NF Audio RA15

NF ACOUS (NF Audio) RA15​

• Driver Type: Dual-cavity dynamic driver with dual magnetic circuit.
• Frequency Response: 10Hz - 40kHz.
• Sensitivity: 108dB/mW.
• Maximum SPL: 125dB.
• Impedance: 32Ω.
• Distortion: <1%.
• Sound Isolation: 25dB.
• Jack Connector: 3.5mm SE gold-plated.
• Capsule Connection Type: 2Pin 0.78mm.
• Cable Type: 5N OFC.
• Dimensions: 150x132x50mm.
• Overall Weight: 160g.
• Starting Price: 89$.

• The two RA15 capsules.
• Four pairs of white silicone tips size XS*S*M*L, model MS42.
• One leatherette carrying pouch.
• 5N OFC cable.
• Instruction manual.
• Two pairs of tuning mouthpieces: warm (brass mouthpiece) and bright (stainless steel mouthpiece).

• EPZ TP50.
• Tempotec V3.
• Burson Audio Playmate 2.
• Aune X8 XVIII Magic DAC + EarMen ST-Amp.
• Aune M1p.

​

Another great company is joining to our project: the NF Audio. I have already reviewed one of their IEMs, the NF Audio NA3, but it was sent to me by a store. Now, we are directly in contact with the NF Audio! Our first collab will be with the NF Audio RA15.

PS: From what I have heard, the company will be changing its name soon… it has already changed, but the official announcement will be made later.

Price: $89 USD
Color: Matte silver
Cable: Without Mic

NF Audio reviews: NA3 (only in portuguese)



NF AUDIO LINKS:

https://s.click.aliexpress.com/e/_DFRjsUr



SPECIFICATIONS:

Single DD:

• (1) Dynamic Driver (DD) MC2L-10M

– Frequency: 10Hz – 40kHz
– Effective frequency: 20Hz – 20kHz
– Impedance: 32Ω
– Sensitivity: 108dB/mW
– THD: <1%
– SPL max: 125dB
– Filters: detachable nozzles
– Termination plug: 3.5mm (straight design)
– Connectors: 2pin 0.78mm QDC (detachable)
– Cable size: 1.2m
– Cable: Silver-Plated Copper 5N OFC
– Shell: All-Metal
– IEM weight: 9.1g (one side)(without eartips)
– Cable weight: 15.9g
– Total weight (packaging, iems, etc): 154.3g
– Packaging size: 14.8cm [H] x 13cm [W] x 5cm [D]



UNBOXING:

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PHYSICAL ASPECTS:

Construction: Just by looking at the images, we already know that the RA15 is an IEM made entirely of metal. I found it to be a very robust IEM, with a very resistant construction quality, so I think it is an ideal IEM for you to carry around or use on a daily basis without needing to be too careful… of course, I’m not saying you should drop the IEM on the floor, but you don’t need to worry too much either because it’s not a glass IEM.

Metal IEMs always have the weight issue, they are usually twice the weight of resin IEMs. Before the RA15, I evaluated the Dunu Titan S2, and I also mentioned this weight issue, both have practically the same weight. So, in the ear, this issue doesn’t really appear, but I always prefer lighter IEMs, resin ones, for example. I think the less weight, the better.

The RA15 seems to be a large IEM, but it’s not, on the contrary, it’s quite small. Maybe the photos and videos of it on the internet make it seem a little bigger. When I inserted the earphones into my ears, I noticed that they were quite compact. I think this is a very positive point because they will be compatible with more types of ears (small, large, etc.).

Filters: The RA15 comes with detachable nozzles that act as filters. There are two nozzles: one made of stainless steel and the other of brass. I found it very easy to change the nozzles, they are screw-on and very secure. Both nozzles are very similar in construction, both are the same length and also have foam inside the tube. The only difference I noticed was the internal diameter of the brass one, which is a little narrower.

Eartips: Here’s a pleasant surprise… Although there was only one type of eartip in the kit, I found the ones that were made available to me to be very interesting, they are the NF AUDIO MS42. Great eartips, the silicone is very soft and the tube is thin (generating more comfort). Another interesting detail is that they are a kind of middle ground between the eartips that exist on the market, that is, the hole is neither too closed nor too open (wide bore), which makes them have a better balance between bass and treble. I admit that they aren’t that cheap (especially for Brazilians), but they are a little more affordable than the Final E eartips or the Divinus Velvet, for example.

One not-so-good part is that there are not many stores selling these eartips… I only found them in one store on AliExpress, and they don’t sell the pack with all sizes, only the pack for individual sizes (so it’s only good if the person already knows which size is right for them). Here at RA15, the pack came complete with 4 sizes: XS/S/M/L. In my tests, I usually use size M, and the M of the MS42 fit me well. I used the size M to review the IEM.

