Nuforce Primo 8

Like fjhuertasaid, these IEMs are horrible. You can find a $10 ROSS headphone sounding better than these.
No highs, no lows, extremely muddy, no imaging, no nothing. They are selling for $199 and I returned these immediately. I don't know how they are able to sell any at the original price of $499.
I highly doubt any of these highly rated reviews are real. If it is a real legit review, I don't think the reviewer have heard any good headphones in their life.

Lately, I've been reading praise after praise heaped upon pieces of garbage here that don't deserve any accolades at all.

It's here, and it's everywhere. And they are always prefaced by "I got these from the manufacturer in an exchange for an unbiased review..."

Ha. Bull.

Why do you think these guys keep receiving free stuff? Because they say things like they are? Or because they have a following, and manufacturers know that unsuspecting people will eventually buy their crap? I'll give you one chance to answer that question.

The fact is,I've been following the headphone scene for quite a while (22+ years). While at the beginning people were pretty honest about their reviews (having bought their stuff with their own hard earned cash), now manufacturers have realized its far easier to buy a couple of good reviews (from most of the usual sites - except, say, Innerfidelity- ) and a couple of reviewers, who post amazingly good things about pieces of crap.

These are a piece of crap. These are the worst in -ears I've ever listened to . These are $500 in ears. These sound worse than my $10 Samsung in ears. These are awful.

People in these reviews say "they are a hard earphone to get into", but that "in the long run, they shine" or whatever. What a bunch of lies. These sound awful, and the more you listen to them, the more you get used to listen to crap, and think these are listenable. They are not. They are simply, stunningly awful.

No highs. No lows. Weird midrange. Colorations everywhere. They are so incredibly bad I can't even imagine where to start.

This is what happens when marketing people control reviewers and gullible people (including me) on the Internet.

Save your money, and get a real in-ear, with real R&D behind them. Etymotic ER-4SR's. iSine 10's. AKG N20s. Each one far cheaper, and incredibly better performing. If you want to have an idea of how these sounds, buy a $5 in ear at Wal-mart. And no, I'm not kidding.

Not even worth $10. I'm not kidding.

About Me
To get started, let me tell you a little about myself.
I’m a gigging musician (lead guitar/backup vocals), an audio forensic analyst, a novice sound engineer, and an avid music lover with a wide taste in music. Being an audio forensic analyst is a plus I find when reviewing audio products simple because I know what bad audio sounds like and usually know how to correct it. My experience allows me to be familiar with the limitations of my own ears and the equipment I’m using.
For the consumers, my perspective for all my IEM reviews will be based on these things. I won’t sugar coat things or make things sound better than they are. I’m just like you and I want good value for the money I pay for any product.

To the manufacturers, I’ll always give you an option to respond to any concerns such as quality that I have during my review. I’ll contact you directly and will do so before my review is published. I want to provide an honest and tangible review for your prospective customers without being unfair to you as a manufacturer.
I’ll always be fair and my review will be based on my perspective and my experience.
Now on to the important stuff.

About the product/expectations
I purchased these IEM’s for the purpose of reviewing and using these as a backup.


Build/Design
The Primo 8 seems to have a decent build but lacks a bit of firmness. It just seems to light to me and the plastic housing seems thin.


Comfort/Fit
After using them for a few days these are comparable to the Shure SE series in comfort. The shape of them seems very similar and they seat in my ears very similar.

Sound
The sound on these is very good, the soundstage is decent, and seems a little too centered. The lows are present but not overpowering, it seems to be a very neutral bass response and the sub-lows are there just pulled back a little from the rest of the lower end.

The mids are outstanding and in my opinion is where these really shine. Listening to a song like Lorde - Royals makes you feel like she's right in front of you.

The highs are clear and detailed. No harshness or sibilance that I could detect, very natural sounding.

Compared to Shure SE215’s, I found the Primo 8 to have a more neutral response. Instrument separation was much better and light nuances in the sounds could be heard. In AC/DC's Hells Bells the bells in the beginning were so real sounding you could hear the decay of the sound so clearly.

My Westone UM Pro 10’s are my normal listening IEM’s because they give somewhat of a neutral sound in my opinion while being extremely comfortable. I usually forget that I’m even wearing them. Compared to the Westone's the Primo 8 had a better overall presentation and may replace the UM Pro 10's as my everyday listening IEM.

Compared to UE900s I felt the sound signature was very close, however the Primo8 had a narrower soundstage and less sub-lows. I've typically felt the UE900s could stand to have a slight boost in the lows but after comparing them to several "Neutral" sounding IEM's I realize the UE900s actually could just use a little more clarity and resolution in the lows versus a boost. That was clear in this comparison as the Primo8 just did a better job in resolving the low end.

Based on my findings, I felt these were a very good choice for anyone looking for a neutral sounding IEM, especially if comfort is an issue for you. I did compare them briefly to some Shure SE535 and felt the Primo 8 just barely slipped by the SE535 in its ability to resolve across the sound spectrum.

Isolation
Isolation was very good. I used the provided foam tips but felt there was a little less bass. I then used a cheaper "Kinden" foam tip with a larger bore that was modified to fit using the Spinfit nozzle adapters provided with the
SpinFit CP240.

Value
I hesitate when trying to gauge value in any product unless there are issues with build quality or the product is just an outstanding value. Based on what I got for the price I paid though I think these are a really good buy. Probably some of the best in the $150 range.

Conclusion
The NuForce Primo 8 although a few years on the market are a really good purchase. The phase coherence crossover apparently really makes a difference in the sound presentation and overall clarity.

Disclaimer
This unit was bought at my expense for the purpose of review. So firstly I would like to thank me for this review sample. I kid, but seriously glad I made the purchase for a few of the reasons I will go on to explain. 
 
Equipment used
 
For the purpose of this review I used my beautiful AR-M2 with a wide array of music, also my iPhone 6 which partnered fairly well with the Primo 8. Whilst the Primo 8 requires no really amping to reach very content listenable volumes the added output power and weight of the AR-M2 really gave the Primo a push in the right direction to accentuate all of its best features and qualities.
 
Introduction
 
So if there is one thing about this hobby I love it’s just the way sound and the way you perceive it can all change at a moment when you hear something new. I’ve had this experience with headphones and earphones alike. However, the Primo 8 certainly got my blood racing and head hurting as I was figuring out this whole new presentation. I will expand on the sound signature and each component a little more, but to give you a flavour of what these are all about I’ve added a little teaser section. 
 
Teaser
 
Since trying out a fair few variations of earphones I’ve got quite used to a diverse variety of presentations, when first listening to the Primo 8 I knew there was something different. I still can’t decide today whether or not it’s a good thing or a bad thing possibly both or, maybe more of a marmite kind of deal here. Let me just state it isn’t because these sound bad just different, special, unique and individual in its own right. Okay synonyms aside let us get down to business. 
 
What to expect when listening to these exclusively distinct earphones is a light airy presentation full of space. A midrange that is dependent on a good recording but has the ability to sound oh so suburb like liquid silk running through your soul. The bass line is quick but has a nice amount of rumble on bass heavy tracks it lacks body but on acoustic and orchestral pieces just sounds ridiculously organic and natural. The highs are marvellous maybe one of the best representations I've heard so far, strings come across just as you were listening to the artist playing for you live in front of you, detailing can be a new experience I won't claim you will hear details you haven't heard before, you might, but you will certainly may hear them more vividly and clearly then you may have before. 
 
