Sennheiser HD 350BT Review. Falls A Bit Short

In this review we’ll cover the Sennheiser 350BT wireless headphones which we’re going to dive into immediately.

In terms of how many devices you can keep in memory before pairing them again and learning them all over again on the device, Sennheiser documentation says you can have up to eight devices in memory. In my testing I got up to four devices, which will be a lot for most people.

Accessories

When it comes to accessories, there’s no carrying case included in the box, which is kind of anticipated at this price tag.

The only real accessory you get is the charging cable, which is a USB-A to USB-C fitting. Unfortunately, it’s not USB-C all around so it’s kind of a bummer, but the cable is lengthy measuring in about 60 inches. There’s also no power adaptor included in the box. Sennheiser expects you to use your own power adaptor or plug it into computer directly for charging.

Design & Comfort

The design itself has a pleasant looking body. It doesn’t stand out in any way except for the logos of Sennheiser being on the side. But again, you’re not looking for anything too amazing and outstanding at this price tag. In fact, it looks almost identical to the Sennheiser 450BT headphones.

It does have a folding design, but it’s a huge let down for a very particular reason is that the earcups don’t fold flat so it doesn’t work well. When you’re putting it in a laptop bag, it will kind of bulge out unnecessarily.

For comfort and wearing them they’re very comfortable for me and I’ll explain what that means shortly. I can wear them for 3 hours straight, non-stop, no problems, very comfortable on the ears. There are two main reasons for that. One is that the ear cushioning thickness is, well, it’s thick and soft. The other thing is that the interior of the headband has some cushioning but it’s not very thick. It’s just enough for people with no hair to be somewhat comfortable.

Wearing them with glasses in my testing it, they’re also very comfortable, but there’s a catch with that, but I’ll talk about that in the audio quality section.

There is one major letdown to these headphones when it comes to wearing them. As I mentioned, they’re comfortable for me, but they won’t be for everyone else. That’s because the ear cushion designs are very narrow. They’re meant to kind of wrap around your ear as tight as possible, which again, for me and other people, that’ll work fine. But for people with larger ears, that could be discomforting. I’m not sure why they decided to do this. Not the most well thought design.

I mentioned I can wear them comfortably for 3 hours straight, which basically means no sweaty ears, no discomfort. Can you use them for working out? Yeah, you can but they’re over the ear headphones. The headband flex is tight enough to prevent them from moving around, thankfully not too tight though, so great for working in that regard. However, the thing is that they’re over the ear headphones along with the fact that the ear cups are very narrow against the ear itself, so your ears will sweat excessively when wearing these headphones during exercising. That would make it far from comfortable at that point when working out.

The body comes in two available colours; black and a white colour option.

They weigh 238 grams, which is not too heavy and not too light. For this price tag it feels sturdy in the hand. It’s not like there is a concern that if you drop it a couple of times, the plastic on it will break or anything. But of course, the folding design is a bummer because I mentioned earlier it’s almost useless. On top of that, whenever you have a folding design on headphones it automatically makes the body weaker than it would be if it was a solid frame (non-folding design).

These are not dust and water resistant. It specifically says to keep them dust free and dry in the manual. When it comes to earcup damage there are earcup replacements available from the Sennheiser website, but they’re hard to find in stock. Thankfully there are plenty of third-party vendors selling them.

The headband uses a notch slider to adjust the length, which is decent. Earcup rotation does a pretty good job when rotating up, down, forward, and back.

When resting on my neck, it’s not too bad looking left and right, it just barely touches my chin. Looking down, it does rub against my chin and cheeks, but not too big of a deal.

Controls

Jumping over to the controls, there’s nothing on the left earcup, everything is on the right.

For the right earcup starting on the front, there’s a multifunction button which is used to power the device on and off and holding it will enter Bluetooth pairing mode.

Next in line is the volume rocker buttons. Next is a slider, pressing down on the slider will play/pause music, sliding up will go to the next track and sliding down will go to the previous track.

That same slider, if you press it will also be used to answer a call and pressing again will hang up the call. The slider can do other functionalities and controls, especially when it comes to phone calls, but we’re not here to dive into it because it’ll just be too long for this review.

Lastly is a dedicated button for a voice assistant function if it’s connected to a smartphone and in my testing, I used Google Assistant. When the Assistant was listening to commands, response time is adequate. There is a problem though, is that when you press the button it doesn’t make the typical Google sound that it’s listening for a command. Instead, the only way to notice that it’s listening to you is when sidetone turns on, which basically means you can hear your surroundings. I’ll explain sidetone later when going over the app. So not a big deal, but something to keep in mind.

Sennheiser could have done a better job when it comes to the control layout. I’ve been using these headphones for several weeks and for the most part I’ve got muscle memory to memorise where each control is, but sometimes I might press volume up when I meant to pause music, it’s annoying. Why didn’t they divide the controls between the left and right earcups? That would have made it a lot easier to know exactly which thing you’re trying to press on which earcup. I wish they had thought it through a little bit better.

The last thing when it comes to controls, in case you’re curious, there’s no active play/pause. That basically means when you’re listening to music on the headphones and when you take them off, your content will automatically pause. When you put them back on, it’ll detect that you’re wearing them and then automatically resume the media content you’re listening on these headphones. That capability isn’t present on these headphones. I expected that at this price tag, but I just wanted to mention it.