Cable: Excellent cable! I really liked it, very thin, light, and aesthetically beautiful. Easy to roll up for storage, doesn’t create memory (waves), has good malleability, and doesn’t have microphonics. The only observation I would make is that the connectors are of the “QDC” type… The QDC is even safer than the “normal” 2-pin, the problem is that it’s a little harder to find a replacement cable (if necessary) with the QDC. The earhooks are smooth and have a good curvature, which is a positive point. The chin slider works 100%, it even takes a little force to move the piece.

Fit and comfort: Another very positive point of the RA15. As I said in the construction paragraph, it’s a very small IEM, and this made it easy to fit and feel comfortable. The IEM fits well in my earcup, there are no protruding parts, looking at it from the front you can’t even notice that I’m wearing IEMs. Because it’s also small, I didn’t have any pressure points. The shell is very smooth and rounded, the internal part is a very good size, shortened. The insertion is average, and the isolation is good. I consider the RA15 to be a good pair of IEM for those who spend a lot of time listening to music. The weight issue didn’t really come up here, but as I said, for me, the lighter the better.

Accessories: As for the accessories included, the RA15 came with a bag made of synthetic leather (outside) and velvet (inside). I think that for the price of the product, it would have been a good idea for the company to include a hard or semi-hard case. I don’t think this type of case they included is a good way to store IEMs (in my opinion).

SOUND ASPECTS:

I understood the sound of the NF Audio RA15 as being a Neutral with a mild bassboost. The IEM has a very pleasant sound, and at the same time it’s quite technical, because the presentation is very clean and defined. It has a slight emphasis on the mid-bass region, a pinna gain with emphasis but without excess, and very linear treble without losing detail.

I was surprised by the RA15, I didn’t expect the sound to be so good. I confess that this is not my favorite sound, but I will say that among the last 3 single DDs I listened to (Tanchjim 4U, Dunu Titan S2, and NF Audio RA15), the RA15 was the one I liked the most in terms of sound, and the one I found most comfortable for my ears (physical and sound). I tested the IEM with the stainless steel filter/nozzle.

Bass:

Quantitative: The bass is moderate, or we can say that the RA15 is neutral. It isn’t bass for bassheads. Not even changing the filters/nozzles made the bass jump to the bassheadism side. The bass is mostly emphasized in the mid-bass region. The sub-bass is present but doesn’t dominate the presentation. The difference between the two regions isn’t very big, although the mid-bass is more audible. I didn’t feel any roll-off, the extension is good. I think this bass will go well with genres in which the bass doesn’t need to be the star of the show, for example, instrumental music, Bossa Nova, MPB, some Rock, Hard Rock, and older Pop.

Qualitative: The RA15’s bass is very clean, defined, fast, and controlled. In terms of texture and physicality, the RA15 doesn’t stand out, but make no mistake, the bass isn’t thin, there’s a good dose of substance there. This question is certainly due to the IEM not focusing on sub-bass. The impact is very firm and tight, the impact is audible and not exaggerated. The bass doesn’t invade the mids, nor is it bloated or muddy. The resolution is a very positive point, very similar to the bass of some planar magnetic IEMs. Here in the RA15, percussion instruments such as a drum, for example, you feel that the sound becomes firmer and more delineated during the beats.

Mids:

Quantitative and qualitative: I really liked the RA15’s mids, they are indeed “forward”, but compared to the Dunu Titan S2, I think the RA15 is a little more recessed. The difference is small, in fact, but this small difference already makes me feel more comfortable. It’s not that the Titan S2 was uncomfortable for me, the point is that thinking in the long time, a softer sound will be more pleasant to me (it’s subjective). It’s true, this difference in the Titan S2’s pinna gain made it more airy, but I didn’t think there was any technical detriment in the RA15’s mids, for me, they sounded transparent and very detailed.

Voices: If on the Titan S2 I thought the victory went to female/high-pitched voices, here on the RA15 it was a tie, because both high-pitched and low-pitched voices sounded good. But the following is true: it can balance the vocal range, but it cannot excel with either type of vocal. In other words, it won’t be the best IEM to extract the maximum potential from a specific type of vocal, because it will be good for both. It’s difficult to understand this, but you can better visualize this issue when, for example, you get a pair of IEMs that have a lot of sub-bass, and then it leaves the bass vocals with a lot of texture and warmth.

Treble:

Quantitative: I think the RA15’s treble is at a moderate level. I should say right away that this isn’t an IEM for trebleheads, perhaps the Tanchjim 4U would please those people more. I think the RA15 is on the list of IEMs that don’t cause hearing fatigue due to the treble. If you are very sensitive, you may be able to change the eartip for a more closed one, which can slightly reduce the treble. I recommend the Sony EP-EX11 or the SpinFit CP100 for this issue (if necessary, but I don’t think it will). I didn’t notice any roll-off, and the extension is good. I think that more acoustic genres will be more suited to the RA15, but of course, this is subjective, you can listen to whatever you want with the IEM.

