Sennheiser IE PRO Series Models IE 40 PRO, IE 400 PRO, IE 500 PRO…and the new Sennheiser IE 300 – What’s The Difference?

EXECUTIVE SUMMARY

Our previous reviews of Sennheiser’s three recent in-ear monitors aiming at musicians are summarized – and the models ranked according to their sonic performance. While build, fit and accessories are nearly identical, the mid-price IE 400 PRO lead the pack in terms of sound quality, followed by the budget IE 40 PRO. It may come as a surprise that the premium-priced IE 500 PRO fail our test completely both sonically and value wise. The company is currently addressing audiophiles with their new Sennheiser IE 300, which is price wise close to the IE 400 PRO.

INTRODUCTION

German company Sennheiser is one of the world’s most competent headphone and microphone manufacturers – operating since 1945. For the last dozen of years or so, they have also very successfully moved into the in-ears monitor segment, among others. Their latest addition is the IE PRO series of three in-ear monitors aiming at DJs, sound engineers and musicians using them live on stage. These three models, the Sennheiser IE 40 PRO, Sennheiser IE 400 PRO (for drummers and bass players), and Sennheiser IE 500 PRO (for vocalists) are priced at €/$99, €/$349, and €/$599, respectively. The IE 400 PRO and IE 500 PRO were released in March 2019 and are Made in Germany (press release). The IE 40 PRO were launched in 2018 and are manufactured in China.

OUR DETAILED REVIEWS OF THE SENNHEISER PRO SERIES

Sennheiser IE 40 PRO (2019-04-25)

Sennheiser IE 400 PRO (2020-10-05)

Sennheiser IE 500 PRO (2019-06-23)

TECHNICAL AND PHYSICAL SIMILARITIES/DIFFERENCES

All three in-ear monitors (iems) use the same dynamic driver principle: the IE 400 PRO and IE 500 PRO was Sennheiser’s latest 7 mm driver, the IE 40 PRO an older 10 mm generation. Note that the IE 400 PRO and IE 500 PRO are technically and haptically identical, despite their considerable price differences. In terms of accessories, The IE 40 PRO and IE 400 PRO share the same black cable with a round cross section that shows some microphonics. The IE 500 has a white, braided cable without noise transfer that tangles up easily. All three models feature the same proprietary cable connector and Sennheiser offers both kinds of cables individually so that people can “upgrade” their IE 40 PRO and IE 400 PRO.

In terms of accessories, the IE 40 PRO has a soft storage sleeve whereas the two premium models come in a hard case.

SONIC DIFFERENCES

The big difference between the IE 40 PRO and IE 400 PRO is: the more modern driver of the more expensive model is faster; it deliver a tighter bass, more midrange clarity and transparency, the sound is a bit more lifted off the ground. But these sonic differences are much smaller than the pricing suggests. The IE 500 PRO lags both in terms of sound quality because of a dip in the upper midrange. This produces a muffled and congested sonic image. For details see the three individual earphones reviews and the video below.

STRANGE MARKETING

Considering that the Sennheiser IE 400 PRO and IE 500 PRO are technically IDENTICAL, they are only tuned differently, and share the same packaging and accessories, one is wondering how Sennheiser assigned a completely different pricing to these models: €/$349 vs. €/$599 is a difference of €/$249…for…? In my opinion, the IE 500 PRO is not worth its money by a long shot as the €/$99 Sennheiser IE40 PRO sound better. The factor of 6 in price difference would be unjustified by any scale. Sennheiser may have speculated on different types of customers: the ones that don’t want to make compromises would go for their flagship IE 500 PRO and the ones who want a bang for their back go for the IE 40 PRO. Not sure where the IE 400 PRO fits in there and I speculate it is the least selling of the PRO series. The problem is that the IE 500 PRO does not deliver what is advertised, particularly in the midrange that is unacceptably muffled and congested.

THE NEW SENNHEISER IE 300 PRO

In mid February 2021, Sennheiser released the IE 300 model in Asia – the rest of the world is following in March. At $300, it is priced slightly below the IE 400 PRO. The IE 300 have essentially the same frequency response as the IE 400 PRO and both are therefore very similar sounding. The main sonic difference is in the midrange. Vocals in the Sennheiser IE 300 are more intimate and lively, but also leaner, and the midrange as a whole has increased transparency. This results in a better midrange atmosphere and spatial cues compared to the Sennheiser IE 400 PRO, which, in comparison, have fuller bodied, more relaxed, smoother vocals and a shallower stage. Depends what you prefer!

In terms of physical differences, the Sennheiser IE 300 have standard MMCX connectors – which fit third-party cables. They do not come with the classic Sennheiser silicone eartips but shorter and thinner ones, and taking into account the relatively short nozzles, the IE 300 do not sit as deep in the ear canal as the PRO models. This may create fit issues for people with large ear canals. Full review and video to follow.

CONCLUDING REMARKS

The Sennheiser IE 400 PRO has crystallized as the best of the three PRO models. It is a very good sounding earphone agreeable to most of us. It has no significant weakness and is a very good deal when occasionally on sale. The Sennheiser IE 40 PRO is not far behind, sonically, and is always a good buy. The Sennheiser IR 500 PRO flagship, however, has a muffled, muted sound and, at 6 times the price of the IE 40 PRO, is only third in the race.

Until next time…keep on listening!

COMPARATIVE PHOTOGRAPHY OF THE PRO SERIES MODELS