AAW Halcyon Electrostatic Hybrid Custom IEM

Name: Null Audio
Address: #01-03, LHK2 Building, 76 Playfair Road, Singapore, 367996, SG
Telephone: +65 8731 5476
Price range: $$

Drivers

Four Electrostats, Kept in Step

Halcyon was designed to draw everything from its quad electrostatic super tweeter, and to cure what usually follows one into a hybrid: low sensitivity, arrivals out of step, and phase conflicts between the drivers.

Two precision balanced armatures lock in the voice and the midrange; a 10 mm graphene-diaphragm woofer carries the weight of the bass. A 4-way passive and acoustic crossover divides the spectrum cleanly between them and hands each band on in phase. It moves air like a dynamic, resolves like an armature and extends like an electrostat.

BassFlow

The Bass, Set by Air

BassFlow Control regulates how much air reaches the dynamic woofer, through a tuning plate built into the body. In doing so it shapes both the amount of bass and its texture, independently of the crossover.

Halcyon has three settings, set with the BassFlow filters in the box, with up to 10 dB between them.

Design

Made Your Way

Choose the shell and faceplate colour for each side, wood, glitter, foil or Atelier faceplates or your own artwork, the nozzle tips, the AAW logo finish and engraving, and watch it come together in the configurator’s live 3D preview.

Choose a recessed or flat 2-pin socket. The photos show finishes from AAW custom IEMs.

In the box

Thera Cable Included

Halcyon Custom comes with our Thera cable in monocrystalline silver, the cable AAW pairs with Halcyon, with 2-pin connectors. Choose the player plug in the configurator: 2.5 mm or 4.4 mm balanced, or 3.5 mm single-ended.

You can also upgrade to a higher-tier Null Audio cable when you order.

Compare

Halcyon Custom vs Halcyon universal

Same seven drivers, BassFlow Control and Thera cable. The custom is made from your ear impressions, in shells you design; the universal has an aerospace-grade aluminium shell that fits with ear tips.

See Halcyon universal

Halcyon Custom vs Halcyon universal
Feature	Custom	Universal
Fit	Shells made from your ear impressions or 3D scan	Aluminium shell with silicone and foam ear tips
Look	Your choice of shells, faceplates, artwork and logo	Aerospace-grade aluminium
Drivers	4 electrostatic + 2 BA + 10 mm graphene dynamic	Same
Bass control	BassFlow Control, 3 settings	Same
Cable	Thera silver; plug chosen in the configurator	Thera silver; 2.5, 3.5 or 4.4 mm
Socket	Recessed or flat 2-pin	Recessed 0.78 mm 2-pin
Returns	No change-of-mind returns; 30-day free refit	14 days, unused

In the box

Ready to listen

AAW Halcyon Custom in-ear monitors Made from your ear impressions
Thera monocrystalline silver cable 2-pin
Player plug 2.5, 3.5 or 4.4 mm, chosen in the configurator
BassFlow Control filters For the three bass settings
Genuine leather carrying case
Cleaning tool
Owner’s Club card

Ordering and care

Process

How It Works

Configure your Halcyon Custom and place the order.
Get ear impressions: at our studio in Singapore, or post physical impressions or email a 3D scan with your order number.
AAW builds your Halcyon Custom in 6–8 weeks from the day we receive your impressions.
We ship it to you, or you collect it at our studio.

Fit

Ear Impressions

In Singapore, we take ear impressions at our studio for SGD 50, by appointment through WhatsApp +65 8731 5476 or sales@null-audio.com.

Elsewhere, post physical impressions from a local audiologist to Null Audio, #01-03, LHK2 Building, 76 Playfair Road, Singapore 367996, or email a 3D scan (STL) of your impressions or ear canals to support@null-audio.com. How to order custom IEMs explains what a good impression or scan needs.

Care

Caring for Custom IEMs

Clear the nozzles with the brush after use and wipe the shells with the dry cloth. Keep them in the case, away from heat and moisture, and avoid alcohol-based cleaners on the faceplates.

If the fit isn’t right within 30 days of delivery, we refit them for free (overseas return shipping is charged separately).