Technology
 
The Primo 8 uses a quad balanced armature design, with two drivers working together for the bass frequencies, and single balanced armature drivers for the midrange and treble. Not unlike many high end multi BA driver earphones the Primo 8 uses a crossover which is basically an EQ filter designed to mitigate the frequencies not allowed through a particular speaker. The frequency range that is allowed to pass is called the passbands.
 
Any crossover with poor implementation usually leads to a lesser sound and sometimes frequency drop out. Whereas a well implement and well thought through design will lead to a fluid seamless sound resulting in natural decay and layering, a poor crossover will tell your brain where a mid-range driver cuts off and where that tweeter picks it up.
It can kill the fluidity of the sound, making things translate as artificial and un-natural. The Primo 8 NuForce decided to use a first-order filter. “This type of filter is preferred in the recording industry for mixing and mastering as it reduces the ripple effect in the passbands providing for a less grainy, more natural sound. NuForce's crossover approach, what they call their "Linear Phase Crossover" network, is also patent-pending.
  
Thankfully for us, NuForce got it right. There is a magnificent continuity in the low-end, something much more akin to a three-way speaker system rather than a four-way design. The music sounds wonderfully fluid, more natural, which is key in any speaker system: headphone or loudspeaker.

The Primo 8 is a quad balanced armature design, with two drivers working in tandem for the bass frequencies, and single balanced armature drivers for the mids and highs. While this is intuitively easy to understand, it's also devilishly tricky to get right... especially with regards to the crossover network that is used. A crossover is an EQ filter designed to attenuate the frequencies not allowed through a particular speaker. The frequency range that is allowed to pass is called the passbands. A poorly designed crossover leads to graininess and sometimes frequency drop out. As opposed to a wall of sound, or sounds having natural decay and layering, a poor crossover will tell your brain where a mid-range driver cuts off and where that tweeter picks it up, etc. Your brain tells you immediately that it's not actual instruments and artists performing this music in front of you. It can kill the liquidity of the sound - making things translate as artificial. It sounds like poor hi-fi trickery, and un-natural.
In the Primo 8 NuForce decided to use a first-order Butterworth filter. This type of filter is preferred in the recording industry for mixing and mastering as it reduces the ripple effect in the passbands providing for a less grainy, more natural sound. NuForce's crossover approach, what they call their "Linear Phase Crossover" network, is also patent-pending.
 
Thankfully for us, NuForce got it right.
There is a magnificent continuity in the low-end, something much more akin to a three-way speaker system rather than a four-way design. The music sounds wonderfully fluid, more natural, which is key in any speaker system: headphone or loudspeaker.”
Source: http://www.audio360.org/iems_a0026_review_nuforce_primo_8.php
 

 
Design, Fit and Cable

Due to the highly detailed reviews already posted regarding this earphone I have decided to upload a few links to a more informative description of these earphones so as not to waste any space and time. I would like to say this is down to sheer laziness but I’ll just sugar coat it by saying everyone else has just done such a fantastic job.
 
Basically the design of the Nuforce Primo 8 holds true to the design of many multi BA earphones from offerings such as Westone and Shure. It’s an over ear design with memory glides to hold the earphones securely in place. These things area a really beauty to behold and I must admit I am extremely fond of the metallic blue colour choice Nuforce decide to go with on the Primo 8. There are some waves/ridges adding a subtle detail to a seemingly plain and fairly brilliant design, below are some pictures to add to the visual affect. 
 
The fit for myself I found extremely tricky to start with but this isn’t that uncommon, especially with earphones that seem to use, in my opinion, that tricky MMXC connector type. I don’t know why but I have yet to get on well with this design for a few reasons. One is the connection does seem to break on very rare occasions and with the added ear glide design can make for one pain in the ass to get the earphones to settle in, especially when you’re a user of glasses like myself. 
 
However, after a bit of fiddling and finding the right set of comply ear tips comfort became way less of an issue, still not perfect but stable enough to hold in place and manoeuvre around the house, but don’t go jogging they will fall out and cause frustration! 
 
Complaints aside I am thankful Nuforce decided to put some effort into the cable and quality of it. The cable consist of a Kevlar silk core, an inner layer of 7x silver wire and an outer layer of copper wire which is made up of 9 bundles of 7 insulated strands. So as you can see no expense was spared here to make this a completely durable cable and one of great sound quality. As a bonus you also get a fairly clumber sum microphone which works surprisingly well. I did try it on occasion with no issues, the microphone also doubles as a play and pause button when using it with compatible devices.  
 

 
Upgrade Cable
As Nathan mentioned in his brilliant review although a lot of thought and time has been spent on the cables audio reproduction and build quality. The fit will be tricky for some however, switch the cable out for something like the Lithum BaX cable and you’ll be set with one of possibly the comfiest iems on the market. 
 
Packaging
Okay so what are you getting should you decide to drop the £299 on these shiny blue gems? , Something of excitement and joy comes to mind from the premium box, well thought-out layout, vast array of accessories, and encapsulated display of the magnificent, awe capturing earphones really give the Primo 8’s packaging that sense of quality and luxury you would expect to experience and see. 
What's in the Box: 2 pairs of Comply Isolation foam ear tips (M, L), 8 pairs of silicone ear tips (S, M, L, XL), 51.2in (130cm) detachable cable with microphone, 3.5mm to 6.5mm adapter, Primo8 soft faux leather pouch, cleaning tool and microfiber cleaning cloth
Here are some pictures below:

 
Sound
Although this section will be a little tougher to describe I am going to go off the basis whatever I say about these earphones holds true generally overall because your milage will vary! From recordings,
ear tips to fit the sound becomes somewhat of an enigma. Swiftly moving on let's explorer that airy, detailed sound I started to tease you with in the start. 
 
Treble
 
Screw saving the best till last, let’s start with one of the best features you get from this earphone from the get go! Right, now on a poor recording or on an overly bassy track things will get masked a bit, a smear will occur detracting from some of that drool inducing timber and neutrality. 
 
Natural and organic are just two words I want to use so much with this earphone. When listening to “Sound of your voice” one of the soundtracks from “Courageous” (The Movie), strings and instruments just come across with such a timber and sparkle it’s almost unreal. But that is a choice of word I can’t use as the guitar strings just twinkle and mesmerize you with its own reality and truth. 
 
Air! My word talk about room to breathe if you ever needed a light spacious display you need to hear these for yourself! Honestly yes it can cause its own issues but overall the soft touch and presentation combined with the immersive soundstage just adds to the depth, sparkle and neutrality these earphones offer. 
 
I am in love with the treble of these earphones everything is so well presented there isn’t a slight hint of grain or too much warmth, or even a tinge of metallic texture just unadulterated brilliance. Smooth incredibly detailed treble is what this earphone brings to the table with just the right amount of weight to make everything sound oh so perfect.
 
