Comparison: Sennheiser HD350BT vs HD450BT

Sennheiser HD350BT and HD450BT nestled together

A few weeks ago, Sennheiser really got my reviewer blood pumping by sending us here at MajorHifi a couple new products: the HD350BT, at $120, and HD450BT, at $200. I’m not always a fan of the Sennheiser sound as applied to budget Bluetooth headphones, but I found these two intriguing. They sounded different from each other, but they also shared some important characteristics: a large soundstage, and a sort of airy, weightless sound that was a surprise to me, coming from a pair of Bluetooth headphones.

Those two individual reviews are already out in the wild. They can be read here and here.

But today, I’d like to do a more direct head-to-head comparison of the two. After all, I suspect there are many out there who wonder how worthwhile it is to spend the extra $80 for the HD450BT. My answer? It really, really depends.

Sennheiser HD350BT and HD450BT sitting next to each other with controls visible

Build, Accessories, Functions, etc.

The HD350BT and HD450BT are identical in almost every way when it comes to build, comfort and appearance.

The HD450BT does come with a few extra little goodies, like a carrying bag. I would’ve liked to see this with the HD350BT as well, and it’s unfortunate that it doesn’t come with it. But I suppose that’s one advantage to upgrading to the HD450BT. The HD450BT also allows connection directly with an audio source via an included 3.5mm-to-3.5mm cable, while the HD350BT does not. Moving on…

Both headphones work with the Sennheiser Smart Control app, which includes an equalizer. Essentially, it looks like the decision point with these headphones is mostly going to come down to sound.

The most obvious difference is that the HD450BT has noise cancellation, while the HD350BT does not. Indeed, that difference may account for many of the changes in sound signature between the two. The HD450BT’s noise cancellation isn’t that good, though (in fact, I didn’t notice it at all at first), so I wouldn’t let that be the deciding factor.

Sennheiser HD350BT and HD450BT, one leaning against the other


Luckily, these two headphones don’t sound remotely alike. There are significant differences when it comes to tone and timbre. While the HD350BT carries an airy, thin, wispy, distant tone, the HD450BT adds weight and body while maintaining a wide soundstage. In addition, the HD450BT boasts slightly better resolution and a much improved bass response.


So, let’s talk about that bass. To put it gently, the HD350BT is bass-light. Or I could ramp up my bluntness a bit to say that the HD350BT completely lacks a bottom end. When you do get bass, it’s a bit distorted and unsure of itself.

The HD450BT fills in the bass quite a bit. No, it’s not a basshead’s dream, and there are headphones that, for $200, offer significantly more low-end texture and “slam.” But the HD450BT is competent, and for that, I’ll give it the point (although I’m not keeping score).

Sennheiser HD350BT and HD450BT with model labels visible


When it comes to midrange, it’s largely a matter of taste, as far as I’m concerned – there aren’t many headphones with a midrange that I can conclusively call “bad.” It’s here that these two headphones share both their biggest differences and their strongest similarities.

Both the HD350BT and HD450BT manage a kind of balancing act between timbre and soundstage. What you see with most headphones is a gradual rise throughout the midrange as you increase in frequency, up until a peak in volume at around 4kHz. With these headphones, though, this peak happens slightly sooner, at around 2-2.5kHz, with a slight suckout at 4kHz. While this does rob instruments and voices of some “presence,” it’s responsible for the huge soundstage you get with these headphones.

For the less-nerdy amongst the readership, what this means is that these headphones are both tuned somewhat unusual. However, this unusual tuning grants these headphones some characteristics that most headphones in this category don’t have – a wide soundstage and a sense of distance.

As for differences, I find that the HD350BT leans further into that unusual tuning, boasting a midrange that is very thin and lacking in body, but also very airy and floaty. This means that it’s lacking some dynamics, but it also means that it has a kind of tantalizing, exotic quality that I really like.

Meanwhile, the HD450BT sounds more…normal, I guess. It fills in the thin lower midrange, lending notes more heft and body. As a result, I think the HD450BT will sound better to most people. But if you’re a weird nerd like me, you might prefer the unique characteristics of the HD350BT.


Neither of these two headphones is particularly strong in this area. I’m not sure how much the treble differs between the two, but the characteristics of the treble do change somewhat in reaction to the sound of the midrange.

Specifically, because the HD450BT is warmer than the HD350BT, I find that the HD450BT’s treble sounds a bit more recessed and a bit less airy. I think these two are actually very similar in treble resolution, but I find the HD350BT to sound a bit more detailed, while the HD450BT is a bit more veiled and smooth-sounding.

No peaks jump out to me in either of these headphones.


When I put on the HD350BT, I was immediately struck by the wide, airy soundstage. With the HD450BT, I didn’t get as much of this effect.

But then I realized: while the warmth of the HD450BT’s sound robs it of a little bit of a sheer “sense of distance,” it also means that the soundstage is more realistic. Things that are meant to sound intimate sound intimate; things that are meant to sound distant sound distant. This puts it a cut above the HD350BT, where everything sounds a bit detached and unengaging.

Still, as far as personal preference goes, I slightly prefer the airy presentation of the HD350BT – but like I’ve said, I don’t think everybody will share that preference.

Sennheiser HD350BT and HD450BT sitting next to each other, folded up

In Conclusion

I think most people will prefer the HD450BT. Of course, that makes good sense: the more expensive model should sound better. The HD450BT has a more robust bass response and a weightier, more versatile sound, as well as active noise cancellation.

Still, the HD350BT has its charms. For $80 less, you sacrifice some bass performance and some warmth, but you get a very unique-sounding headphone, with a sound signature that I personally prefer. And both headphones offer an exceptionally wide soundstage.

No matter which route you choose, you can get it for a good price at Audio46. The HD350BT can be found here and the HD450BT can be found here. At Amazon, you can get the HD350BT here and the HD450BT here.

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Evan - that is to say, I am a composer of music that could be described as sad and fragile, or so weird as to be offputting, depending on who's asking. I've been excited about headphones for years now. Need to get in touch? Email!