INTRODUCTION
NuForce made its name under Jason Lim's leadership developing high-performance audio products that didn't break the bank. Jason Lim has moved on, but the NuForce brand is still going strong under the new Optoma NuForce brand name. Optoma is a well-known projector company that decided to diversify into the home and portable audio markets with its acquisition of NuForce. Recently, @jyri at Optoma NuForce reached out to me and asked if I'd be interested in reviewing their new HEM IEM lineup. This is an expansion of the work NuForce did with the Primo8 quad-BA IEM, with HEM2 single-BA, HEM4 double-BA, HEM6 triple-BA, and HEM8 quad-BA. I'd already heard their single-driver titanium-coated dynamic IEM, the NE800M. While that was an enjoyable IEM, it had more bass than I typically look for in an IEM. While well-received, I got the impression that I'd probably have similar thoughts about NuForce's Primo8. Would the new HEM lineup be more of the same? I'm here to tell you that in my opinion, the answer is a resounding no. Beyond just expanding the lineup, each of these IEM have their own character to satisfy the varying needs of music lovers. If the HEM lineup is any indication of things to come, I'd say the future is bright for NuForce. In this review, I'll let you know what I think of the HEM8 and also touch on the other IEM in the HEM lineup. And a big shout-out to @jyri from NuForce for letting me test these out!Optoma NuForce Website: LINK.
Dedicated NuForce HEM thread: LINK.
DISCLAIMER
There is no financial incentive for writing this review, and this is my honest opinion of NuForce's new HEM IEM lineup. I hope my feedback is useful for my fellow Head-Fi members as well as for NuForce.[size=17.03px]ABOUT ME[/size]
I'm a 44 year old father who listens to a lot of electronic and metal, although I do listen to a wide variety of music. I'm primarily a portable audio enthusiast and have been in the game since the venerable Shure E2C was first released. Bought one, plugged it into one of my many MD players, and have been hooked ever since. I do enjoy listening at home and am becoming increasingly interested in building up a nice desktop setup. As with a lot of people my age, my hearing isn't perfect but I've be listening for a long time and feel confident in assessing audio gear.
SPECIFICATIONS

*Please click for a larger, easier to read table.
PACKAGING & ACCESSORIES

This is the basic package you're going to get with each of the IEM in the HEM lineup. You'll get a larger pelican-style case that you can stash everything in plus a smaller semi-hard fabric case that you can use when you only need the IEM. Of course, you get the actual IEM which come nestled in protective foam. You get two cables to choose from. Both use standard two-pin connectors. There is a more "boutique" SPC quad-braid cable with shrink wrap y-splitter and cinch. There's also a more conventional OFC non-braided mic cable. I'm glad NuForce gives you the choice because, being mainly a DAP user, I always choose to use a non-mic if given the choice. I'm sure there are plenty of you who'll want to use them with a smartphone, so you'll probably put on the mic cable and never look back. Both cables come with a relatively low-profile 3.5mm L-plug that's smartphone case friendly. NuForce includes two sets of S, M, and L narrow-bore silicone tips. One set is softer, and the other is firmer. They also throw in M and L Comply tips. Rounding out the package, you get a 1/4" adapter, cleaning tool, and shirt clip. Again, you get all of this regardless of which HEM IEM you purchase. What's missing? Wide bore tips. As @Dsnuts pointed out, you can coax a different presentation out of the HEM IEM by using a wide bore tip. Something along the lines of SpinFit tips would be a welcome addition to allow user to fine-tune the sound to their preference.
BUILD & ERGONOMICS

Here's a close-up of the HEM8. The same shells are used across the HEM lineup just varying in color as shown at the top of the specs chart a couple sections up. HEM2 is a nice red color, not overly bright which is appreciated. HEM4 is a nice shade of blue that shifts in color to a dark purplish blue as you move it around, which reminds me of the pics I've seen of the Primo8. HEM6 and HEM8 are both a classy matte black. The lightweight polycarbonate shells feel tough and are very ergonomic, making it easy to listen to them for extended periods of time. The connectors are color-coded. White lettering and line for the left side and dark yellow for the right side. It's subtle yet helpful. Another subtle yet helpful addition is the knurled texture on the connectors, making them very easy to grip while inserting and removing the cables. Finally, you can see that the cable is shaped to fit over your ear. That's not memory wire. Instead, there's a shrink wrap coating that helps the cable maintain that form. While it's not as form-fitting as memory wire can achieve, it is much slimmer, comfortable, and glasses-friendly than most memory implementations. I like it. And as a bonus, this makes it easier to wear the HEM IEM either up or down. I tried out both successfully. The only caveat with wearing down is that the knurling on the connectors has the potential to rub a bit. I didn't find that to be a problem, but it might bother those of you with more sensitive ears. I bet most of you will just end up wearing them over ear anyways.