Midrange
 
A few reviews have mentioned this section a lot and in all honesty I expected something so different when I heard these for myself now I will go on to describe my own experience with vocals and midrange in this section however there is a paragraph I read in another review which mirrors my own impressions so well there is almost no point in writing it myself so I am using it as a quote. 
 
“The mid-range however seemed a bit veiled, hanging around in the back of the mix, like it was quite possibly shy and didn't want to join the party. After a few days of listening the mid-range decided to join the fray, and like a dance floor after the drop, the party erupted.” Quote from: http://www.audio360.org/iems_a0026_review_nuforce_primo_8.php
 
(Also please check out their review as it’s offers more detail than the review I am writing, only due to time constraints) 
 
Now adding to this well-articulated analogy of the midrange I’d like to throw in some of my own impressions of how the midrange comes across after brain burn in and with the right track. Smooth, gorgeous, liquid and actually slightly forward. It’s almost too natural especially when listening to some acoustic recordings. What I mean by this is it’s almost like your sitting in the microphone as you hear the subtle details of the singer open their lips or strings as you breathe in this totally immersive sound. I love it, I wouldn’t say it’s been my favourite earphone for vocals but that is simply a preference thing as I prefer a more coloured syrupy type of sound. On the other hand I have discovered a whole new appreciation for vocals and the way they are reproduced which has lead me away from some of my typical conventions. 
 
I am going to miss this earphone when it’s gone but man when I look for my next big choice of earphone the presentation of this earphone will be used a reference. I can’t get over the space and spatial cues and organic sound this earphone offers. Truly as cliché as this sounds because the term has been so excessively used I’m tentative to say it, but still tempted, this may be one of the truest and closest representations of vocal reproduction I have ever heard in an earphone. 
 
Bass
 
Awkward, why? Because this area is so good and really one of the areas that stops me from making it my go to earphone and potentially settling with it for the rest of my life. The bass reproduction is accurate fast paced and actually not timid. 
 
Mid bass is present on tracks when it’s called for and there is even a deep sub bass rumble that really adds to the overall flavour of the sound. Unfortunately, I always ask myself where the body to the sound is, it doesn’t sound hollow or empty because you know it’s there but it lacks that fullness and meaty texture you expect and get used to with so many earphones. I don’t know if it’s the bass that is causing this or just how the earphones were created to sound but this is literally one of its biggest pit falls.
 
The bass rarely bleeds into the midrange and remains extremely clean, clear and tactile. But there is something about the sound which reminds me of the echo heard in in a great hall. You hear and feel the bass and it’s of great quality but the soul of it fails to add to the sound like it’s missing the part of the music that makes it complete. 
 
Sound stage and Imaging
 
Amazing what a new sound can do to your thinking. Absolutely love this hobby as you discover sound reproduction more and more just when you think you’ve sussed it all out. The soundstage is vast on these bad boys. If I could find an earphone that had the soundstage of these earphones added comfort more body and thicker vocals think I’d be sold for a good long while. (A cry out to anyone who has).
 
So with the Primo 8’s soundstage you get a hall like sound, spacious breathy, wide and fairly deep. Listening to well mastered tracks in DSD quality just add a whole new lease of life to the music. These earphones make the top 5 list of most competent earphones I’ve heard for soundstage perhaps not imaging but I’ll get to that.
 
I hope you’ve managed to get how spacious these things sound, with this also comes the spatial cues it throws out. Instruments decide to be played from wherever there positioned although I find sometimes because of its try hard attitude placement is slightly alluded. Most of the time everything is accurate but sometimes because these offer so much detail you end up feeling like too much is happening all, at once. 

Conclusion
Summarising these earphones won’t be a hard thing to do. Simply put they will be some audiophiles dream. Especially those lovers of classical, orchestral and acoustic pieces. Please try these out with the highest quality files you can and a warning for hip hop lovers don’t expect these to fulfil that full body sound hip hop usually requires. Fit can be tricky yes, but overall these will offer a unique sound a lot of purists will find extremely addictive so it’s almost worth the trade off if you can manage.
 
Honourable mentions:
http://www.digitaltrends.com/headphone-reviews/nuforce-primo-8-review/
http://www.audio360.org/iems_a0026_review_nuforce_primo_8.php
http://www.hifiplus.com/articles/nuforce-primo-8/

 Nuforce primo 8 http://primo8.nuforce.com/ 
 
I remember reading a while back about these from HeadphoneAddict's thread and was intrigued right away. I messaged a few friends about these as thought it would be nice to try these out and so I managed to wrangle a pair from Nuforce to write this review and I am so happy I did..I would like to fist publicly thank Wolfgang0119 formerly of Nuforce for reaching out to me for my views regarding various Nuforce gears and phones.
 
Little over a week ago I got a brand new box containing the Primo 8 and it was like unwrapping a Christmas gift on Christmas morning as I knew what contained inside the box.
 

 
"Isn't She Lovely" Stevie Wonder..
 
Isn't she lovely
Isn't she wonderful
Isn't she precious
Less than one minute old
I never thought through love we'd be
Making one as lovely as she
But isn't she lovely made from love..
 
This very tune was going through my head as I was opening up this package..This presentation would make anyone giddy of anticipation of what lies inside the beautifully anodized blue color inside them shells. The attention to detail in this box opening was clearly apparent. An all leather pouch..Various tips, including complys, velvet cleaning cloth, cleaning tool, airplane adapter, 1/4inch adapter but most of all these wonderful looking earphones the Primo 8.
 
 
reading HeadphoneAddicts thread about these I did have some high expectations on the sounds and I did what every person would have done in this situation. I plugged them in immediately to my Ibasso DX90..Only to be met with a somewhat underwhelming sound. I remember messaging my friends about how disappointed I was on initial listen but I am not a person that judges a sound on open listen..I think I was more impressed with my FX850 and IM03 on open listen than these to be honest but again I refuse to let open box impression weigh in anything regarding the actual sound of these so I kept on listening to them. That evening I did realize this sound was not going to be a one night impression type of sound. I will have to learn about what it is I am listening to and started to realize they were opening up while I was listening to them more and more.
 

 
FR 18hz-22Khz
Imp 38Ohm
Sensitivity 118 db
Max Power 5 mW
 

 
With 4 BAs in a patent pending three way phase coherent crossover design with perfect linear phase performance per housing, using proprietary 7X silver wire w/outer layer copper wire using a Kevlar silk core..Nuforce is pulling all the stops on this design from the housing down to the cable and I kept on thinking to myself.. This sound should have grabbed me by the jugulars but no that wasn't how I felt listening to them. I was just not hearing what the big deal was. How can all this tech and design fall to the way side..Yet they continued to sound more coherent and I was starting to hear layers of music. I realized that the sound at that moment was not to their full potential..Then I grabbed for my box of tips.

 

 
Here lies the issue with these for me. The nozzle is very narrow and so are the tips. I initially tried the complys that was already on the primo8 only to take them off immediately. Above the picture to the left are the supplied silicone tips and you can see the size of the small sound hole/ nozzle end of the tips. The tips to the right are my beloved JVC FX850 tips aka Sprial Dots. I will get to those later but for now I settled on the silicone tips provided.
 
