I've been out of the loop for a while when it comes to budget IEMs. Back in the day, the low priced options were simply not very good. I remember paying $40 for the V-MODA Bass Freq as a workout IEM because I liked the massive impact, though it was obviously not an "all purpose" type IEM. I used them with my Creative Zen Micro Photo which I believe was $300 for the 6GB model, just to put things in perspective. I knew things had improved since then, but I didn't realize just how much IEM you could get for so little money.
The IEM in question is the Nuforce NE-600X. It sells for $25 and comes in several colors - the housing is always black and silver, but the cable is available in red, green, or black. Nuforce also has a version with an inline mic called the NE-600M. The one I have is standard, no mic, with the red cable. Specs are as follows:
Driver Size: 11mm
Impedance: 32 Ohm
Frequency Response: 20 to 20kHz
Rated Power: 10mW
Max. Input Power: 40mW
Connector: 3.5mm 3-pin stereo plug
Weight (without packing): 12.5 grams
Length: 110 cm (43.3 inches)
Advanced-technology extra large drivers
High-efficiency acoustic design
Excellent bass impact
Self-untangling flat OFC wire
As can be expected for $25, the NE-600X uses a dynamic driver. The housing is what I'd call fairly "generic" - I don't mean that in a bad way though. It has a good size to it and does not attempt to reinvent the wheel. I was able to get an excellent fit using the standard medium sized tips, which seem to be of somewhat higher quality than some other bundled tips I've seen. Some of them are so thin that they will practically tear when you handle them; not so with the NE-600. The housing has what appears to be a fairly large vent in the rear. Looking closer, I don't think it actually goes through. Instead, there is a tiny little port on each housing next the "L" or "R" symbol. Isolation is on the lower side because of this, as is the case with many similar dynamic IEMs. These also do best (for my ears anyway) with a somewhat shallow insertion. I can usually just shove them in quickly and get a great seal right from the start. I like not having to fiddle with them much.
The cable seems a bit on the short side compared to what I'm used to. It's a flat cable which is relatively tangle resistant if not completely tangle proof. One thing I like is the slider: when did universal IEM makers suddenly decide it was not necessary to have these? The last "budget" IEMs I've owned, from Meizu and HiSound, both lacked this feature, so I'm glad to see it here. The Y split and angled 1/8" plug are both fairly basic, low key affairs. They get the job done without being fancy and seem durable enough. Wearing the cable up over the ear is possible (contrary to what I has assumed based on the flat cable) and is actually rather comfortable. It does make the super-fast insertion a bit more complicated though, and the short cable becomes that much shorter. The cable does seem pretty microphonic when worn down, but going over-ear takes care of that nicely.
As with all the gear I review, I burned in the NE-600X for over 100 hours. At times I paired these little IEMs with associated equipment costing over 100 times the price - a comical mismatch to be sure. But most of the time I used a more sensible approach: Sansa Clip+, Hisound RoCoo D, iHiFi812, iPad, etc. Honestly the NE-600X does not require extensive amplification to reach its full potential. It sounds about as good as it will ever sound from the little Sansa player.
The sound did not blow me away at first, but I'm used to far more expensive IEMs so that's not surprising. What did surprise me was that I could listen to them for long periods of time and not be too fatigued. The sound is somewhat U shaped, with exaggerated lows and a slightly tipped up top end. More boost applies to the bass than the treble though, and the mids remain fairly present so as not to be majorly unbalanced. Many of the low priced IEMs I've experienced are vastly more colored than this, so it's actually a pretty tame bass boost in comparison.
Most cheap IEMs use dynamic drivers, and often times they are fairly large. That means bass reproduction is usually a strength compared to other frequencies - especially when the mids and highs are a muddy, recessed mess. The NE-600X does impress with solid lows, but in this case they don't outshine the rest of the spectrum. The bass does bleed into the mids a little but not as bad as many other cheap IEMs I've used. I did find the overall presentation enjoyable if somewhat unremarkable. No, they aren't the last word in articulation or clarity, but they aren't bad either. They sort of succeed by doing a lot of things pretty well, and not doing anything particularly poorly. Remember - we are talking about $25 IEMs here. That's less than the weekly coffee budget for a lot of people.
