Thanks to its built-in microphones, this unique IEM system  lets you bring the outside world into your monitor mix. - Sound On Sound Magazine

Thanks to its built-in microphones, this unique IEM system lets you bring the outside world into your monitor mix. - Sound On Sound Magazine

Dec 01, 2023


ASI Audio are a joint venture between Sensaphonics, a company founded by leading music audiologist Dr Michael Santucci, and Think-A-Move, who produce speech recognition software and audio communication hardware for military, sports and security applications. Between them, they’ve developed the 3DME in-ear monitoring system, a unique proposition that adds an ambient microphone to each earpiece, allowing you to dial room sound into your IEMs.

    Courtesy of a small bodypack, controlled through an app on your smartphone, you can create a personal monitoring experience that avoids the detachment from both your fellow performers and audience that wearing IEMs can often bring about. Could this be the end of ‘one ear in, one ear out’ monitoring?

Body Parts

The 3DME system ships in an attractively designed box with an outer sleeve and a magnetically fastened flip lid that gives it a professional and reassuringly expensive look and feel. Inside is a large, zipped hard case that contains the bodypack and headphones, housed within a cut-foam liner. A 3.5mm stereo ‘jumper cable’, USB charging cable, three pairs of foam ear tips, earpiece cleaning tool and shirt clip are neatly stored in a mesh zip pocket in the other half of the case. It’s nice to have everything shipped in the case, and not to have to fish around the packaging to find the various elements. 

    On first inspection, the headphones look and feel like a typical set of IEMs. It’s only when you look a little closer that you notice the grilles that house the tiny microphones on each earpiece. This certainly doesn’t make them any larger or odder-looking than any other IEMs. In fact, the classy, matte-black, moulded design wouldn’t look out of place as an accessory in a Batman film. As is the case with most IEMs, the cable exits the earpieces at the top and a short plastic sleeve surrounds the cable, making it curve slightly and allowing it to fit neatly around the top of your ear. The unique functionality of the 3DME requires a unique cable design, and the cables from each earpiece meet at a moulded plastic connector that combines them into a single, slightly thicker cable, terminating in a right-angled connector. This connector features not one, but two 3.5mm jacks, which connect to the corresponding sockets on the body pack. Unlike many other IEMs, the cables aren’t detachable from the earpieces, so if they got damaged I suspect you’d need to buy a complete new set of IEMs.

    The earpieces themselves feature dual balanced-armature drivers. Unlike dynamic drivers, which use a coil and magnet to create sound, balanced-armature drivers vibrate a tiny reed balanced between two magnets inside a tiny enclosure. The motion of the reed is transferred to a stiff diaphragm and on to an output port. This compact design makes the balanced armature ideal for in-ear monitors, and the drivers in the 3DME system are configured back-to-back. This balances the mechanical forces and reduces the potential for mechanical coupling from the drivers back to the ambient mics to virtually zero. The dual drivers are both full-range units with no crossover, and have a neutral frequency response that can be tweaked using the seven-band EQ within the 3DME app.

    The mics themselves are wide dynamic MEMS types, effectively a mic etched into a semiconductive silicon wafer. Their balanced output is then routed through very low-output-impedance integral preamp/ buffer circuitry in the earpiece, which eliminates the need for a thick, shielded cable to connect to the body pack.

    The body pack is around the same size as a standard IEM wireless receiver and runs on an internal lithium battery that lasts around eight hours when fully charged. It is both lightweight and simple in design, and features a sprung belt clip. On the top are raised plus and minus buttons, enabling you to easily adjust the ambient microphone signal level without having to access the 3DME app. The battery status LEDs are also located on the top of the unit, making them clearly visible during performances.

    On the left side of the pack is the 3.5mm input jack; typically this would be fed from the headphone output of a wireless pack, which is where the supplied 3.5mm connecting cable comes in. The bottom of the pack features a USB-C charging port, small on/off switch and 3.5mm output jack, which directly reflects the combined microphone and monitor input signal reaching your ears, along with any added EQ and limiting applied by the 3DME app. The manual suggests this is useful for monitoring your listening level and for binaural recording.

