Sennheiser ie40 pro: Sennheiser IE 40 PRO – Dynamic In-Ear Monitoring Headphones

Sennheiser IE 40 Pro review

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  • £83
  • €95
  • $99

MusicRadar Verdict

A decent, pretty robust in-ear monitor; the selectable tips and mouldable cable deliver up a comfortable, secure fit.


  • +

    Comfortable fit.

  • +

    Detachable lead.

  • Rather short lead.

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The IE 40 Pro is the most affordable model in Sennheiser’s new pro in-ear monitoring range. 

With three models topping out at £500 for the IE 500 Pro, all three designs use single-wide band dynamic drivers, with a 10mm design in the IE 40 Pro and 7mm designs in the IE 400 Pro and IE 500 Pro.  

Many in-ear monitors use single or multiple balanced armature drivers, and both these and wide band dynamic drivers have their strengths and weaknesses. Nevertheless, one big advantage of a single broadband transducer is that it offers a wide frequency response and doesn’t require the crossovers found in multiple driver designs. 

The IE 40 Pro follows a reasonably established design path for in-ear monitors. The earpiece module itself incorporates a removable tip and the box includes four pairs – three silicone and one foam. These vary in size, allowing you to achieve a reasonably sealed fit, vital for both frequency response (particularly the bass end) and isolation from surrounding noise. On some in-ear designs we’ve tried, the tips have proven hard to fit or remove. Thankfully, this is not so with the IE 40 Pro, and auditioning different sizes proved reasonably straightforward. 

We really like the IE 40 Pro in-ear monitors. They deliver decent sonics without costing silly money

The small section of cable into the earpiece is thick and stiff. This lets you mould the cable round your ear, keeping it out of the way and helping hold the earpiece in place. The earpiece connects to the wire via a push/pull detachable plug and this also rotates, which helps take the strain off the wire and plug when you adjust the earpiece positioning. Finally, the IE 40 Pro comes with a pocket-sized storage pouch, a small cleaning tool, 6.3mm jack converter and either black or clear finish. 

Sonically, the IE 40 Pro sounds reasonably natural, with good articulation in the high frequencies and a full but not overpowering low end. We did find them a tad too bright in the top end at higher volumes, but this isn’t a deal killer. Either way, they do sound considerably better than standard earbuds, making them a decent multipurpose purchase. 

Also rather positive is the comfort and fit. With a medium-sized in-ear module and quickly replaceable tips we quickly achieved a decent fit – important if you’ll be wearing them for long stretches. In fact, we’d say these are some of the most  comfortable off-the-shelf in-ear monitors we’ve tried; impressive given the modest price tag. The only real gripe we have is the rather short lead (1.3m) and lack of lead extender. 

We really like the IE 40 Pro in-ear monitors. They deliver decent sonics without costing silly money, and suit live use as well as general playback duties. The only real gripe is the short cable and lack of extender, but, all told, these would make a wise buy for either live, monitor or simply everyday listening duties. 

Sennheiser IE 40 Pro review

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Pro-styled headphones at an affordable price
Tested at £83 / $100

What Hi-Fi? Verdict

A solid pair of wired in-ear headphones, but they trade Sennheiser’s traditional warmth for a more austere sound


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Though Sennheiser has been making pro audio equipment since the company was formed over 70 years ago, most of its headphones are aimed at the consumer market. Even the high-end HD 800 S headphones (£1200) are a more comfortable fit for a lavish listening room than a recording studio filled with Genelec monitors.

But that changes with the Sennheiser IE 40 Pros, the ‘pro’ equivalent to the Momentum M2 in-ears. The sonic tuning is radically different to the Momentum series, taking a more honest approach that aims for accuracy above all else.

It’s not an unreserved success, but the Sennheiser IE 40 Pros are a solid choice for people who want to enjoy their music with less hyped bass, as well as those with home studios.


Our first comparison for the IE 40 Pros isn’t another Sennheiser model, instead this pair brings to mind the Shure SE215s, introduced eight years ago.

Many hallmarks of pro-style in-ear monitor (IEM) headphones are present. The cabling is removable, and uses what appears to be a customised MMCX socket with an ultra-slim housing on each earpiece. 

