EarFun UBoom X

An expertly tuned Portable Bluetooth Speaker for all occasions

The Earfun UBoom X is a large (and heavy) Bluetooth speaker that probably looks fairly “generic” in photos, but it has 2 (maybe 3) things which I think set it apart from other bluetooth speakers in this price range. Earfun really wanted to make this speaker have “proper” sound and after using it for a few weeks I do believe they made some smart choices and those choices are the only reason I decided to write up a review of the speaker.

But before I get into the details I thought I would provide some context as to why I am even looking at bluetooth speakers.

An ongoing journey to get decent audio in the garden

So I have had a love/hate relationship with bluetooth speakers. Mostly they are a convenient way to have audio in a garden or park once the weather starts to get better and each year, for the past few years, I have bought a bluetooth speaker thinking this one “is the one” but up to now, every one of those speakers has been a let-down as far as sound quality.

Last year I thought the much hyped Soundcore M600 (which even had some “audiophile” friendly reviews) was going to be the one, but sadly it was not. I still have it, and it is a very nice looking speaker with its metal case but I ended up deciding I would not review as it didn’t really offer anything sound wise, other than a gimmick of “surround sound” that didn’t really work that well. I even tried to use some of Soundcore EQ capabilities to see could I get something reasonable from that speaker but the lack of any bass at any decent volume meant it was not much better than the tiny “pocket-able” bluetooth speakers you see on Amazon all the time.

So I was somewhat cautiously optimistic a few months ago when I spotted some reviews about the Earfun Uboom X. But I waited a few months to see if there was any negative sentiments and in general I think it has gone well with most people (there will always be ‘fanboys’ and ‘haters’ on the internet). So since there is no point in buying a mainly ‘outside’ speaker in the middle of the winter, I waited until a few weeks ago before deciding that this speaker would be this year’s attempt at decent outdoor audio.

Note: I have had a generally a great experience with Earfun products, while often their marketing can still be very much in the Amazon consumer “boomy” audio market (competing directly with Soundcore and JBL), I believe, there is a part of that company that believes in audio science, good tonality and providing an accurate reproduction of sound.

So lets get into what you get with the UBoom X.

Unboxing and Build Quality

The EarFun UBoom X arrives in a sturdy box that protects the substantial speaker inside:

Here is the back of the box:

Opening the box reveals the speaker itself:

And finally here are all the contents of the box:

In the box, you’ll find:

• The UBoom X speaker
• USB-C charging cable
• A strong carrying strap
• User manual
• Warranty information

The UBoom X has a substantial, quality feel to it and this weight is why it comes with that carrying strap. I do think this heft contributes significantly to its acoustic performance, particularly in the bass department.

If you have any decent bookshelf speaker around your house, you will always notice the difference in weight the designers have done to reduce vibrations, against cheaper lightweight bookshelf speakers which typically have no internal padding. There are 2 x 30W woofers on each end of the UBoom X:

The design is relatively understated but functional, with a convenient carry handle that makes transportation easier despite its weight:

The control buttons are located on top of the speaker, providing easy access to all functions:

Note: One minor drawback is the lack of backlighting on these buttons, which might make operation in low-light conditions more challenging but was not a problem for me.

The UBoom X features multicolor LED lighting that can be customized through their app. And compared to some large “fun” bluetooth speakers I think these lights are nicely understated, but if you want a full lightshow, I think you might want another speaker:

There is a “rhythm” option in the App where the lights flash based on the bass response and that is a fun option for a while, but I mainly turned off the lights.

With an IP67 rating, the UBoom X is fully waterproof and dustproof, making it suitable for outdoor use in various conditions, there is an excellent flap on the connectors on the back of the UBoomX:

Features and Connectivity

The UBoom X comes packed with features that enhance its usability across different scenarios:

EarFun Audio App and Oluv’s Tuned Presets

Perhaps the most significant feature is what the integration with the EarFun Audio App provides:

So you get the now typical features like firmware updates, modify latency ( via ‘Video mode’) and adjust the lighting settings via the App

Here is that lighting effects configuration screen:

And there is the now typical 10 band EQ available for some personalised customisation of the sound:

But the real benefits here are the very detailed and tasteful presets that Oluv Sone have specifed. These presets go way beyond the 10 band EQ customisations using various DSP ’tricks’ where appropriate to really emphasis aspects of the sound in different real-life scenario’s:

Oluv’s Tuned Presets in Practice

The real magic happens when you start exploring Oluv’s custom presets and other than the excellent bass performance and this is really my second reason for writing this review.