Fitted Up

The package ships with Comply premium foam tips in three different sizes. Once they’re fitted to the earpieces, you roll the tip between your fingers to compress the foam into a thin cylinder, before inserting it into the ear as deeply as is comfortable. Holding the earpiece in place for 20 or 30 seconds allows the foam to expand and conform to the shape of your ear canal. This creates a ‘custom fit’ and, hopefully, a perfect seal, which is paramount to getting the best from any IEMs.

    In practice, this is quite an odd experience, as initially it seems the tips are not producing a good seal, but as the foam expands, the outside world gradually disappears and the full extent of the noise reduction is revealed. Figures of up to 45dB isolation and 37dB broadband average isolation are quoted on the ASI website, which allows for direct numerical comparison against other models of IEM.

    More importantly, what I found in practice was that, with correct tips and careful insertion, the 3DME offered a very similar level of noise reduction to my custom-fit IEMs. It is this isolation that is both a benefit and a curse when it comes to using IEMs. A good level of isolation will ensure not only that your hearing is protected from high levels of audio, but also that the monitor mix you listen to is both balanced and accurate. However, many people find it difficult to adjust to the resulting detachment from the outside world, leading to the familiar ‘one ear in, one ear out’ compromise or, worse still, using no hearing protection at all. This is where the magic of the 3DME begins.

App & Away

The only adjustment possible from the bodypack is the ambient mic level. The other main features and settings are accessed through the app, which is available for both iOS and Android and connects over Bluetooth. The app has three main screens: Mic Level & Limiter, Equalizer and Options, plus a neat little feature called the Seal Test. This plays back alternating low- and mid-frequency tones (one at 50Hz and the other at 500Hz), with the principle being that you should hear both tones at equal volume. A weaker lower tone would indicate a poor seal and compromised performance.

    The Mic Level slider has a range from off, through -24dB attenuation, to +12dB boost. As a default, the left and right channels are controlled together, but a Separate/Join button offers independent control. A Level of 0dB corresponds to an ‘open ear’ (as if you weren’t wearing anything in your ears), so this seemed a good place to start to get a feel for the 3DME system.

The Main screen lets you adjust the built-in microphones and limiter.

    It’s initially quite an odd sensation to be wearing tight-fitting IEMs, yet be able to hear everything as normal. Typically, when using headphones, you may have an open mic in the studio or on stage picking up the ambience, but it’s not picking up exactly what you would hear, and as you move around, the ambient mic remains static. Not so with the 3DME. Because the microphone placement is on your ears, you experience a natural binaural listening environment/sensation. The mics do add a slight coloration to the sound, and having something in your ear does create a certain amount of bone conductivity but, overall, the sound is very natural.

    The limiter threshold can be set between 76dB and 104dB SPL (in 4dB increments). Specifically designed for use with music, and featuring adaptive attack and frequency-selective operation, the limiter can apply up to 20dB gain reduction. As well as doing a great job of keeping a lid on the audio signal overall, I found the limiter fattened up the sound of the ambient mics in a very pleasing way, without adding unnatural qualities or artefacts. As with the mic levels, you can unlink the channels and apply different amounts of limiting to the left and right ears independently, should you need to constrain the level of a particularly noisy bass player on your left, for example.

    The Equalizer screen presents a familiar seven-band graphic EQ offering 12dB of cut or boost from 60Hz to 10kHz. Like the mic and limiter settings, the left and right ears can be equalised independently and, like the limiter, the EQ affects both the ambient mic and the monitor input signal.

The app gives you access to a global seven-band graphic EQ.


The Options screen includes several setup and configuration settings, one of which is Contralateral Routing of Signals (CROS). In CROS mode, the bodypack routes the ambient and monitor audio signal from one earpiece to the other, which means that anyone with severe hearing loss on one side literally has the missing audio routed to their ‘good’ ear. I’m pleased that this isn’t a feature I needed, but I can imagine that it’s a major asset for anyone suffering from unilateral hearing loss.

    At some point while reading this review, it may have occurred to you that placing microphones in very close proximity to speakers has the potential to cause feedback, particularly if you place your fingers on or around the microphones when inserting the earpieces. This is only an issue if the system is ‘live’, with the bodypack turned on, and during the many times I inserted the earpieces, I experienced no feedback issues. However, as a precaution ASI have included a Start-up Squeal Suppressor option. If this is enabled, the built-in limiter is automatically set to its lowest threshold (76dB) when the body pack is first switched on, ensuring that any feedback is suppressed. Pressing the plus or minus bodypack buttons restores your stored limiter threshold settings.

