Reviewing the ISK HD 9999 Monitoring Headphones – Reference Quality On A Budget?



ISK HD 9999

Available Now
Type Headset (Studio Monitors)
Price $76 (Discounted price from GearBest)

I recently received a very interesting pair of fully enclosed cans from a relatively unknown manufacturer called ISK Pro Audio. The company has a manufacturing plant in China as well as Japan and have been gaining popularity in Europe as of late for their brand of budget studio equipment.

Budget is something that is usually interchangeable with low quality, but this is exactly the claim that the company wants to eradicate. This pair of fully enclosed cans will only set you back $76 and promises to give competitive studio monitoring quality without any compromises. The review sample was provided to us by e-commerce website: GearBest

My testing methodology for testing headsets is simple. Since listening is a very subjective experience and waveform analysis in an anechoic chamber isn't particularly helpful in that regard, I run the cans on a standard break-in sound file for 24 hours (I know there are various opinions on whether modern cans actually need a break in but it doesn't hurt to err on the safe side) and then put them through various subjective tests. In this case, I will be doing the standard music/gaming profiling as well as testing using amplifiers and lossless digital instruments.

The ISK HD 999 features luxurious aesthetics and a fully enclosed design.

Let's start with the basics. For those who don't know, the primary difference between a studio monitor and your average gaming headset is that the soundstage isn't modified in any way. A gaming headset or a music headset in this price range usually produce a soundstage (what you hear) that has portions of the frequency boosted or altered in some manner. The usual suspects are the bass - which results in more oomph to the sound but also produces a much muddier listening experience. Studio Monitors promise the exact opposite. The basic premise underlying a monitor is to reproduce the exact frequency that it is fed - hertz for hertz.

They are in essence, reference output devices, and are usually used in conjunction with a powerful receiver (amplifier). So what makes the ISK HD 9999 so special you ask? Well, reference headsets are usually very very expensive. Just look up the price ranges of Sennheiser's' reference lineup and you will know what I mean. Cans such as these easily go over the $250 mark without breaking a sweat.

Of course regardless of what the manufacturer claims, a $76 pair of cans is not going to be able to compete with $300+ monitors like the Sennheiser HD650, but they should be able to get close to the middle-end lineup of monitors - and this is exactly what I will be looking for today.  The specifications of the ISK HD 9999 are as follows:

  • Speaker Driver: 50mm
  • Transducer: Dynamic
  • Impedance: 32Ω
  • Sensitivity: 96dB ± 3dB
    Frequency Response: 8Hz-30kHz
  • Maximum power: 1500mW
  • Cable length: 3 metres
  • Plug Size: 3.5mm (1/8") or 6.35mm (1/4")

On paper, the cans have pretty impressive specifications. The human ear can usually distinguish sounds in the 20hz to 20khz range so these specifications appear to be fairly on point. These feature 50mm dynamic drivers in an enclosed format. This means that not only outside sound will be minimized (think of it as passive noise cancellation) but also that very little sound should leak out - making it an ideal commute partner for audiophiles.

1. Unboxing and Contents

The headset arrived in a very unassuming cardboard box and I must admit at first glance, I was a bit disappointed. The feeling only lasted for about as long as it takes to open the box, because inside the cheap looking cardboard was a full size carrying case - something that was pretty high quality. The fact that the manufactured managed to include so many things for that low a price is indeed a testament to the value of this product. Not only was everything impeccably packed, but the attention to detail given to the contents was fairly obvious.

To sum it all up, inside the box you will find:

  1. A nice carrying case for the headset and its accessories.
  2. The ISK HD 9999 headphone.
  3. A 3 meter 3.5mm audio cable.
  4. A 1.5 meter flexible, 3.55mm audio cable.
  5. A single 3.5mm to 6.35mm audio adapter.
  6. A pair of spare ear pads with a less enclosing design.
  7. A strap for the case.

All the included accessories show off the modularity of the ISK HD 9999 design. The headset retails for $99 on some American retailers, but you can grab them for $76 over at GearBest. So in that price buyers are getting quite a lot of bonus items along with their actual order. A bad wire or worn out earpads are usually the first victims of a well loved pair of cans but the inclusion of these spare parts will make sure that you will be able to breathe new life into it when the time comes. The detachable cabling system would also make replacing a bad cable a walk in the park.

2. Build Quality

The stitching and fabric quality of the default ear pads is visible in this picture.

So they haven't compromised on the included accessories. What about the build quality? The ISK HD 9999 doesn't disappoint in this case either. Build quality is pretty good. In some cases, it's downright impeccable and in some cases its fairly acceptable. You don't have the complete and utter consistency of a high-end headset, but rest assured, the build quality and design is good enough for all things that matter!

Let's start with the pads first. We have had cases in the past of low priced studio monitors that had exceptional drivers - but were an absolute disaster in terms of the comfort level. Yes, I am looking at you Superlux. The company has made exceptionally high rated budget monitors but I dare anyone to wear them for any extended period of time. I was very pleasantly surprised to see that the HD 9999 does not suffer from this flaw at all. In fact, the padding of the headset, as well as the supporting headband, make for a very very comfortable experience. The only downside is the fact that since this is a fully enclosed pair, it might get a bit hot around the ears after some time. But this is true for pretty much any enclosed pair.

