Thank you 1MORE for sending us the SonoFlow Pro HQ51 to review!

While I have reviewed a ton of over-the-ear headphones and headsets, I’ve only reviewed a few with Active Noise Canceling (ANC). Active Noise Canceling is where the headphones have a built-in microphone that listens to outside sounds, and then plays the mathematical wave inverse of the same sound into the ears of the listener, mostly canceling out what is going on outside. The 1MORE SonoFlow Pro HQ51 is 1MORE’s latest over-the-ear headphone/headset designed to do just that, and it does an amazing job doing so.

When I first put on the SonoFlow Pro HQ51, I was struck by a few things. First, is how light and comfortable these things are. They weigh 246 grams, which is certainly on the lighter end for headphones. The ear cushions are very soft to the touch, and quite plush. They do get warm after a while, but not unusually so for leather. The headband has a similar cushion on the top, and the weight distribution on your head is very good. They also don’t clamp your head too hard. While I wouldn’t say they are the most comfortable headphones I own, they are certainly quite good, and probably the most comfortable set I own which offers noise canceling.

I was also surprised to find the 2.5mm audio in jack on the right ear cup, as on most headphones I’ve reviewed, that jack is on the left side. Hardly a big deal, and I’m not aware of any standards in this area, but it’s something I noted when I first put them on. Instead, the USB-C charging port is on the left ear cup. The power button, noise canceling mode button, and volume buttons are all on the right. The volume buttons also double as next/previous track, if you hold them down. I would have expected volume up to go to next track and volume down to be previous, but it’s the other way around. Not intuitive to me, but once I understood it, not terrible. You can also play/pause with the power button, as well as answer and disconnect from phone calls. I also appreciate that these are button controls rather than touch, since I certainly prefer buttons almost all the time.

Despite a mostly plastic build (there is metal reinforcing the headband), they don't feel cheap or brittle. I'm sure I could break them if I tried, but they seem built well enough, and the ear cups both fold in and twist, which allow you to fit them in the small included carrying case. I love that it's a common thing to include a hard case with noise-canceling headphones, as I just love it when things come with a means to carry them around. My favorite headphones, controllers, earbuds, and so on mostly include a carrying case of some kind. Even a simple carry bag goes a long way in making them seem more premium. It's also a convenient place to keep the included USB-C charging cable, as well as the all-important 3.5mm to 2.5mm cable, with a buit-in inline microphone.

Too many headphones are wireless only these days, and so I always highlight when an analog-in jack is included. In many cases you can bypass the internal DAC, though I'm not sure if it's the case here or not. The SonoFlow Pro includes an analog-in jack, though it is 2.5mm rather than the more common 3.5mm, so you will need a special cable. One is included, and more are easy to find on Amazon, though you're unlikely to find one in a local store in a pinch. In any case, unlike most headphones with an analog-in jack, this one requires the headphones to be powered on to use; plugging them in alone isn't enough. Thankfully, there is no shortage of battery life with these things.

Regardless, the analog input means you can use these headphones with almost anything. Old Walkman? Classic Game Boy? All works great. I did give these the ol' 3DS test, and they did okay. What's the 3DS test? I have a New Nintendo 3DS XL that I'm grateful to say is in perfect working order. They are no longer produced, and the prices just keep going up and up. Regardless, the 3.5mm audio out jack on the 3DS is not very loud, and lots of headphones struggle to get to a usable volume. I understand why, since Nintendo doesn't want kids to blow out their ears, but it can be frustrating if you want to get the most out of some games' soundtracks. Regardless, the SonoFlow Pro is what I would call medium sensitivity; you can hear everything, but IEMs (in-ear monitors) get a bit louder. Active noise-canceling does help keep everything else out, though.

Considering how light these are, they did a good job stuffing a fairly large battery inside. They are rated for 100 hours of life when noise-canceling isn't in use, and 65 hours when it's active. I'm sure there is some variance on that with volume level and such, but no matter the case, it's still plenty of time for most people, and they charge quite quickly if you let them get low. In a pinch, you can get 5 hours of battery life, from just 5 minutes of charging. Very nice!