Qualitative: The RA15’s treble are linear, controlled, coherent, and versatile. No peaks, no coloration. They have great definition, detail, and airy. The sparkle is very consistent with reality, that is, there are no excesses or absences. The treble aren’t shrill, sharp, or harsh, and there’s no sibilance. Piano, string instruments, acoustic guitar, and violin are presented with great naturalness. Drum cymbals have the right amount of brightness and detail, that is, they perform without sounding harsh or aggressive.

Soundstage: I found the soundstage to be very good. For such a small and compact IEM, the spatiality impressed me. It’s true that it’s not as deep because of the upper-mids, but the upper-mids are less emphasized than with the Titan S2, that is, the RA15 gives a greater sense of depth than with the Titan S2. I really liked the height and width.

Imaging: I found the instrumental separation to be good. The IEM has good detail, the sound as a whole is very clean, and this helps to prevent the sound from getting congested. The stereo image is good. The good soundstage also helps to separate the instruments from each other. It’s worth remembering that this aspect is strongly influenced by the quality of the recordings.

Filters: The result I found was that the bronze nozzle made the sound warmer and increased the bass a little, basically that was it. In my opinion, I think it took away some of the detail and made the IEM “less technical”. I didn’t really like the sound with the nozzle mentioned, so I preferred to do the review with the stainless steel nozzle. As I always say, some companies choose removable filters/nozzles, but for me, most of the time, a different eartip can change (the sound) more.

Driver flex test: I didn’t heard any driver flex sound when inserting the IEMs into my ears.

Amplification: I used the FiiO KA11 dongle connected to my notebook to do this review. The volume was at 20% of the 100% available through Windows. I can say that the NF Audio RA15 is an easy-to-play IEM, and doesn’t require dedicated amplification. The RA15 will play well on smartphones, iPads, and computers. As usual, I recommend that the person at least have a good quality dongle to play the IEMs. Currently, I recommend the FiiO KA11 as a good cost/benefit dongle.



COMPARATIVE: NF Audio RA15 x Dunu Titan S2

The IEM I reviewed before the RA15 were also single DD IEM, the Dunu Titan S2. I imagine that some people are interested in knowing a brief comparison between the two. Well, first, regarding the accessories: There’s nothing to say here, the Titan S2 wins by a good margin over the RA15. The Titan S2 kit, for the price charged, is something incredible for the consumer (the RA15 still costs $10 USD more than the Titan S2). Now, in terms of aesthetics, comfort, and fit, the RA15 is my preference. Not that the Titan S2 is bad in these aspects, it’s just that the RA15 manages to be even better (in my opinion).

In terms of sound, here we enter a very subjective field, mainly because both have similar tuning, but yes, there are differences. The Titan S2 has slightly stronger and more textured bass, the boost in the mid-bass is greater than in the RA15. The RA15, on the other hand, has tight and more defined bass. In the mids, the Titan S2 has a greater emphasis, the pinna gain is clearer and more airy, while the RA15 is softer and more silky. The detail in both is very good, but the Titan S2 gives the sensation of a little more because it has more emphasis on the pinna gain. In the treble, the two IEMs are very similar, both have a very good balance. I still found the RA15 better because the treble are closer to the upper-mids, while in the Titan S2 the upper-mids are a little higher in relation to the treble, that is, I feel more linearity in the sound of the RA15. I think the RA15 wins in terms of soundstage, and in terms of imaging, the Titan S2 wins by a small margin. Both are easy to play, I think the RA15 is even a little easier.

In general terms, I think the RA15 is like “2dBs” less than the Titan S2, so you get a less energetic sound, it’s a smoother, more comfortable sound. I say “comfortable” because if you read my review of the Titan S2, you saw that I made an observation about the issue of the upper-mids of the IEM, there I warn that perhaps people who feel some sensitivity in this region may be bothered in the long times (assumption). Here with the RA15, I think the IEM don’t have this issue, the pinna gain sounded very natural and euphonic to me. The interesting thing is that if we look at the frequency responses (FR) of the IEMs, the result of the comparison would be the opposite, since in the graphs the RA15 seems to be more energetic there in the upper-mids and treble. I listened to both IEMs, and for me, the RA15 manages to be a calmer IEM.

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Muito obrigado!

• Driver Configuration: Single 10mm Dual-Cavity Dynamic Driver
• Impedance: 32Ω ± 5%
• Freq Response: 20Hz-20Khz
• Sensitivity: 108 dB/mW @1 kHz
• Distortion: <1%
• Sound Isolation: 25 dB
• Cable: 0.78mm 2-pin 5N OFC with 3.5mm connector

• Tonality: - After listening to different genres of music on RA15 with many sources for several hours we at Aural Cafe can confidentially state that the RA 15 flaunts a neutral to slightly bright and clean sound. The brass sound tubes definitely have better and smoother tonal balance across the frequency in comparison to the stainless-steel sound tubes. Although the sound tubes don’t have a sizeable effect on the overall tonality and the overall sound remains transparent and clean both on brass and stainless-steel sound tubes it’s the brass sound tubes that add the soul to the instrument's timbre and the vocals texture. Since the RA15 exhibits a smooth tonal balance with the brass sound tubes we can recommend it for the sound designers who are sitting on a tight budget. We especially loved listening to slowcore, indie rock and vocal-centric soundtracks such as “Apocalypse” by cigarettes after sex on RA15.

