Alpha & Delta KS3 Earphones Review

Alpha & Delta KS3 featured
Tested at $99

Hi, there fam. Today, we review the Alpha & Delta KS3, a 3D printed IEM with a 6mm dynamic micro-driver. The KS3 is currently available through their Indiegogo crowdfunding campaign where you can pick up some great discounts and bonuses. Once the campaign has ended the KS3 will also be available from the Alpha & Delta online store and the Singapore-based Lend Me Ur Ears retail store.

Alpha & Delta has been in the portable audio industry for over 8 years. In 2015, they opened their first retail store in Singapore and in the same year launched the Alpha & Delta in-house brand.

Launch campaign on Indiegogo.

Official online store:

This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

Alpha & Delta KS3 Review

  • Lightweight and comfortable 3D printed shells
  • Cohesive, inviting sound
  • Solid accessory bundle
  • Detachable SPC cable

  • Modest detail retrieval

This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

Package and Accessories

One of the things that Alpha & Delta has been very consistent with is providing outstanding accessory bundles with their earphones and the KS3 is no different. Let’s take a look at the package first though.

The KS3 comes in a black box with gold print on the front plus a little transparent window that gives you a view of the earpieces inside. Inside, the earpieces are held in a foam insert and there is also a nice hard carry case in which all the accessories are stored. Here’s a list of everything in the box.

  • Alpha & Delta KS3 earphones
  • Hard carrying case
  • Detachable SPC cable
  • 4 pairs of foam eartips
  • 3 pairs of wide-bore silicone eartips
  • 3 pairs of narrow-bore silicone eartips

The carry case is a nice addition. It has foam padding on the interior to protect the IEMs and is water resistant. The quality of the cable is good but I’ll talk more about that later on. I’m quite pleased with the quality and variety of included eartips as well. The largest of the foam tips are almost big enough for my ears but ultimately I had to dig into my personal stash for some tips to get a proper seal.

KS3 accessories

Build Quality and Design

The KS3 utilizes a 3D printed resin body that is similar in shape to a custom in-ear monitor. They’re smaller than they look in photos are actually close to the size of the diminutive CTZ-6 (review here). There are currently 2 colours available, one is dark blue and the other is gold nugget.

On the faceplates is an A&D logo but apart from that the rest of the housings are unmarked. A single, small vent is located on the top of the housing, just in front of the 2-pin socket.

The nozzles are metal and have a nice ridge at the top to securely hold on your eartips. There’s also the obligatory mesh covering the nozzle to prevent ear wax from entering the shells.

Comfort and Noise Isolation

I find the KS3 to be a very comfortable IEM. Its small size and smooth curvaceous body fit naturally in my ears and I can easily wear them for hours nonstop without any discomfort. Noise isolation is moderate making the earphones suitable for most everyday environments. With minimal noise leak, it’s unlikely others will hear what you’re listening too.

KS3 nozzles and 2-pin connectors

The 8 core braided Silver-Plated-Copper (SPC) cable is the same as the one found on the Alpha & Delta D6 and it is also sold separately. The fact that the cable itself is priced at around $60 gives you an idea of how good the value of the KS3 is, but I digress.

KS3 cable

At the top end are metal, colour-coded aluminium 0.78 mm 2-pin connectors. Neither memory wire nor pre-formed ear guides are present which is great because it means that the cable can be worn either over-ear or cable down.

A sturdy, cylindrical, metal Y-split sits further down and has Alpha & Delta printed on one side. The Y-split also has some really solid strain relief on each end. There is no cable cinch present and although I personally don’t really use them I would like to see one added.

The cable terminates in a 3.5 mm right-angled, rubberized metal plug with a steel spring strain relief (other terminations are available during the crowdfunding campaign). This is a high-quality cable for an entry-level IEM; it drapes well and has minimal microphonics.

KS3 cable terminations


Gear used for testing includes the Shanling M5s and iBasso DX120 as my portable sources. For desktop listening, I used my PC and MusicBee to feed the FiiO K3.

The KS3 likes a bit of extra juice which is quite surprising when you look at the specs. A phone or regular DAP should be fine to drive these earphones but you’ll need to bump up the volume a bit more. It has a mild V-shaped signature with an emphasis on the upper midrange.

Earthy, cohesive and natural are a few words I would use to describe the sound. It’s not the most detailed, or technically nimble but it’s very musical and easygoing.

KS3 frequency response

The KS3’s bass is moderate in quantity and fairly evenly spread from the mid-bass to sub-bass. It has a fairly speedy response but also plenty of punch.