Noise Cancelling

There’s no ANC (active noise cancelling), but when it comes to passive noise cancelling (just wearing them because they’re over the ear headphones), people talking around you in the same room as you just regular volume, no shouting or anything of that, it kind of gets muffled out. You can just slightly make out what people are saying. But of course, if you’re listening to music, then this can be a non-issue, you won’t be able to hear anything at all.

Battery

Performance is pretty good on these headphones, especially at this price tag. Sennheiser advertises about 30 hours and during my multiple battery drain tests I kept averaging 43 hours, which is way over what Sennheiser claims.

When it comes to recharging time Sennheiser claims 2 hours and in my testing, I average the exact same thing, 2 hours. That might seem like a lot of time but considering you’re getting 43 hours of playback for a 2-hour charge, the trade-off is well worth it.

The USB-C charging port is located on the bottom of the right earcup.

One thing to keep in mind is that you cannot charge these headphones while they’re on. They must be powered off before they start to charge the battery.

Microphone Quality

The microphone might leave a bit to be desired. At this price the quality is what you would expect. In a quiet setting, what’s being said can be understood easily but it’s not just vocals that come through at odd times, there is a slight echo from the room. The echo of the room I tested in wasn’t overbearing like from my camera microphone but it’s slightly noticeable.

Switching to a replicated noisy café setting, the echo disappears, and the vocals continue to sound decent as they did in a quiet setting. However, the noise of the replicate noisy café comes through just a tiny bit. The noise won’t bother the person on the other end of the call, but they’ll be able to tell you’re taking the call in a public setting.

Where the microphone is a bit disappointing was when replicating a windy setting. You can still make out what is being said from the person using the 350BT, but the wind noise comes through a bit strong. While these are budget friendly headphones, if you plan to use them while walking often in a windy area, these might not work for you.

Audio Quality

I was rather surprised mainly about audio for one thing, the supported codecs. It supports SBC and AAC which is no surprise. What surprised me is that these support aptX, even a lot of other more expensive Sony headphones don’t support that.

The audio quality itself out of the box, with a flat profile surprisingly at this price tag it does a pretty darn good job. Everything I found was well-balanced. There was no overbearing sound type over the other. So, for example, when I reviewed the Sennheiser Momentum 4, the bass punched up slightly out of the box. Here that’s not the case. Everything’s just well balanced at a flat profile. So, you can kind of just enjoy the music straight out of the box.

You can adjust the equaliser, it’s a very basic one in the app which I’ll cover in the app section. Adjusting bass a little bit higher, it doesn’t get as deep as other headphones. For example, the Sony WH-CH520, which are in a similar price bracket, those are still a little bit better in punchiness for bass. Although the 350BT is not bad, again at this price tag.

When I increase vocals, it stood out slightly, but not by a huge amount. What’s weird is that when I reduced vocals all the way in the equaliser, just for fun in my testing, it didn’t degrade the quality at all, but when you punch it up, it will isolate the vocals slightly, but not by a large margin.

The one thing that I like the best about the equaliser controls is treble, and I noticed this with the Momentum 4 as well, is that when you increase the treble, it doesn’t get overbearing like some other headphones. Other headphones from other manufacturers can make the noise too sharp and a bit annoying for my ears. Sennheiser doesn’t do that, the 350BT will increase it to get slightly sharper, but nothing overbearing for your ears.

When wearing glasses, these headphones do suffer considerably, especially when it comes to bass. What happens is that when testing with my nonprescription glasses on, and testing audio I noticed that the gap in the earcups will slightly open to let the frame of the glasses poke out. That’s fine, except a lot of the bass would leak out and the punchiness on it would drop dramatically. If you’re a bass enthusiast, you wear glasses, you might want to avoid these headphones. When it comes to mids and highs, it suffers slightly, not as much as the bass, but there’s a slight degradation in the sound quality. Something to keep in mind if you wear glasses and you’re looking to buy these headphones.

Software

There’s a Sennheiser app available for smartphones. One of the main things we have is the equaliser, as I mentioned earlier, it’s a very basic equaliser. One adjustment notch each for bass, mids, and treble. It doesn’t have a full-blown equaliser, but it gets the job done.

Going over to “Sound Check”, this is more of a gimmick feature to be honest. What happens is that you start playing music and you go through these hearing tests and the app will try to recommend to you what is considered the best equaliser setting. Once you finish completing the process, you’ll notice that if you go back to the equaliser, it’ll have adjusted based on the Sound Check hearing test. The problem is that if you adjust the equaliser a bit and you go back to Sound Check, you have to redo the entire process again. Sound Check is honestly more of a gimmick.

Moving along is the earlier mentioned sidetone which basically allows you to hear your own voice during phone calls so you’ll know if you are speaking too loudly, too softly, and will also project the exterior noise around you into the headphones so you can hear if the area you’re in is too loud for your phone call. For example, will the person on the other end of the call hear the surrounding noise of the noisy café you’re in?

The next section tab of the app is “Discover”. This comprised of kind of like advertisements from Sennheiser.

Lastly under “Settings”, the most important thing here is firmware updates, which are stable and installed at a decent speed (roughly 12 minutes per update). I got a few updates out of the box. Next you can select which tiles of options you want to see on the home screen of the app.

Conclusion

Considering the price point. These headphones are not bad, but they could have been much better. There are some weird decisions made for the 350BT from Sennheiser.

One is a folding design of the earcups because they don’t fold flat. Putting it in a laptop bag doesn’t make much sense, it bulges out like crazy.

The other thing, which is the most bizarre to me, is the very narrow earcups. Again, if you have larger ears, they’re not going to work that well for you, your experience is not going to be comfortable at all.