ISN Audio D02 Review

ISN Audio’s journey from an affordable cable manufacturer to an Earbud manufacturer happened gradually. Luckily, I was using both of ISN Audio’s cables and Earbuds from the very first day when ISN Audio was not even so popular. If you ever have used any of their cables or Earbuds, you may know how good their products are for their price. When I first saw that ISN audio also entering the field of IEM, I thought well; now we will get some great IEMs that may sound good without breaking out the wallet. Now ISN Audio has three IEMs in three price segments, under 100$, 150$ and 200$. On paper, these IEMs are looking nice so I was very much excited to try these and ordered ISN Audio D02 to see its sound.

ISN Audio D02

Please note that the unit has been purchased by me from Penon Audio and haven’t received any discount or any compensation from the brand in exchange for this review. So let’s start.

Specifications of ISN Audio D02

  • Model – D02,
  • Type – In-Ear,
  • Color – Blue,
  • Material – Medical grade resin 3D Printed,
  • Driver – 10mm carbon crystal diaphragm dynamic driver,
  • Sensitivity – 108 ± 3dB @1khz,
  • Frequency Response – 20-20kHz,
  • Impedance – 32 Ω @1khz,
  • Cable Type – 4 strands of silver-plated MMCX cable,
  • Cable Length – 120cm,
  • Mic – No,
  • Plug – 3.5mm Gold plated L,
  • Dip Switch – Single,
  • Weight – 15g approx. (Without Cable).

Product Link – Here.

What’s inside the Box?

  • ISN Audio D02 IEM,
  • 4 strands SPC cable,
  • Blue medium bore silicone ear tips (S/M/L) 3 pairs,
  • Green medium bore silicone ear tips (S/M/L) 3 pairs,
  • Red narrow bore silicone ear tips (S/M/L) 3 pairs,
  • 3 pairs of Blue Foam ear tips (S/M/L)
  • Hard Carry Case,
  • Carabiner,
  • Dip switch slider tool.


ISN Audio product’s presentation has not changed that much till now. I have seen some new packaging in their other high-end products but in D02 it’s still the same. D02 comes in the same blue hard paper box which was common in their cables and Earbuds.

Inside the box, the hard carry case has been packed with the IEM, Cable, and all the accessories. Now there are so many items in the case that it feels like they could have used a bigger carry case or a better presentation. The good thing is every item has been separated and packed inside separate plastic pouches. So overall presentation is ok for ISN Audio D02 but the scope for improvement is there.

ISN Audio D02


The design of ISN Audio D02 is very nice. Even at first look, it is hard to believe that D02 is a sub 100$ IEM. Due to its 3D printed resin glossy finish and attractive blue color, D02 looks more expensive than its price.

ISN Audio D02

The body is semi-transparent and you can still see the internals from outside. The design of the shell is almost like a custom in-ear monitor and fits perfectly in-ear. The design is not only ergonomic but also for its smooth finish very comfortable to wear. The size of the shell is neither too big nor too small, so it fits most of the ears perfectly. There is also a big dust grill covered air vent present on the shell near the MMCX connectors, to decrease air pressure while using the IEM.

ISN Audio D02

ISN Audio D02 could be the least expensive IEM, where you can find the sound tuning dip switch. D02 has a single sound tuning dip switch on its body and it alters the sound when being turned on or off. Now the dip switch is very tiny and hard to notice from a distance. The ISN logo is present on the faceplate of the IEM and there is no other banding on the out shell. The metal nozzle is also covered with a fixed dust grill in ISN Audio D02. Overall the design is good and beautiful.

ISN Audio D02


The build quality of ISN Audio D02 is good. Where in this price point most of the IEMs are made out of plastic, D02 has been made out of 3D printed resin. After close inspection, I can confirm that there are no bubbles or imperfections on the resin shell which proves the quality of the resin and manufacturing process. I have some 3D resin printed IEMs which a bit heavy but ISN Audio D02 is lighter than them.

The quality of the SPC cable is also good. I think it is the same cable which Penon Audio sells for 15$, so yes no cheap stock cable. The cable has been hand-braided, soft, and well builds too. MMCX connectors on both the IEM and cable are good, and easily removable on applying only a little force.

ISN Audio D02

Dynamic Driver

ISN Audio D02 comes with a single 10mm carbon crystal diaphragm dynamic driver in each IEM. Nowadays buyers are highly motivated by the material of the diaphragm of the dynamic drivers and act like a fool if they don’t have the IEM with a precious metal coating on the diaphragm of the driver. I would like to advise at least my readers that please focus on the sound of the IEM, not its diaphragm coating. There is no guarantee, that your next IEM with a precious metal coating on the diaphragm would sound better.

ISN Audio D02

So I am also not concerned about what coating or from which the dynamic driver of the ISN Audio D02 is made out of. Inside the D02 a tube guided design has been applied. The opening of the dynamic driver and the nozzle of the IEM has been connected using a sound tube.


When comes to accessories, ISN Audio has supplied a lot of them. Total 12 pairs of tips including foam, now the quality of the tips is good especially the red ones. All the tips are soft and comfortable to wear. A Carabiner and Dip switch slider tool is also in the box. So no complaint on accessories too.