The supporting head rods over the headband.

The material of the padding is high quality and fairly sturdy. As far as the structure goes, however, the build is less than stellar. It's not flimsy - not at all. But it's not as solid as some of its higher-end brethren - but hey you have to compromise somewhere right. That is not to say that these can't handle abuse - for all I know, they will fare quite well - but from what I could tell, it would be a good idea to not stress them too much on a structural level. The weak point lies where the metallic head pole connects with the ear pieces. The joint is plastic, and too much stress should, in theory, rip it right off.

3. Subjective Testing of the ISK HD 9999

For the first part of my testing. I decided against using a dedicated amplifier. I am not going to say that I did not use an amplifier because that would be an inaccurate statement to make (all electronics have an amplification circuit built in, that's how your headphones work at all!). Subjective tests are extremely hard to do since the results may vary significantly from person to person. My job is a little bit easier than normal, however, since the product I am testing is a "reference" product which basically means I just need to look for clarity and a boost free sound stage.

A lossless instrument is usually a good test for headsets claiming to be "reference".

Unlike gaming headsets, a studio monitor's soundstage is free from modification. This means that without a dedicated amplifier, a gaming headset will usually sound more pleasing to the laymen because of the boosted frequencies. I must say, however, that the ISK HD 9999 faired quite well even without an external amp. I connected it up to my laptop and smartphone and proceeded to listen to songs using everyday applications and every time I could hear more detail than my Steel Series Siberia headset was able to provide.

The bass was fairly decent as well - although not as warm as the Siberia. So in terms of music listening, the headset should prove to be a pleasing experience for both audiophiles and casuals alike. Next up was movies/gaming and in that case, the lack of a boosted soundstage was apparent. Movies and games lacked warmth and were unnaturally clear (although some might take that as a good thing). If you are listening to a monologue between the protagonist and antagonist, you do not want to hear how throaty his voice sounds. But I digress, these headsets were not made for this purpose and it shows.

Lastly, I hooked them up to my Casio Privia PX150 Digital Grand, which has a lossless sound engine and played some tunes and this time the result was stunning. The ISK HD 9999 was able to reproduce the tonal quality of the sampled voices far better than anything else (including the speakers of the piano themselves). There was a richness to the sound that was not present before that I could clearly here now. This was a textbook case of sound monitoring and the HD 9999 excelled.

The ISK HD 9999 sits snugly over the Onkyo HT-R592 receiver.

As you might have guessed, it is now time to include a high-quality amp in our setup. For the testing, I am going to be using an Onkyo HT-R592 AVR which has more than enough juice and coloring options to drive the hell out of any headset. Using the 3.5mm to 6.35mm adapter, I plugged in the headset into the receiver and set it to its default settings (without any DSP) and turned on some music. The difference between powered and un-powered performance is safe to say, was night and day. The amplifier was able to give it enough power to make the 50mm shine to their full potential making highs crystal clear and powerful clean bass at the same time. And this is without any coloring or Digital Signal Processing added to the mix.

I played some FLACs as well as gave movies and gaming another try and the results were far better this time. Of course, for those who are really worried about too clear a sound can use DSPs present in most amps to color the sound stage anyway they like - but that would be besides the point for a studio monitor. Combined with a powered source, the headset was able  to deliver a crystal clear soundstage that was pretty close to the reference one that more expensive headsets provide.

There are two use cases why you might actually be considering buying this headset: you are an audiophile on a budget (likely) or you are an actual studio on a budget (unlikely). In both cases, it's safe to say that you will be adding an external amplifier into the equation and with that, the performance level of these cans is very competitive (given the price point of the product). There were times (Read: negligable for the most part) when I could hear performance that was slightly lacking as to what you would expect from a reference can but to be fair to ISK, this is to be expected from the price point.

4. Conclusion and final thoughts

I am a self-proclaimed  audiophile and when offered to review what was apparently a cheap pair of studio monitors, I was skeptical at best. The business world is quickly moving towards a very value oriented design and multiple price points are popping up all over niche segments. If you are a studio that is on a budget cut or an audiophile who doesn't want to break the bank these cans will do the job nicely. My only real problem with these was the silly name (HD 9999) which undermines its otherwise spotless profile.

The company has managed to give buyers more than what they asked for, both in terms of the overall package and in terms of competitive performance; and for a cost of just $76 (which is about what gaming headsets go for nowadays) this is a very good deal. If I were to put these cans in terms of performance per dollar, their powered capabilities would score well upo there with all the big names. They might not be cut out for studios or professionals with thousands of dollars of budget, but for everyone else - they will more than suffice.

Here is a gallery of some more pictures if you havent had enough:


High value, monitor-quality pair of enclosed cans for audiophiles on a budget.

Design & Aesthetics8.5


  • Unaltered, reference soundstage.
  • High-quality build.
  • Detachable cables (+spare).
  • Spare ear pads.
  • Excellent value for audiophiles on a budget.


  • Needs an AVR/AMP to achieve its full potential.
Share on Reddit