The Best IEM No One Has Heard Of

The Best I.E.M. No One Has Heard Of


Last year I received a phone call from a fellow (who happened to be a recording engineer) looking to purchase a set of Technics over the ear headphones. After listening to countless headphones – using his own material as a measure – he settled on the Technics as being the most natural and accurate. We brought those in for him and he subsequently purchased two more pairs.

When Technics announced their EAH-TZ700 in-ear monitors (IEM) earlier this year, he immediately placed an order. Shortly after receiving his pair, he wrote:

“Hi Galen, Got the new Technics [EAH-TZ700] earbuds tonight, just as I was leaving to record a concert.

“I am back, and just now taking a listen…….so far pretty incredible sound from these buds…….much more accurate than any of the other buds I have……and they are not broken in yet.  

“Very happy with the sound as they break-in on my recordings. I hope you like them when yours arrive. If all continues to go smoothly (as they break-in, they should only get more accurate), I will order another pair.” Thanks again, Ron

As you might imagine, that note and his enthusiasm piqued my interest, and I ordered myself a pair.

I own a few pairs of IEM’s, even a pair that cost $1000, but none of them had I considered outstanding, from an audiophile perspective. I’d purchased the various IEM’s to be used while exercising, working in the yard, or traveling. In none of those activities can you listen seriously, so they satisfied the need.  Frankly, I wasn’t expecting much more from the Technics EAH-TZ700. However, true to Mr. Meyer’s findings, the Technics blew away the IEM’s I had.

Over the ensuing months, and his additional orders for more Technics IEMs, my conversations with Mr. Meyer underscored his excitement about the product, so I asked if he would be willing to put fingers to keyboard for a brief review that I could share with others. He agreed. I am grateful for his time and efforts. Read on.

“I am a recording engineer who is constantly on the hunt for accurate playback devices so that I can a) get better at my ‘on location’ audio recording job by being better able to hear what I am actually recording, and b) have a more believable audio playback experience that brings me closer to the original concert event, allowing me to be transported back to the concert whenever I want. The techniques I use to evaluate a new headphone and/or earbud product depend on me having access to both the original concert event because that allows me to compare the playback transducer to the original sound live during the rehearsal pre-concert, and reference measurement equipment that will allow an unbiased suite of data to help me determine why some earbuds/headphones some better (defined as more accurate) than others, which helps me corroborate what I detect with my listening experience with the data.

“Since I record acoustic instruments generally with only 2 microphones in a stereo pair at live concerts, I have a really good reference suite of concert data to help me judge sound quality. And since we all have access to measurements taken with world-class measurement tools, provided we ask/hire the right companies to do the work, we all can have at least some way to adjudicate between products. I fall into the camp that appreciates an accurate 3-dimensional playback image as well as a lifelike transient response, and, in my experience, both of those things go hand in hand if all the parts of the playback path contribute nothing extra, or detract from, the original musical signals. That does not mean those without 2 channel ‘acoustic’ recordings have an impossible task in properly judging between one earbud and the next, but it does mean that they must be more careful in how they compare products…….some recordings will do well with one set of earbuds but not well with others, so great care must be taken to not get misled!


With all that being said, I currently own probably 10 different pairs of earbuds and 4 pair of headphones, purchased over the last 15 years, and those are just the ones that I have kept for comparison purposes, and does not include all those I have sold. All were originally purchased in the quest for more accurate sound, and as time has progressed, so has the quality. I have paid all range of $$$ for buds/headphones including the most exotic electrostatic, open ear, closed-ear, and anything else I thought might have a shot at being accurate. I have been to most CES events the past 30 years as well as multiple RMAF and The Shows, taking along my ‘at that time’ own reference recordings and player with my best transducer reference. I then have put on literally hundreds of buds/phones over the years at these shows, so I have as wide a range of experience with ‘the market’ probably as anyone who does not do audio reviews for a living! I use multiple DACs as the source for my listening experiments; I currently have 2 A&K, 2 Questyle, and 1 FIIO portable audio player, having sold others that were too far from accurate to enjoy, in addition to studio-quality Grace, Antelope, Nagra, Metric Halo, and Sonic Solutions DACs for use. Of course, I have my current ‘most accurate’ playback setup, which I will say now includes the new Technics TZ700 earbuds. They provide accurate frequency response, superior transient response, super low and accurate deep bass, uncanny three dimensional sound, and high frequencies that reveal subtle detail and ‘air’ that no other earbud/headphone rig can match, as well as the same sound quality over the entire loudness range (presuming no damage to your ears). Now if you have a player or studio DAC, or recording that has a touch of edginess in the high end, these buds will tell you that……but don’t shoot the messenger. This is not a review of recordings or recording or mastering techniques, it is a review of the absolute sound quality accuracy of the new TZ700 earbuds. These buds are extraordinary, and I can’t imagine how much effort must have gone into making them work so well. The single driver idea allows for super transient response as well as the best imaging I have ever heard……kudos to the designers. They are lightweight in design, come with high-quality rubber tips (so I do not have to use the multiple other tip types I have had to resort to with the other buds I have in an attempt to make them listenable as well as comfortable). My only gripe is that to enable all of this super sound, they are microphonic. As a suggestion for improvement in an already great product, if they just added a tiny clip to the cable so that it could be attached to your shirt button (like I have found) that problem would get solved.