• Lows: - The lows on RA15 are tuned using dual magnetic circuit systems which end up providing more than 1 Tesla of magnetic flux. When we started listening to music on RA15 right out of the box we felt that the lows on RA15 were just average at best but after the burning period, the lows surprisingly improved for the good. There is a negligible effect of sound tubes on the bass, but the brass sound tubes do add a bit more warmth to the overall lows. The midbass in terms of quantity and quality just hits the nail on the head. The dual magnetic circuit adds superb speed to the tight midbass which makes the whole listening experience quite fun and foot-tapping. The overall dynamics and transient response are surprisingly good on RA15 considering the price. We loved listening to ‘Bad Guy’ by Billie Eilish and ‘Vadiya’ by Amit Trivedi on RA15. Now coming on to Sub bass, the Sub bass on RA15 is just average at best. The Subbass lacks both in terms of quantity and quality. We definitely missed the rumble and sub-bass layering and decay while listening to different soundtracks. We would also like to add here that the bass is tuned quite precisely without adding any muddiness to the mid-frequency.

• Mids: - We at Aural Cafe feel that the NF Acoustic team have tuned the mids on RA15 very tastefully. When it comes to positioning the mids on RA15 is a tinge more forward and immerse smoothly with the lows and high frequency. When it comes to the effect of the sound tubes on mids we felt that the stainless-steel sound tube does make the upper mids a bit more exciting but it’s the brass tube that takes the lead as it adds the soul and lovely texture to the vocals in the mids along with a smoother upper mids suitable for long listening hours. The lower mids are not the best we have heard whereas the upper mids are smooth and decently open and airy with the brass tubes but become a bit shouty with stainless steel tubes. Both the Male and Female vocals are absolutely outstanding taking the price into consideration. The male and female vocals on RA15 sound authoritatively clean without compromising on texture and feel while listening to complex rock numbers. The integrated tuning PCB board also plays its role amazingly well to add soul and life to the timbre and tonality of the instruments. While the micro details retrieval capability of RA15 is above average we at Aural Cafe would love a touch better layering. Since the vocals on RA15 with brass tubes on are outstanding we at Aural Cafe loved listening to vocals-centric soundtracks such as ‘Out of Time’ by the Weekend and ‘Scar Tissue’ by Red-Hot-Chilli-Peppers.

• Highs: - The Highs on RA15 are clean, smooth and airy with brass tubes but become quite shouty with the stainless-steel tubes and thus not suitable for long listening hours. The micro details are not on the face but come in a much more organic way while listening to different genres of music. While the lower treble is smooth and clean the upper treble lacks extension. Taking the price of 89 USD into consideration we are overall satisfied with the smooth and airy treble keeping in mind the overall neutral tonality of the RA15. We at Aural Cafe would like to suggest using brass sound tubes over the stainless-steel tubes as highs are smoother and thereby suitable for longer listening hours. We loved listening to ‘Stairway to Heaven’ by Led Zeppelin, ‘Paayalliya’ composed by Amit Trivedi for the movie Dev D and sung by Shruti Pathak and enjoyed the high notes listening to ‘Ae Watan’ sung by Arijit Singh for the movie Raazi.

• Soundstage & Imaging: - The soundstage on RA15 has a beautiful immersive feeling which makes the whole listening session quite enjoyable. The soundstage width takes lead over depth which is just average at best. The separation between the instruments is above average which makes listening to “Hotel California” by the Eagles quite enjoyable. We also loved the shimmer coming out of different instruments while listening to ‘Zariya’ composed by AR Rahman for Coke Studio India. While the micro detail retrieval ability, speed and transient response are outstanding on RA15 the layering is just average at best. When it comes to imaging the imaging on RA15 is just decent but nothing exceptional to say.