D02 is very easy to drive IEM, as its Impedance is only 32Ω. It can be driven to its full potential from any source available like Smartphones, affordable music players, etc. In this review, I have used my phone, Hiby R2, and Lotoo Paw S1 to D02.


Before describing the sound part, please note that I have been using ISN Audio D02 for at least 2 months now so it should have completed the 50hours burn-in process. Another thing is that D02 does have driver flex and only can be heard while inserting into the ear. The driver flex doesn’t have any negative impact on the sound and performance of the dynamic drivers in the long term.

So now from the below frequency graph measurements, you can see D02 is close to ‘V’ sounding IEM. The channel balance is very good and the impact of the dip switch also can be seen below. When the switch is on the ‘ON’ area the impact is only visible on the higher frequency part. Now good to see it doesn’t have created any roll-off, instead a -2dB to -3dB drop from the 5 kHz to 16 kHz can be seen.

ISN Audio D02
ISN Audio D02 Left Channel and Right Channel
ISN Audio D02 ( Dip Switch On vs. Off)


Dynamic drivers usually never feel shy when comes to bass. D02 has only one dynamic driver so all my hopes were from it. Fit is something that needs to be taken care of seriously before judging the capability of ISN Audio D02’s bass section otherwise you may have going to miss it completely. D02’s lower frequency part hasn’t been too much boosted but the main focus on the mid-bass rather than the sub-bass. Still, the rumble and punch are there; and with bass-heavy tracks, most of the listeners may not going to miss anything. Speed is medium and decay is ok. The quantity of bass is there but the quality is here needs appreciation. The entire album ‘Thriller’ by Michael Jackson sounding very much energetic. The song ‘Family Man (Extended Vocal Remix)’ by Fleetwood Mac with ISN Audio D02 also sounding outstanding.

ISN Audio D02


The midrange is slightly recessed but not like other typical ‘V’ shaped sounding IEMs. Instead, a clean and detailed Mids can be heard from ISN Audio’s D02. Though there is a dip in the 500 Hz area but the peak before 2 kHz giving instruments clarity and definition too. Another small peak at around 5 kHz is present and as a result, the upper midrange sounding sharp and crisp. Male vocals may sound a bit relaxed but I have enjoyed the texture present in songs like ‘Just Strong Enough’ by Michael McDonald. Female vocals are not too shouty yet you can tame it down using the adjustable dip switch. For sensitive ears, the ‘ON’ position of the switch is much advisable.


The higher frequency part has been extended nicely without any harsh spikes. Out of the box, D02’s higher frequency area has been packed with air and sparkle. Lots of energy and details present too. Now if you don’t like so many details in that region, you can simply use the dip switch to lower the forwardness. I have enjoyed both settings. For the vast majority of people, I think the lowered treble setting would be appropriate. For example, the song ‘Victim of Love ‘by Eagles sounding airy and sparkling in the forwarded treble setting but sometimes the cymbals sound a bit harsh so after lowering the dip switch the harshness is not present anymore. So ISN Audio’s D02 is going to please both the treble lovers and haters which is a very clever move from ISN Audio.

Soundstage & Imaging

Another good thing in D02 is its capability of producing excellent soundstage. With well-mastered tracks paired with moderately good sources, you can enjoy an airy and spacious soundstage. Depth is less but both width and height are there. Imaging is also fine; you can identify the placement of instruments and artists easily. D02 is also handling busy tracks nicely.

Noise Isolation & Tip Selection

In terms of noise isolation, D02’s shell with supplied tips is doing well. You can wear them for hours without any pain or discomfort and noise isolation is also very good. The bore size of the tips didn’t change the sound that much, which you can see below from the frequency graph comparison.

Tips Comparison (Switch Off)
Tips Comparison (Switch Off)


ISN Audio D02 vs. iBasso IT00

I had iBasso IT00 but sold it to my friend a few days ago, so this comparison is only based on my memory. Other than IT00 I don’t have any other IEM in this price range to compare with D02.

From the point of view of build and finish, D02 is going to win easily anytime. Where IT00 is made out of plastic, D02 has been made of 3D resin. Looks-wise D02 is also more appealing. D02 also comes with a better set of accessories and a good SPC cable. The biggest benefit ISN Audio D02 has is the sound changing dip switch which IT00 doesn’t have.

Sound-wise, D02 can output better bass than IT00. The speed of bass is better in iBasso IT00 but the quantity-wise D02 is superior. Mids almost the same in both the IEMs but the male vocals in D02 sounding fuller and resolving. In the treble region D02 also have more sparkle and air than IT00. Soundstage where ISN Audio D02 is also a clear winner. Imaging is though similar. So overall I can say, ISN Audio D02 is an upgrade over IT00.


Under 100$ price point, now there are plenty of IEMs from different brands but none of them are perfect. Some of them have poor build quality or limited accessories, others just not properly tuned. ISN Audio in the IEM field may be new but like their other products; ISN Audio D02 IEM is an extreme value for money from every aspect. Attractive design, good build quality, loaded with accessories, and overall very good sound.

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