Sub-bass notes have a surprising amount of rumble and I love it when an IEM can do this without making the bass extra loud. It gives you that powerful impact without drowning out the rest of the spectrum.

Mid-bass has a slower attack speed and moderately quick decay. This gives it sufficient weight while maintaining good control. I’ve been going through a Devin The Dude revival phase lately and the KS3 is fantastic for this type of bass-driven music. In “Go Somewhere” (Explicit) the rolling bassline sounds effortless, big and bold but all the while tight and controlled.


In the midrange, the KS3 is smooth and emotive. Male vocals sit a little further back but there’s still sufficient body and good articulation. Female vocals and the upper midrange, in general, get a bit of a boost, making the sound vibrant and increasing presence.

Clarity is moderate and mids are neither revealing nor muddied but very organic and laid back. The underlying warmth of the bass carries over giving notes some roundness and solidity.


The treble is fairly relaxed and avoids any sibilance or harshness. A significant dip from 7-10kHz reduces definition a bit but it maintains the smooth approach that the KS3 is aiming for. The upper treble extends well which adds ambience and a hint of air.

Overall the treble has good density with more prominence in the presence region and provides a non-fatiguing but light top end.


Moderate in size, the KS3 has more depth than width and creates a space like a large room. Layering is average but the instrument separation is fairly good which helps to prevent congestion. Imaging and placement is consistent with other IEMs in this price category and feels natural.


Alpha & Delta D6

KS3 vs D6

Bringing out the D6 (review here) for this comparison reminded me just how good it is. Looking at the measurements you might think it would sound anaemic or excessively bright but it neither. Somehow its meek amount of bass still works its way out of the sound as a whole. Bass notes are thinner but more defined on the D6 but they don’t carry the impact of the KS3.

Sub-bass is more subdued on the D6 and doesn’t rumble quite like the KS3 can. It’s the midrange where the D6 really shines, being very linear from the lower mids right through to the lower mids. Male and female vocals get equal attention. Mids are more forward but they do sit behind treble and this is reversed on the KS3.

The D6’s treble is very pronounced and forward in the mix although surprisingly it’s not harsh. It’s more like the Tin Audio T3’s treble while the KS3 is more laid back albeit less detailed. Soundstage on the D6 is larger and has superior layering but it does demand more of your attention than the KS3 which is more relaxing. Depending on the music the D6 can be fatiguing after a time but the KS3 is perfect for long and casual listening.

SImgot EN700

KS3 vs EN700

The EN700 has a little more bass, most notably sub-bass and its lower end is punchier in general. The KS3 has better bass definition and a little extra texture plus it is a little faster. The EN700’s lower mids are more forward making the sound thicker and warmer.

There’s more crunch in the EN700’s upper midrange making percussion snappier and working to balance the extra thickness in the lower mids. Male vocals are more neutral on the KS3 while the EN700 has more body but less articulation.

Treble on both IEMs is reasonably close but the EN700 has a hint more sparkle. While the EN700 has a bit more treble presence, its enhanced bass and lower midrange counterbalance it so it ends up sounding similar in quantity to the KS3. Soundstage area on both IEMs is close to the same but the Simgot sounds slightly wider.

TFZ Series 4

KS3 vs Series 4

The Series 4 (review here) has a similar amount of bass but its sub-bass digs deeper and feels very powerful. There is more texture in the Series 4’s bass and it is punchier. Throughout the midrange, the two IEMs share many similarities, especially the neutral lower mids and enhanced upper midrange.

The Series 4’s boost in the 3-4kHz region makes things like snare drums sound snappier and vocals pop. The KS3 sounds thinner and more diffuse here, losing some solidness. In the upper treble, the Series 4 adds more clarity and brightness, while the KS3’s dip after 7kHz darkens the tonality.

Treble extension on the KS3 is greater and has more air up top while the Series 4 is denser. The soundstage on both IEMs is comparable in size but the TFZ has more width where the KS3’s stage has more depth.

2-pin connector


The Alpha & Delta KS3 is a welcome addition to the company’s product lineup. It falls somewhere between the warm and bassy D3 and the bright and detailed D6 finding a more balanced approach. With its 3D printed shells, I find the KS3 more comfortable than the previous offerings as well.

I’m a big fan of the cohesive sound that single dynamic drivers produce and that’s what you get with this earphone. It’s lively, engaging and non-fatiguing. With the addition of the excellent detachable SPC cable, this becomes a really compelling package.

  • Driver: 6mm Micro Dynamic
  • Impedance: 16Ω
  • Sensitivity: 105 +/- dB/mw
  • Frequency Response: 10Hz – 40kHz

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