Etymotic Research ER4P MicroPro Earphone REVIEW

March 5, 2014
7 mins read

4.5 Stars

Kramer gives a much-lauded legacy brand a blast, and takes the varnish off his ear canals with a highly accurate earphone that won’t suit all tastes.

ANYONE WHO’S BEEN into ear-fi for any length of time will have heard of Etymotic Research, because the company has been producing high-quality earphones since the early 1980s. The products have garnered something of a reputation for being exceedingly accurate, which is no surprise given Etymotic’s background in acoustic research and the hearing aid industry. In fact, the company claims to have invented insert earphones using balanced armature drivers back in 1984. The ER4 series has been on sale for around two decades, which is in itself a very good sign.

WD-Etymotic-ER4-2I’d never had the opportunity to try a set of Etymotic ‘phones, so I was stoked to be presented with a box full of them by the new local agent. I resolved to be conservative and work my way up the range, starting with the MC2 model, which is priced at $169. Well, that plan lasted exactly one day – I used the MC2’s at work and was impressed enough to rip into the box of the much more expensive, range-topping ER4P MicroPro model that very evening.

Features & Construction

If you judged the audio performance of the ER4’s based on their looks, you’re in for a shock. The body of the ‘phones is a tiny cylinder made of an industrial looking black plastic – they’re certainly a durable looking bit of kit, but seven hundred smackers worth? Hmm, not too sure, but Etymotic is a practical company and is all about function over form. Inside the body is a single balanced armature driver, which seems an out-dated concept in a world filled with multi-driver in-ear ‘phones, but this is very much a product from the “if it ain’t broken, why fix it” school of thought.

I did wonder just how effectively the Etymotic engineers could generate music in a capsule that small and then to get it to zoom down what has to be the narrowest tube in the history of earphone design. As it turns out, they know exactly what they’re doing – more on that later.

WD-Etymotic-ER4The ER4’s are supplied in a large plastic case with an impressive list of accessories:

6.35mm adapter

Assortment of eartips (3-flange, foam, glider)

Earwax filter tool and filters

Shirt clip

Airline adapter

Cable to convert ER-4P to ER-4S

Travel pouch

Channel matching graph

Cable-wise, the ER4’s come with a replaceable 1.5 metre braided cable, and as befits a set of high-end in-ear-monitors, there’s no inline mic or remote. There is however, a rather chunky plastic tube where the single cable splits to go to each ear – it’s designed for the shirt clip. It’s not a big deal, but the size does add a bit of heft where a smaller and thinner join might be in order.

From an ease of use perspective, one thing that’s worth noting is that the body of the ER4’s is long, and it’s made longer by the way the cables join. As someone who prefers an aisle seat on aircraft and who’s had his ear bumped hard by a passenger trundling past, I can say with certainty that you don’t want these ‘phones driven into your ear canal by a speeding stewardess’s hip.

WD-Etymotic-ER4-3Etymotic claims to offer greater noise isolation than any earphones or headphones on the market today, and with the foam or 3-flange eartips, the ER4’s sure do manage to shut out the world. The glitch with the 3-flange tips is that while they’re soft, easy to insert and durable, they’re also quite long, which made them a touch uncomfortable. That’s saying a lot in my case because generally I’m fine with having all manner of eartips inserted for long time frames. The foam tips are super comfortable, but unlike the silicone 3-flange versions they’ll get dirty in short order, so replacements will be needed often.

The aforementioned tiny tube leading from the body of the ‘phones to the ear is surely going to be a magnet for earwax, but Etymotic has taken this into account because hidden in that tube is a miniscule little earwax filter. When the filters clog, you just whip them out and put in a new one. An interesting and proactive approach but again, I had to wonder if having a filter in the tube would adversely affect the sound.

Sound Quality

Ten seconds after firing up the ER4’s (following an hour of very high volume break-in connected to a CD player while I was at gym), I realised that my sonic trepidation had been in vain. These ‘phones sure do sound good.