In order to get the most out of the 1MORE SonoFlow Pro HQ51, it's important to install the 1MORE mobile app. I use Android, so that's what I'm testing with, and some key features only work on Android phones, since Apple limits what audio codecs headphones can use. Once you have it installed from the Play Store, pair your phone if you haven't already. Once you launch the app, you will need to grant the app location permissions for nearby devices; after that, as long as the SonoFlow is connected to your phone via Bluetooth, the app should see your headphones. (Some headphones and apps support Bluetooth LE for app control, but these don't seem to, so being connected to the headphones directly is important.)

The app seems simple at first, but there are some important features buried under nested menus. On top shows a picture of the headphone and current estimated charge level, between 0% and 100%, in steps of 10%. Under that is 'Listening Modes', which is where you can enable Active Noise Canceling (ANC), or Transparent, which lets you hear the room around you while wearing the headphones. This can also be accessed via the 'NC' button on the center-rear of the right ear cup.

Below 'Listening Modes' in the app is 'Sound Options', which is where the equalizer (EQ) modes are located. First there are 12 'Preset Eqs'; Studio is flat and the best choice if you don't know what else to use. Other EQ options include 'Bass reducer', 'Bass booster', 'Acoustic', 'Classical', 'Podcast', 'Deep', 'Electronic', 'Hip-Hop', 'Lounge', 'Pop', and 'Voice Enhancement'. I usually use 'Studio', but several are useful on this headphone, especially ones with simple and clean lines, like 'Bass reducer' and 'Bass booster', since they are just a reduction or raising of the bass, which is handy. Classical is a gentle 'V' shaped curve, which sounds pretty good for some music. The others aren't bad, but those are the Eqs I used the most. You can also create three 'Custom EQs' that allow you to raise or lower each of the 10 bands by up to three dB. I have to admit I was surprised by such a tight level spread; most headphones I've worked with have a built-in custom EQ have typically allowed at least twice that.

Outside of the main audio settings (EQs), there are some features for the most technical among us. Under 'Shortcuts' are three seemingly unrelated settings, but they are all really important. First is 'Spatial Audio', an optional setting that turns on a bit of custom digital signal processing (DSP). This setting expands the sound field noticeably, and makes it sound just a bit livelier, too. As someone who almost never uses DSP modes, this one actually sounds quite good, and is certainly worth checking out.

The rest of the 'Shortcuts' are other key features. Second, under 'Spatial Audio', is 'Gaming Mode'. This lowers the audio latency by quite a noticeable amount, making listening over Bluetooth much for useful for anyone playing a game or even watching a movie while connected wirelessly. I found 'Gaming Mode' to lower audio latency to something around 100ms-150ms; a usable but not amazing result. Connecting via the analog input cable eliminates all audio latency, and I recommend that where possible for gamers.

The last and key feature hiding under 'Shortcuts' is 'High-definition Codec(LDAC)'. This is a headlining feature on the box, and is very important to Android audiophiles everywhere. What this means is this headphone supports Sony's LDAC audio codec, which allows a supported device to send high-resolution audio, via a 24-bit at 96kHz sample rate, which is a favorite among audiophiles (like me!). I own some music in that bitrate/sample rate combination, so I'm thrilled the SonoFlow Pro supports it. If you have trouble getting that to work, as I did, I was able to fix it by pairing the headphone to my Android, then later going to my Paired Bluetooth devices list, then selecting the '1MORE HQ51'. Then I selected 'Connection type: Best sound quality', after which the headphones were able to connect to my phone with the LDAC codec, the best sounding codec currently available for Bluetooth devices. It's worth pointing out that LDAC mode cannot be used at the same time as either 'Spatial Audio' or 'Gaming Mode', so you have to pick either of those two, or the high-resolution LDAC codec.

One of my favorite features of modern Bluetooth is something I use daily in my work from home setup. This setting is called 'Dual-device connection'. This is accessible from the 'Settings' menu, under 'Experimental Features'. What it allows you to do is connect via Bluetooth to two different devices simultaneously, and if nothing is playing, the next time an audio event happens you hear it - from either connected device. It's a game-changer for work from home, since I can be connected to both my personal phone and my work laptop. When a meeting starts, I can join and everyone can hear me. If I get a call, I can talk and that works, too. You can't hear from both sources at the same time, but it alternates between them in a very intuitive way.