Sennheiser IE 40 Pro tech specs

In-ear Yes

Driver size 10mm

Noise cancellation No

Detachable cable Yes

In-line remote No

Cable length 1.31m

Weight 18g (with cable)

The IE 40 Pros are worn with the cable trailing over your ears, with the top part holding its shape using what Sennheiser calls its ‘innovative internal cable duct’.

In practice, this flexible part of the cabling is much like that of the Shure SE215s or Brainwavz B400s. This over-ear fit won’t suit all tastes. But while Sennheiser says it’s designed for on-stage musicians, it also helps reduce cable noise when exercising. 

The Sennheiser IE 40 Pros lack some of the common features of today’s most popular headphones. There’s no wireless option or noise cancellation, and no in-line remote. The accessories package consists of a small synthetic leather case, three pairs of silicone and one pair of foam tips.


In many ways, these are quite unlike most headphones Sennheiser currently makes. But in one crucial respect, they are the same. While most higher-end professional IEMs use balanced armature drivers, the IE 40 Pros use a pair of 10mm dynamic drivers.

Higher-end models in the Pro line, the IE 400 Pro and IE 500 Pro, use smaller 7mm drives, but Sennheiser has done a good job of wrangling what seems like a conventional dynamic driver into producing audio suitable for the Pro label.


These in-ears are detailed and balanced, though they lose a little warmth and weight bass in the process.

Mid-bass has been whittled down to avoid lower frequency clogs, often used by rival earphones to produce a listenable sound with relatively low-end hardware. The bass does still have some depth and punch, though, which is a clear benefit of using a dynamic driver rather than a single balanced armature.

There are other trade-offs to the surprisingly non-Sennheiser-like signature sound. Mids sound slightly recessed, and notably anaemic. Vocals lose some of their natural body and warmth, making them harder on the ear for longer periods of listening. The treble has also been emphasised to enhance the perception of detail. It doesn’t end up distractingly harsh or sibilant, but can be a little obvious.

Sennheiser has rejected its usual sonic security blankets here, making the IE 40 Pros a better pair for monitoring a mix than its mainstream equivalents. However, in aiming for studio monitor-like sound, Sennheiser has made them a less easy-going listen than some rivals, including the Shure SE215s.


Sennheiser has left out many of the trappings of ‘normal’ earphones at the price, including an excess of mid-bass and even an in-line remote.  

The result is a nicely balanced sound and a detailed, more truthful presentation, but also one that’s less easy on the ear. This is worth bearing in mind if you’re after a pair of headphones for enjoyment, rather than analysis.


  • Sound 4
  • Comfort 4
  • Build 5


Awards 2018: Best in-ear headphones

Best headphones 2019

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Sennheiser IE 40 Pro. Review of the new model of in-ear headphones. Portable. Blog.

Most recently, the famous German company “Sennheiser” introduced a new model of in-ear monitor headphones IE 40 Pro. And although the company representative told me that IE 40 Pro is a further development of the IE 4 model, however, the phrase appears on the official website: “IE 40 Pro. Every detail is from scratch.” In this review, we’re going to take a look at the IE 40 Pro headphones and do a little comparison with the IE 4. Most of us have heard that evolution is usually a spiral, but in the case of the new IE 40 Pro, it’s more of a stepwise process. And this affected absolutely all the main characteristics of the headphones: sound, appearance, ergonomics and packaging.

Packaging and contents.

Based only on the appearance of the packaging, I already want to confirm the phrase: “Every detail is from scratch.” The headphones come in a colorful cardboard box with a retractable foam base in the middle, and the headphones themselves are fixed in the recesses. An additional cardboard form with the company logo covers a niche in the foam rubber, where the headphone cable is hidden, instructions, a storage bag (not on strings, but with snap plates), a set of accessories (silicone tips of sizes S and L, M – already put on the headphones; foam nozzles (1 pair, size M), cleaning brush). The kit may not be the richest, but compared to the previous IE 4 model, it’s just great. The storage bag is more likely designed only for the headphones themselves, since my attempts to pack the headphones with the cable into it did not lead to a result – it is too small.

The cardboard box itself contains a lot of different information (Russian language is present): features and benefits of this model, package contents, technical characteristics of the headphones, a list of possible additional accessories. Everything is pretty securely packaged, so during transportation should not suffer.

Appearance . Construction . Ergonomics.

