Review: Sennheiser IE 40 PRO

Alistair McGhee gets to grips with Sennheiser’s professional in-ear monitoring system…

In-ear monitors or IEMs have been big business for a while now, with the move away from waves of on-stage monitoring washing over every open mic. That’s not to say of course that IEMs are without their own problems, but many performances now rely on in-ears to get the monitoring job done.

Sennheiser has a serious reputation in the IEM world, not least because alongside its IEM product ranges, it is a massive player in the radio hardware side and there are thousands of musicians and bands relying on their Sennheiser IEMs every night. So when Sennheiser produces a new range of IEMs everyone sits up and takes notice. There’s some new tech to shout about too in the PRO range, notably new wideband drivers and what Sennheiser describes as internal cable ducts within the cable.

There are three new models: the now available IE 40 PRO which we’ll be covering here, and two bigger siblings, the IE 400 PRO and the top of the range IE 500, both coming soon. At the sub £100 point the IE 40 PRO sits in a very competitive part of the market and one in which it has to fight not only its peers but on two other fronts. Is it really worth the extra over the competition at half the price and of course there’ll always be: ‘what if I spend more…?’

Only one way to find out: fit them and fire them up. I’m always slightly concerned opening new IEMs – I don’t know if I have ‘difficult’ ears but I often struggle to get a good fit. And fit is a crucial aspect of in-ear monitoring – nowhere else is technology so firmly in the ear of the beholder. To say nothing about sound quality, when you are putting the speaker in your ear for a couple of hours, you really do want the best fit and the best finish to your monitor sound. Initially, the IE 40 PROs just fell out, however a quick rummage in the neoprene carry case revealed a cleaning tool and three sizes of spare silicone tips – small, medium and large. I swapped the fitted mediums for large, which was large enough for big eared Scotsmen as it turned out, and the final fit was good enough to be described as excellent.

I’m always concerned that even a marginally less than perfect fit will cause loss of bass but these bad boys seemed very, very close to impeccable. Horizontal pressure on the ear pieces resulted in no real boost in bass. They were tight, but while the fit was snug the lightweight and discreet dimensions of the IE 40 PRO make them very easy to wear. The product finish on the ear pieces themselves is also of a very high standard. The cable is anti-tangle and replaceable which is a given really for a professional product. But you cable swappers note Sennheiser is using a proprietary connector.

So over that hurdle and onto the sound. Sennheiser makes much of the new wideband dynamic driver in the 40 PRO and you know, it’s not just marketing hype. From the off, the 40 PROs are clearly not just a well designed product but a good sounding one. Many cheaper in-ear products struggle to present a balanced picture of the audio spectrum – usually a hump in the midrange dominates the sound with the bottom end struggling and the top sizzling at best. The IE 40 PRO is just in another league all together. It has solid bass extension, great clarity through the mid range and a detailed top end.

If I were to point a finger at a weakness, it would be that the detail in the top end sometimes shades over into brightness and a touch of sibilance: more money does buy you better bass. Yet here we are in the world of legitimate personal taste. I dragged out some Audio-Technica ATH E70s which are a big favourite of mine and the comparison was instructive. The E70s have class leading bass and a monster bottom end that contributes to a considerably warmer balance than the IE 40 PROs which suits my taste, however the Sennheisers are a better fit for my ungainly ears and in sound terms, they were in no way disgraced when compared to a product at a much higher price.

Sadly I didn’t have a pair of ATH E40s to hand for a more direct one-to-one price comparison but I don’t think the IE 40 PROs are going to be easily embarrassed. In fact, I think the IE 40 PROs are going to be pretty much at the top of the class when it comes to sub £100 in-ears. You heard it here first.

Key Features

Dynamic 10mm broadband transducer for precise monitoring

Dynamic driver system reduces acoustic stress factors

Secure fit and high level of wearing comfort with single
driver design

Internal cable duct fit for stage use

RRP: £83

The Reviewer

Alistair McGhee began audio life in Hi-Fi before joining the BBC as an audio engineer. After 10 years in radio and TV, he moved to production. When BBC Choice started, he pioneered personal digital production in television.