The app offers exceptional customization options, but the highlight is undoubtedly the Oluv-tuned presets that include:

• Indoor (neutral, studio-monitor-like response)
• Indoor+ (enhanced stereo width with subtle bass and treble boost)
• Outdoor (optimized for outdoor listening with controlled upper bass)
• Outdoor+ (maximum stereo enhancement with strong bass)
• Boom xXX (for those who prefer pronounced bass)
• Ground O (optimized for placing the speaker on the ground)
• Studio (neutral presentation without enhancements)

As Oluv explains in his notes about the tuning process:

“Unlike mentioned everywhere these ‘EQs’ are complete DSP programs, consisting of several sections not only EQ, but the entire compressor/limiter, dynamic EQ, psychoacoustic effects for stereo enhancing and bass, volume curve etc.”

This level of attention to detail in the presets represents something truly unique in the portable speaker market.

Each preset creates a noticeably different listening experience optimized for specific scenarios and I thought it would be worth including Oluv’s own explanation for each of these presets:

Indoor vs. Outdoor

Switching between the Indoor and Outdoor presets reveals thoughtful adjustments designed for these different environments. The Outdoor preset reduces certain bass frequencies that become boomy outdoors while enhancing others to maintain presence, and boosts treble to ensure clarity at a distance.

As Oluv explains:

“The outdoor modes have a completely different approach to compression than the indoor modes, which are rather conservative and should retain most bass up to maximum with overall volume not being pushed that much. I also tried to get the most kick out of the outdoor modes up to maximum volume and you should notice that the UBoom X has more attack with more basskick than most other similar speakers.”

Ground O Preset

The “Ground O” preset is particularly clever, compensating for the boundary effect that occurs when placing a speaker on the ground:

“Ground O which stands for ground omnidirectional should offer you the most bass possible when placed at the ground due to the boundary effect without the boominess you would get with Boom xXX, at the same time treble is boosted a lot to allow for omnidirectional listening when the speaker is aimed upwards.”

Advanced Bluetooth 5.3

The UBoom X utilizes Bluetooth 5.3, providing stable connections with minimal latency. During testing, I experienced no dropouts or connection issues, even when moving around with my phone at a reasonable distance from the speaker.

Party Connect Mode

The UBoom X supports pairing with up to 50 additional UBoom X speakers for enhanced stereo output and greater volume. While I obviously didn’t test this feature with multiple units, it’s sounds like a crazy appealing option for larger gatherings, I am surprised Earfun haven’t sponsored some ‘world record’ outdoor audio experience.

Power Bank Functionality

This particularly feature is very useful I think. I have gone on a few picnics where after a few hours I need to charge up my mobile so having the ability to use the UBoom X as a power bank to charge other devices via USB-C, making it a dual-purpose companion for extended outings.

Battery Life

EarFun claims up to 30 hours of playback, which seemed fairly accurate at moderate volume levels during my testing if you play louder this will be much less, though I never found it lacking on any trip I have brought it on the battery has been down at 60% after 7 or so hour’s playback, so I would guess 15/20 hours easily at louder volumes.

Sound Quality

The sound quality of the UBoom X is where this speaker truly excels, especially when utilizing Oluv’s custom presets.

Given the customisation options available I thought I would just provide an overview of the “default” profile here which is one preset by Earfun themselves.

Default Sound Signature

The UBoom X delivers an impressive audio performance with its 80W (2 x 40W) four-driver design and JumboBass technology. The bass response is particularly noteworthy those large “heavy” drivers really do provide a deep resonant bass response that you can ‘feel’ across the room. I would not bother with the JumboBass unless you are a “Bass Head”.

The mid-range is well-balanced, allowing vocals and instruments to come through clearly without being overshadowed by the bass. The treble is detailed without becoming harsh, even at higher volumes.

Overall the default sound signature might be described as neutral with a bass emphasis.

