each of the required channels. After measurements have been taken, the listener can compare the speakers’ live sound directly to the sound played back over the headphones.

Figure 3 – Right in-ear microphone

Additional options

If access to a good multi-channel HT or recording studio is not an option, it’s still possible to create a virtual multi-channel system by only using a single pair of stereo speakers for measurements. Using this method, you can create a multi-channel “dream” system, for example, consisting entirely of a set of virtual Magico M9 ($750k) speakers (assuming you have access to a pair of M9s, of course).

Additionally, you can build a custom multi-channel room by mixing-and-matching speakers from other PRIRs/BRIRs.


The other unique feature of the A16 is Headtracking. This feature is implemented using two devices, a Head-Top (Fig. 4a) attached to the headphones’ headband, and a Set-Top (Fig. 4b) placed on top of a speaker or TV in front of the listener. Headtracking generates real-time headtracking data used to capture your head movement relative to the front of the room. SVS algorithms reposition all virtual speakers in real-time, so they appear fixed in space relative to the listener even when the listener moves their head. Several positional sensors, inertial, magnetic, and optical, are incorporated with the headtracker for stabilization. The ability to fix the speakers’ location in a 3D space makes the headphone experience much more convincing, especially when listening to music with your eyes closed. Additional information on the various headtracker stabilization modes can be found in the A16 manual.

Figure 4a – Head-Top

Figure 4b – Set-Top

NOTE: As an aside, if you move your Realiser to a different room to listen to music and are not using the headtracker, I’ve found it useful to have visual cues like a small piece of paper or tape to draw your eyes to the position of where the speaker should be located as you look forward. Without visual clues, the illusion of virtual speakers can become less convincing. I believe this highlights the fact that both your eyes and ears work together with your brain to help you perceive the world around you.


All listening tests were performed using an Atmos 9.1.6 multi-channel PRIR generated from my D&D 8C two-channel system. A Windows 10 based Azulle Quantum Byte Fanless PC running Roon connected via HDMI was used as a source, and an Amazon Fire TV 4K Stick streamer was the source for Tidal Atmos, again connected via HDMI.

Two-Channel Audio

Describing the Realiser’s sound is difficult, not because the A16 is without flaws or coloration, but because (by design) the A16 has a chameleon-like ability to take on the measured system’s sound be that an entry-level two-way speaker or a state-of-the-art full-range tower. When paired with good headphones, the level of realism is quite remarkable. With a good album, the soundstage height, width, depth, and tonality can be so convincing that you may be fooled into believing you are NOT listening to headphones. By every measure, the sound from the D&D 8C virtual speakers was indistinguishable from that of the actual speakers. I’ve found the quickness of the STAX SR-009 electrostatic headphones bring to the A16 a level of realism that is difficult to beat. Even with the Sennheiser HD800, while not as quick as the STAX, sound almost as convincing. Good results can be had with a variety of headphones, even in-ears, but better headphones will likely produce more convincing results.

Add to that Headtracking, and you have a product with potentially the highest return on investment of any audio device currently on the market. With these features, the A16 can come remarkably close to recreating virtually any two-channel system. In one case, the A16 sounded even better than the original speaker.

One afternoon, I noticed an unexpected benefit while listening to a Quad 57 PRIR from another Realiser owner. Surprisingly, I discovered the simulation sounded better with the Realiser than when listening to an actual Quad system. How was this possible? For the answer, you need a bit of background on the Quads. The Quads are an electrostatic speaker known for their realistic midrange. Unfortunately, the Quads are also known for their tendency to be quickly overdriven when played at high SPLs.

Listening to the A16 with my STAX SR-009, the Quad’s characteristically beautiful midrange was present with classical music. So was the quickness and detail one would expect from a pair of Quads. Then as a test, I tried bass-heavy electronic music to see how Quads would fair. The bass was present, and the Quads seemed to handle the rest of the music with the same clarity as Classical. As a further test, I raised the volume, and again the music played without incident. I played all types of music from rock to jazz to EDM. All genres played with surprising clarity at volume levels no Quad owner would dare to try. This realization came as a complete surprise, and I suspect, a welcomed revelation for any Quad owner. With the Realiser, not only was the Quad midrange faithfully reproduced, but I was also able to listen at previously unattainably high SPLs from a pair of Quads. Not a bad secondary benefit.