Headphone appearance Sennheiser IE 40 Pro is another reason to mention the phrase above: “Every detail from scratch.” According to this criterion, the new IE 40 Pro has nothing in common with the IE 4 model.

We see a completely reshaped headphone, a significantly larger housing, ear hook and detachable cable. The latter is also significantly different from the IE 4 cable – thicker, but elastic and not prone to tangling.

The ergonomics of the new IE 40 Pro are also very good. The behind-the-ear fastening can be adjusted to your ear size, you can choose the required size of the ear cushions and the headphones are no longer felt in the ear. The previous model IE 4 also fit well in the ears, but I prefer the behind-the-ear fit, as I don’t like small in-ear headphones that are deeply planted in the ears so that they do not fall out. I noticed that people who listen to ordinary in-ear headphones with the wire down, when trying to switch to the behind-the-ear mount, at first have some difficulties, such as: “how to wear it, what and where to hook it?”. But in the IE 40 Pro model, all elements are movable (each earphone easily rotates around the wire), the behind-the-ear arches are adjusted to the ears, so the problem of “dressing” is quickly solved.

The right earpiece is marked red and the left earpiece is black, i.e. the color of the wire. Noise isolation is average, however, a complete pair of foam nozzles definitely improves the situation. The headphones themselves are made of plastic, and although it is of good quality, it is still not metal and unnecessary mechanical stress is unlikely to benefit them.

Since I only wear earphones under my clothes, I can’t tell if the cable gets tanned in the cold, and I didn’t put the cable in the refrigerator on purpose. The microphone effect is weakly expressed and in most cases it is not audible – both the behind-the-ear fastening and the slider-splitter on the wire are responsible for minimizing it.


I give technical information taken from the box Sennheiser IE 40 Pro :

  • Frequency range: 20 Hz – 18 kHz
  • Sound pressure level: 115 dB
  • THD: < 0.1%
  • Resistance: 20 ohm

Sound description is known to be the most biased part of the review. I got the Sennheiser IE 40 Pro Clear model, where Clear is the designation of the color of the model (the manufacturer also claims black). But if I were asked to describe the sound of the new IE 40 Pro in one word, then I would choose Clear. Purity and transparency are the words that best fit the sound of these headphones, which would enroll them in the category of “light”.

When evaluating the sound, you need to take into account the price of the headphones, which is far from the highest – about 115 dollars. The bass is not accentuated, but at the same time it is heard wherever it is and has a good speed. Perhaps a little added bass weight would have benefited the overall sound, but probably it would have been other headphones. The bass in IE 40 Pro obviously doesn’t “pump”, but the headphones weren’t created for that either – they are positioned as monitor ones. In the previous model (IE 4), the bass is more massive and does not have the clarity and accuracy that the IE 40 Pro has. This is especially audible in fast multifaceted compositions, including electronic music.

Medium frequencies. If in IE 4 the vocals are accentuated and brought a little forward, then in IE 40 Pro everything is in its place – the vocalist sings along with the group (as if in a row), and does not stand in front, and the musicians accompany him. The new IE 40 Pro reproduce the sound of live instruments very well – guitars, pianos, flutes – every note is heard, and one instrument does not “climb” onto another. Good for listening to female vocals, especially in slow jazz compositions.

Treble. A very difficult part of the frequency response for many headphone models. And it seemed to me that the situation with HF in IE 40 Pro is not so unambiguous. No, this does not mean that the HF sound bad. In fact, they are detailed and clearly audible, but sometimes even unnecessarily. I note that the sound of the treble was most influenced by the musical material itself – not by the file formats (mp3, Flac, etc.), but by the quality of the mixing of the track itself. This feature was well heard on tracks with live percussion instruments (bells, cymbals, shakers, bongs, etc.). If everything was mixed correctly, then the sound was detailed – sometimes you even had to wonder how much percussion enriches the music. But if any percussion instrument was pushed forward, then even the composition as a whole could score with its high frequencies. The very haunting shaker sound in several jazz themes was such an example. On electronic music with a predominance of high frequencies, the situation was also not the best. I think that for IE 40 Pro, in order to avoid sibilants, it is better to select music without the predominance of HF or a normally controlled HF sound source (better even a little dimmed).

The HF range of the IE 40 Pro differs from the IE 4 in its pitch – more detail and better separation of instruments. But IE 40 Pro won’t work for high-frequency phobes.

