The world of audio is as confusing as it is exciting. As most of the world has shifted to wireless headphones, many audiophiles swear by the prowess of wired headphones for high-resolution listening, including in-ear monitors (IEMs).
Besides having detachable cables, IEMs also come with different types of connector pins. This guide will review four of these IEM connectors and explain their pros and cons.
Why bother with detachable cables?
Unlike regular wired headphones, IEM headphones have plugs that allow you to attach and detach their cables. For this reason, you can customize your IEMs by plugging in third-party accessories such as Bluetooth modules or cables made of different materials, including copper, silver, or gold.
Now, there’s already a huge debate going on in the audiophile community about whether different cable materials actually affect sound quality, but that’s a whole different topic.
When it comes to EMI connectors, there is no single universal standard; brands kind of resort to doing their own thing. So if you’re considering buying replacement cables for your IEMs, make sure they’re compatible first. Here is a quick guide to help you navigate better.
1. 2-pin IEM connectors
The 2-pin connector is perhaps the most common type of IEM connector, especially among budget in-ear monitors. They are available in two sizes: 0.75 mm and 0.78 mm. They fit more securely in place because their shape limits any movement; however, they have no locking mechanism and are instead friction sealed.
Some users complain that the 2-pin connectors sometimes sweat inside the earbuds, especially if they are of poor quality. To solve this problem, some manufacturers add a plastic or resin sleeve over the pins of the cable to increase friction and create a tight seal.
For example, 2-pin QDC connectors come with a rounded sleeve that plugs into a rounded socket protruding from the earphone. Similarly, the 2-pin NX7 or TFZ connectors have a square sleeve that plugs into a square socket, much like that of the popular Blon BL03. It’s like playing shapes, really.
2. IEM MMCX connectors
Another common type of IEM connector is MMCX (Micro-Miniature Coaxial); you may have seen them on IEMs from Shure or Audio Technica. Instead of pins, these connectors have a cylindrical nozzle and come with a locking mechanism that helps snap them into the socket, producing a satisfying click sound.
However, if you keep plugging and unplugging them repeatedly, they will wear out and become less sturdy over time. The looser they become, the easier it will be to accidentally unplug the connector from the socket by pulling on the cable.
Unlike 2-pin connectors, MMCX connectors can be rotated on the plug, allowing you to wear the cable in either direction, i.e. on and around your ear or hanging down like regular wired headphones. They are more common among expensive IEMs than budget ones, yet many consider 2-pin connectors to be superior.
3. 4-pin IEM connectors
4-pin IEM connectors are less common than MMCX in that they are mostly found on IEMs from JH Audio or Astell & Kern. Chances are your favorite performer wears IEMs of this configuration on stage. To install a 4-pin connector, push the plug into the socket and screw the collar clockwise; do the reverse to remove it.
What makes these 4-pin connectors unique is that some models come with a bass attenuator panel on the cable. Using a bass adjustment tool (which looks like a screwdriver), you can manually adjust the bass level of your IEMs to your liking for each ear.
And just in case all of that wasn’t cheesy enough already, you can even get one of JH Audio’s variable bass module adapters with a built-in bass attenuator and convert your 4-pin plugs to 2-pin plugs, which facilitates customization.
4. 7 pin IEM connector
The 7-pin connector is the rarest type of IEM connector since it is only available on certain JH Audio IEMs. They are installed like 2-pin or MMCX connectors, i.e. they push the plug into the socket to secure it and pull it to detach it.
Like the 4-pin connectors, they are also equipped with a bass attenuator on some models, although they are expensive. If your IEMs have this configuration, be careful when plugging or unplugging them, because in case one of the tiny pins bends, you won’t be able to use your cable.
Does the shape of the connector really matter?
Not that much. For any pair of earphones, the sound quality is affected more by the type of driver used inside the earphone than by the material of the cable or the shape of the connector. After all, that’s what does the most work.
Note that different speaker types handle different sound frequencies better; for example, the dynamic speakers push air well inside the earpiece, making them a good option for bass-heavy music. Balanced armature speakers handle high (treble) frequencies well, so they more accurately represent female voices.
This is why some in-ear monitors come with multiple types of drivers, such as a combination of dynamic and balanced armature drivers; this is done to give you a more balanced sound signature.
Since 4-pin and 7-pin connectors are only found in expensive IEMs tuned by reputable audio engineers, this might lead you to believe that connectors play a major role in sound quality; they don’t. In reality, the driver for these IEMs is simply higher quality. Hence, the best sound quality.
If you’re considering buying a pair of IEMs, there’s no surefire way to know how good they’ll sound to you, because listening is a very personal experience. However, you can almost always find YouTube reviews on a particular pair of IEMs and sub-reddits where other audiophiles would be happy to discuss their experience with you.
The rabbit hole of in-ear monitors
In-ear monitors are a niche product line aimed at sound engineers, artists, live performers and audiophiles. If you’re new to the hobby of hi-res listening, it’s a good idea to talk to other enthusiasts and ask for recommendations on your first pair of IEMs.
If your IEMs have 2-pin connection ports, it will be easier to customize them since most third-party accessories are designed to be compatible with them. Anyway, note that the sound quality is affected more by the driver of the earphone than by the connectors or materials of the cables.
In-Ear Monitor Buying Guide: 9 Things to Check
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