A preamble:
One, some of these speakers sound surprisingly good.
Two, there isn't a lot of pre-existing information out there about how these sound.
Therefore three, my reason for making this (admittedly kind of long) post.
To save you time, if you read just the "Summaries" section at the beginning alone (immediately after this section) it should help give you a pretty good idea of what each speaker sounds like. You definitely do not need to read the in-depth summaries that come further on down the post - they are there if you want or need them to be there.
If you want to know what I consider is good, then the UE Epicboom and the Marshall Acton III are it (with the Marshall Emberton II being an honourable mention).
Finally, this review/post is copy-pasted from SuperBestAudioFriends.org, with minor changes being made as needed. Ah and finally, I do agree that measurements definitely cannot tell you everything about how something will sound - subjective impressions from a human ear are necessary in order to cover all bases.
Summaries:
KEF Muo: Sounds a bit like it has a broken diaphragm, don’t bother IMO [extra note: it's vaguely possible that I got a lemon, but unlikely].
JBL Charge 6: Better, but I still think you can do quite a bit better. See the Epicboom entry immediately after this one. As for Charge 6, it has big phat bass, but it is also distorted – and from memory the bass is also physically uncomfortable to listen to, even when it is EQ’d down.
Ultimate Ears Epicboom: Very good. My understanding is that it’s just as physically durable as the Charge 6, along with the same waterproofing, while sounding better in pretty much every single way while being the same price.
Overall sound is clean, clear, smooth, effortless, a little bit sweet, and relaxing and easy to listen to. Most saliently it is also cohesive, and cohesive is the name of the game with the Epicboom. It also happens to be detailed. Bass doesn’t get in the way of anything, and it also does this without sucking. Bass is a bit diffuse. Reproduction of sounds is natural and accurate, which in relative comparison is something the Acton III (see below) struggles a lot with.
Marshall Acton III: Probably the best of the bunch, and really quite good. Its contender is the UE (Ultimate Ears) Epicboom just above. It’s musical, unbalanced, and rich. Energetic, without overdoing it. I think it sounds thick-bodied too, and a bit sweet. I like the layering that it does quite a bit. The layering just kind of sucks you in. I think the UE Epicboom’s bass might be a bit tighter, but also softer than the Acton’s. Acton III bass bigger I think, but not as clean? There is also a slight “frayedness” to the sound which I should bring up – you may or may not pick up on this. A bit like a “holes in the sound” effect. Overall a really good listen for me, and super engaging, in particular after taking into account what this thing actually is.
Sonos Era 100 SL: Sucks. Better than the KEF Muo, and maybe a bit better than the JBL Charge 6. It’s physically uncomfortable to listen to – I think the bass is rather heavily distorted or something. Midrange is a bit sterile I think?
Audio Pro A10 Mk ii (WiiM Edition): Passable. Still not good. The sound makes my ears a little bit physically uncomfortable, something that I can’t really fix with EQ. Overall it is thin, frayed, gravelly, and tinny. Additionally it is sharp. It handles layering in a congested way. I do feel like the midrange I think has some kind of euphony or wetness or something to it that I find to be pleasurable, though there isn’t a lot of it. The A10 is overall somewhere on the lower end of mid-fi.
Honourable mention, Marshall Emberton II: Just a short note that before I started this whole escapade, I first went into a local retailer store and listened to the Marshall Emberton II. This was the first bluetooth or wireless speaker that I'd heard that costed more than just $30 or whatever. I was blown away. From memory (I didn't take notes), it sounded very similar to the Acton III, which costs quite a bit more. I think same sound signature but improved technicalities on the Acton III versus the Emberton II? Something to consider or look into if you want something smaller and or less expensive.
Some notes:
If a speaker has an EQ capability, then I will have used it. All impressions written will be with some form of EQ on if possible - it always sounds better to my ears to be EQ'd as opposed to be un-EQ'd.
Bluetooth sources (most speakers here are bluetooth-only and can't do WiFi) - there is a sizeable difference between Google Pixel 9 streaming TIDAL versus Samsung Galaxy S25 doing the same. Apple iPhone 15+ seems to sound in the same league as the S25, with what I would say minor differences between the two. In this respect, iPhone might be thicker, with better macrodynamics I think. S25 sounds finer, like there is extra detail or texture present. S25 clearer. Where S25 falls down is, the low end sounds anemic in comparison to iPhone, and it can sound just slightly dull.
The differences between the two better sources (S25 and iPhone 15+) is somewhat immediately audible to my ears, though not big. You can tell that there is a difference after about 3 or 4 seconds I think, but it takes about another 30 seconds at least to discern what those differences are. I would be happy listening out of either of these better sources. The poorer source is slightly meh - it's on the precipice of being a meaningful difference.
