FLC Technology FLC 8N

Tuning System.

FLC 8N has a 3 point tuning system. What that means is, you can tune 3 distinct frequency ranges of the IEM at the same time. This is achieved though swappable tuning filters. You get; 3 x Ultra Low Frequency filters (ULF), 3 x Low Frequency filters (LF) and 4 x Mid Frequency & High Frequency filters (MF & HF). The port for the ULF is located on the inner side of the IEM that faces your ear. The port for the LF filters is on the faceplate of the IEM shell. The MF & HF filters are screwed in at the nozzle of the IEM.


Ultra-Low Frequency and Low Frequency Filters (ULF & LF):

ULF – ULF filters are the ones those look like a rivet and are made of plastic. These filters primarily affect the lower bass and the sub-bass region, which are all frequencies below the 100Hz. This filter determines the sub-bass extension, power, rumble and weight of the impact. You get 3 pairs of filters: 1) Red = Most ULF, 2) Gunmetal = Med ULF and 3) White = Min ULF.

LF – LF filters are the ones made of rubber with a small flange on one end. These filters primarily affect the mid-bass, upper-bass and lower-mid regions, which are frequencies between 100Hz to 700Hz. These filters determine the warmth, weight and body of the notes in the lower mids. You get 3 LF filters, but the color codes are different. 1) Black = Most LF, 2) Grey = Med LF and 3) Transparent = Low LF.

When it comes to ULF and LF filters, these need to be analyzed in combo rather than individually. This is because they go hand in hand and the result they produce are relative to each other.

Red + Black (Most ULF + Most LF)

This is the bassiest combo and meant for bass lovers. You get great sub-bass extension, lots of sub-bass power, rumble and impact. The bass starts to bleed a little into the mids and starts to tighten the stage that the instrument separation is not the best. Bass takes a dark tone and the pace of the IEM is slowest on this combo.

Gunmetal + Black (Med ULF + Most LF)

This combo is more like a more controlled version of the above one. There is adequate sub-bass power and impact supporting the warm and thick upper-bass and lower-mids. This is not the cleanest sounding combo, but works well if you want to unleash male vocals.

Transparent + Black (Less ULF + Most LF)

This combo creates a bump in the upper-bass region and makes the IEM to sound thick and syrupy. This creates a veil over the mid-range. Not the best combo, unless an upper-bass bump is exactly what you are looking for.

Red + Grey (Most ULF + Med LF)

This combo has a slightly enhanced bass response, but with strong bass impact and power. Sub-bass kind of steals the attention with the bass impact and power. This combo actually quite nice for electronic music when paired with the Green MF&HF filter as it creates a nice U shaped sound.

Gunmetal + Grey (Med ULF + Med LF)

This is the default combo. This combo gives a slightly enhanced bass that is slightly warm and full-bodied with good sub-bass extension. Sub-bass and mid-bass don’t fight for attention and so there is a nice balance in low end of the spectrum. This is a very versatile combo that would work for all genres. It just won’t give you any extreme effect.

Transparent + Grey (Less ULF + Med ULF)

This is another good combo that works well for male vocals as it is warm and the sub-bass is rolled off and the impact and rumbles take a back seat. The notes are not too warm and thick, so you don’t have the congestion and veiling problem like the Transparent+Black combo.

Red + White (Most ULF + Less LF)

With the White LF filter, bass becomes very neutral. But with the Red filter, you still get some nice impact and sub-bass power. This is also another combo that would work well for electronic music if you prefer slightly leaner bass notes.

Gunmetal + White (Med ULF + Less LF)

This is another highly recommended combo. You get a neutral level bass with good the sub-bass extension but without strong impacts and rumble from the sub-bass. What this combo also does is, because the bass is nicely controlled, it lets the mid-range pop out a little more, so that you don’t feel it is too relaxed in the upper-mids, as you would on the Gunmetal+Grey combo. You get nice separation and an airy stage. This is not only the best combo for classical, but is also one of the versatile combos. People preferring some warmth may prefer the Gunmetal+Grey combo over this one. But if you like a neutral, ruler flat bass that goes well into the sub-bass, this is just the combo you need.

Transparent + White (Min ULF + Less ULF)

This is really a bass light combo with the mid-range in the spotlight. Bass lacks body, warmth and weight. But if you like lean bass and want to get a mid-centric signature, this might work.

Mid Frequency & High Frequency Filter:

These are the screw able metal filters. These filters affect the upper-mids, lower-treble and the center-treble, which are frequencies between 1kHz to 10kHz. These don’t have much of an impact on the upper treble, so do not expect to customize the upper-treble per your preference. As I already discussed how the Gold filter sounds in the sound impressions section, let’s see what changes are observed when going from the Gold filter to the other 3 filters. Btw Gold filter is Most MF & Less HF.

Gold to Green (Less MF & Max HF)

This relaxes the mid-range further, but brings up the treble noticeably. If you want to improve the articulation in the treble or if you are shooting for a bright and airy treble, or if you are trying to get to a U shaped sound, this is the filter you would choose.

Gold to Gunmetal (Med MF & Med HF)

Compared to the Gold filter, the Gunmetal filter relaxes the mid-range further, while keeping the treble at the same level. This creates an even more laidback sound. Can come in handy if you want a completely forgiving and a too laidback sound.

Gold to Blue (Less MF & Less HF)

Blue just shelves the mid-range and the treble down even further compared to the Gunmetal. I seriously wonder why this filter even exists. Because even the Gunmetal filter is already relaxed enough. Unless all you want to hear is bass and lower harmonics of an instrument/vocals, I can’t imagine anyone using this filter. Although one could argue it can be used to create a light sound signature when used in combination with Transparent+White filters, you could achieve that with the Gunmetal filter already.

FLC should have made this filter into a Most MF & Most HF filter, as I feel that is what is missing in FLC’s configuration.

Possible Combos for some Popular Signatures:

  • Warm and Balanced: Gunmetal + Grey + Gold
  • Neutral Balanced: Gunmetal + White + Gold, Transparent + Grey + Gold
  • Mid-Centric: Transparent + White + Gold
  • Treble-Centric: Gunmetal + White + Green, Transparent + White +Green
  • V/U shaped: Red + Grey + Green, Red + Black + Green
  • Balanced with Strong Bass: Red + Black + Gold, Red + Grey + Gold
  • Dark and Bassy: Red + Black + Gold, Red + Black + Gunmetal
  • Warm and Thick: Gunmetal + Black + Gold, Transparent + Black + Gold


Page 3: Comparison, Source pairing, and Conclusion.

3 thoughts on “FLC Technology FLC 8N

    1. Not sure about the question, bud. FLC8N gives you combination of different filters to fine tune the sound to your favorite signature, similar to 8s. It’s a refined/improved version of 8s. And in the review, there are different examples of filter combos where Vishnu pointed out various sound signatures.


    2. Hi Jam. I am the Vishnu, who wrote this review. It is possible to get a neutral-to-bright signature using the White LF and the Green MF&HF filters. However, in this combo, the mid-range might be slightly pushed back.
      That is one of the draw-backs of this IEM. It is not possible to have sufficient mids and at the same time have a bright treble.


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