Specifications

Technical details

Monitor

Type: Custom-fit electrostatic hybrid in-ear monitor
Drivers: Four electrostatic super tweeters, two precision balanced armatures, 10 mm graphene-diaphragm dynamic woofer
Crossover: 4-way passive and acoustic
Bass control: BassFlow Control: 3 settings, up to 10 dB swing
Sound bores: Triple bore
Impedance: 24 Ω
THD: < 0.5%
Shells: Custom-fit, made from your ear impressions or 3D scan; shells, faceplates, artwork and logo of your choice
Socket: Recessed or flat 2-pin

Cable

Cable: Thera, monocrystalline silver
Player plug: 2.5 mm or 4.4 mm balanced, or 3.5 mm single-ended; chosen in the configurator

Ear impressions

In Singapore: At our studio, SGD 50, by appointment
Elsewhere: Physical impressions by post, or a 3D scan (one STL file per ear) by email

Service

Lead time: 6–8 weeks from receiving your ear impressions
Refit: Free within 30 days of delivery; overseas return shipping charged separately
Warranty: 1 year, on the monitors and the cable
Returns: Custom IEMs can’t be returned for a change of mind; defects are covered by the warranty

Very good sound. I am satisfied.

Awesome CIEMs

Fit feels great, W900 definitely is something special. Phenomenal sound!

earphonia.com - review - Extended Aural Immersion

Technically this is strong at all aspects but somehow all the musicality is still present, many other technically strong earphones seem to result in a clinical feel.
With the W900 you get a smoothness, even in all the complexity, the signature is so very well balanced across the whole spectrum.

As I’m sure you can tell I really am impressed with the W900 and it has the perfect balance between musicality and reference.

Sound stage is so very expansive and the signature coherence really gives a level of refinement, placing the W900 in amongst the top tier league of high end earphones.

Excellent hybrid reference monitor done right

The W900 a hybrid reference monitor with good layering, imaging and instrument separation. It is easy to pick up alot of details and instrument positions with this monitor.

The mids have enough body without being overly forward or aggressive, making vocals a pleasure to listen to.

The bass is another strong trait of the W900, the strong, impactful bass kicks in at the right time and moment with great control.

For years, I have been more accustomed to a warmer/fuller sound signature such as the fitears/westone monitors, but owning a W900 made me appreciate what a hybrid reference monitor can do; bringing out immense amount of details in an exciting manner.

Brilliant piece of musical masterpiece

To start off, i am not a advanced reviewer who can describe a piece of equipment in detail technical aspect. But i would like to share my experience of my W900. i was auditioning W500 back in Nov and really like the bass it was delivering. I then sent a msg to Kevin and realized that W900 will be launching and he was asking if i would like to hold on for a while. When i auditioned the W900 for the first time, i didnt find it as intriguing as W500. The bass didnt seem as impressive as the W500. In fact it sounded a little flat to my taste as i was looking for a V-shape sound signature. However, i noticed that the W900 was a very revealing piece of iem. I could suddenly hear a lot of details that i did not hear before. Essentially it was like upgrading from full HD to 4K. I therefore made the leap and ordered a pair. Now, I am getting hooked to W900 as i am rediscovering all the albums that i have with even more details that i have never heard before. As for the build, they were very well built with no bubbles or flaws. i have requested for custom artwork for my order and they look lovely when i got them. Although there was some fitting issues but it was resolved promptly and now i have perfect fit and sealage. Fantastic job to the guys at AAW.

AAW900, an elegant musical reference

I really like this iem, and I have high expectations (I own SE5 Ultimate, KSE1500, S-EM9, Prophile 8. etc.) and I was not disappointed.

It is airy and spacious, very detailed, and musical without being too colored. What is particlulary impressive, is that besides have 9BA + 1dynamic, they sound very coherent. The bass is very punchy but tight, controlled and detailed. Mids are clear and even, high are extended yet completely smooth and non peaky. Some could think the highs are not so sparkly but I like this sound, it is not fatiguing yet technical.

All in all, if you look for a great reference all rounder, you should consider these.

