Etymotic ER-4p MicroPro Review

Etymotic Research was founded in 1983 and manufactures high-fidelity products that measure, improve and protect hearing. The name ‘Etymotic’ (pronounced ‘et-im-oh-tik’ ) means ‘true to the ear.’ They were the first company to develop noise-excluding high fidelity insert earphones back in 1984. These two models, the ER-1 and ER-2 earphones were developed for use in auditory research. These were followed by the ER-3, which was developed for clinical audiometry research and is still used today in hearing clinics.

Returning back to present time, their core consumer products today consists of isolating earphones, ETY* COM mobile phone handsfree headsets, Musicians earplugs, ETY* PLUGS earplugs and Companion Mics Multi-talker noise reduction systems. Lately they also introduced the Ety8, a Bluetooth in-ear earphone model. In the coming months we will also be reviewing their midrange ER* 6 and ER* 6i Isolator models, but today the topic of our review is Etymotic’s flagship earphone the ER* 4 MicroPro. These were introduced way back in 1991 for stage musicians during live performances. I’m reviewing the ER* 4P (Portable), but Etymotic also included the adapter to transform the ER* 4P into ER* 4S (Stereo). In-ear earphones are not unknown to us here at, but the ER* 4 MicroPro was a particular model I wanted to review for some time now to see how it would stack up against previous products we tested. How does the ER* 4 fair and does it compare among other strong competitors like the Sure E4c? Without doubt some of you have also considered the cheaper ER* 6 series, is the ER* 4 worth the extra price? I will try to answer all of these questions in this review. The converter: The ER* 4 MicroPro

The ER* 4 MicroPro is positioned at the top of Etymotic’s line, the Ety8 might have a higher number in its name but its performance is just below the ER* 4. They both retail for $299, but the ER* 4 gives you the better performance while the Ety8 has the convenience advantage of being wireless through the use of Bluetooth. A quick check online shows the ER* 4P selling for prices well below the $200 range, which to me is simply a bargain. The ER* 4 is also positioned above the midrange ER* 6 and ER* 6i Isolator models and falls firmly in the Canalphones or In-Ear Monitors (IEM) category. IEM are ear buds that sit directly inside the ear canal and fully envelop it. Noteworthy is the ER* 4’s impressive noise isolation numbers: 35 dB with 3-flange eartips or 42 dB with foam eartips. The ER* 4 MicroPro comes in three styles: ER* 4B, ER* 4S and ER* 4P.

The model I received was the ER* 4P: these are perfect for normal usage, like MP3 player, CD player, DVD player or even music phones. Basically it was designed for all sources that don’t require an added amplifier. Compared to the ER* 4S, the ER* 4P has 10 dB greater output at high frequencies and 13 dB greater output at low frequencies. The higher sensitivity and enhanced bass of the ER* 4P makes it the most popular model of the three and perfect for you’re the consumer. I also received Etymotic’s $65 ER4P-24 Cable that allows you to easily convert the ER* 4P to ER* 4S model, thus essentially giving you two models in one.

The ER* 4S (Stereo) earphones were designed to compensate for the high frequency emphasis in all CD recordings, in order to provide accurate sound reproduction. Performing musicians often use them as in-ear monitors because the response of the ER* 4S matches the response of most typical monitor loudspeakers. The high accuracy and sound isolation of the ER* 4S makes them a better choice for musicians, recording engineers and audiophiles. ER* 4P earphones can be used with a headphone amplifier when using low power portable devices. The last model is the ER* 4B, this particular flavor of the ER* 4 is perfect for binaural recording. For most consumers the ER* 4P is the model to get, with the possible upgrade to the ER* 4S.

Before we continue let’s take a look at the specs.

ER* 4 Technical Specifications

Response Accuracy:
ER* 4S MicroPro Earphones: 92%
ER* 4P MicroPro Earphones: 86%
Noise Isolation: 35-42 dB
Frequency response: 50-10 kHz + 2 dB; 20-16 kHz +4 dB
Acoustic polarity: + electrical = + acoustic
Transducer type: balanced armature
1 kHz sensitivity (ER* 4B/ER* 4S): 108 dB SPL for a 0.79 V input
(90 dB @ 0.1 V; 100 dB @ 1mW)
1 kHz sensitivity (ER* 4P): 108 dB SPL for a 0.2 V input
(102 dB @ 0.1 V; 106 dB @ 1mW)
Impedance (ER* 4B/ER* 4S): 100 Ohms nominal
Impedance (ER* 4P): 27 Ohms nominal
Maximum output: 122 dB SPL
Maximum continuous input (ER* 4B/ER* 4S): 3.0 Vrms
Maximum continuous input (ER* 4P): .75 Vrms
Weight: less than 1 oz.

The Unboxing

It has almost become a tradition to include an unboxing video when doing a review. The ER* 4 MicroPro is going to be our first review featuring an unboxing video. Hopefully it won’t be the last either.