• Synergy: - We here would like to state that we at Aural Cafe do believe in burn-in when it comes to DD-based IEMs and would suggest at least 20 hours of burn-in period to get the best out of RA15. When it comes to drivability, we are happy to communicate that RA15 is easy to drive but would definitely suggest using it with a hi-fi source to get the best out of RA15. Although RA15 is just an 89 USD IEM we tried it with numerous sources, cables and tips to see how it affects the sound quality for fun. We tried it with several cables from Linum, PW Audio, Rhapsodio, Modular Workshop and Linksmith cables and felt that RA15 Synergise really well with Linum SuperBax cable which adds a bit more soundstage width to the RA15. When it comes to ear tips we felt that RA15 goes decently well with the stock narrow bore ear tips but it really shines well with Divinus Velvet Silicone ear tips which adds a touch more depth and body to the lows. When it comes to sources we tested RA15 with a line of dongles such as iFi Audio GO Link, Go Bar Kensei, Aune Yuki, and Tanchjim Space and felt that RA15 sounded best with Aune Yuki and iFi Go Bar Kensei. We also tried RA15 with a number of portable daps and desktop sources from our source banks such as Astell and Kern SP1000M, Dethonray Prelude DTR1, DTR1+, DTR 1+ LE, Listening M1, SG1 Gold Bluetooth USB DAC/Amp , Aune M1p and felt that it goes really well with Dethonray SG1 Gold and Aune M1p as it adds a bit of warmth and rumbles to the lows whereas the new Dethonray Listening M1 and Dethonray Dtr1+ LE improved the layering and soundstage depth and make us feel that we are listening to more expensive IEMs. Overall we would suggest a source with a black background and neutral tonality, a high-quality SPC cable and narrow bore ear tips as it goes well with RA15.

• https://hifigo.com/products/nf-audio-ra15
• https://www.amazon.com/HiFiGo-Cloud-Diaphragm-Air-Assisted-Circulation/dp/B0D6GMFP1L?th=1

• Aune S9C
• Macbook Air M2 3.5 Out
• NF Audio RA15 with stock cable and stock eartips (Gold Nozzle)

• Bass on the RA15 is not lacking by all means, It is punchy has good quality bass with sufficient quantity, but certainly not a set where i would recommend to basshead
• It has good textures and body to it, doesn’t sound loose and thin
• Mid bass has good slam and punch to it, listening to Metallica’s Lux Aeterna is very pleasing as every hit on the drum be can felt
• Sub bass rumble is there when the track calls for it, doesn’t really extend that deep, it is evident in Hans Zimmer’s Why So Serious, slightly lacking the rumble
• The speed is also excellent on the RA15, handling complex tracks with ease without sounding muddy and bleeding into the mids

• The midrange is good with sufficient note weight, not sounding too thin and vocal positioning is not too forward nor laid back
• Female vocal has good energy to it and good texture
• Male vocal that has low baritone voice such as Zhao Peng retains the warmth and texture to it, it doesn’t sound thin at all, very pleasant experience
• The upper mids are not shouty at all and it does very well in terms of giving the female vocal a slight boost
• Slightly recessed in the mids, but not really a deal breaker

• Treble response on the RA15 is energetic but not harsh nor sibilant
• On the stock silver nozzle, the treble can be too much to handle for those who are sensitive to treble
• Good amount of air and presence and contributed to good sense of staging and imaging as well
• Detail retrieval is good and i can hear the nuances distinctively without having to try hard, an example of such track is Faye Wang’s 旋木，the finger slides from the guitar can be heard easily

• Soundstage for RA15 is good for the price, having a good sense of width, depth, a little lacking in height but very good overall. It is quite spacious sounding, listening to orchestral or live tracks is very enjoyable on the RA15
• Imaging is also a strong point for RA15 as well, instruments can be pinpointed easily even on complex tracks such as Slipknot’s People = crap!, well layered and good separation

• RA15 is not hard to drive, give it something like Apple’s Dongle is actually sufficient to get good sound and listening volume out of it
• It scale very well with source but not so much on the amplification

• From the bass response to the mids, it is more or less similar sounding to my ears
• Vocal positioning however is more forward compared to red ring nozzle
• Female vocal is even more lively compared to red ring nozzle, this is due to an early rise on the upper mids, i find the female vocal to be very enjoyable on this nozzle, but i can’t say the same for those who are sensitive with the upper mids boost, do take into consideration that your experience might vary
• Soundstage is slightly smaller on this nozzle, but imaging capability is excellent
• The treble is also being boosted to give more resolution and better perceived detail retrieval capability
• I would say this is a more of an analytical kind of tuning compared to the gold nozzle which is slightly tame on the top end with slightly thicker note weight

• The tuning of Simgot’s EA500LM is more on the harmanish side, overall note weight i would say they are more or less quite similar
• Soundstage is just slightly out of your head compared to RA15 which has a wider and bigger perception of stage, imaging is more or less similar
• Mids are forward on the EA500LM and the upper mids might be perceived as slightly offensive for those who are sensitive in this region
• Mid bass on the EA500LM is not as punchy, sub bass does have a slightly better extension compared to RA15
• Treble is slightly smoother on the EA500LM
• The EA500LM is easy to drive and scales with better source, similar to RA15, but doesn’t benefit much from amplification based on my listening impression

• IEM shells & cable
• Carry pouch
• 4 pairs of MS42 Eartips
• Tuning Nozzles

• The cable is of a pearlescent white color. It’s very thin and feels like it can easily be damaged. despite that, it’s very well behaved and easy to wind or position.
• The silver chin clutch and black splitter are both made of plastic.