Sennheiser IE 40 Pro

SENNHEISER IE 40 PRO are professional-grade dynamic in-ear monitor headphones that reproduce sound with maximum fidelity and expressiveness at both low and high sound pressure levels, allowing you to hear music clearly even in very difficult acoustic environment. The IE 40 PRO’s rich audio features are complemented by a well-thought-out, ergonomic headphone design and ruggedized cables that ensure the IE 40 PRO can handle the rigors of stage and live performance.

The SENNHEISER IE 40 PRO headphones are aimed at the user who needs modern, high-quality monitor headphones for full-fledged work. The model is equipped with an advanced system of dynamic radiators and even at the maximum level of sound pressure it generates an extremely accurate and clear signal, and its improved diaphragm retains the natural warmth, detail and expressiveness of the sound in any conditions (including on a very noisy stage).

Plus, the earbuds can quickly adapt to the anatomy of their wearer’s ears. SENNHEISER IE 40 PRO – light and compact, always securely held in place, do not tire and therefore are perfect for artists and DJs for whom the stage is, first of all, work. And that’s why these monitor headphones, from the connector to the cable channels and earcups, are built from the ground up to unconditionally withstand any mechanical annoyance that can happen during performances and travel. So, in your IE 40 PRO, you not only always hear everything as it should, but you can also work even better and with real pleasure!

Next Generation Dynamic Drivers

Unlike the vast majority of today’s personal monitoring systems, which tend to use multiple transducers at once (and are actually a descendant of hearing aids), the IE 40 PRO features just one next-generation Sennheiser proprietary dynamic driver .

The fact is that the entire range of reproducible frequencies does not have to be divided into separate segments at all and it is quite possible to keep it unified. With this natural and harmonious integrity, the sound of the SENNHEISER IE 40 PRO is uniform and powerful over a much wider range. And without the slightest distortion, as the special headphone diaphragm resonates easily even at the highest volume levels (unlike the stiffer diaphragms of multi-driver models). Last but not least, the single transducer design also eliminates another problem of older multi-driver systems – fatal phase distortion and dissonance in the inner ear. That’s why the sound quality of the new Sennheiser IE 40 PRO is so noticeable, despite the fact that this is only the first model of a whole series of professional monitor headphones from Sennheiser.

Small, powerful and extremely handy

The quality and power of sound in such a compact size can and will truly amaze. And more than once. And not only because for an experienced artist, sound engineer or DJ, the advanced driver system of the IE 40 PRO model and the widest audio potential are a whole range of new possibilities.

The headphones themselves have gone through several stages of optimization and have been repeatedly tested by a wide variety of users, in a variety of conditions and in hundreds of ears. As a result, Sennheiser engineers managed to achieve the main thing – that the new IE 40 PRO always, everywhere and for everyone would give guaranteed smooth sound, sit well in their place and work equally comfortably in them, even when you need to work much longer than usual.

Every detail – from scratch

Good performances are not made today without quality monitoring. And IE 40 PRO is designed to ensure that each of your concerts, each of your performances takes place at the proper level and with maximum impact. And given the fact that every detail is of great importance on stage, even the cables of these headphones are designed anew and in a new way. Their internal cable channels and connectors are unique to Sennheiser (patent pending). Simply put, with your new IE 40 PRO monitors, you can work comfortably on any stage and with any workload. They will definitely last!


  • Improved 10mm dynamic wideband transducer design for superior sound quality and precise monitoring;
  • dynamic driver system minimizes the effect of acoustic stressors on signal quality and reproduces powerful and smooth sound without interference;
  • model is made with the expectation of a very long and active use, is durable, thoughtful ergonomics and wears well;
  • thanks to the innovative design with a single transducer, the headphones turned out to be very light and compact, so you can work in them for a very long time without any discomfort;
  • soft ear tips (silicone or porous) securely hold the headphones in the ears and well isolate hearing from external noise;
  • The

  • patented ruggedized cables are designed with the inevitable rigors of stage performance in mind.





Pro Headphones

Connection type


Emitter type


Acoustic design


Design Features

Detachable cable

Mounting type

Ear hooks

Microphone included


Active Noise Cancellation


Volume control


Frequency range, Hz


Sensitivity, dB


Resistance value, Ohm


THD (nonlinear distortion factor), %