IPX9 & IPX9K Ratings Explained (Resistance to High-Pressure High-Temperature Water Jets)

IPX9 and IPX9K are the highest IPX ratings in the IEC and ISO ingress protection nomenclatures. They are given to devices that can survive extremely powerful high-temperature water jets. 

While an IPX9/IPX9K are the highest IPX ratings, devices with these ratings are not considered waterproof. This term is reserved for ratings IPX7 and IPX8 because only IPX7 and IPX8 tests include submersion in water.

IPX9 and IPX9K ratings are rarely given to outdoor audio equipment. They are mostly given to specialized industrial gear, vehicle parts, and similar equipment. 

Keep reading to find out more about IPX9 and IPX9K testing conditions and learn about the only pair of IPX9K-certified swimming earbuds I was able to find.

IPX9 & IPX9K Ratings

What Is an IPX Rating?

An IPX rating is a confirmation of a device’s waterproofness. Based on the device’s IPX rating, you will know exactly what kind of contact with water a device can survive. 

Some devices can survive just a few drops of water falling at a specific angle, some can survive splashes or water jets, and some can be submerged in water (temporarily or continuously) without suffering any damage. 

How Does an IPX Rating Look?

IP in an IPX rating stands for Ingress Protection. X in IPX rating means the device was not tested for dust ingress protection. The number following the X describes the level of water ingress protection. 

IP ratings usually consist of two digits following the IP. The first one describes protection against the ingress of solids and dust. The second describes protection against the ingress of water.

If the device was not tested for dust ingress protection, the first digit will be replaced by the letter X (hence, the IPX rating). If the device was not tested for water ingress protection, the second digit will be replaced by the letter X (for example, IP5X or IP6X). 

Some devices will have another letter in their IP rating following the digits. This letter gives information about additional testing conditions (resistance to oil or other liquids, increased temperature or pressure, etc.).

IP Rating – Basic Form

IP Rating – Basic Form

How Many Different IPX Ratings Are There?

Before I answer this question, it’s important to learn who defines these levels of ingress protection and tests for each ingress protection rating. There are two international standards – the IEC 60529 and the ISO 20653

Each of these two standards has its own ingress protection scale. The scales are very similar, but there are one or two subtle differences. 

International Ingress Protection Standards

Both standards recognize 6 degrees of protection against the ingress of solids and dust – IP1X to IP6X. 

The IEC standard recognizes 9 degrees of protection against the ingress of water – IPX1 to IPX9. The scale also recognizes an IPX0 rating, which is given to devices that don’t offer any protection against the ingress of water.

The ISO standard also recognizes ratings from IPX1 to IPX8. However, it also introduces two ratings that don’t exist in the IEC standard – IPX6K and IPX9K. 

IPX6K doesn’t exist in the IEC standard in any form. This is an improved version of the IPX6 rating, where the water pressure is increased compared to the IPX6 rating. 

IPX9K rating doesn’t exist in the same form in the IEC nomenclature, but the testing conditions for the ISO’s IPX9K rating are the same as the testing conditions for the IEC’s IPX9. In other words, IPX9 and IPX9K offer the same level of protection against the ingress of water.

IPX Ratings Explained

What is IP Rating? (Ingress Protection Rating)

Below, you have a list of IP ratings, as defined by the IEC 60529 international standard.

IEC’s levels of dust and water ingress protection

IEC’s levels of dust and water ingress protection

IPX9 and IPX9K Ratings – Meaning and Testing Conditions

As explained in the introduction, IPX9 and IPX9K ratings guarantee protection against high-pressure, high-temperature water jets. The testing conditions for IPX9 and IPX9K ratings are precisely defined by the IEC and ISO.


When small devices are tested, they are put on a rotating stand inside a testing chamber. The rotation speed is 5rpm. For large devices, the IEC standard allows tests in an open space (outside the testing chamber). 

For both standards, the water temperature is set at 80°C (±5°C). The distance between the device and the spray nozzle is 100-150mm. For large enclosures, the IEC allows a distance of 175mm ±25mm.

Small devices are sprayed from 4 positions/angles (0°-30°-60°-90°), measured from the horizontal axis. Large devices are sprayed from all angles.

IPX9/IPX9K Test Illustration

IPX9/IPX9K Test Illustration

Water pressure is 8-10 MPa, and the volume is 15 l/min. 

The test duration is 30sec per position for small devices or 1min per m2 for large devices. The minimal test duration for large devices is 3 minutes.

IPX9 and IPX9K Testing Conditions

Testing ConditionsIPX9IPX9IPX9K
Small EnclosuresLarge Enclosures
Water Temperature80°C (± 5°C)80°C (± 5°C)80°C (± 5 °C)
Distance100-150mm175mm ± 25mm100-150mm
Angle0°/30°/60°/90°All directions0°/30°/60°/90°
Turntable Speed5rpm (± 1rpm)N/A5rpm (± 1rpm)
Water Pressure8-10 MPa8-10 MPa8,000-10,000 kPa
Water Flow Rate15 l/min (± 1 l/min)15 l/min (± 1 l/min)14-16 l/min
Test Duration30sec per position1 min per m2 (at least 3min)30sec per position

IPX9 and IPX9K Water Ingress Protection Test

What Products Require an IPX9 or IPX9K Rating?

Certain car and motorcycle parts, as well as industrial equipment, are tested for IPX9 and IPX9K ratings. The load these devices have to withstand is tremendous, so it’s only natural for them to be IPX9/IPX9K certified.