Unfortunately, at least for me, the dual-device mode is finicky on this headset. It's strange, because I have reviewed other 1MORE headphones and there it works perfectly, so something must be funky with this HQ51. My issue is sometimes my work Mac would work with audio but not Teams calls, or would require me to disconnect from my phone before it started working. Hopefully it's fixed soon in a firmware update. The app can also act strangely, with some of the options not responding as expected. I have found if I go into the Android app settings and clear app cache, it seems to fix things for a while. Whatever the case, I hope they fix it all up soon in a firmware update.

Fortunately, the noise canceling is excellent. 1MORE rates them to have a 42dB noise reduction level, which is truly impressive. I wore these while mowing the lawn on a riding mower, and the amount of noise reduction is fantastic. There is a small amount of hiss in the background with noise canceling enabled, but overall, it works really well. And unlike some headphones, these sound largely similar with ANC on and off, which is great since you can choose whether you want ANC on, off, or use them in transparency mode based off of circumstance rather than need. On some ANC headphones, I found they sounded noticeably better with it enabled. Which is neat, but not ideal in every circumstance. For example, I wore these while riding my bike once, and in those cases, you want ANC off, unless you want wind noise in your ears, as wind noises are notoriously difficult to cancel out for ANC algorithms.

And last but not least: the sound quality. How do they sound, and do I like it? Well, it's complicated. When I first listened to them, I noticed the midrange-focused sound, which some people do prefer. The lows are reasonably present, but the highs sounded quite recessed. Not missing, just recessed. I tried playing with the built-in and custom EQ modes, and it did help some. I also found Spatial Audio mode to help bring out the details a fair amount. I listened to this headphone for a couple of weeks, trying to tweak them to get them to sound just right, but had a tough time at it. They don't sound bad by any means, but something is just a bit off with the details and treble. This probably wouldn't bother most people, but I am not quite most people, in that I know what I like and I have modded several headphones to get closer to what I want. No headphones are perfect, but I definitely have strong preferences I seek out.

So, after perhaps resigning myself to having to write a mixed review on the sound for these headphones, something popped into my mind. I've modded several headphones over the years, and one thing I often do when modding is reducing or removing the tuning foam some earphones place in front of the driver. It almost always brightens them up a lot, and sometimes too much - it's often there for a reason. But I figured why not take a peek, and peel off the ear pads to see what's there. To my great delight, it turns out there is a single layer of tuning foam sitting there, between the driver and the ear pad. And it's not glued in or anything - it's trivial to remove, and put right back if I don't like the change.

And oh man did I like the change. The highs brighten up. The details come out. The space between instruments and voices expands. The soundstage overall improves. In virtually every way, this headphone sounds dramatically better. I was able to find a few songs that trend bright now which sound that way, and might be uncomfortable for some, but overall it's a dramatic improvement. So much so I feel no need to use EQ anymore. Before this I was trying my best to tune via EQ, but couldn't quite fix what was wrong with the sound. Now, I quite literally removed a veil that was over the music, and it sounds fantastic.

Before, sometimes I would be in phone calls, and the other person's voice would sound muffled and hard to understand. I ended up having to grab a different pair to understand them during a meeting. This fixes that issue, and makes music of many kinds so much more enjoyable. It also makes it usable for video games, since it had gotten to the point where I just wasn't going to use it for that, because the sound was so disappointing.

I really do not understand why 1MORE put the tuning foam in there. The difference with it removed is so dramatic and for the better that eliminating mild treble discomfort isn't worth the significant cost in overall sound quality. On virtually every other 1MORE device I've owned, their tuning has always been a highlight; they all sound really good at any price point. That's why I was particularly shocked at the problem with this one. Thankfully, with a simple mod virtually anyone can do, this is largely resolved. So, if you decide to check out the 1MORE SonoFlow Pro HQ51, please do yourself a favor and listen to them as they are out of the box, then peel off the ear pads (they come off with a little effort, as they are held in by clips) and remove the black foam oval sitting there, and toss them in your included carrying case. Then snap the ear pads back on. Unless you are incredibly treble sensitive, you'll thank me later.

The 1MORE SonoFlow Pro HQ51 is a headset with excellent Active Noise Canceling, and very good audio performance, with the simple mod I strongly recommend. Out of the box, it's being held back from its full potential by a simple foam disc. Thankfully, it has an excellent feature set that should satisfy most people; hopefully some of the bugs work themselves out soon through software and firmware updates. The light weight, decent comfort, and good performance once modded makes this pretty easy to recommend, especially if they fix those bugs.