Initial impression of the sound out of the provided silicones was much better over the Complys. Immediate thoughts of the Vmoda M-80 crept into my head as I kept on listening to these with the silicones for several hours. Cycling through all my test tracks..Clarity was there. Speed is very excellent, detail was clearly apparent.. Vocals was brought out in full and had great presence.. Layering of music was also very apparent at this stage. So potential for a higher end sound was there. But something was off to my ears. Upon more listening it was the treble while extended nicely was behind the mids a bit and I thought maybe this was what Nuforce meant by fatigue free listening.
 
At this point my expectations was that these would beat out my other neutral in ears the ZA Doppios and ATH-IM03 in the treble arena but I found it actually lacking in comparison to both..I am a fan of fatigue free listening but this was somewhat unexpected.  The sound FR initially was very similar to the fatigue free Vmoda M-80 with a forward mid signature and neutral bass presentation.To be fair these already left the portable cans from Vmoda behind in imagery and detail in the mids but that treble area kept nagging at me.  The more I listened the more this was apparent. I left them on my burn in station as I resumed my every day life for a week straight.. Listening in on them when I got a chance..
 
I got used to the sound more and more and started to understand more the abilities and the sound quality I was hearing yet at the end of the weeks worth of burn in.. That treble was still somewhat behind the mids in sound..Most of my box of tips did not fit the narrow longer nozzle of these earphones so tip rolling proved to be a bit of a challenge. A week later I finally had a chance to sit down with them and try something I have been thinking all week about.. Somehow fitting my Spiral Dot tips onto this nozzle.. I had to do it.
 

 
Standard tips to the left, Spiral Dots to the right.. Made by JVC has been a revelation to me as they are simply one of if not the best silicone tips on the market and well worth the $15-$18 price tag to get a 3 set pair from Amazon japan..Highly recommended for guys that own more than a few earphones. Tip rolling is all about optimization of provided sound using your own tips from your left over collection of tips or in this case using these much wider bore spiral dot tips. So far I use the spiral dots the most out of all my tips simply because these open up the sounds and gives the best clarity and detail to just about every phone I have used them on.  But here lies the problem. How was I going to get these much wider bored Spiral Dots on that narrow nozzle. This is how I did it.
 

 
So this is the smallest stock silicone tips provided with the Primo 8. I usually just throw all the small and extra small tips together and give them away as I have no use for them but in this case these provided exactly what I needed.. What you guys are seeing is the tips applied backwards onto the nozzle and this is what you get.
 

 
So I folded the cap sleeve of the tips backwards onto the earphones base leaving a thicker half of the nozzle and a much thicker stem to put on another more wider tip on there. The great thing is there was no cutting or modification on my part. I just simply put the tips on backwards and this was the result..The back end of the small tip nozzle sit absolutely flush with the sound nozzle of the Primo 8 so it doesn't extend the sound nozzle but just widens it.
 

 
Then I throw on the the Spiral Dots on top of this configuration and it looks like this.
 

 

 
Notice just how much space we are dealing with here? Compared to the stock tip configuration? 3X the diameter space with proper depth spacing so the sound channels to your ears correctly. With fingers crossed I tried the Spiral tips on the Primo 8.
 
Sound with spiral dots:
 
That treble that was a bit laid back is now fully realized and even with the mids.  Bass end now has more authority and punch, the lowest of sub bass notes come through with ease. Much better sense of spacial cues and extension on both ends while taking nothing away from the fantabulous mids of these earphones. I am now hearing their full potential firing off on all directions. This sound is now finally realized. It is exactly what Nuforce was meant to create to my ears now. Clarity and depth is even more improved with a wider bore configuration as the sound now expands in my ears. More layering and spacing of sound improved. The balance improved while providing more authority in all regions of the sound..
 
To me this is how I imagined the Primo8s..This sound is exactly how I expected they would sound like from reading reviews and impressions from tomscy2000 and a_recording aka Lachlan..The sound main attraction is the full bore wide open mid section that does mids 100% to full capacity. Even on NuForces cheaper earphones mids has been one aspect of their house tuning that is never overlooked so I expected the mids to be in full bloom and they are in deed. Vocal performance is exemplary from these in ears and has some of the speediest bass I have ever heard. 3D special qualities about this sound is all about little things that add up to a higher end sound to my ears. Finally realized with the Spiral dots. For guys that own the Primo8s. Throw on a much wider bore tip and use the smallest provided tips fit backwards for a new take on the Primo8. I am very certain it will surprise you guys in a good way..
 
Bass end of the Primo 8 I find fantastic for this sound. I would say it is above neutral in presentation and has an exact amount of punch layering and low sub bass to do even Hip hop correct. Which actually surprised me as I was thinking these might be bass light but to my surprise the dual bass BAs are in sync like the rest of the BAs to give you exactly what the recording has for bass..Sure the bass end is not colored like my H3 or FX850 but very satisfactory none the less. I would not have expected any less from Nuforce in the bass arena..
 
So previously it was Treble <Mids>=Bass. Now it is Treble=mids=Bass=+space+depth+clarity.. I noticed because of the added energy of the treble region, tonality is less leaning toward warm and much more neutral better even balanced across the board. Overall much better sounding to my ears.. And you get the best Nuforce sound I have ever heard.. 
Trying various daps and amps these sound much better when amped with more power so try out your amps with these as they will expand accordingly..
 
I would like to conclude by saying I think Nuforce has got a real hit on their hands and even without my tip rolling experiment these are worthy of the price for admission but please try out this tip experiment for the absolute best resolution from the Primo8. I think it does everything NuForce claims it does but now even better. Thanks for spending the time to read over this review and as always Happy listening.
 

REVIEW - NUFORCE PRIMO 8 - AN AUDIOPHILE PHASE COHERENT QUAD BALANCED ARMATURE DRIVER IEM
 
BACKGROUND:
 
My first venture into the world of IEM was with the Shure E2c in 2007, when I wanted some isolation for private listening at home in bed. Prior to wanting the extra isolation I used some Bose noise-canceling headphones, because they helped remove the noise of my window air-conditioning unit. But I was mostly into using speakers, and felt that the entry level E2c didn't have the clarity or frequency balance of my vintage Polk Compact Reference SDA speakers. Those speakers are still amazing sounding today, despite the treble fading a few dB as the crossovers age and show signs of needing to be refurbished.
 
Within 6 months of getting the E2c I began to wish for an affordable upgrade that would give me more of an "audiophile" level of performance. I tried the jump to the Shure E4c and the detail and sonic balance was much improved, at the expense of having a less energetic and efficient performance, and worse bass impact. My iPod just didn't drive them very well. I then bought some $200 Denon IEM with dynamic drivers that had much improved efficiency and bass impact, at the expense of worse sonic balance and less accurate timbre and tone. At low volumes the sound was fairly enjoyable, with a "V-shaped" frequency response, but the sound would become fatiguing at higher volumes. That brought me to head-fi where I started looking for portable headphone amplifiers to improve the impact of my E4c without losing the sound quality.
 
