NoxGear 39g Bluetooth Speaker Review.

Small and light is an understatement – the product’s name of 39g doesn’t lie. Most of us don’t actually know what 39 grams feels like. If you have felt any other Bluetooth speaker, well, the lack of 39g’s weight speaks for itself. For comparison a JBL blue tooth speaker weighs 550 grams, and the Boombotix REX (which I considered a smaller speaker) is 490 grams. This combined with battery life and ease of use might make you think differently about using a speaker for exercise purposes.

Small and compact, not to mention 39grams is light!

Why might I care? One might say – i’m not a weight weenie – The low weight makes total sense for the runners market, for which this speaker was designed. Think about low inertia of something bouncing up and down every stride, and 39grams is sensible, yet untouched engineering. That’s an insight into the product name, but in this case the small size and high brag-a-bility on features is why I’m reviewing for cycling specific application.

First things first, out of the box, it connected to my iPhone and playing music in less than 30 seconds – and, no, I didn’t read the manual. Easy to use, yes. With the unit in hand, my first impressions were that there has been some serious design thought here. The integration of a clip and a magnet system, the nice size buttons on the front and the angled speaker shows someone has been thinking.

As I got some music through it, the sound was impressive… when close to the ear. It’s a personal audio device, so it needs to be on a garment, at shoulder level. Once I did this, my fears of lack of audio quality dissolved. This is a personal audio device and a major difference to most Bluetooth speakers.

Cycling background and speakers

For years I have been riding on and off with speakers on commutes. I enjoy the ability to beat the mundane route and stay updated with a podcasts or chill out with some music. I have taken for granted larger sizes and weights, and the way a a speaker projecting music to the world when riding. Don’t worry, I almost always rode with speaker close to my shoulder and the volume down, so as not to draw attention, but also not to distract from the sounds of the road.

This is my 39g setup. Located on a backpack strap. More below.

In Use

Testing Procedure

Ridden on my bike on typically an hour commute through the city and suburbs. Has been cold and wet of recent. Temps ranging from 28f to 45f and on the battery life test, 4 trips, were in the wet to test the weatherproofing. Total test time 17.75 hrs with ~4hours in the rain.

Acoustics & Audio Quality

The 39g requires the unit to be close to the ear, this is a main difference between this and a “boombox” bluetooth speaker. For cycling purposes sitting the speaker on a backpack strap was the perfect location to optimize listening distance and battery usage (see below).
Audio Quality-
The design is slightly better suited to voice and talk, rather than music. That’s not to say it’s bad with music, but it’s not great, compared to one of those larger speakers, which have a fuller range and the ability to produce lower notes more effectively.


The unit is rated as IPX-7, which is a high rating, meaning the unit can be submerged for a short period of time. Four times I rode in the rain, downpour for an hour each time. No problems, the unit seems to be solid as far as cold and rain. The cold was tested by a couple of morning rides where it hit 24f and 28f

Buttons, Usability and Apps

The play / pause /power is square and in the center, easy to use and find while riding with gloves. The other buttons are a bit more tricky. But, most of the time, this central square button will perform most needed tasks.

Compatibility. I used it with youtube, spotify, i-tunes no problem. I even used it with a safari (web browser) based audio player (npr radio) and could start and stop it from the square control. I had one phone call for which it seemed fine. I don’t really plan to talk to people while riding because it’s obnoxious, but it’s good to know it’s there and it works without audio / mic issues.


These are critical for riding and the 39g comes with two methods. 1. Magnetic Clip – using a strong magnet mounted on the unit and a small metal plate that goes behind clothes – cool idea, but its really not strong enough for riding, if you hit a small pothole it will un-attach itself. 2. Spring Clip – a molded in clip like a hair beret – I found the spring clip (provided) worked great. Is it as powerful a clip as others on the market. I never had an issue with mine.

Magnetic attachment , the small part goes underneath your shirt or material. Both parts have high strength magnets.

My most successful attachment was using clip on the backpack strap at a position near the shoulder. In a riding position this put the speaker 6″ from my ear. Depending on your backpack / bag design you might have to use some zip ties to secure it.

Battery Life

The unit is nice, because at each power up it announces it’s charge – high, med or low. I found that with my phone and ride conditions, I needed the volume to be 70-90% of max volume. This was still the case, even though 50% of my rides were very quiet ambient noise in the AM’s. Before studying the battery life test, I fully charged and then completely depleted, charged again to full, and logged hours and conditions. The largest negative is at battery level medium or below. It’s very unreliable and will power down whenever it feels like it. You can power it back up at the risk that a few minutes later it will power down again.

By the numbers: 5.75hrs before turning itself off. This was almost 6 rides / commutes, it only ever announced “battery medium” then turned off (several times). I subsequently managed to squeeze another 90mins out of it the next day before it announced “low” after repeated shut downs and re power ups around the 70min mark. I wanted to see how long it would go.

Battery Conclusion : Good battery life, even though packaging says 12hrs. Considering with wind, low temps and higher volume probably make 6hrs more realistic. Disappointing measurement of remaining life in unit. The “low” announcement should really say “dead” and “Med” should be rephrase as “close to dead”.

Corded headphone jack (only god knows why) and the USB charge port.

Alternate Uses

I found a very nice additional use for this personal speaker around the house or in the garage. Clipping it to a shirt while working using the magnetic clip is perfect. And in your own workspace you can use low volume levels, preserving the battery. It’s great to be hands free and still be able to hear the activities you are working on.


Long battery life, easy to use, super light weight make this an easy choice. You are not going to be throwing summer parties in a field with this, but as a personal audio device where you can still hear traffic and not be tethered by buds, it’s a fantastic choice. My only drawback is the monitoring of the battery level (indicator of when it needs to be charged) which could be greatly improved.


One thought on “NoxGear 39g Bluetooth Speaker Review.

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  1. I had the same experience this weekend on a long run with it turning off when it wanted to. I was so frustrated because look, I LOVE the thing. LOVE it. But, it’s 100% accurate to say that when it says “Medium,” get ready. It’s going to die. And, will power back on and reconnect for about 30 seconds. Over and over. I was thinking about reaching back out to Noxgear about it, but it sounds like we aren’t the only ones with this issue. Other than that, when you aren’t out for long runs, it’s AMAZING and I can’t say enough nice things about it. And, I’d buy another one in a minute.

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