Design and Package

The earphones themselves have gold connector and are finished in this black, almost glossy looking finish that looks very stylish. The cable is thick at the bottom and opens up in two separate cables like a Y-shape. In the middle there is this bulge that separates the thick cable at the bottom from the two thin cables at the top, this bulge is not in the same glossy black finish as the cable. At the top, where the left and right earphone cables are separated the cable is much thinner making it more flexible. This extra flexibility at the upper part of the cable is needed as it would otherwise be too thick and actually hamper head movement. The actual earphones part is long and thin as compared to other earphones that are much shorter and wider in size. I know that previous version of the ER* 4 distinguished the left from the right earphone by coloring part the left and right with respectively blue and red color. The new full black style looks much better and Etymotic has decided to go with a much more subdued ‘R’ and ‘L’ markings.

The ER* 4 comes with a good amount of accessories in the package and comes sealed in a nice black storage box with ‘Etymotic Research’ in red on top. The box adds a nice place to display your earphones and is second option to store unit as a storage pouch is also included. The box adds to the overall ‘pro’ look of the product and contains almost everything you could ask for in this price range. Besides the ER* 4, in the storage box you’ll find: a 5 ft. cord with 3.5 mm stereo phone plug, 1/4′ stereo phone adapter plug, Six 3-flange eartips, 10 foam eartips, filter changing tool, 4 replacement filters, shirt clip and storage pouch. The package is quite complete for what you pay for and the only things I would really add is a tool to clean and take out ear wax. Ear wax is an inevitable part IEM, so including a wax cleaning is important and can be manufactured at a very low cost, so I don’t see the reason for them not to include it. I’m sure you could find some pointy object to get the ear wax out, but at the $299 price range you would expect it in the package. I liked the fact that Etymotic includes a lot (10 pieces, 5 pairs) of the foam eartips, as these provide more noise isolation and can easily achieve a tight seal. Other manufacturer only provide 1 or 2 pairs of these and mostly offer them in a bright yellow color that looks out of place and gets dirty without any difficulty. The foam ear tips included are a black in color. This black color hides the ear wax that gets on the ear tips with usage, they are also made of a higher quality foam material that seems to last longer. With other types of ear tips it’s a bit more difficult to get the seal just right. With the foam tips it’s less of a hassle, so the inclusion of more foam ear tips is a good one. The 3-flange ear tips seems to be Etymotic ear tip of choice as they come connected to the ER* 4 as standard and are even pictured with the ER* 4 in the product shots. They have included 3 pairs of these in the package. There are 2-flange (large and small) eartips available (white or gray) for the ER* 4. I was also informed by Etymotic that complimentary eartip samples are available upon request through their Customer Service Department. I don’t like triple flange ear tips as they need a little more work to get a tight seal. Many people don’t like them either as they require you to push them a bit deeper compared to other types of ear tips and when you do get them in it feels a little less comfortable compared to let’s say the foam ear tips. Seeing that the Ety’s do come with them as standard I decided to try these out first, I initially wanted to go straight to the foam tips, but decided to start things of with the 3-flange type and than move on to the foam tips.. I found it peculiar how they don’t offer flex sleeves, seems that they believe that the 3-flange eartips and foam eartips are enough.
Leaving flex sleeves out is not really a big problem as having both triple flange and foam tips in the package will cover most of the targeted buyers out there, but the thing is that not everyone will want to buy these disposal foam tips as they will eventually wear out and not everyone is willing to use those 3-flange ear tips as they go a bit deeper in the ear canal than usual. I would like to see the inclusion of flex sleeves in the package as variety and the option to choose makes the package more complete.

Overall the ER* 4 exudes quality and is well built. Other competitors like the Shure E4c don’t offer a storage box. It’s this storage box that adds to the overall presentation of the product. The package is good and the only real thing missing is a tool to clean ear wax. It would be nice if Etymotic included flex sleeves, but most users will be happy with the included triple flang and foam tips. Extra points for including more foam tips that are of higher quality compared to those used by competing products.

As for the performance area I used the Ety’s on variety of mobile devices ranging from MP3 players to Music/Smarphones. Audio test were conducted on a Nokia N93 and N91 Smartphone, Apple iPod and Mobiblu Cube2. Since a lot of us also do some listening at the PC I also did a test on my PC equipped with X-FI Platinum sound card.
Build quality and package aside, this is the area where it comes down to. As with all IEM the sound will lack bass, depth and volume without the tight seal. Through testing of various models I have acquired a feel for the way it should be done, but first time buyers will be disappointed as they won’t able to explain why their new costly IEM is sounding not much different from a $25 model. It takes about a week to get it just right.

First impression I got from the ER* 4P is that they are really balanced, this is done without emphasis on any frequency: no aggressive upper range and most importantly no boomy bass. This balance and clarity is even better than the Shure E4c I tested a while ago, but Shure E4c is much more capable in the bass department. Compared to the Shure E4c they do sound overall very similar with a slight nudge to the ER* 4P in balance, highs, mids and uniform sound without any noticeable gaps. The highs and mids are the ER* 4P’s strong part, with the highs just being excellent! The midrange is clean but doesn’t have the ‘in your face’ approach with again balance being the deciding factor. The top end is very detailed and will quickly reveal compression flaws in low quality audio files. The bass is defined and adds a solid foundation, but by default is not exaggerated nor pronounced, with tweaking you could of course raise the bass output, but clearly they had to make a choice being either balanced or bass heavy and ultimately these are not build for excessive bass in mind and will not win any ultra bass contests.