After my introduction to Head-Fi it seemed like I began an almost endless journey through every popular IEM and portable amplifier, trying to see just how good audio reproduction in such a tiny package could get. During that time several IEM stood out well above the crowd for me, starting with the Westone 3 in 2008 when used with the proper tips for my particular ears. With silicone tips the treble could get a little boosted, and with triple flange tips the treble could sound a little artificial, but with the Complys foam tips the treble was sweet and smooth, with strong powerful bass and detailed mids. With Westone UM-56 custom tips the midrange was more present and vibrant, with a good balance between bass, mids and treble. To this day it is hard to fault the W3 with Complys foam tips or UM-56 custom tips.
 
Subsequently the Westone UM3X caught my ears, and offered a more audiophile frequency response while working with a wider variety of tips and ear canal shapes. But the UM3X had slightly less midrange warmth and a bit less depth of soundstage than what the W3 offered. Still, performance was on a comparable level, depending on your tastes, with the W3 being slightly recessed in the mids and the UM3X being slightly forward in the mids. Both IEM perform well un-amped, and scale up as the source and amplifier are upgraded. My main complaint with the UM3X was that they could sometimes sound a little congested in the mids with complex musical passages.
 
Then the Westone 4 came out, which I had the pleasure of secretly beta testing early versions through production, and they corrected most of the issues with the W3 and UM3X, which I still own and love. They brought back the larger soundstage of the W3, with the balanced bass of the UM3X, and added just the right amount of midrange presence. The problem with the W4 is that they are more laid back in the highs and less energetic in general than the others, and sometimes they need an amplifier to wake up a little better. The W4 did need a redesign of the silicone tips to sound more open and detailed, which happened after a couple of years, and the new tips took the W4 up a notch in performance (sounding slightly veiled like the HD650 with the original tips, and more crisp like the HD600 with the new tips - the comparison between Audeze LCD-2 rev1 vs rev2 could also fit here).
 
At that point I stopped looking at high-end universal fit IEM, because between the W3, UM3X, and W4 I owned three top-tier IEM that could be rotated through depending on the source, amp, and program material I wanted to listen to. Plus I had many flagship custom IEM that I would use for more serious listening.  I mostly use the universal fit IEM when I am out and about, so I worry less about damage or loss because they cost less than my custom IEM. 
 
I did get a pair of HiFiMan RE-600 as a gift, and when well amplified by the HiFiMan HM-901 with balanced amplifier, they sound very much like a well amplified Westone 4, with slightly smoother treble but otherwise similar timbre and tone. Basically I mostly enjoy the RE-600 with my HM-901, which I will occasionally use at my bedside table; but I don't feel that my iPhone or iPad properly drive the RE-600, and so they also get limited use.
 
I still own many other nice high-end IEM that I have enjoyed and didn't want to part with, but they rarely get any listening time these days, including the UE Triple.fi 10 Pro, Shure SE-530, Image X10, Westone 2, Monster Turbine Pro Gold, and HiFIMan RE-262.  Each of those has something I'd want to fix - more mids in the TF10Pro or W3, more detail in the W4 and MTPG, more bass in the W2, More treble in the SE-530 and Monster, more treble and bass in the RE-262, more efficiency in the RE-600, and less upper-bass bled into the mids with the X10.
 
So, because of my large experience with universal IEM in the past, and also with 7-8 different custom IEM ranging from low-end to flagship, I was asked last November to beta test Nuforce's new Primo 8 IEM. I've worked with Nuforce to beta test other products, and they have always been very responsive to suggestions and the final versions have always been improved and something that I would want to own.  
 
I have heard 4 different versions of the Primo 8, including the final production version, and must say that Nuforce has done a great job bringing out an audiophile quality balanced armature universal fit IEM.
 
SPECIFICATIONS & FEATURES FROM NUFORCE:
 

Model Name: NuForce Primo 8 - MSRP $499
Full Product Name (for online store): NuForce Primo 8 Phase-Coherent Quad-Speaker Earphones
Slogan: Your Personal In-Ear High End Speaker System
 
When the goal is to replicate the sound quality of reference-class, multi-driver high-end speakers in your ear, the NuForce Primo No. 8 earphone stands well apart from the crowd. To achieve this elusive goal of breathtaking realism, explosive dynamic and natural sound, the Primo No. 8 embraces patent-pending technology to capture the best of both worlds: the coherence and seamlessness of a one-driver earphone, with the detail and transient speed of a balanced armature speaker array.
 
Balanced Armature Drivers:

 

Balance armature drivers deliver the highest efficiency of any in-ear speaker design available.  NuForce has fitted the Primo No. 8 earpiece with four proprietary balanced armature speakers to form a unique 3-way design. Two units operate as one for bass frequencies, with one speaker each for the midrange and treble bands. With two speakers working in tandem to reproduce the lowest frequency ranges, the listener experiences the purest, most natural bass possible - in effect, doubling up on bass speakers reduces overall harmonic distortion by over 75 percent. The Primo No. 8’s swift, rock-solid bass operates as the foundation for dynamics heretofore available only in the most costly over-ear dynamic and electrostatic designs.  Music lovers who have used balanced armature earphones will discover that the Primo No. 8 is far more refined and coherent than anything that they have ever experienced before.  The Primo No. 8’s remarkable midrange resolution, clarity and neutrality are among its most distinctive features.
  
Patent-Pending Linear-Phase Crossover:
 
The graininess of other balanced armature earphone designs is often the result of crosstalk between drivers due to their crossover network’s inability to prevent overlapping. That is the achilles’ heel that plagues all other balanced armature earphones until now. In contrast, Primo No. 8's four-driver speaker array employs a crossover network that seamlessly distributes music’s frequency bands utilizing a proprietary first-order Butterworth filter design.
 
First-order Butterworth filter designs are not without its problems. It offers an often insurmountable challenge for home stereo speakers owing to the required power levels along with difficulties relating to off-axis performance and room interactions. As a consequence of an earphone’s far smaller size and implementation, these issues simply don’t apply. However, an obstacle that does stand in the way of the Butterworth filter used in earphones is, again, size – a lack of space for the crossover’s parts. Here’s where the Primo No. 8 shines.  NuForce has addressed the size issue by developing a proprietary first-order Butterworth crossover network requiring fewer and smaller parts than ever offered before. The Primo No. 8’s proprietary crossover design has the earphone’s four speakers singing as one.
 
While the technology is far too complex to summarize here, the results are abundantly audible. Transient speed is incredible. Plucked strings take on an amazingly life-like presence. Vocalists sound as if they are there in the flesh.  Percussion explodes in a truly three-dimensional sound field. The subtlest of details appear magical and the sound never fatigues. The audiophile can now enjoy the promise of a true linear-phase crossover design absent the drawbacks plaguing products that have employed these topologies in the past.
 
Proprietary Cable Design:
 
To achieve the Primo No. 8's unprecedented sound, nothing less than the best audio cable will do. There is more to the apparently smooth and lightweight cable than meets the eye. Inside this unique NuForce star-pattern Litz cable are several advanced technologies to achieve the most accurate sound reproduction possible.
 