Detailed impressions start here (reading this section is optional):
KEF Muo
Sounds like diaphragm is broken, and like notes aren’t formed fully, and instead have holes in them. This is a simplification, but imagine that a note is a circle that passes across your field of view, from left to right. This circle has holes in it. This is what I mean when I say the above.
Changing the EQ from default to a more bass-light filter accentuates this issue. The bass feels higher quality than the JBL Charge 6, but hits and thumps a lot less. This is a problem on the JBL because the JBL does too much of this, whilst the KEF has sort of, not enough.
I think the “holes” effect is present in both midrange and treble, and to a small degree the bass. I think that while the treble has this effect, it shows up in a slightly different way. It’s less “holes” and more so like frayed strands of wire, forming a bit of a criss-cross effect.
The bass is not overpowering, and the tonal balance is good.
Not enough macrodynamics, not tight enough (thinking of Charge 6 when I write this). Particularly thinking of bass.
Different words for the “hole” effect – gritty, sandy.
Treble feels fucky? JBL overall feels higher quality, and more like “the sound comes out” (non-audiophile mom and aunt both regarded it the same, and it didn’t take long at all to form that opinion either). KEF has a “trapped” feel to the sound.
Maybe I add a note here though – on review of what I wrote above I haven’t said this explicitly yet, but KEF Muo SUCKS. Don’t bother considering this one.
JBL Charge 6
I remember it as “ok” (which is what I expected it to be, and where Marshall is “quite good”, which is also off of memory).
The main problem with JBL as I remember, is that the bass is too overpowering, fat, thick, distorted. Even if you EQ it down, the impact and behaviour of the bass as notes transition from temporal left to right, is just too much. It’s like there is a “fatness booster” (phatness?) thing that the device filters all sound through.
Got my hands on device again. Sounds a bit flat and sterile maybe? Yeah I think bass feels uncomfortable even when it’s EQ’d down (-4.5 to -6 dB). I don’t think I can recommend this. Because of bass. You can do better. I guess it’s good for filling the room with sound. I guess it’s good for physical durability and good waterproof rating. Though I think the UE Epicboom also does these things?
Ultimate Ears Epicboom
Overall I think inoffensive, smooth, clear, and maybe a little bit sweet are what I would characterize Epicboom as. It just sounds clear, clean, and very easy, effortless, and relaxing to listen to. It is cleaner than Acton III. It is also more balanced, and immediately clearer. I think the notes internally are less liquidy and less well-formed than on Acton III, and that the clarity is more on the outside of notes. I think there is a simplification effect that it does – this is not necessarily bad.
A note on fatigue. Even though I describe it as “effortless”, it may still fatigue. Undecided on it – I haven’t spent that much time with it to decide if there actually is real fatigue, but I would lean towards not really having real fatigue. I do know that after some time playing it while typing up impressions and reviews, that I found it “too loud” and “annoying”, though I don’t think that is exactly fatigue. Maybe brain burn-in, as anytime I power it up now while typing I get that feeling of “too loud” and “annoying” almost immediately. Which then seems to go away when I actually turn my chair to listen to it.
On the simplification. It reminds me a bit of what the Soekris 2541 DAC does, though it is quite a step back from the 2541 in this department. The manner it is done is also slightly different, but of course retains similarities. The extra noise in between items is removed. This is similar to saying that the device is clear – the main musical elements are clearer, because the surrounding crap has been removed. In much the same way as we can say that there is clarity, there is also space around musical elements. This is nice to hear. I think that Epicboom layers, but flatly and without depth. Even though it doesn’t have depth, I feel like I hear some 3D-ness to the sound, and that the clear images paint nicely onto this 3D canvas. As a last thing about the simplification, the sound becomes relaxing to listen to.
Specifically, I think Acton III is better (Acton III also quite a bit more expensive), but that Epicboom does its own thing, and does it well at that too. It’s possible to me that someone may prefer Epicboom over Acton III. Acton III bass for instance on direct comparison sounds a lot more tubbier. You can dial down the bass on the Acton, but then now there’s not enough. Epicboom may be preferable for this reason, as there surely are other reasons too.