You will rarely see these two ratings on audio equipment and other devices we use every day. I honestly can’t imagine a scenario in which your Bluetooth speaker is sprayed by such a powerful and hot water jet. 

Are There Any IPX9/IPX9K Speakers and Earbuds?

At first, I just assumed there were no speakers or earbuds featuring an IPX9 or IPX9K rating because it seemed unnecessary. However, I found out that there is one pair of earbuds that has an IPX9K rating. The earbuds are called Soundswell

Introducing IPX9K Soundswell Earbuds

SoundSwell - The World's Most Waterproof Headphones

Soundswell buds feature quite an unusual neckband (or rather necklace) design with sealed in-line controls and a smartwatch slot in the middle. The slot is compatible with Apple and Samsung smartwatches. 

Soundswell IPX9K Swimming Earbuds

Soundswell IPX9K Swimming Earbuds

Unlike swimming earbuds I prefer using, these buds don’t have metal charging contacts. Instead, they have a USB-C charging port, located on the inline controller. Also, they use Bluetooth and don’t have built-in storage. As discussed in one of my previous articles, the in-built storage proved to be the best solution for swimming earbuds. It’s way more resistant to interference than Bluetooth, especially in water.

My biggest concern regarding these buds is their design – it simply doesn’t look comfortable enough for swimming. The whole neckband thing is too chunky. 

Soundswell IPX9K Earbuds Review

While searching for IPX9/IPX9K earbuds online, I came across one more fairly cheap model that was supposed to be IPX9-certified. At least the advertisement claimed so. It’s the PALOVUE sports earbuds. 

After investigating the earbuds and going through the specs, I discovered they don’t feature the IPX9 rating. To be honest, I have absolutely no idea what kind of rating they have.

The advertisement claims IPX9, but the product description on Amazon says IPX8, while the product description on the official website says they are sweat-proof without stating the IPX rating. I also went through the user manual and didn’t find any information about the IPX rating. 

If you are considering these buds because of their IPX rating, I would suggest avoiding them and buying swimming buds made by more reputable brands, even if their IPX rating is lower

Frequently Asked Questions

  • Question: What is the IPX9K rating?
  • Answer: IPX9K is the highest IPX rating in the ISO 20653 nomenclature. It is given to devices that can survive high-temperature, high-pressure water jets. 
  • Question: How is the IPX9K test done?
  • Answer: IPX9K test is done in a special test chamber. The device is placed on a rotating stand (5rpm rotation speed), and the IPX9K nozzles are placed around it at 4 angles – 0°, 30°, 60°, and 90°. The distance between the nozzles and the device is 100-150mm. 
  • The water temperature is 80°C, the flow rate is 14-16 l/min, and the pressure is 8-10 MPa.
  • The device is sprayed from each nozzle for 30 sec. If the device stays fully functional, it will receive an IPX9K rating.
  • Question: Is IPX9K waterproof?
  • Answer: Even though IPX9K is the highest IPX rating in the ISO nomenclature, the term waterproof is usually used to describe IPX7 and IPX8 devices. This term is used because IPX7 and IPX8 water ingress tests entail submersion in water. 
  • The IPX9 and IPX9K tests don’t include submersion in water, which doesn’t necessarily mean an IPX9K device can’t survive submersion. Still, the term waterproof is not used to describe IPX9K devices.
  • Question: What is the difference between IPX9 and IPX9K?
  • Answer: There’s practically no difference between IPX9 and IPX9K. They are two different names introduced by two different ingress protection standards for the same level of water ingress protection. 
  • Question: Can you swim with IPX9 earbuds?
  • Answer: Yes, you can. However, there’s only one pair of IPX9 swimming earbuds that I know of (Soundswell earbuds). Unfortunately, these earbuds don’t seem like the best choice for swimming. I would suggest getting some IPX8 swimming earbuds with built-in storage instead of these IPX9 earbuds.
  • Question: What is the difference between IPX7 and IPX9K?
  • Answer: Both IPX ratings are high and offer great protection against the ingress of water. However, the water ingress tests for these two IPX ratings are very different.
  • An IPX7 device can be submerged in 1m deep water for 30 minutes, and it’s usually considered waterproof. An IPX9 device can survive extremely powerful (8-10 MPa), high-temperature (80°C or 176°F) water jets for 2-3 minutes.  However, IPX9K devices are not necessarily submersible in water, which means they are not waterproof.
  • Question: How waterproof is IP69?
  • Answer: An IP69 device is fully dustproof and can also withstand extremely powerful (8-10 MPa), high-temperature (80°C or 176°F) water jets.
  • Question: What is the most waterproof IP rating?
  • Answer: If you’re looking for a device that is submersible in water, the highest waterproof rating is IPX8. If you’re looking for a device that can withstand the most powerful water jets, you should be looking for an IPX9/IPX9K device.
  • Question: Is IP69K better than IP68?
  • Answer: That’s a difficult question. I guess it all depends on what you are looking for. Both ratings offer the same dust ingress protection – they are dust-tight. 
  • When it comes to water ingress protection, an IP68 device can survive continuous submersion in water, while an IP69K device can survive extremely powerful high-temperature water jets, and is not necessarily submersible in water.


I hope this short guide helped you understand the meaning of IPX9 and IPX9K ratings, realize the difference between the two, and learn a few things about IPX9 and IPX9K devices. 

For more info about IPX ratings, check out my other posts about ingress protection.

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