It’s well worth qualifying that “good” because if your version of good is something along the lines of “highly accurate”, then you’ll like these ‘phones. They are nothing if not accurate, which makes sense because Etymotic designs them that way using custom-tuned drivers that are matched and measured. I initially compared the ER4’s to Sony’s $399 four driver XBA-4 ‘phones (review here), which I described as being “musical and involving, especially with the wick turned up slightly. They offer a cerebral, slightly cold sound that some would say is lacking only that last degree of emotional connection. But that often comes from less than accurate behaviour – these ‘phones are anything but inaccurate.”

At nearly twice the price, the ER4’s take the accuracy part of the sonic equation and run with it, bringing even more detail retrieval along with them. They really don’t add a thing to playback, transferring music with the spirit of a set of studio monitors. Which can be a good or even a great thing with high-quality recordings but will provoke a rush for the volume control with bad or bright recordings. Analytical is probably the word that best describes the sound of the ER4’s, and while it’s not a big leap to move from analytical to cold, that’s not really the case here, perhaps except for listeners who like a warm sound with a noticeable boost in the lower frequencies.

However, there are many who’ll listen to the ER4’s and long for less insight, less detail and a balance that’s not as neutral, especially at the top end where they tend towards bright, especially when exacerbated by the recording. For example, ‘Going On’ from Gnarls Barkley’s The Odd Couple was unbearable at high volumes, when it’s actually a favourite track on less revealing ‘phones. The top end was just too harsh to take for more than 10 seconds. The midrange is in much the same vein: you simply hear what’s there. So the inherent character can’t be called smooth or rich or anything really, it’s just a matter-of-fact transfer of what makes it down the cable. And these ‘phones will bring the tiniest of details to the ear of the listener. If digging deep into recordings is your thing, then these are just the instruments for you.

The bass balance is reminiscent of some of the Shure earphones I’ve heard over the years – the bass that’s on the recording is there and not an iota more, but still, that’s more than enough unless you’re used to being presented with a boosted version of the bottom end of your music. Playing a few of my preferred bass test tracks back-to-back with the Sony’s or the quad-driver $599 Logitech UE 900 (review here) showed that the ER4’s weren’t able to deliver the same impact or slam on something like ‘Stand Inside Your Love’ from Smashing Pumpkin’s Rotten Apples. The initial drums sound big and an enormous amount of detail is on hand, but the strikes should ideally fill your head to bursting, and via the ER4’s that’s just not happening.

Fans of the two very distinct presentations will argue the merits of each, but the great thing about hi-fi, head-fi and ear-fi is that there isn’t one answer – listen to your music the way you like.


Remember way back in the beginning of this piece in the accessories list, a certain ‘Cable to convert ER-4P to ER-4S’ was mentioned. This short length of 3.5mm adapter cable is basically an inline resistor that changes the tuning of the ‘phones from P (for Portable) to S (for Stereo). The S tuning is designed to “compensate for the high frequency emphasis in all CD recordings”. The result is a more relaxed, less bright sound. There’s still loads of resolution on hand but recordings such as Powderfinger’s ‘Lost And Running’ from Dream Days At The Hotel Existence are suddenly fun at high volumes. Without the adapter, this track was harsh enough to sear my eardrums.

So ER4 users have an option to turn down the intensity of their ‘phones, but would they really want to have an extra bit of cable in the way? Another consideration is that the ‘phones become noticeably harder to drive with the cable in place – there’s still just about enough headroom from the output of an iPhone but best results were achieved with the ER4’s plugged into my Perreaux SXH2 headphone amplifier. But then again, less revealing ‘phones can’t exactly be tuned to be more revealing, so this is quite a feather in the ER4’s cap.


Etymotic has identified a niche that’s been profitable enough to justify a 20-plus year run of these ‘phones. Audiophiles who prefer the unvarnished sound of their music have made the ER4’s a success, and will no doubt continue to do so.

A very interesting set of ‘phones to say the least, kept back from a five star rating only by the big price tag. Still, even at the lofty local asking price, they’re good enough to be a serious contender against the likes of the less expensive UE 900’s, but punters need to be under no illusions that the audio balance on offer here is likely to end up with them skipping tracks at times, unless they either really like to hear everything (and I do mean everything) or they use the adapter cable. These ‘phones will also be less than kind to those old 128kbps rips, they’re really much happier with CD quality files, so prepare to feed them the best you have to get the best results.   ASHLEY KRAMER

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