Bass

The bass performance is exceptional for a speaker of this size. Testing with bass-heavy tracks like Massive Attack’s " Angel" reveals deep, controlled low-frequency response that you can feel as well as hear. Unlike many competitors, the UBoom X produces actual sub-bass rather than just a mid-bass hump, creating a more authentic listening experience.

Mids

Vocal clarity is excellent, with both male and female voices reproduced with natural timbre. In tracks like Adele’s " Someone Like You," the subtleties of the vocal performance come through with impressive detail.

Treble

High frequencies are crisp and detailed without becoming harsh or fatiguing. Cymbal crashes and high-hat details in jazz recordings maintain their sparkle and presence without overwhelming the mix.

Specifications and Measurements

Note: One thing I didn’t mention earlier was the codec support which is limited to SBC and AAC so does lack LDAC or AptX codecs, so while not ideal I didn’t find it affected the sound quality though I was mainly streaming from an iPhone using the AAC codec.

As I mentioned earlier the Boom X is a heavy speaker - here is what I got on my weighing scales with the carrying strap also attached:

Measurements

Measuring a bluetooth speaker is difficult for a number of reasons - there isn’t just one driver to measure as a typical bluetooth has many drivers in different locations around the speaker. Bluetooth speakers are also typically moved and placed in various locations, so it doesn’t really make sense to worry about specific placement or distance from a back wall. So what I tried to measure capture “typical” indoor placement (on a coffee table) and outdoor measurements (on a table and on the ground) and showing the relative difference of the various presets.

Also, it is mostly impossible to measure distortion outside so I will just show one of the indoor distortion measurements to give you an impression of how the speakers handle being pushed.

Note: I have talked allot about presets but if you never switch presets, the default Earfun sound signature will be “good enough” but in my opinion it won’t give you the real differential that this bluetooth speaker provides.

Frequency Response

Note: because Oluv’s presets are more than just DSP frequency response tweaks, these measurements only really give a feeling of the tonality changes but there will be other DSP changes (like a compressor) that you won’t see in these measurements.

So lets start with the default UBoom X profile compared to the Jazz profile:

Note: I mainly focused on Oluv’s presets in these measurements but for example the Jazz profile does a subtle increase in midrange and treble (i.e. a decrease in bass).

So here is some Indoor measurements comparing the Jazz preset with Oluv Indoor and Indoor+:

While these do show a ‘bright’ treble I thought it was interesting to compare the ‘brightness’ of the outdoors and outdoors+ when measured indoors and outdoors - you can see an almost inverse treble, so I think whether you get ‘bright’ treble or dark is very dependent on position:

The outdoors and outdoor+ presets do very well outdoors in my measurements:

I thought this was interesting also - slightly different position for the outdoor measurements:

And this measurement maybe makes it clearer than ourdoors+ is more V-shaped:

I tried the ground preset on a few different surfaces and depending on the surface you can get more or less of a bass boost:

I thought this presented the different presets you might use outdoors with a nice contrast:

Finally, this is Oluv’s Indoor preset showing mostly a well controlled FR with very little distortion for a bluetooth speaker:

Rating

The EarFun UBoom X earns a 5-star pragmatic rating for several compelling reasons:

1. Exceptional sound quality that genuinely impresses, especially in the bass department
2. Oluv expertly tuned presets that adapt to different environments and preferences
3. Excellent value for the features and performance offered
4. Robust build quality with full waterproofing
5. Long battery life with fast charging and power bank functionality

There are some drawbacks (weight, lack of backlit buttons, lack of high def codecs) but these are outweighed by the speaker’s strengths, especially considering its price point.

Conclusion

The EarFun UBoom X is an exceptional “portable” Bluetooth speaker, it is heavy, but can deliver audiophile-grade sound quality if you use the right preset in the right scenario. For me, it has worked well so far and I hope the Irish Spring weather continues, so I can enjoy this speaker in the garden and out on a few picnics.

For anyone looking to enhance their outdoor gatherings this season with quality audio, the UBoom X represents one of the most compelling options available outside a dedicated outdoor sound system. The collaboration with Oluv has resulted in a speaker that doesn’t just sound good “for a Bluetooth speaker” – it simply sounds good, period.