Part 2: Subjective review


General Usage Impressions

• The shell is a little slippery due to the shape and material. You need to be very careful when handling these
• Despite being heavier than the Hidizs MP143 Salt at 9.4g, I didn't have trouble getting used to the weight. Maybe because the center of gravity was inside my ear instead of outside.
• The shells are small, and are able to give me a good seal. This set made me realize that my right earhole needs one size smaller eartips than my left earhole.
• You won’t have trouble with fitting the shells to the cable, there’s a jacket over the 2 pins that will only fit on the correct pair so it’s much easier to fit the two sides together!

• Gold Nozzle
  • The treble is less pronounced, so it’s just warm. I guess this nozzle is supposed to be the “balanced” one.
• Silver Nozzle
  • The treble is more pronounced, more bright. Some songs are are a bit more sibilant to me.
  • I don’t like using this as it seems exhausting to me.
• The soundstage is average at best, it’s not as wide as I hoped, but it’s good nonetheless.
• I used this set for gaming competitively (Overwatch 2) and it was able to give me good information on where certain enemies are, details were great.

Introduction​

Context​

Disclaimer​

Unaffiliate links​

Gears Used​

• ddHiFi tc44c (for Bass details)
• Fosi Audio DS1 (for Sound stage)
• LG V60 (for phone sound test)
• Xduoo XD05 Basic with N5532 op amp (overall sound

• Driver configuration: Double Cavity Dynamic Driver
• Frequency response: 10 Hz - 40000 Hz
• Impedance: 32 Ω
• Sensitivity: 108 dB/mW
• Cable: 2-pin 0.78mm 5N OFC cable.

• - Iem
• - 4 pairs of MS42 silicone tips (XS, S, M, L)
• - cable
• - carrying pouch
• - 2 pairs of tuning nozzles

Build Quality​

Design​

Fit and Comfort​

Internals/Tuning Nozzles​

Sound Impression​

Sub-Bass​

Mid-Bass​

Male Vocal​

Female Vocal​

Treble​

Instruments​

Soundstage​

Gaming Performance​

Overall Ratings​

Conclusion​

NF Audio RA15 Review!

(Video review here)
Good day! After 5 days of casual and critical listening, here’s my written review for the NF Audio RA15.The energetic pebble!​

• I don’t read FR graphs. I only use my ears, as earphones should be used.
• NF Audio sent this unit to me in an exchange for an honest, transparent review. Rest assured that this review will do its best to devoid from any bias/es as much as possible.
• The following remarks and observations shall be made and owned only by me.
• No monetary compensation is/was involved before, during, and after the period of creation of this review.
• Your mileage may (and always, will) vary.

• - Non-HiFi smartphone (Infinix Note 12 G96), PC.
• - Tanchjim Space DAC
• - Hidizs S9 Pro DAC
• - Aiwa XP-V710C CD Player (12 sec. EASS)
• - Sony Xperia X Compact
• - Local Files via Foobar, YouTube Music, Deezer, and Qobuz with UAPP.

• The NF Audio RA15, in its stock silver filter, exhibits a fairly neutral sound signature that leans to the brighter side of the spectrum. On certain setups and ears, it may sound as a mild-v-shaped, bright sounding set.

• First things first, the NF Audio will never be a basshead set and will never be the IEM for die-hard bassheads who prefer a chunky, lingering bass. The bass of the RA15 is a clean, well-controlled, firm bass, with both midbass and subbass having equal levels. This means that the RA15 also exhibits a good amount of detail and texture in this region, but does not exhibit any slouch or slow decay, which can be a necessity on some genres and tracks.

• The mids are well done on this set. It is not too forward nor recessed, and exhibits a very good amount of presence, openness, and detail. Lower mids do not sound too thin or too thick on this set as well. Male vocals, and instruments in this region are presented well. Upper mids are elevated, with a good amount of clarity, air, and sparkle. The upper mids also exhibit mild peaks but nowhere near piercing, or certain ears and tracks. This can be a deal breaker to those who have a pair of ears that are very sensitive to upper frequencies. This however is also greatly reduced when the gold nozzle is paired or used with this set.

• As for the treble, it is well extended, bright, and airy. This isn’t a surprise for those people who already auditioned NF Audio IEMs before because they tune this region well-done and favorable for those people who are accustomed to brighter signatures. This region doesn’t have the peaks that the lower mids have, as the cymbals seem to sound alright and not too much to my ears. Detail retrieval is above average most of the time as it renders microdetails excellently, if we are talking about IEMs under 100USD.

• NF Audio has always been one of the top performers in this department in their respective price points, to my book, at least, and it shows here in the RA15. The soundstage is wide and has a good amount of depth and height. Separation and layering is well rendered, clean, and does not suffer from any congestion or any abnormalities. Imaging is precise and has no problems rendering vocal and instrument positioning.