I tried all types of music with the NE-600, and nothing stood out as a particular weakness. As far as strengths, they seem to do well with more dynamic tracks that call for a lot of gusto. The new Tron soundtrack by Daft Punk sounded great, as did Immersion by Pendulum. I think my favorite album though was 7th Symphony by Apocalyptica. Track 10, titled Rage of Poseidon, sounded fantastic - if I had to guess, I would have sworn I was listening through an IEM costing at least $75 or so. Bass had depth and rumble but remained controlled, and I got a good sense of texture from the crunchy guitars. Very nice.
Weaknesses? Sure. Obviously these are not going to have the same incisive clarity as a more expensive IEM. Vocals don't quite have that lifelike breathiness, and you miss a bit of shimmer on the top end of cymbals and other percussion. While the frequency response is admirably full, you don't get a correspondingly high amount of articulation. To put it another way - resolution is pretty good, transparency not as much. But none of this is really a glaring error. They sound good enough to where my cynicism is mostly kept in check while listening. No, these won't compete with my entry level custom IEMs. But that's an unfair comparison since those generally start in the $300-400 range and quickly move north from there. Taken as they are, the NE-600X is pretty good.
I'm not an expert in budget IEMs, but I dug up a few things to compare. First I tried an old set of V-MODA Bass Freqs ($40). They sounded comparably terrible. The bass had good impact but was grossly over-exaggerated, and the rest of the spectrum was muddy and unclear. These have not held up well with age.
Next I tried a set of JVC FX-33 Marshmallows ($40). These were closer to the NE-600X but still lacking in some clarity in the highs, and the bass was still too boomy. They also didn't fit my ears as well either. These used to be a somewhat common budget recommendation, but again the NE-600X outclasses them.
Moving up in price, I tried the Hisound Popo ($59), which sounded incredibly recessed in the mids compared to the Nuforce. The Popo has satisfyingly tight bass that unfortunately leaks too much into the mids for my taste. Sometimes it is enjoyable but other times I wish it were more controlled. The highs on the Popo seem a little more rolled off compared to the NE-600X, which has a nice bit of sparkle without going too far. The Popo does take the lead in terms of soundstage though - its biggest strength in my opinion. And its wood body is far more attractive than the plastic of the NE-600. Still, I'd tend choose the Nuforce more often than not, even without considering the price disparity.
Lastly I used the Meizu EP-40 ($40). I really like these IEMs. They offer more refined lows and seem faster than the NE-600X. Vocals are more transparent and the entire presentation is more cohesive. In many ways, these are the better IEM. The one drawback is with the upper mids - the EP-40 strives for greater detail but is sometimes comes across as peaky and grating. So no matter how good they sound, on some tracks they become annoying, despite their other good qualities. The NE-600X, while never soaring quite as high, remains consistently enjoyable from song to song. Less important (but still worth mentioning) is the fact that the NE-600 can be quickly and easily inserted. The Meizu takes some effort to get it right.
At $25, the NE-600 is clearly not intended to blow you away with amazing sound. And it probably won't. What it does do is offer a performance that is unobjectionable, and even enjoyable, for a very low price. Folks new to the IEM game could do substantially worse for the money. And for people who already own some more expensive models, these would make an excellent backup pair. They are suitably "fun" sounding without veering too far into unbalanced territory, and have no flaws that I'd consider fatal. I've had better sounding IEMs, and cheaper IEMs, but nothing that can beat the NE-600X in their price range. In a world of ever-advancing technology and correspondingly ever-increasing prices, I like seeing releases like this. Definitely recommended for what they are.