 ​

For strain relief, typically a weak point of earphones, the Primo No. 8’s cable is built around a core of Kevlar Silk.  This core is then surrounded by a star pattern of seven silver wires. A layer of insulation envelops the silver wires, which in turn is surrounded by another star-pattern of nine bundles of fine gauge, seven-stranded, individually insulated OFC wires – a technique called Litz construction. Litz cables, most often encountered in radio-frequency transmission technology, are especially effective in the delivery of high frequency signals. The entire cable assembly is jacketed in a pliable polymer to eliminate mechanical noise contamination. Taking cable design to its zenith, the Primo No. 8 employs isolated left and right ground wiring to reduce inter-channel crosstalk and maximize channel separation.
  
Maximum Noise Isolation:
 
A reference-level earphone requires ear tips that provide a good, solid seal, particularly important for good bass performance and privacy. Toward this end, the Primo No. 8 employs maximally effective Comply Isolation Foam tips.
  
The Final Word:
 
In capturing the best of both worlds – the coherence and seamlessness of a one-driver earphone, with the detail and transient speed only a balanced armature array can offer – the Primo No. 8’s innovation, performance and value are nothing short of unique. Having experienced the Primo No. 8, the listener will see that no detail has been overlooked. The NuForce Promo No. 8 earphones deliver the most natural sound that audio technology is capable of providing.
 
Additional Features:
 
Included with the Primo 8 are:
 
-        Four (4) sizes (two pairs per size) of silicone ear tips
-        Two (2) pairs of Comply Isolation foam ear tips
-        A designer carrying case
-        Two (2) sets of cables (with and without microphone)
-        Cleaning cloth
-        Cleaning tool
-        3.5mm to 6.5mm adapter

 ​

Selling Points​

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-     In-Ear Audiophile-Quality Speaker System: Four balanced-armature drivers in each earphone deliver a smooth, extended response, explosive dynamic realism and fatigue-free sound.
 
-     Ideal Balance and Accuracy: A patent-pending three-way phase-coherent crossover design achieves perfect linear phase performance resulting in a natural, fully dimensional soundstage, lightning-fast transients and crystalline transparency.
 
-     Breathtaking Realism: A captivating midrange and delicate highs envelop the listener in musical textures almost real enough to touch.

Click to expand...

 
 
GEAR USED:
 
15" Macbook Pro Retina as transport, with CEntrance HiFi-M8 and DACport DAC/amp, Audioengine D3 DAC/amp, or iPhone 5s and iPad Air headphone out and with Pico DAC/Pico Slim amp via CCK.
 
IMPRESSIONS - HANDS ON:
 
Before I comment on the sound, I want to note that the combination of Complys foam tips, over-the-ear guides, and the rotating coaxial cable connector make it harder to get these earphones inserted without the cable getting in the way. 
 
The weight of the ear guide would sometimes cause the cable to rotate in the socket, and that often puts the guide and cable right between my ear and the ear phone, blocking it from being inserted. This usually happens because I'm rolling up and compressing the foam tip and then keeping it compressed with two fingers while inserting it with one hand, while the other hand is pulling the ear lobe back to open up the ear canal better - and so there is no extra hand left to control the cable when it decides to rotate under it's own weight.
 
My pre-production Primo 8 came with only the foam tips, but when I switched to some Westone silicone tips (old style) it was much easier to insert the IEM one handed without issues, because I don't have to use my other hand to pull my ear lobe back to open the ear canal more. So I can use my other hand to keep the cable from rotating out of place during insertion. 
 
I mentioned this to Nuforce, and suggested that a removable guide like with the Sennheiser IE8 might make more sense, or a tighter coax jack that doesn't let the cable rotate as easily. That was when I found out that the Primo 8 will be shipping with a small notch around part of the edge of the cable socket, with a small bump on the end of the cable's plug, which will engage with the notch and will lessen the chance that the cable will rotate more than 20 degrees total. You can intentionally force it to rotate farther if you want, as the plastic bump is flexible and can deform under enough pressure to rotate the cable.
 

 
 
Once the IEM are in place, with either foam tips or silicon tips, they are very comfortable to leave in for hours. I also very much like the 3.5mm plug which works with the small hole in my Apple Brand iPhone case, while others like my JH Audio custom IEM cable won't fit through the hole in my case. 
 
We discussed the possibility of a cable with microphone, and it looks like that option may become a reality. The problem is that the coaxial copper/silver combination Litz cable is actually fairly costly, as they ship the Primo 8 with what is already the equivalent of an upgraded aftermarket cable.
 
LISTENING EXPERIENCE:
 
Since these are balanced armature IEM they should not need a lot of burn-in, and with the most recent pair, which had no hours on them before I got them, I didn't hear much of a change in the sound outside of the first 24 hours - they opened up slightly in the first 24 hours with no change in sound signature. It was immediately obvious that the Primo 8 was a very detailed and well balanced sounding IEM.
 
I did most of my early listening with the Complys black foam tips that came with them (Westone compatible bores), and later as I wrote this review I re-listened to most of the music with some old style Westone grey silicone tips. I am expecting to get some Nuforce silicone tips to try later, but until then I can say they sound great with the old Westone tips which are readily available. The sound is slightly more detailed and open with the Westone silicone tips which I preferred, but the foam tips do an excellent job as well. Isolation was good with either tip.
 
I first tried them using the iPhone 5s and CEntrance HiFi-M8 digital DAC/amp, and I tried a wide variety of my favorite lossless Jazz and New Age music, and then listened to some Blake Shelton country music, Maroon 5 rock music, and some Christina Aguilera pop music. I moved on to try at least 50 different artists in a wide variety of genres, with 90% of the music in Apple lossless format as high as 24/192 bit rate. I then tried other sources like iPhone and iPad headphone out, and other DAC/amps.
 
BASS:
 
Unlike the earlier prototypes where I was often wishing for more bass impact, the final version has just enough bass to satisfy most people including me. The Primo 8 are not bass-lite or cold sounding in any way, but they are also not a bass-head's dream. The bass response is what I would call neutral.
 
It's there and present, and it's very fast and detailed, as well as very nicely extended to below 20Hz with test tones. Bass texture is excellent (timbre & tone). String bass plucks sound crisp and speedy, with the low notes keeping up with the upper harmonics. Bass drums have that nice deep bass ring, just with slightly less impact than my W4 or UM3X. I do think that the bass impact was slightly improved with the silicone tips vs the Complys foam tips.
 
I switched the HiFi-M8 DAC/amp output impedance from 1 ohm to 10 ohm and the low-end impact improved a little more, so I left it there. It wasn't necessary to use the bass boost switch, although the Primo 8 were able to handle the bass boost very well without being overdriven at high volumes. My DACport also has a 10 ohm output impedance, and the Primo 8 sounded good with that as well.
I also tried the iPhone 5s headphone jack, and thought this had a little better bass impact than the HiFi-M8 at 1 ohm output, although the 5s is not as clear and spacious sounding in return. So source and amp choice will make a difference, and the Primo 8 scale up very nicely but don't require an amp. ** 
 
** Note - The iPhone 5s headphone jack also sounds a little more forward in the mids when compared to the HIFi-M8 or Pico DAC/Slim with a CCK, and you definitely benefit from adding a DAC/amp to the iPhone 5s when trying to wring out the most from any IEM. Changing to the Macbook with most any DAC/amp confirmed that the iPhone 5s headphone jack is lacking the detail, freq balance, and space of a nice DAC/amp. If listening un-amped I would prefer to use my iPad Air which sounds smoother and more detailed than the iPhone 5s.
 