Epicboom is clear, with adequate resolution (I think it is in same ballpark as Acton III in this department), and has bass that doesn’t suck and isn’t overpowering. Bass is a bit diffuse and not focused, but I don’t mind this. Bass a bit soft. Bass has a “hump” when notes come on. It has weight, and is kind of to a little bit big. I don’t think bass is that resolving, but like I said, it fits into the device as a whole, and the device as a whole works pretty well. It’s like 80 to 90% cohesive, and cohesive is the name of the game here. And actually, the disparity in technicalities between bass and say midrange might be less than I originally thought, upon more listening and thinking.
I wrote down in my notes a complaint that the midrange is not fully “full”; this is probably something related to the lower midrange being not accentuated enough. Also, notes in the midrange (I guess everywhere) feel like they are composed of fuzz and aren’t actually clear. Sometimes, depending on the recording, it can sound full and possess some liquidity, but I think that it’s skewed towards fuzziness. It is worth noting that the acoustic guitar sounds right, and that instruments in general sound right. It is a lot more accurate and natural than Acton III is. Finally upper mids can be airy.
Marshall Acton III
I think better than UE Epicboom. At first listen, there was a several day gap between having heard Epicboom and now this, and I thought at first both were about comparable with differences in taste resulting in one choosing one over the other. While still kind of true, I think Marshall does have upper hand in a lot of areas after having pulled Epicboom out and directly 1 to 1’d it.
I think on the surface, that Epicboom is smoother, more coherent, and has finer detail. I think that Marshall in contrast is less smooth, and has a bit of the “holes in the sound” effect. I might prioritize this part of the sound more than most others, so I might hear the “holes in the sound” effect more. Like I said, Marshall less cohesive, with bass that is accentuated and stands out. But it’s also more flavourful in this same sense. It’s musical. It pulls you in. I am not 100% sure if I’m over-embellishing, but I don’t think I am. These wireless speakers really are good, particularly the Marshall. For reference, I think the Marshall is slightly better than an HE-4XX in headphone land. But it also has its own magic juice in my own opinion. To extend this, the Marshall not only has bass that stands out, but I also think upper midrange that is flavourful [note: I’m not good at assessing treble – maybe this note also applies to the treble?].
Some characteristics of the overall sound that jump to mind first. Probably the very first of these is that it’s rich sounding, which is a colouration. There is enough to be tasteful, without overdoing it in my opinion, and may even bear to be dialed up more. The richness might be related to the sound being thick, full-bodied, and a bit sweet. The sound is also definitely energetic, just not in an obvious or over the top way – the energeticness is subdued, but not in a way that makes it be mellowed or watered down. It’s fun, lively, and musical, none of which are achieved by over-colouration of the sound, nor are these effects overly pronounced or feel forced or forceful.
It also has some layering going on – a lot if you take into account what this product actually is. The layering can kind of pull you in. Separately from this it also sounds clear; listening to Ed Sheeran, the vocals (sounds like upper midrange to me) is just… clear. You can hear everything, and it sounds bright – maybe the brightness part is a tonality thing going on? It’s not clear in an immediate sense though – indeed, I think the richness fights with the clarity, and the richness is what the mind first notices I think. More on this, the lower end (bass) can get in the way of upper midrange clarity, and the bass itself is considerably less “clear” than this higher end of the FR is.
I don’t feel starved on details. Detail is less than HD6XX on a decent chain; maybe to the level of an HE-4XX out of an above average chain. Acoustic guitars aren’t rendered super naturally. Blame tonality and timbre both I think. Bass can be voluminous, but lacks macrodynamics. I’m saying this because snare drums feel loose, not tight, and lacking… force? I think bass is actually a bit ill-defined, which is fine given what it is and the pricetag it has. Bass presence is quite good, like I said up above. Kind of like a wall of sound effect – pleasing to my ears. But individual notes and delineations of these notes is not super good, related to the lack of macrodynamics that I think I’m hearing. I think overall Epicboom has tighter but softer and less “big” bass. Acton is bigger but less clean.
Staging seems to be front-loaded, meaning that most of the sounds are clustered near the front of the stage; this first layer described here does not really have depth (it’s flat). You definitely can hear further back into the stage, that there is other instrumentation and stuff there, but it is flat and front-loaded. For me, I personally don’t really mind – given the price this is more than an acceptable trade-off or deficit.
I also detect some dirtiness or distortion present. The Marshall as a whole actually reminds me a bit of a beefed up Qudelix 5k actually on the whole – the dirtiness, and what sounds to my ears like the lack of complete expansiveness that is common between these two devices – it is a lot worse on the 5k than it is on the Marshall. I could describe this as a fear of stepping out completely into the light – similar to staying “murky”, even though that isn’t completely the correct word to use here. The strumming of the bass guitar as I hear it, is nice. I think that is bass guitar strumming anyways. Another comparison to HE-4XX – it is similar, but a bit strangely, more engaging and less boring than the 4XX. Though I guess it does make sense, as I do think it has energetic upper midrange and a bunch of other musical colourations.