• The gold nozzle tones down the upper frequencies, turning it into a balanced sound signature. Bass exhibits a bit of additional chunk when compared to the preinstalled nozzle, which also adds a slight tinge of warmth to the lower mids. The peaks are greatly reduced and are somewhat gone to my ears. Technical performance isn’t affected that much as well.

• To keep things short and simple, the EA500 LM and the RA15 nearly share the same sound signature and quality. The EA500 exhibits a bit more bass quantity when compared to the RA15, while the RA15 is more detailed and brighter with the stock preinstalled filter applied. The mids is a bit more laid-back/relaxed on the EA500 LM when compared to the RA15. As for the technical performance, the EA500 LM is wider in soundstage when compared to the RA15. The rest is more or less the same in terms of level of quality for their respective retail price.

• These two sets are literally night and day in terms of their overall sound. The Xuan NV is thicker, warmer in sound, a bit harder to drive IEM when compared to the RA15. The RA15 leans to the brighter side of the spectrum, more resolving, and better in technicalities, while the Xuan NV has smoother, lush, sound to it.

• The Tanchjim 4U on monitoring filter is a flatter, thinner sounding set with an evident sub bass roll-off. Technical performance is better on the RA15, but the Tanchjim 4U has better transparency in mids.

• The KZ ZS12 Pro X actually shares the same sound signature when compared, as both sets can sound mild-v-shaped that leans to a brighter spectrum most of the time. However, the NF Audio RA15 has more energy to it, making the ZS12 Pro X sound a bit “reserved” when compared side by side. Surprisingly, both IEMs share the same level of technical performance given that the ZS12 Pro X sports only 1 dynamic driver per side, while the ZS12 Pro X is hybrid configured IEM.

• A well-balanced, all rounder yet technically capable IEM!
• Clean, detailed sound!
• “Relatively neutral” sound signature (on preinstalled silver filter).
• “Balanced” sound signature (on gold nozzle filter).
• Tight, speedy, controlled bass response.
• Open, detailed mids, the NF Audio way!
• Bright, airy upper frequencies!
• Excellent technical performance under 100 USD!
• Straightforward yet effective modular tuning nozzles!
• Very good fit, comfort, and isolation.
• Durable, premium build quality!
• Premium quality accessories!
• Cohesive, minimal packaging!
• Easy to drive!

• Upper frequencies can be peaky to some ears.
• QDC connectors slightly ruins the aesthetic (nitpick, subjective)
• An included hard case would’ve been nice treat (nitpick, subjective)

• Source: The NF Audio RA15 is bright sounding IEM, and it is easy to drive. Any warm-sounding USB DACs and devices will suit this well.
• Eartips: The eartips are more than enough for the most part, but it does feel a bit shallow to my big ears sometimes.You may use your preferred eartips.
• Cable: The cable in my opinion is well-done as it is not too thick, bulky, and not too thin either. You may still use your preferred cable.

https://hifigo.com/products/nf-audio-ra15

Additional Photos Here:

• Driver configuration: polymer composite diaphragm dynamic driver
• Frequency response: 10 Hz - 40000 Hz
• Impedance: 32 Ω
• Sensitivity: 108 dB/mW
• Cable: 2-pin 0.78 mm; oxygen-free copper silver-plated cable; 3.5 mm termination
• Tested at: $89 USD

NF Audio RA15​

Balance with a Twist!​

For a brand that has produced several interesting lineups since 2014, it seems this brand is relatively unheard of in Indonesia. Yet, if you look at the quality of the products and even the packaging, it’s clear that this brand is serious about its offerings. Let’s start with their entry-level IEM priced at around $89.
Here it is... NF Audio RA15

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==DISCLAIMER==​

All impressions were tested using my usual setup (list below). So, if there are differences in sound impressions, they are likely due to our subjective hearing differences, defective units, or the sources used.
All my impressions and reviews are subjective, following the belief that "I might lie about my savings, but my reviews are always honest." Agree? Good. Disagree? Fine. I review because I want to and enjoy it, not because I need to, haha.

Important!! I recommend auditioning it yourself, as my ears might need an ENT doctor, or maybe yours do (haha).

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==MY DAILY DRIVERS==​

• Symphonium Crimson
• Kinera Verdandi
• Sennheiser IE900
• Empire Ears Legend X
• Sound Rhyme SR8
• Fiio Q15
• Chord Mojo 2
• HibyDigital M300
• Hiby R4
• Ear Tips: Eletech Baroque, Spinfit W1 Premium, Azla Sedna Crystal, Penon Liquor, EPZ M100

==Unboxing==​

For the price of $89, or about 1.4 million IDR, I really enjoy the unboxing experience of this IEM due to its unique internal box design, which is reminiscent of opening a CD case. However, the accessories included in this price range are standard, which are:

• The IEM itself, with a QDC pin
• Silver-plated copper cable, 2 braided, 2-pin connector, 3.5mm jack (I dislike the material feel, it's like an aquarium hose)
• 1 Brass Nozzle (the IEM comes with a Silver Nozzle installed, so there are 2 pairs of nozzles in total)
• 4 pairs of different sized ear tips
• Pouch
• Manual

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==Fitting==​

Featuring a Single DD configuration with a small but heavy design, this IEM gives a royal impression, especially with its minimalist, glossy, dark silver design that feels even more elegant. The small body is also supported by a nozzle with standard length and diameter. For my ears, it was quite difficult to find ear tips that fit properly because my ear canals are quite large while the IEM body is small and heavy. So, if the ear tips aren't snug, the IEM tends to slip. For those who prefer larger IEMs, finding suitable ear tips is crucial.