Anyway, I don't consider myself an exclusive bass-head, as I can enjoy neutral and spacious sounding headphones like Sennheiser HD800 and Stax SR-009. Some would say that these two headphones are bass-lite, but when the SR-009 are driven by a Blue Hawaii amp or the HD800 are driven by an EF-6 amp then they cannot be called bass-lite. 
 
Yes, headphones with really strong bass are a lot of fun, but it can be a problem if the headphones add more bass than what the recording calls for at the time. The HD600, HE-500, or LCD-2 rev2 are other example of headphones with a good balance between bass, mids, and treble, and they are less picky about what amp you pair them with to get strong bass out of them (vs the HD800 or SR-009). 
 
So I played some music looking for ways to characterize the Primo 8 vs those two full-size flagship headphones, and one particular track was Ryan Adams "Dirty Rain" where it opens up with an acoustic guitar and then after a few seconds the bass guitar comes in, and after that the drums rise to a slow beat. I was able to place the singer at front center stage with the drums just behind him, with the acoustic guitar off to the left and slightly behind, and the bass player slightly to the right, with the piano farther back and more to the right. 
 
The bass guitar and bass drum were present and accounted for, and although they wont make your ears rattle they did offer a deep bass foundation. In fact, all the different instruments and vocals seemed to be at similar levels to where I expected them to be, having listened to the same songs with the HD800 or SR-009. Some IEM like the V-MODA Vibratto can exaggerate the bass too much, and generally sound less accurate or muddier, with recessed mids in relation to their bass. That puts the singer further back, and almost on top of the bass drum behind him. 
 
I also could not place the location of the bass guitar with the V-MODA at all. It was like having a "bass cloud" surrounding me with the V-MODA. The Westone 3 also made the bass player a little more difficult to locate than with the Primo 8, although the bass speed/detail was much closer to the Primo 8 and a big step up from the V-MODA.
 
I switched to electronic music with the Primo 8, including Infected Mushroom "Dancing with the Kadafi", and the music surrounded me from all directions during the intro, and then when the bass synthesizer kicks in around 1:20 I could feel the pulsing rhythm with decent impact (same thing with some Lindsey Stirling electronic music, and others). No, these wont hit you like a V-MODA, Westone 3, UE11Pro, or JH16Pro, but there really isn't anything really missing down there either. 
 
Would I say that the V-MODA or Westone 3 are a little more fun with bass heavy electronic music like Infected Mushroom? Sure, but when it comes to actual acoustic instruments and vocals the Primo 8 leaps ahead. The Primo 8 did sound punchier with electronic music as volume levels went up, but then that could become harmful to your hearing with longer listening sessions. Speaking of volume, I'm finding that they are a little more efficient than my Westone 4 as well.
 
MIDRANGE:
 
In general, the timbre and tone of the Primo 8's midrange is spot on. The Primo 8 has a slightly more forward or slightly more aggressive midrange in comparison to the W4, so loud listening isn't always appropriate with all music choices. Pianos sound lovely with the Primo 8, but if you crank them up too loud in order to enjoy the string bass more, then the piano might occasionally start to intrude too much. 
 
I'm not saying that the midrange is aggressive per se, but rather it's that way in comparison to the more laid back Westone 4, and in relation to their bass output. If I try to remove anything in the midrange via EQ then something sounds like it's missing. It's better to add 2-3dB of bass than mess with the wonderful midrange, but 99% of the time I use no EQ at all to listen to these (but an amp with 10 ohm output impedance helps).
 
In direct back to back comparisons, even when amped the W4R can still sound a little less energetic and less exciting after having just heard the Primo 8. The W4 mids can also sound a little less rich and engaging in direct comparison. However, switching between these IEM is a slow process as the combination of the ear guides and the rotating cable jack makes it hard to insert the Primo 8 quickly. Plus I have to take time to unplug the IEM from amp and plug in the next one, and then volume match them. This slower process makes the memory of the previous IEM's sound fade a little, and complicates making impressions with back to back comparison.
 
Regardless, midrange clarity and vocal presence is very good, like the singer is in the same room with you. The Primo 8 seemed to do a little better job with male or female vocals than most of my other top tier universal IEM. The realism does improve as source and amp improve, and the midrange of the iPhone 5s built-in amp is not as good as that of the DAC/amps that I used (or even my iPad Air). Nevertheless, they are still very enjoyable un-amped.
 
However, with some songs via iPhone 5s headphone output, such as Maroon 5 "Payphone", the upper-mid/lower-treble could get slightly fatiguing, due to the combination with a less than perfect built-in amp. Basically you can hear the colorations in the iPhone 5s amp easier with the Primo 8, as they are not what I would call a very forgiving IEM. They show you just how good the mastering or the source and amp really are.
 
For use with the iPhone 5s I tried subtracting about 1.5-2 dB at 6Khz and that helped with this song, although it's not needed when using DAC/amps such as the HiFi-M8. And it's not needed with all songs via the iPhone headphone out, just some recordings. And I don't feel like the Primo 8 actually has a bump in the frequency response at 6Khz, because they don't seem to exacerbate sibilance. For example, with Diana Krall "Temptation" the song can sound sibilant with many headphones but not at all with the Primo 8. So this was clearly more of an issue with the iPhone's amp than with the IEM.
 
TREBLE & EVERYTHING ELSE:
 
The Primo 8's treble is smooth and extended. How extended I can't say because my 51 year old ears roll off a lot by 12Khz, and I have to turn the volume up a little with any headphone in order to hear the 16Khz tones. But 16Khz tones are as audible with the Primo 8 as they are with my other phones.
 
The W4R being a little more laid back or "mellow" sounding can make them feel a little more refined in the treble at times, but the Primo 8 don't seem to have any high-end grain. And they are transparent enough that they just seem to disappear at times.
 
Cymbals have great timbre and tone, with proper decay, and snare drums sound real rather than sounding plasticky or like an electronic drum machine. The treble detail and extension offers a great sense of air, ambience, and space with recordings; so even with the Primo 8's slightly forward mids the venue doesn't ever become small. Only your placement in relation to the performers is affected.
 
The W4R's less forward mids can make them seem a little more spacious than the Primo 8, but also slightly less intimate. Again, I'm not saying that Primo 8 have a small soundstage, but it's not exactly what I would call "holographic 3D surround sound" although the stage imaging is very precise with a wide stage. 
 
I would say that the Primo 8 seem to put me on the 1st or 2nd row of the venue or auditorium, instead of 5-8 rows back like the W4 (but not on stage either). The W3 might put you even further back, while occasionally the Westone UM3X would put me on stage. The ambience from a live venue such as with Eric Clapton "Unplugged (live)" is actually quite good, lending to the realism of a large venue with a more intimate seating placement. 
 