“So, if you want to hear everything that your favorite recording has to offer, you really should try a pair of these, because you will hear things you did not know existed there before, even in the recordings you thought you knew well. You will hear things you won’t hear in speakers because the information level is too low to be heard across the room….and you will be amazed. If you have some recordings that you really like but were not well recorded, there is still hope. There is a multitude of earbud/headphone extension cables, and you can simply purchase one of those to put in series with the stock earbud cord when you want to listen to ‘that’ recording; pick one that slows down the high end and you will be fine. Don’t penalize all of your listening pleasure because a couple of recordings you like were not particularly well-executed, or were recorded a long time ago. These TZ700s do such a great job, and I liked them so much, that I purchased 3 pair……1 for use on location in single-ended mode because my ‘on location’ DACs do not have a balanced output (and I don’t want to have forgotten a pair in the office), 1 for use at home in the studio office in single-ended mode (again DACs without balanced output), and 1 pair for my portable player use in balanced mode. They do sound better in balanced mode, but as noted, many DACs do not support that option. But I do not want to be without a pair of these, and since some products I have liked in the past have been discontinued just when I thought they were the ‘best in class’ of whatever they were……and when my one copy of the product died I was left without……I made sure that in this instance, at least, I am covered. So, thanks Technics, great show……I do not even want to be without a pair of these buds.” - Ron. Meyer, July 2020

Again, my thanks to Mr. Meyer for sharing his most knowledgeable insights into the Technics EAH-TZ700 in-ear monitors.



Precision Motion Technology delivers amazingly pure sound

A newly developed free-edge driver featuring a proprietary diaphragm and magnetic fluid technology -

The newly developed 10-mm driver uses a 5-micron-thick diaphragm made of a combination of a high-strength, special aluminum material that suppresses unwanted vibration and a supple, free-edge suspension material. The special aluminum contributes to improved high-frequency reproduction, while the free-edge material lowers the LF resonance to achieve outstanding low-frequency sound reproduction. Furthermore, magnetic fluid is used in the voice coil section to maximize its characteristics to ensure high stroke accuracy of the supple-edge diaphragm and to provide a high damping effect, which was previously difficult to achieve. The result is the reproduction of sound over a wide frequency range with ultra-low distortion.


Super-wide and flat sound tuning (Air Control Precision Structure) -

The coaxial design cylinder-type housing of the EAH-TZ700 maximizes the potential of the driver. The proprietary Air Control Chamber inside the unit precisely controls the internal airflow and optimizes the balance among frequency bandwidths. As a result, sonic resolution improves, and stunning sound space is created.


A housing design featuring different metal materials -

The unique housing features a combination of different metal materials to maximize both sound quality and strength. The port housing section is made of lightweight high-strength titanium (also used in the Precision Motion Driver). It holds the driver rigidly and suppresses unwanted vibration. The main housing body is made of diecast magnesium for its lightweight and excellent vibration damping characteristics. The 3D shape ensures the most suitable angle of insertion in the ear and provides an optimal fit to realize exceptional comfort.


Dedicated cables and earpieces designed in pursuit of ideal audio quality-

The EAH-TZ700 comes with two types of cables: balanced and unbalanced. The user can choose the one to suit his/her preference or connection environment. The general-purpose MMCX connector used for the connection to the main unit allows for the use of aftermarket cables.

The earpieces are important parts that also affect the sound quality. In addition to the normal type and round type, oval-shape earpieces with excellent sound insulation are provided. What’s more, each earpiece type comes in four different sizes. So, every user can enjoy a high-quality music experience with optimal comfort.


SoundStage! Solo: "I’m surprised to say I think these tiny, inauspicious-looking earphones are as good as any I’ve heard. You might find earphones you like a little better -- I’m still trying to decide if I prefer the Campfire Solarises to the EAH-TZ700s, or not -- but I think you would have a very tough time finding earphones that sound more natural and less sonically colored. It’s perfectly understandable if you want something fancier, with more drivers, interchangeable filters, a cooler-looking design, an ostentatious woven cable, and/or a fancy leather case. But for pure performance, with none of the fussy fit often encountered with earphones using over-ear cable routing, I think the EAH-TZ700 earphones are a sure bet." - Brent Butterworth

SOUND: 10/10
VALUE: 7/10



Technics Sound Technology: Precision Motion Driver, Air Control Precision Structure

Driver Unit: 10 mm

Impedance: 37Ω

Sensitivity: 102 db / mW

Power Handling (IEC): 100 mW (IEC)

Frequency Information - Frequency Response (with cord): 3 Hz - 100k Hz

Weight: Approx. 7 g (without cord),  Approx. 22 g (with cord)

Supplied Accessories: Earpieces Set (Normal Type, Oval Type; Size: S/M/L/XL), Detachable Cord: Approx. 1.2 m, Detachable Balance Cord: Approx. 1.2 m, Carrying case

Plug:(3.5 mm) Stereo Mini Plug

Cord - Cord Length: 1.2 m