Multi-Channel Audio

Home theater (HT) users are familiar with the 3D surround sound effects of legacy Dolby and DTS, and the newer, more immersive Dolby Atmos audio format. This same 3D audio experience is now available with headphones. With the Realiser and headphones, you can watch movies into the wee hours of the morning at realistic volume levels without disturbing other family members, partners, or neighbors.

Watching a Dolby Atmos movie for the first time with my D&D 8C PRIR was a truly gratifying experience. With scenes that had all 16 Atmos channels active, the power of the 8C speakers seemed to fill my room with sound, making the immersive headphone experience so much more engaging. A physical multi-channel HT system of this magnitude would have cost $100k in speakers alone.

Currently, only Dolby Atmos decoding is available, with DTS:X and Auro-3D supported in the future. Up to 16 surround channels are available for two listeners, and up to 24-channel virtual surround channels are available for one listener (Fig. 5).

Figure 5 – Activity display showing 24 active channels

Much of the appeal of a quality HT system is the ability to recreate, with one or more subwoofers, the visceral seat rumbling movie theater experience you feel with high-intensity action sequences. While headphones are capable of plunging into the nether regions of bass, some moviegoers may miss the visceral impact of a subwoofer while listening to their HT systems with headphones. For those listeners, Smyth Research has you covered. The Realiser includes a two-channel tactile output jack for physical subwoofers or a bass shaker tactile transducer made for HT systems. I’m quite satisfied with the bass from my headphones, so I’ve   not felt the need for additional bass augmentation.

As with two-channel listening, headtracking is also available for all multi-channel audio decoding formats for both users.

Tidal Dolby Atmos Music

As I mentioned, I use the Realiser more for music than for movies. That said, with the release of Dolby Atmos Music support earlier this year by the Tidal music streaming service, I decided to delay completion of this review until after I had an opportunity to try Atmos on Tidal. I’m pleased to report; my Atmos Music experience was favorable.

I compared the Dolby Atmos version of Grant Green’s Idle Moments to the standard remastered version. The two versions were very different, but the differences were comparable to 2-channel audio vs. multi-channel HT listening. With an Atmos mix, you lose some of the 3-dimensional soundstaging I usually associate with the Realiser. But in return, you’re rewarded with an immersive and expansive, albeit artificially generated virtual experience. HT users may like the experience; some two-channel fans may not.

For me, Atmos worked better on some recordings like live concerts in large venues. For studio recordings or live performances in smaller, more intimate settings, the music can be overly expansive and less realistic than traditional 2-channel masters. This varied with each recording with some Atmos mixes sounding less expansive than others. For music, I’m inclined to prefer the more natural non-Dolby Atmos experience. But again, those who enjoy the HT movie-going experience may prefer the more immersive Dolby Atmos Music presentation.

The Bad, and the Ugly

Up until this point in the review, I’ve only been extolling the virtues of the Realiser. I would be remiss if I neglected to describe the dark side of the A16.

Due to the Realiser’s complex nature, you can expect a steep operational learning curve with the A16. I’ve never encountered a piece of gear that required hours of reading to understand how to properly operate the unit. You’ll also need to become intimately familiar with many of the buttons on the remote as the A16 is almost entirely controlled via the remote. That said, Smyth Research has created several tutorials on their YouTube channel to help bring users up to speed.

On the front panel, a small 3 ½” LCD panel is used to navigate the complex multi-level user interface for configuring A16. This display is impossible to read from across the room, requiring the user to move to the unit to make any settings adjustments. A modern smartphone-based app would go a long way to address these issues. However, I suspect the availability of a smartphone app from Smyth Research in the near future is highly unlikely.

If your Realiser requires service, there are no US repair centers. All units must be returned to the UK for service/repair at the owner’s expense. Due to international customs and delivery delays, the entire return process can take weeks or longer.

