What are In Ear Monitors?

What are In Ear Monitors (IEMs)?

Lets go straight to the point, what are in ear monitors (IEMs)? Audiophiles, sound people and musicians know a lot about them but not a lot of lay people do.

So if you don’t know what they are, you are in the right place. Seriously, you are. Lets get started.

What are IEMs?

What are in ear monitors (IEMs)?

An in ear monitor is specialized listening device. It offers better sound fidelity and output than regular earphones and earbuds. They can be wired or wireless (if attached to a bluetooth adapter).

A brief background to in ear monitors

In ear monitors have existed in several forms for a very long time now. They began roughly in hearing aids for older people and for those with hearing deficiencies before being modified into their current form.

What are In Ear Monitors?

The modification from hearing aids to in ear monitors arose out of a need for musicians to be able to hear what they are singing or playing on stage in concerts. Concerts are very noisy, the speakers, the raucous crowd etc. and as a result musicians who need to play off each other may become disorientated.

The loud noise too may cause damage to their ears leading to hearing loss or tinnitus much later in life. So in ear monitors were developed to help musicians listen to each other whilst on stage and also to protect their ears (sound isolation).

Since IEMs can do these very well, they have been adopted by almost every artist that performs live or in concert. It is standard practice to have one on while performing.

IEMs have transcended and crossed over from the professional space into the everyday person’s space. Whilst in ear monitors, especially the custom built ones, are expensive, there are very affordable ones around today. The Chinese companies KZ, QKZ and co are at the forefront of driving this new trend, bringing cheap and affordable IEMs to all and sundry.

What are In Ear Monitors?

Components of in ear monitors

Whilst TWS and earphone/earbud manufacturers tend to be very sketchy with the specs of their products, IEMs are a lot more transparent…

What are In Ear Monitors (IEMs)?


It doesn’t get any more transparent than this, like you can actually see what is in there…

AN IEM is made up of:

  • Drivers
  • Digital to Audio Converters (DAC reciever)
  • Sound tubes
  • Housing
  • Cables

QKZ AK6 review


An IEM is a listening device and thus we are going to judge it by its sound output. The sound output is dependent on the drivers that are present in the IEM.

Most IEMs have one or two classes of drivers:

  1. Balanced armature drivers
  2. Dynamic drivers

A driver is a small speaker unit made up of magnets, voice coils, diaphragms etc. It converts audio from electrical signals to the vibrations that we can hear. In other words, a driver is a fancy name for a speaker. It’s that easy.

Balanced armature drivers (BADs)

So a balanced armature driver is a type of speaker that that is tuned to offer a specific frequency/tone of sound. It could be high, mid or low.

When you have BADs on an IEM, each BAD has a specific tone to give out, one could as a subwoofer and give out bass while another could handle mid or high tones. This division of labour leads to a better output.

BADs offer better sound clarity and sharpness. They also provide richer and detailed sound especially when compared to Dynamic drivers and other small listening devices. BADs are also very small so a lot of them can be packed into an IEM, thereby increasing the quality of the sound output.

On the flip side, they are very expensive and can only be found on mid to high end IEMs, even from manufacturers like KZ or AKZ.

Dynamic Drivers (DDs)

A dynamic driver is a type of speaker that is tuned to cover all the sound frequencies/tones from high to low. A DD is a jack of all trades and the master of one (low tones or bass).

Since DDs can cover every tone and output heavy bass, they are used alone in low end (entry level) IEMs. However, since they have to cover every tone, the output quality of the mid and high tones will not be as good as those given by the BADs.

Dynamic drivers are quite cheap, offer a lot more bass and give out warmer sound but the sounds they give lacks clarity and detailed and they are much larger,.

What are In Ear Monitors (IEMs)?
The bigger DD is on top while the smaller BAD is just below it

So in the image above, the big round speaker is a dynamic driver while the tiny speaker is a balanced armature driver.

The BAs offer specific sounds while the DDs offer the bass. Think of the BAs like regular speakers while the DDs behave like subwoofers.

Read: KZ EDX review

How to rank IEMs

  • High end IEMs can have as many as 10 BADs and 1 (or 2) DDs is usually enough.
  • Midrange IEMs usually have 1, 2 or 3 BADs and 1 DD.
  • Entry level IEMs have only 1 DD. Some entry level IEM may have a DD with two diaphragms and these may be reported two DDs. This is false advertising.

So if you want to judge IEMs against each other. You can use the dynamic driver and balanced armature driver count as a good standard.

An IEM with 1 BAD and 1 DD will sound better than an IEM with just 1 IEM.

An IEM with 3 BAs and 1 DD is will sound better than an IEM with 1 BA and 1 DD.

DAC/driver tuning

Another thing to consider is the tuning of the DAC that converts audio from digital (wire) to vibration (sounds) in the speaker.

On both the QKZ AK6 and the KZ EDX, both IEMs are advertised as bass champions but for my money, the QKZ AK6 gives out a lot more bass whilst on the KZ EDX, the bass is also heavy but there is a slightly more balanced listening experience.

So it depends on what you want at the end of the day. My brother who loves bass will pick the QKZ AK6 over the KZ EDX while my sister prefers the balance of the EDX over the heavy bass of the AK6.

In conclusion

I want you to know this. The worst IEM is better than a lot of earphones/earbuds out there. I don’t care if it’s Oraimo, Infinix or Samsung AKG. IEMs are simply much better.

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