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Review - Sennheiser IE600

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Also available on YouTube in Spanish: Acho Reviews YouTube 

The Sennheiser IE600 have been loaned to me directly by Sennheiser as part of a tour that was arranged on Head-Fi. The terms of the tour were that I would spend a maximum of 2 weeks with the IEMs, posting my honest opinions of them on Head-Fi at the end of the period. The also requested that any other reviews or comments on social media contain the hashtag #IE600Tour so they could be easily found.

There were a couple of other requests (such as at least trying the stock tips and comparing them to any other tips used, etc.) which you can find by visiting the first post of the Tour thread here:

No other requests have been made outside of the above thread, therefore, I will do my best to be as unbiased as I usually am, taking into consideration that it has not cost me anything to try out these IEMs.

Rather than sharing a specific official page link, I suggest you use this link: which will take you to the relevant Sennheiser page for your location, from which you can navigate to the IE600.


While I am someone who has been using Sennheiser gear for a very long time, due to me working in the pro audio field, I really haven’t had the chance to try any of their more hifi orientated IEMs. I have tried plenty of the consumer class stuff, along with plenty of their stage focused stuff, but the IE series is something that I just haven’t come across before.

I was very tempted to pick up the IE300 when they were released, to get a taste of what Sennheiser were doing with this line, but in the end I ended up not doing so. I was also interested in trying out the IE900, the TOTL in this series, but the price tag is something that doesn’t make it easy to blind buy.

So when the IE600 was released, priced at just under 600€, I was interested in finding out what they were all about and, when Sennheiser announced the tour, I was very happy to make the selection of people to get to try them.


The IE600 comes packaged in a very professional way. Upon opening the outer box, the two IEMs sit in a foam surround, which either makes the IEMs look tiny or the box look huge!

Beneath this top layer we find multiple documents, user manuals etc. and below these we get to the accessories.

The accessories included are 2 cables, one 3.5mm and the other 4.4mm, a square transport case, 3 sets of foam tips, 3 sets of silicone tips and a cleaning tool.

To be honest, the included accessories are what I would consider to be just the correct amount. There is nothing missing that we need to enjoy (and look after) the IEMs but at the same time, there is nothing included that is just to fill a void (except maybe for some of the packaging itself).

Balanced and unbalanced cable options are included, a nice travel case that is not overly large is included, basically offering a presentation that I would consider very well thought out.

Build and aesthetics…

Starting off with the IEMs, they are small and fairly lightweight (although they could be considered heavy for their size I guess). Completely made of what seems to be some kind of sandblasted metal, they look rugged and discreet at the same time. When wearing them, they are even more discreet, as they fit inside the ear very well, sitting flush inside the ear (at least in my ears).

Speaking of comfort, I find them to be probably the most comfortable IEMs that I have ever worn. Recently I said that the Airship were one of the most comfortable sets of IEMs that I had worn in a long time. Well, the IE600 came along and blew those out of the water as far as comfort.

Added to the comfort of the IEMs, there comes the cable. While I wouldn’t say the cable is anything special, it’s just a simple grey cable, the mouldable hooks over the ears are great. This reminds me of the moldable hooks on pro gear, such as DPA mics, that are made to be comfortable and not move throughout a show, no matter what the artist is doing. However, in the case of the IE600, these moldable hooks are covered with a slightly thicker outer sheath than the DPA mics (for example), making them work even better in my case.

When inserting the IEMs at the beginning, you do need to fiddle around a little to get the perfect fit, but onese they are in place and the hooks are moulded to the correct shape, they are extremely comfortable (for me) and are going nowhere unless I want them to.

The cable itself is nothing special, as I already said, which sort of keeps up with the “pro” functionality of these IEMs. I would expect to just run the cable down the artists back, connect it to the belt pack, and not have to worry about it.

One thing that may be a negative for some is the fact that, while the cable does use MMCX connectors, they seem to be Sennheiser proprietary connectors. This means that you can't just grab your favourite cable of choice and expect it to fit the IE600 (I believe this is the case with the IE300 and IE900 also). However, the connectors used are so smooth and so easy to connect/disconnect, without worrying about them being too loose or too tight, that it makes it almost worthwhile having to stick with the stock cable.

At the other end, while the 3.5mm/4.4mm is plastic, I have no doubt that it is also of great quality. I have Sennheiser cables that I have used thousands of times over the tears and not once have I had to worry about the connector.

Another thing to point out, which I will discuss more in sound, is the included tips. These tips are also proprietary to the IE line of IEMs, as they include tuning material inside the actual tips. While I do know that some people have had issues with these tips, personally I find the included foam tips to be extremely comfortable and while I did try a few other tips, I also found that I preferred the sound with the foams.

The rest of the included accessories are of a quality that seems just as good and, while 600€ is not exactly cheap for a set of IEMs, I feel that the build of all of them are up to the standard of the price point.


(Note: All tracks mentioned are clickable links that will open the track for reference in the streaming service of your choice)

As the IE600 is part of a tour (which goes back to Sennheiser between each person on the tour, for cleaning and replenishing with a new set of tips), I didn’t have to bother with putting it on the burn in rig for days to avoid the “it’s because you didn’t burn it in long enough” comments. So I opened the box, put them in my ears (marvelling at the comfort) and connected them to the Go Blu. Within 30 minutes, I had decided that these were the best single DD IEMs I have heard to date.

I have said many times in the past that I don’t put together any detailed impressions of things until I have been using them for at least 4 or 5 days as sometimes that period will either show more flaws that I hadn't noticed upon first listen, or even get me used to the flaws and dfind that I enjoy them more than I originally thought.