HEM + MIC CABLE

Here's a close-up of the HEM8 with the mic cable. The cable is supple and the strain reliefs are very soft and bendable. As you can see, the mic module contains a single-button remote to take/end calls and play/pause, ffwd, and rew music. Again, I have no use for those, as I listen with DAPs.
SOUND
As mentioned in the intro, I've had these for a long time and as such have given them plenty of listening time with DAPs from various manufacturers. I've also listened to all the typical music I enjoy, mainly electronic and metal with a smattering of jazz and modern composition thrown in for good measure. As I'm writing this review, I've been jamming them with the brand spanking new Shanling M5 DAP and my trusty Cayin N5. Neither combination doesn't disappoints. And if it wasn't obvious from up above, all listening was done with foamies which might make my impressions differ a bit from others who I've noticed tended to use the silicone tips that just wouldn't stay in my ears. For this review, I thought I'd give you an overview of the lineup from HEM2 to HEM8. I'll start with HEM2 and work my way up to HEM8. As I've been writing this review, I've also seen some reviews come in and think it'll be interesting to see how my thoughts on these align or differ from others. Okay, so here we go...HEM2
HEM2 are the entry-level, single-BA IEM. I'll be honest with you and tell you upfront that these clicked with me right from the start, whereas the others grew on me. HEM2 has a nicely-balanced sound signature on the warm side of neutral. There is a bit of roll-off on either side of the frequency range. This is more apparent on the upper end, where they lack sparkle. This helps cover up any sibilance in recordings but also makes HEM2 feel restrained / polite. Soundstage is fine but feels held back by the warm sound signature, coupled with a lack of sparkle. I'm left wondering how much a bit of sparkle up top would help out here. It would add a bit of excitement and spaciousness to an otherwise relaxed / polite listen. All that said, I quite enjoy these. They remind me a bit of one of my favorite configurations of the FLC8S IEM (red, gray, gunmetal). And by remind me, I don't mean they sound the same. I mean they're reminiscent of the sound. The FLC8S is a triple-hybrid known for fantastic separation, imaging, and soundstage. FLC8S in my preferred configuration also has very linear, visceral bass, perhaps even skewed a bit towards sub-bass. Being a single-driver with a bit of roll-off on either end, HEM2 can't quite match up as far as spacial cues or bass extension and impact are concerned. I can't hold that against the HEM2, though. The mere fact that I really liked them on first listen and was reminded of one of my all-time favorite IEM is pretty damn impressive in my book. This isn't your dad's single-BA IEM!
HEM4
Stepping up from the HEM2, we come to the HEM4 double-BA IEM. These stick out as the more "reference" sound signature in the lineup. In comparison to the rest, HEM4 has the leanest bass and is more upper-mid focused to my ears. Again I'll be completely honest with you and tell you that I didn't like this one much at first listen. Compared to the others, it lacked the full, rich, organic sound. They made HEM4 sound a bit too lean and a bit bright. As I've spent more time with it, my thoughts have changed. In fact, I've come to really like HEM4. Like I said, coming from the others it sounds lean, but when I take some time away from the others and just listen to HEM4 in isolation it sounds really good. In fact, the more I spend time with it, the more I realize it's giving me what I was looking for in the HEM2. While the bass quantity is less, the bass quality is improved and isn't quite as soft. There's a noticeable increase in upper mid presence and sparkle up top. As such, it can be a bit more revealing of sibilance than HEM2, which is a sibilance killer. It's not accentuating sibilance like some IEM I've tried recently, just revealing what's there. Spacial cues are kicked up a notch, a noticeable improvement. Yes, I'm liking this one more and more with each listen. Funny how that happens sometimes. In fact, if you look over my initial impressions of HEM4 in the HEM thread, you'll see I was ready to write this one off as a loss in my initial impressions. Not that it was bad, I just didn't think it suited my taste on first listen. Given some time, they're growing on me. And that's why I like to listen for awhile before judging anything...