Lastly, I must reiterate, “optimum” performance from the Realiser A16 can only be achieved if the following two conditions are met:

  • You must be willing to go through the process of creating PRIR personal measurements.
  • You need access to good speakers in an acoustically optimized space, that being a professional studio or home. As a general rule, great speakers in a mediocre room will sound mediocre. Mediocre speakers in a great room can sound surprisingly good.

If you can meet these conditions, you will be treated to the best 3D multi-channel virtualization experience currently available.

If these conditions are not met, you’ll still have a good virtual multi-channel experience with headphones. Nevertheless, you might be better served by looking at other less complex (and possibly more cost-effective) alternative 3D headphone virtualization products.


If you are a headphone enthusiast but prefer the lifelike presentation of 2-channel audio, the Realiser really could be your holy grail. If you enjoy the immersive effect of watching movies (or playing games) on a multi-channel home theater system, you can now have that same immersive experience with headphones. After living with the Realiser (and several good PRIRs) for some time, I no longer feel the need to upgrade my headphones, amp, or DAC. In fact, after my initial A8 purchase, I decided against upgrading to an uber-expensive Blue Hawaii amp ($6k) for my STAX headphones. It became clear that an amp upgrade (or any other upgrade for that matter) would not provide the order of magnitude sonic improvement afforded by the Realiser and a PRIR of a great system.

In my experience, the Realiser represents one of the most revolutionary (and underappreciated) products in audio today. Even though the A16 is not a plug-and-play device, having the ability to recreate the sound of any system with headphones is priceless. While not always 100% accurate for all users, the Realiser convincingly recreates the sound of actual speakers playing in a room for many.

I’ve tried to convey my Realiser experience to you, but the only way to understand the Realiser’s true magic is to hear the A16 first hand. More than with any other audio component, the Realiser MUST be heard first hand to be believed. I’m a Realiser A16 owner, and I’m a believer.

Now, where can I go for a PRIR measurement of a pair of Wilson Master Chronosonics ($850k)?


  • Smyth Research Realiser A16 Virtual Surround Sound Processor
  • Sennheiser HD800 Headphone
  • STAX SR-009 Headphone
  • STAX SRM-727II Amplifier
  • Amazon Fire TV 4K Stick Streamer
  • LG 47LE8500 TV

Atmos 9.1.6 Room w/PRIR based on the following 2-channel system

  • Dutch & Dutch 8C Active Speaker
  • Azulle Quantum Byte Fanless Win10 PC (running Roon & Tidal)
  • M2Tech hiFace EVO USB to AES Converter


Personalized 3D Audio for Headphones Features:

  • Precisely emulates up to 16 speakers in a sound room over stereo headphones
  • Full suite of personalization routines
  • Internal audio bitstream decoding:Dolby Atmos, Auro-3D, DTS-X and all legacy Dolby and DTS formats Employs state-of-the-art SVS virtualization with integrated head-tracking for realistic rendering
  • Azimuth + elevation head-tracking
  • Audio source inputs / outputs: USB 2.0 : 16ch in / 2ch outHDMI 2.0 : 8ch PCM i/o + bitstream inAnalogue : 16ch in + 16ch outOptical : 2ch PCM i/o + bitstream in
  • User interface and configuration via web browser (TBD)
  • Illusonic N:M channel upmixer
  • Supports two simultaneous listeners with fully independent personalization and head-tracking
  • Hi-Mid-Lo headphone output gain modes
  • Dedicated audio i/o for video gaming


  • Stereo line in
  • Tactile out
  • External Sync/Control
  • Head-Tracking Reference
  • Ethernet (for web control)
  • S/PDIF optical /coax in
  • S/PDIF optical /coax out (Headphone A and B)
  • 0 Audio
  • eARC
  • HDMI 2.0
  • 9-16v 3A DC
  • 16ch analogue I/O
  • Headphone A & B Out

Audio decoding:

  • Dolby Atmos (16 channels*)
  • Auro-3D (Future release)
  • DTS:X (Future release)
  • All legacy Dolby and DTS formats

*Note: 24-channel support available in the future.

Form Factors:

  • Headstand
  • 2U (rackmount)


  • 3,995.00 USD

Manufacturer Info

Smyth Research

Unit 66 Enterprise House

2-4 Balloo Avenue Bangor