During these two weeks, I haven’t used the IE600 exclusively as other things need to be reviewed, but I did find that, apart from the exclusive use for 4 or 5 days, that any time I felt like listening at other times of the day, I reached for the IE600. That is already something that goes to prove my very positive experience with these IEMs. They are not perfect, I will get into details in just a second, but I still feel that the overall sound of these IEMs is very very good. 

I have to say that when I put them on the measuring rig, I was very surprised at the results. I do remember noticing that they had elevated bass on the graphs when I first saw measurements of them, but measuring them for myself brought me to realize that either:

a) I have become a bass-head without realizing it.


b) These do not sound like they measure.

Before moving on and explaining what I mean, here is the graph of the IE600 with the usual foam tips I use for measuring, along with the included foam tips (the ones I have been using) and the included silicone tips:

As you can see, the low end is way above my usual preference target, but as I have said in the past, if an IEM is capable of producing very clean and articulate bass while still being boosted, I will often find that I like the low end. And that is the case with the IE600.

Starting off with the subbass, we are almost 10dB above my preference on paper. Yet to the ear, this subbass only comes into play when the song needs it. The IE600 don’t produce subbass on their own, they just boost what is already in the track and, as they do it in such a  clean and articulate way, they come across as impressive with many subbass tracks.

Putting them through the usual “Chameleon” test, there is a large quantity of subbass but there really isn’t an overly present sensation of rumble, at least not to the extent I would expect looking at the graph. The same happens with Lorde’s “Royals”, although this track does have a subbass that is a bit more “out of control” than “Chameleon”, which is due to the recording more than the way that the IE600 portrays it.

The midbass is where I usually suffer when a set of IEMs is overly boosted in the low end. An overly present midbass is something that I find tiring and can make me want to either stop listening or move to music that has less of a bass presence. With the IE600 I did not get this feeling. Again, it is clearly boosted in these frequencies, yet somehow manages to keep the bass clean and stop it from interfering with the lower mids. 

Listening to “No Sanctuary Here” by Marian Herzog feat. Chris Jones, there is no lack of bass presence to make this track sound excellent in the lower ranges, yet it does not detract from other parts of the song. 

Moving away from more electronic bass focused tracks and towards bass guitars, here I did find on occasions that the low end was not quite as clean or tonally correct as I would like. For example,  “Black Muse” by Prince, where this particular track did give me the sensation that the bass was overly bloated, missing some of the clarity that this needs to appreciate the bass playing. The same could be said for other tracks such as “No Ordinary Love”, where the music is much simpler, allowing the bass to become a little too present. As soon as I moved back to more electronically focused tracks, like “Shot Me Down”, the bass went straight back to being great.

What the IE600 does do is keep the bass away from the lower mids, offering a transition that is much cleaner than I would have expected from such a tuning. In fact, the mids on these IEMs are nothing short of excellent on most tracks. 

Even more simple and melodic songs, such as “No Ordinary Love” that I already mentioned, or “Billie Jean” by The Civil Wars (to move more towards the acoustic side of things), sound very balanced and well defined throughout the mids. The upper mids have a rise around 2kHz which, while maybe not the best I have heard, do a very good job of presenting these voices and instruments with detail and not too much harshness.

Acapella tracks, such as “Hallelujah” or even “Happens To The Heart” (which is not exactly acapella but almost), do sound clear and articulate, although, in the case of Leonard Cohen, I got a sensation that it was maybe not quite as smooth as it could be.

After the 2kHz mark there is a bit of a dip which, thankfully, does not come back with a peak at the 5kHZ mark like on so many other sets. I do feel that the presence just above 2Hz could have extended slightly more, maybe to just past the 3kHz mark, but that is just a personal preference and more of a nit pick than anything else.

As we get into the higher ranges, there is a bit of a peak that can suddenly appear now and again, giving the sensation of a bit of brightness that can come across a little harsh, such as brief appearances in “Sugar” by Francesco Yates. Sibilance is mostly controlled, although not eliminated, making “Code Cool” be just hovering on that sibilance mark, without actually getting there. 

As far as soundstage, I would say that it is not huge, maybe at the higher side of average, yet the image placement and details make it seem like there is much more space than there actually is. With tracks like “Bubbles”, you can focus on literally any of the sounds and follow them, without ever getting the sensation that you have lost them. The same can be said for “Strange Fruit”, where each and every layer of vocals can be tracked on its own.

Last but by no means least, the detail. The details that this small dynamic driver is capable of presenting is very impressive. I never found that I was having to focus on anything to appreciate the details, yet at the same time, it doesn’t push them in your face. It just does a very good job of keeping everything just where it needs to be.


I haven’t mentioned it during the review as I always share my opinions without EQ, yet, I find that with a little bit of EQ, these IEMs go from being very good, to almost excellent. I found that dropping the low end quite a bit (not 10dB to match my target but around 6dB), along with just a little tweak of the upper mids (to extend that 2kHz presence just a little more)  really opened up these IEMs and made them sound amazing (in my opinion of course). Now, I am in no way saying that my little tweaks improved these IEMs, far from it, more that they adjusted them to my personal preferences.

Without EQ, these are still very good IEMs, with a performance that I find spectacular for a single DD, providing details that are way above what I expected. I am sure that others, who prefer more bass than me, will enjoy the tuning as is.

I also feel that the build, aesthetics, cable, accessories, everything really, is well thought out and is presented in a way that I doubt anyone could fault.

In fact, with the possibilities of EQ, I wouldn't hesitate to recommend these IEMs as on stage monitors to any of the artists that I work with. As each artist gets their own in-ear mix, the IE600 can be tailored to almost anyone, as there isn’t anything missing, just some people will prefer to drop certain frequencies more than others.

And then there is the comfort. If ever there was a set of IEMs that I would want in my ears for extended periods and just forget they are there, the IE600 are those IEMs.

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