HEM6
Stepping up once again, we come to the HEM6 triple-BA IEM. These strike me as a marriage of the HEM2 and HEM4 sound signatures. You get the fuller, warmer bass + mids of HEM2 coupled with the upper end sparkle of HEM4. Despite the similar sound signature, the overall sound quality is beyond a mere marriage of those two sound signatures. While reminding me of the HEM2 bass, HEM6 bass is higher quality. It reaches deeper and conveys more detail. Mids on HEM2 were nicely balanced, and HEM6 follows that lead instead of getting more energetic in the upper mids like HEM4. The upper end retains the crispness and sparkle of HEM4 that was lacking in HEM2. Again, this means HEM6 will reveal (but not accentuate) sibilance rather than cover it up like HEM2. Spacial cues and soundstage are better than HEM2 but fall behind HEM4, which has the most open, airy sound of the three discussed so far. In fact, moving from HEM4 to HEM6 is a bit shocking. At first HEM6 sounds closed in, but after acclimating for a bit HEM6 starts to open up. This is another in the lineup that I wasn't immediately taken with but has grown on me the more I listen to it.
HEM8
And we finally arrive at HEM8, NuForce's new quad-BA flagship IEM. These take all the good points I've talked about so far and marry them all together into one fine-sounding IEM. Bass is extended and conveys good detail. To my ears, it sounds like it combines the reach and detail of HEM6 bass but backs off a bit in quantity and sounds nicely tighter as a result. Mids are the most balanced of the bunch. Not as full and warm as HEM2 and HEM6, but not skewed towards upper mids like HEM4. The upper end sounds crisp and has good detail retrieval but isn't as sparkly as HEM4. Sibilance isn't as prominent with HEM8 despite the upper end sounding nicely detailed. Spacial cues are very good. That's probably the first thing I noticed about these when moving up from HEM6. And despite being a fuller sound than HEM4, HEM8 blows them out of the water when it comes to imaging. Doing a lot right with no obvious deficiencies, HEM8 are easily my favorite IEM in the lineup.
FINAL THOUGHTS ON SOUND
I hope that walk through the lineup gives you a good idea of what I think of them. Each of them is unique and earns its place in the lineup, however this is definitely a case where the flagship is the clear winner. That's not always the case. I've listened to lineups where I end up preferring the mid-tier IEM over the flagship. Not here. HEM8 is the clear winner as the most balanced, musical IEM of the bunch. If you prefer a bit more bass quantity, I could see you preferring HEM6 over HEM8. If you like things a bit leaner, HEM4's your IEM. Not quite ready to spend that much, HEM2's got you covered as one of the better tuned single-BA IEM I've heard to date. One thing I've always liked is having a couple different sounds signatures, energetic + relaxed. Along those lines, I could see buying HEM2 (relaxed) + HEM4 (energetic) to fulfill those roles quite nicely without breaking the bank.
As an aside, @Dsnuts pinged me and suggested I try the tip mod he covered in his Primo8 and HEM8 reviews. I did try that mod and was impressed with how much it opened up the soundstage. It really helped me see the potential the HEM lineup had while I was waiting for them to burn in. Now that they're burned in, I don't feel the need for the tip mod any longer. It's still nice to have the option for sonic variety, though, which is why I have a pair of modified tips sitting in the case of whichever HEM IEM I'm listening to at the time. You know, just in case the mood strikes me. Please head over to his excellent HEM8 review for more details (LINK).
SUMMARY
NuForce has done a great job with their new HEM lineup. The lightweight, ergonomic shells ensure comfortable listening sessions. The accessories package with two cables, two cases, and three kinds of tips is generous, although including some wide bore tips to further open up the sound would be appreciated. Speaking of sound, as I hopefully very clearly conveyed up above, it's easy for me to pick a clear winner here and it's HEM8. The other IEM all have their strengths, but HEM8 is the most nicely balanced sound. Couple that with the impressive imaging, and we've got a winner on our hands. But don't let that dissuade you from looking at the others in the lineup. Depending on your sonic preferences and budget, one of the others might just end up being the winner for you.Oh yeah, as of the time I wrote this review, there's a NuForce HEM "Blue Box" ovdr on Massdrop. Go take a look (LINK).
To wrap, I'd again like to give a big thanks to @jyri for providing me with review loaners of the HEM lineup. It was fun taking them for a test drive!