The frequency response can be described as essentially flat . Bass is reproduced accurately with gentle roll off in the lowest octave.

The ER* 4P is capable of is very impressive volume and will reach the limits of the listener way before the sound gets distorted. With sound so good the ER* 4P just begs you to raise the volume higher and once you do they will keep going without any distortion, but due to the nature of IEM you will be able to hear the audio at a lower volume because the sound doesn’t have to compete with external noise. As a matter of fact these reveal the flaws of the source and the audio system used before reaching it’s own limit. I didn’t expect the ER* 4P to offers such good noise isolation, I’m aware how much noise isolation the standard IEM can offer, but with these I could definitely feel that blocked more noise. This was especially true with the foam tips. I’m sure custom made ear tips will offer batter noise isolation, but the isolation offered by these is just excellent, coupled with the detailed sound I could hear all the nuances of the music.

Testing the ER* 4S revealed that these definitely offers a more subdued bass performance, letting especially the mids ‘show themselves.’ Just like the bass the highs are recessed giving the mids more presence. The entire sound is even more balanced and detailed when compared to the ER* 4P. These also do play at a much lower overall volume. For the typical consumer there would not be much point in getting the ER* 4S as these cost more than the ER* 4P by adding the adiotional $65 for ER4P-24 and have performance characteristics that are more tailored to the musician.

The performance of Etymotic’s flagship can be considered excellent and offers one of the best single driver performance on the market. When you reach this type of performance what you really are doing is nitpicking and bass performance is good, but the Shure E4c offers better bass performance, the ER&
ull;4P wins in mids and highs. There is definitely room for improved in the bass department. Maybe Etymotic should consider making a model of the ER* 4P using a dual or tiple driver design seeing the excellent performance offered by using only a single driver. Two particular qualities I liked the most are the balanced approach and uniform sound. The ER* 4P offers excellent performance for prices ranging well below the $200 price. The Etymotic ER* 4P comes close to excellent single driver performance but came just a step from that due it’s less than perfect bass performance. Overall the bass is still really good. While ER* 4S offers even more balanced and detailed mids, it’s really for consumers due the subdued bass, highs and the higher cost should. The ER* 4P offers an overall more pleasing sound.

Lastly, I read several complaints about the microphonic qualities of the cord, so this is something I definitely wanted to test. I tried these during my daily workout at the gym and even did some jogging. I tried using them both with or without the included clip and I must say that only during extreme movements I could distinguish a slight ‘thud’ caused by the cable hitting my shirt. Using the included clip helped to almost completely solve this problem and only in very rare circumstances this would occur. This would also be greatly minimized of they would use the design where the cord would go over and around your ears.


When all the aspects are considered I would say that the Etymotic ER* 4 is one of the best performers in its price range. It offers good performance in the mids and lower ranges, while its ability in the higher frequencies is its strongest point; here is where it performs just excellent. The ER* 4 offers a very balanced performance without any aggressiveness. These are built for fidelity and not really for dramatic sound. This balance does come at the cost of bass and it will most likely not be the first choice for bass-heads, as these users require a more pronounced and booming bass. Don’t me get me wrong the Ety’s do have a very good bass output, putting out a solid lower range foundation, but there is in my opnion room for improvement.
The overall clarity is unprecedented, but this does quickly reveal the weak points of both the audio system and source. So listening to higher quality audio materials and sources is recommended. The ‘defects’ in lower bit rate audio files will easily be revealed, especially in the higher end of the spectrum. Etymotic has proved that they are capable of single driver earphones design with excellent performance, these could stand some improvement in the bass department but I would like Etymotic to come with something with triple driver design. Etymotic’s ER* 4 has proven to be serious competition for the Shure E4c, besting it in balance, highs and mids. The Shure E4c is still king in the bass department.

The package itself is excellent lacking only flex sleeves and a wax cleaning tool, other than this the package and presentation is good as Etymotic can easily include these in later version.

Looking at it’s performance and package I do feel that the Etymotic ER* 4 does deserve a grade of 9.8, but I’m also testing the ER* 6 and ER* 6i Isolator models and these offer performance close to the ER* 4 at a much lower price. If performance was the only key factor the ER* 4 would win hands down, but value is also an important and decisive factor and that’s why I think ER* 6 should get a higher grade. Etymotic’s ER* 4 line gets a good 9.3 out of 10.

-Lot’s of foam sleeves included
-Impressive sound
-Lots of foam eartips included
-quality design
-Quality package and presentation
-One of the best noise isolation available
-Serious competition for the Shure E4c

-No flex sleeves or wax cleaning tool
-Bass could be improved
-Next version should include the over-the-ear-design[lib

Written by Devin