==Sound Impression==​

Note: Base impression with Fiio Q15 + Penon Liquer Orange Ear tips

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The RA15 comes with 2 interchangeable nozzle modules, each offering distinct sound characteristics:
- Silver Nozzle: Elevates treble frequency
- Gold Nozzle: Balanced, neutral

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Bass
- Gold Nozzle: Comfortable is the best word to describe the low frequency with the Gold Nozzle. It has just the right amount of power, neither too overpowering nor too weak, making the low frequencies complement the other frequencies. The subbass impact is average and slightly shallow, but with enough rumble to be noticeable. The bass punch is adequate, not too deep, and well-controlled for both fast and slow songs. However, the bass lacks body and feels a bit weak. Overall, for its price, it’s hard to complain. The sound is neutral and dynamic, with discernible layering.
- Silver Nozzle: No difference.

Mid
- Gold Nozzle: Flat and plain, without any embellishments. The vocal sound is free from sibilance and shoutiness, whether male or female vocals in low to high tones are clearly depicted. Although the vocals are slightly recessed, the power delivered is sufficient to balance with other frequencies. The mids feel very natural without any artificial enhancement, which I like about this IEM, making the vocals feel special.
- Silver Nozzle: Similar to the Gold Nozzle, but with a slight difference in the upper mids. The upper mids sound more engaging and lively, adding more color to the music compared to the Gold Nozzle. However, both male and female vocals in high tones remain well-controlled.

Treble
- Gold Nozzle: The treble has adequate power but is not as energetic as the bass and mids. The treble and upper treble are smooth without being offensive. The extended treble is somewhat short, with micro-details that are just adequate, slightly below other IEMs. Nonetheless, the treble tuning is likely to appeal to many due to its non-offensive power and adequate micro-detail, making it comfortable for music listening.
- Silver Nozzle: This nozzle is designed for treble enthusiasts. The treble frequency feels more engaging and sparkling compared to the Gold Nozzle, making the micro-details more prominent.

Clarity:
Clear and very distinct. There is no muffled sound or distracting noise. Only the micro-details feel very standard for its price range.

Soundstage:
Average. Neither spacious nor narrow. The soundstage is adequate for all types of music, maintaining a sense of airiness.
Imaging: The 3D imaging rotation is excellent for its price range. Instrument layering is very dynamic, with good positioning. Instrument separation is clear and well-defined, allowing precise pinpointing of their locations.

==Ear Tips Selection==​

Due to the fitting issue I mentioned earlier, the number of usable ear tips is limited. I prefer using Azla Sedna Crystall or Penon Liquer Orange, which provide good sealing and snug fit, although there is still a slight gap, keeping it airy and not too tiring.

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==Source Selection==​

- Mojo 2 - Analog, a bit warm
Highly Recommended. Different from Q15, pairing with Mojo 2 makes the IEM sound thicker across all frequencies, especially the low frequencies. The bass texture feels richer and more substantial. The treble is smoother while retaining its engaging power. The vocal position feels more recessed and thicker while maintaining the IEM's airiness.

- Fiio Q15 - Ultra Gain, Neutral and detail
Highly Recommended. Pairing with Q15 makes the IEM sound more refined across all frequencies. The sound is more open without making other frequencies dry or thin. Although it’s not an IEM with the best detail, Q15 optimizes it for better enjoyment.

- Hiby R4 - High Gain, Warm and vocal
Recommended. What I like about pairing with Hiby R4 is the sweeter vocal sound. However, there is no significant improvement in the low frequencies, while the treble is made smoother.

==Conclusion==​

• The 2 modular nozzles make this IEM, which I initially thought was just balanced, provide a very different feel with each nozzle.
• Its "safe" tonal quality with engaging power across all frequencies makes this IEM not only easy to like but also comfortable for long-term use.
• The minimally colored vocal sound is a unique attraction.
• Although the imaging is very good, micro-detail and soundstage are not the primary focus.
• Is this IEM worth buying? For those looking for a balanced and neutral sound without pursuing extensive micro-detail and wide soundstage, this IEM is worth considering.

Initially, I was quite interested in NF Audio, but after trying the RA15, I’m even more interested in trying all their IEMs. Hopefully, someone brings them into Indonesia.

That’s all.
Trust your own ears.
Bye.