SUMMARY AND OTHER THOUGHTS:
 
People are always asking me, which universal IEM is best, or which one should I buy if I can only buy one. And my answer is usually there isn't one best headphone, but there's usually 2 or 3 complimentary ones that cover all the bases. As good as the HD800 or SR-009 are, they are complimented by also having an HE-500 or LCD-2 to rotate with them, maybe adding in a nice punchy closed headphone that isolates a little.
 
The same goes with IEM or earphones. And just like how different earpads or changes in fit on a headphone can change the sound from one person to another, so can the different IEM tips or changes in depth and position in the ear canal affect the sound.
 
So, what I hear with these IEM may not be what you hear. If I tell you what IEM to buy as your "one and only precious", there is a good chance that you will be happy and offer praise, and also a good chance that you will be disappointed. If I offer praise for an IEM and it doesn't sound that way to you, then you either have to change your tips, the positioning in the ear canal, your source/amp, or chalk it up to a difference in personal preference.
 
I want to make it clear that the Primo 8 is a very transparent sounding IEM, without disturbing colorations or veil over the details. Vocalists and instruments are "lifelike" and natural sounding. Often I listened to an entire album when I should have been doing individual song comparisons, forgetting that I was supposed to be evaluating their performance. They don't make it easy to get much work done while listening to them. 
 
I really want to avoid calling them analytical, because some people would interpret that to mean they are cold or clinical, or without heart and soul. That couldn't be farther from the truth. But they certainly can be used to pick out details that may be skimmed over by other IEM. I don't think anyone would argue against these statements, but personal preference can influence how much one enjoys these traits.
 
In my case I think the Primo 8 are a great compliment to my Westone 3 or W4R (now the W30 and W40), or any other top-tier IEM with stronger bass. If I want to rock out to classic rock or electronic music I can go for the extra bass of the W4R, or even more bass with the W3. If I want to rotate to an IEM with a more laid back presentation then it may be the W4R over the W3, although the W3 still make a good low-volume/laid back IEM when used with Complys foam tips. But if I want to listen to a more balanced, detailed, transparent and realistic or lively presentation then I can pull out the Primo 8 as my first choice. This is where they really shine.
 
The Primo 8 are sometimes reminiscent of the Westone UM3X but as an upgrade, where they actually remind me more of my Westone ES3X custom IEM in terms of timbre and tone. I've always said that my ES3X were a great compliment to my Westone ES5 or JH16Pro custom IEM, which offer a little more warmth and impact. The ES3X have a similar life-like and detailed midrange with an energetic sound signature, although they also have a little more bass impact and larger soundstage - not surprising in a $800 multi-bore custom IEM vs a single bore universal fit IEM. In my ES3X review I also compared them to the HD800, for their similar sound signature.
 
In addition to audiophiles, I'm certain that there would be a large number of people out there that would want to use the Primo 8 as a neutral studio or on-stage monitor. Many other universal fit IEM don't have enough midrange to serve in that role, or they may offer a bit too much midrange to be enjoyed as much by audiophiles.
 
MORE ABOUT THE COMPARISONS:
 
As I mentioned before, the W4 and RE-600 are well balanced sounding competing IEMs that sound similar to each other with a good quality amp, but the RE-600 can only keep up with the Westone 4 if the RE-600 are amplified and not driven right out of the iPhone headphone jack. Using a HiFiMan HM-901 digital audio player, the W4 and RE-600 sound almost the same but with a slightly smoother treble in the RE-600 while there is an extremely slight grain to the W4, heard only in direct comparison.
 
The problem is that without amplification the RE-600 have less bass impact than the Primo 8, and the un-amped RE-600 sound fairly bland or lackluster in comparison. So, if both are un-amplified via iPhone headphone jack I would pick the Nuforce Primo 8 every time, although I'd still prefer to use my iPad Air. When I do add that extra little bit of bass (1-2dB) with an equalizer app, I can listen to the Primo 8 un-amped for hours and hours on end, with any genre or artist - it brings them closer to that "one and only precious" that I mentioned before. 
 
Up until now the Westone 4 with their newer "Star" silicone tips were my preferred universal IEM because they have good sonic balance, strong bass, natural vocals, and a large soundstage while using the standard tips that they ship with. The W4 (W40) are one of the more accurate universal IEM on the market, but they can feel slightly veiled sounding vs a few other top tier IEM, making the W4 a little less exciting sounding than the W3 (W30). I was very happy with how well the W4 perform unamp'd with the newly designed stock tips, so it was a real eye opener to compare them to the Primo 8 and hear even more clarity and detail.
 
Nevertheless, I will not attempt to clearly rank the various universal fit IEM I've tried as being #1, #2, and #3 etc. That's very difficult because some IEM do certain things better than others, but then they lack in another area where their competition succeeds. I could go on and on about each and every universal fit IEM that I've owned or tried, about what I would change about them if I wanted to (I actually have that written up, but this isn't the time nor the place for that). So which IEM is #1 depends on what's more important to you.
 
FINAL CHARACTERIZATIONS AND RECOMMENDATIONS:
 
The Primo 8 have the overall detail of the W3, without the recessed midrange of the W3 or the slightly veiled midrange of the W4. The Primo 8 have a more crisp, detailed, engaging and lifelike midrange than the W4, but the mids can occasionally be a little too present and forward like with the UM3X (although the Primo 8 mids are more transparent). Basically, the W4 midrange levels are more balanced in relation to their bass and treble than the Primo 8 (more) or W3 (less).
 
When comparing the bass response and impact, the W3 might overdo things a little, while the W4 bass is just right, and the Primo 8 seem slightly weaker in their bass impact in comparison. On it's own, the Primo 8 is not a bass-lite IEM and the bass is fast, tight and extended. But the Primo 8 sometimes leave me wishing that I could crank up the volume for a little more bass impact without the mids becoming too loud at the same time.
 
The treble of the Primo 8 seems just right, while the treble of the W4 can be a little muted or muffled at times, and the treble of the W3 can be slightly hot or boosted when used with the wrong tips (grey silicone or triple flange). With Primo 8 the cymbals sound crisp and metallic, with better air and extension than the W4 and smoother than the W3. String instruments have the proper amount of texture in the bow on string, and voices do not become sibilant.
 
So, what does a person do when they like three or four different top tier IEM, but one is most balanced and detailed in the treble and midrange, another is most balanced sounding in the midrange and bass with slightly less detail, while the third has the best bass of them all but requires expensive custom fitted tips for the mids and treble to keep up, and the fourth requires an amplifier to keep up?
 
Well, I would tell a "bass-head" that W3 is #1 but they should only be used with Complys tips or UM56, since they can become slightly recessed, fatiguing or bright sounding with silicone tips. I would tell someone that W4 is #1 if they want a neutral monitor with strong bass at the expense of a slight decrease in midrange and treble clarity and openness. I would tell someone that Primo 8 is #1 if they want a warm and more energetic sounding neutral monitor, with the clearest vocals and instruments and a very open and transparent sound, as long as they don't need a higher-than-average or "boosted" level of bass impact. 
 
In my case, I've pretty much moved on to high-end custom fit IEM for any serious listening at home, and I use my universal fit IEM for traveling to places where my IEM might get lost, damaged, or stolen. I don't want to be roughing it when I'm mobile, and with the Primo 8 I don't have to.