Sennheiser IE 300 Review: Bringing cabled back in a big, bass-heavy way

Cables on a pair of earphones in 2021? Surely you jest. While the trend keeps moving towards truly wireless and Bluetooth for high-end earbuds, Sennheiser clearly want to cover all bases.

They’ve already got some of the best truly wireless lifestyle earbuds on the market with the CX 400BT (which I have 4.5 stars in this review), and they want to repeat similar results for the wired Sennheiser IE 300 earphones.

Through very specific construction, paying attention to sound quality in every step, Sennheiser manage to make the IE 300’s stand out nicely amongst cabled earphones. But is it enough? After all, we are sacrificing the numerous smart features of a truly wireless pair of Bluetooth earbuds, such as noise cancelling and voice control.


There’s no Bluetooth for the IE 300s. There’s no nifty noise cancelling either, nor are there any mics to give you direct access to a device’s voice assistant. All you’ve got here is a 3.5mm stereo plug attached to an unbalanced 1.2m cable which can be detached from each earbud and reattached via a gold-plated Fidelity+ MMCX connector. This means you can replace the unbalanced cable with other cables, some of which are much longer and sold separately by Sennheiser.

The cabling you do have here has a nice grip and has been reinforced with para-aramid for better durability and longevity. The material, aramid, is similar for Kevlar so you’ve got a polymide which is extremely reliable here. At the other end of the cable is a 3.5mm TRS jack to be plugged into any compatible devices (or extenders). The problem here is that most high-end smartphones these days are built with Bluetooth in mind, but there are ways around that if you’re determined to use a wired pair of earphones.

Oddly enough, the cable doesn’t include any built-in microphones or in-line playback controls as you would expect from a pair of high-end wired earphones. You’ll be using the attached device to be rocking the volume and skipping tracks, which isn’t much of an issue for me at least since even with Bluetooth headphones I use the device more than I use on-board controls (this is for earphones, a pair of over-ear cans like the gold-standard Sony XM4’s feature such seamless touch controls that it’d be stupid not to use them).

After using Bluetooth buds and headphones almost exclusively for years now it took longer than I’d like to admit getting used to the cabled buds, with me needing to feed them over and around my ears to get a comfortable fit. Thanks for the incredibly flexible MMCX connector, which allows the buds to swivel easily, they are exceptionally comfortable from any angle.

The problem then is with the in-ear element. The IE 300s ship with three sets of silicone tips and three sets of memory foam tips. There’s also a gorgeous soft shell carry case for travellers and some neat organisation straps. But it’s the buds which are most important here. You need to find the perfect fit otherwise the bass response is just not there and these buds can’t perform to their full potential.

I had better luck finding the perfect fit with the memory foam tips than I did with the silicone. But everyone has differently shaped ears so what works for me might not work for you. It’s well worth spending some time finding the right fit, as it is with any pair of earbuds you purchase.


The specific architecture of the buds, from the cabling right down to a low resonance membrane foil, has been worked in complete dedication to sound quality. Sennheiser have taken things very seriously here, building every detail to try and showcase how substantially better wired earphones are when compared to their Bluetooth brethren. At least when it comes to sound, and sound only.

Results aren’t as perfect as you’d hope, but Sennheiser do offer something here that’s a cut above the competition. As per usual.

Sennheiser’s favourite 7mm Extra Wide Band dynamic transducer has been tweaked to better fit the IE 300’s profile, where an optimised membrane foil is used to keep natural resonances and total harmonic distortion to a minimum. In front of the transducer is a resonator chamber meant to compensate for any of the masking effects which occur when air is trapped in the ear canal.

The low end definitely benefits from this. The bass on these earphones is wide, detailed and aggressive but not overly punchy. It’s damn near perfect, except there are times when I would notice the lows encroaching on territory that would be better left alone. The treble suffers here, obtruding on the midrange so styles like jazz an aren’t as bright or rich as it should be. Although this is only really an issue where bass is overworked in a piece anyway, like some of the more dense works of Ahmad Jamal Trio or John Coltrane. Play some Sam Cooke, where bass is kept to a minimum, and the mids and highs have supreme presence.

But really, most people will remember the sonic profile or the IE 300s for the excellent bass. It’s a deep, uncompromising low-end that plays equally well with sub-bass. Throw on a tried-and-tested bass showcase like Big K.R.I.T’s Ballad of the Bass, or Mystikal’s Neck Uv Da Woods. Absolutely slamming.

Regardless of the source, it’s safe to expect some brilliant clarity from the earphones for the most part. Sennheiser have never really faulted when it comes to sound though, and thankfully the IE 300’s continue that reputation.

Verdict & Value

You are looking at $480 if you want a pair of IE 300s. Compare this to the excellent CX 400BT True Wireless earphones which are $300. You’re only paying slightly less than you would if you bought a pair of the ambitious Momentum True Wireless 2 earphones when they first came out. That’s a lot to invest in a pair of earphones that lacks pretty much any feature except just sounding good.

It’s on you then. If you prefer a pair of high-end cabled earphones to a truly wireless Bluetooth pair, and you don’t really care for noise cancelling, voice assistants, and on-board touch controls, then the IE 300s will look very attractive to you. That’s despite the ridiculous asking price.

Although $480 is hard to stomach given how few features this pair has. You’ve got a strong, detachable cable that’ll easily last you many years to come. You’ve got a praise-worthy sonic profile despite it going a bit too heavy on the bass at times. But that’s about it.


Highlights: Very attractive bass frequencies; can handle mids and highs very well providing there’s no aggressive bass; battery life is of no concern; will never need to recharge.
Lowlights: Mids can suffer a bit on tracks with powerful bass; lack of any additional features; if you can’t find the perfect seal, then sound won’t be as good.
Manufacturer: Sennheiser
Price: $480
Available: Now

Unit supplied by Sennheiser for review.

Chris Singh

Chris Singh is the Deputy-Editor-At-Large of the AU review, loves writing about travel and hospitality, and is partial to a perfectly textured octopus. You can reach him on Instagram: @chrisdsingh.