    Another useful option is the ability to change the bodypack mic level buttons from their normal Step Mode operation to Set Mode. Here you can set the plus/ minus buttons to toggle between two preset levels. The obvious and very useful application is that one setting can be used while performing and the other for conversation between songs.

    Any settings made within the app are automatically saved and are loaded the next time you turn on the bodypack, but you can also save multiple presets for different scenarios. This is very handy if you play in several different bands or want to set up configurations for performance and rehearsal situations.

Ear Peace

With no monitor feed connected, the 3DME system becomes the most flexible and high-fidelity set of earplugs you will ever own... and probably the most expensive! Fortunately, this isn’t all the system has to offer, but it is perhaps a more important feature than you might imagine.

    I’ve used many types of ear protection over the years, from custom moulds to earplugs with adjustable attenuation capabilities, and I have always felt detached or unable to hear everything in quite the way I want. Using the 3DME system in a band rehearsal was an absolute revelation. Not only was I able to adjust the level of attenuation precisely, but the fidelity of the music remained perfectly intact — no missing high end or muffled vocals. It really is like using no ear protection... only quieter!

    With careful use of the limiter and EQ, I was able to tailor the sound even further, in the same way you might use similar tools when mastering a mix to enhance certain elements and compress the dynamics. Connecting my iPhone metronome to the monitor input jack of the 3DME body pack also allowed me to play to click while being able to hear the band perfectly — normally an operation that requires some degree of compromise.

    In a performance setting, the 3DME system also performed extremely well. How a pair of IEMs sound is a very personal experience, unique to the wearer and dictated by several factors, with a good fit being one of them. Used as ‘normal’ IEMs, without the ambient mics in operation, the 3DME system produced a balanced and clear sound, with no frequencies poking out or harsh high end to cause fatigue on long listens. If anything, compared to my existing ACS IEMs, the low end was a perhaps a little lacking. However, it remained tight and solid and I was able to add a little more bass using the seven-band EQ. The earpieces were very comfortable, I never felt as though they were going to work loose, and they provided an impressive level of isolation.

    In my usual performance scenario, I have everything — fully miked drum kit, keyboards, guitar, bass DI and vocals — routed to my IEMs, so there is no immediate need for any stage sound. However, introducing the ambient mics into the equation was a surprisingly subtle and pleasant experience. With a particularly full IEM mix, the ambient mics introduced some air around the sound and added a little more life to my drums. I’ve used the 3DME system in many different scenarios, and in each case they have not only performed brilliantly but also solved several problems — some of which I didn’t even know I had! They have also proved invaluable in providing me with a great IEM mix at several festival performances where the monitor feed can be unpredictable, enabling me to feel completely in control of what I’m hearing.

    I’ve got very used to using IEMs, and if you’re working to click or backing tracks, they are impossible to do without. Being able to hear everything perfectly, regardless of what is available through the monitor feed, is an absolute godsend. As a drummer, the benefits of the 3DME system are huge, but I can also see how useful it would be to any musician, particularly singers or performers of acoustic instruments, and not only in rehearsal and performance situations but also in the studio. For many, the studio is an unnatural environment, and performing while wearing headphones can prove challenging. The 3DME system is as close to a perfect solution as you’ll get: performers are able to hear themselves in as natural a way as possible, while still monitoring playback with minimal spill, keeping the engineer happy!

    Applications for the 3DME system, if not endless, are certainly varied and wide, from simple hearing protection to flexible on-stage monitoring, and even addressing medical issues with the CROS feature. Compared to other good-quality IEMs and considering what the 3DME offers in terms of features, I certainly don’t consider them overly expensive. The inclusion of ambient mics is obviously what sets these IEMs apart, and the ability to hear almost exactly what you would experience without ear protection, alongside a great ‘standard’ IEM mix, makes the 3DME a great solution to many IEM problems.

ASI Audio 3DME

• Comfortable fit and good isolation.
• Unique ambient mics.
• Great sound.
• Comprehensive app.

• Cable not detachable.

The 3DME in-ear monitoring system adds an ambient microphone to each earpiece, allowing you to literally dial the room sound into your IEMs, and could mean the end of ‘one ear in, one ear out’ monitoring.