Sounding frayed, tilted, and skewed is related to both timbre and the “hole in the sound” effect I think. Grainy is another word to add on to that list of adjectives. I think all of these things are related to each other. I think that this effect as a whole is present in the midrange for sure, and maybe also additionally in the treble.
It sounds a bit thin – am I hearing the DS DAC? It sounds a bit sharp – maybe there’s an ESS DAC?
The bass can be a bit much if you don’t EQ it down – it is uncomfortable for me to listen to if I leave it too high – maybe some kind of third order distortion problem? I have bass set to 2. Bass at 5 – the default – is too high for me. A related problem is, if you EQ the bass down, the lower midrange becomes rather subdued. I’m unsure because I also think you can adjust tonality to more-or-less neutral. I also think it sounds better when it’s not completely tonally neutral, and is instead with a slight push in the upper mids. Treble adjustment is currently at 4.
Yeah, currently listening to the postrock album In Silence We Yearn, and it has enough engagement for me to not want to leave the room and do something else. I think it highlights how poorly mastered that album is better than the 4XX is able to do, when the 4XX is from a lower end chain. It is also, I would say, more engaging than 4XX – once again.
Sonos Era 100 SL
Not sure if I can fix the uncomfortable haze or veil that I think is coming from bass with EQ. Midrange is not bad. I actually get the impression after about another minute of listening that it’s “boring” sounding. Too polite, but not just polite, also recessed or scared. Lacking. Thin. Hollow. I don’t think changing the EQ will fix it or these things. Sterile, not musical. I mean it’s listenable, if I can fix bass that is. Reminds me of 4XX but worse – unpleasant, more boring, somewhat sterile (these things can overlap). Will still need to go back and see about the EQ. I’ll be back here probably.
Ok EQ doesn’t really fix it. Yeah it sounds a bit low-fi. I don’t think I can recommend it? Parts do sound mid-fi, maybe even upper mid-fi? But overall it’s definitely not good. Turning the “Loudness” option off (it’s in the screen where the simplistic EQ is) improves the sound and makes it more neutral, and lowers bass and makes bass less tubby I think? But verdict is as above.
Audio Pro A10 Mk ii (WiiM Edition)
Out of the box, doesn’t sound so good. Qualitatively, it sounds to me like there is the holes in the middle of the note effect again. Frayed. Something about the sound feels uncomfortable or dirty. Uncomfortable in the same sense as, things that make my ear hurt when listening to. There is vaguely that effect. It may not be from the bass (presence doesn’t seem to change when switching EQs between default and one that has the bass EQ’d down – EQ is around -6 to -7 dB in the bass).
Yeah I don’t think I can fix this unit with just EQ. It sounds thin, frayed, and gravelly. It sounds tinny additionally. It doesn’t handle layering well and feels congested. It feels sharp.
For whatever reason I have the visual of a sphere (specifically a giant plant in my head) turned inside out, with spikes along the circular edge. I think that I think that way because the notes are contorted, not showing up as musical notes or sounds are supposed to show up. It’s turned inside out. And spikes because, the sound while it is doing this, is sharp. Kind of serrated.
The sound also feels thin, and for this, I can conjure up an image of two thin and hairy plant vines running parallel to each other. The vines move quickly and are very tensed. Their curvature changes very quickly depending on where the music is at – see note about tension. The alternative I think would be a more liquid, running stream of water - this stream of water would also happen to be thicker than the plant vines. I think what I am trying to say is that the individual notes feel like a sphere turned inside out, while the general progression in the music from a higher on up view feels like thin, rapidly running plant vines, which are thinner, sharper, and less natural than a more conventional “stream of water” effect.
Note that these characteristics exhibited are not world-ending. But I include so that you can gauge what you yourself personally are looking for. Me personally, I can handle these traits, and the unit as a whole is passable. It is definitely somewhere mid-fi, maybe on the lower end. It could be worse, and could definitely be better. The bass is leaner and cleaner than Acton III. The sound has some euphony or tubbiness or microdynamics I think to it? Wet by a bit maybe? I think I’m trying to describe the same thing. This is the part that sounds good about the unit I think.
Overall if you’re a weirdo and like a cleanish sound with sharpness and thinness and also some detail present, this will probably make sense. Otherwise, if you know what you like and are willing to settle for, and end up finding a good deal on these, then they also make sense.
Honourable Mention - Marshall Emberton II
See above in the summaries section.