5 stars: 6 (100%)
4 stars: 0 (0%)
3 stars: 0 (0%)
2 stars: 0 (0%)
1 star: 0 (0%)

Very good sound. I am satisfied.

Awesome CIEMs

Fit feels great, W900 definitely is something special. Phenomenal sound!

earphonia.com - review - Extended Aural Immersion

Technically this is strong at all aspects but somehow all the musicality is still present, many other technically strong earphones seem to result in a clinical feel.
With the W900 you get a smoothness, even in all the complexity, the signature is so very well balanced across the whole spectrum.

As I’m sure you can tell I really am impressed with the W900 and it has the perfect balance between musicality and reference.

Sound stage is so very expansive and the signature coherence really gives a level of refinement, placing the W900 in amongst the top tier league of high end earphones.

Excellent hybrid reference monitor done right

The W900 a hybrid reference monitor with good layering, imaging and instrument separation. It is easy to pick up alot of details and instrument positions with this monitor.

The mids have enough body without being overly forward or aggressive, making vocals a pleasure to listen to.

The bass is another strong trait of the W900, the strong, impactful bass kicks in at the right time and moment with great control.

For years, I have been more accustomed to a warmer/fuller sound signature such as the fitears/westone monitors, but owning a W900 made me appreciate what a hybrid reference monitor can do; bringing out immense amount of details in an exciting manner.

Brilliant piece of musical masterpiece

To start off, i am not a advanced reviewer who can describe a piece of equipment in detail technical aspect. But i would like to share my experience of my W900. i was auditioning W500 back in Nov and really like the bass it was delivering. I then sent a msg to Kevin and realized that W900 will be launching and he was asking if i would like to hold on for a while. When i auditioned the W900 for the first time, i didnt find it as intriguing as W500. The bass didnt seem as impressive as the W500. In fact it sounded a little flat to my taste as i was looking for a V-shape sound signature. However, i noticed that the W900 was a very revealing piece of iem. I could suddenly hear a lot of details that i did not hear before. Essentially it was like upgrading from full HD to 4K. I therefore made the leap and ordered a pair. Now, I am getting hooked to W900 as i am rediscovering all the albums that i have with even more details that i have never heard before. As for the build, they were very well built with no bubbles or flaws. i have requested for custom artwork for my order and they look lovely when i got them. Although there was some fitting issues but it was resolved promptly and now i have perfect fit and sealage. Fantastic job to the guys at AAW.

AAW900, an elegant musical reference

I really like this iem, and I have high expectations (I own SE5 Ultimate, KSE1500, S-EM9, Prophile 8. etc.) and I was not disappointed.

It is airy and spacious, very detailed, and musical without being too colored. What is particlulary impressive, is that besides have 9BA + 1dynamic, they sound very coherent. The bass is very punchy but tight, controlled and detailed. Mids are clear and even, high are extended yet completely smooth and non peaky. Some could think the highs are not so sparkly but I like this sound, it is not fatiguing yet technical.

All in all, if you look for a great reference all rounder, you should consider these.

Questions

Good to know

How is Halcyon Custom different from Halcyon universal?

The fit and the look. The drivers, BassFlow Control and the Thera cable are the same. The custom is made from your ear impressions, so it seals deeper and isolates more, and you design its shells and faceplates. The universal has an aerospace-grade aluminium shell and fits with ear tips.

How do I order?

Choose your options in the configurator on this page, then get ear impressions made. In Singapore we take impressions at our Playfair Road studio for SGD 50, by appointment. From overseas, post physical impressions or send us 3D scans (STL files) of your ear impressions or ear canals.

How to order custom IEMs

What does BassFlow Control do?

It regulates the air that reaches the dynamic woofer, which sets both the amount and the texture of the bass. Halcyon has three settings, chosen with the BassFlow filters in the box, with up to 10 dB between them.

What is the driver configuration?

Seven drivers per side: four electrostatic super tweeters for the treble, two precision balanced armatures and a 10 mm graphene-diaphragm dynamic woofer, joined by a 4-way passive and acoustic crossover.

Which cable does it come with?

Our Thera monocrystalline silver cable, with the player plug you choose in the configurator. You can upgrade to a higher-tier Null Audio cable when you order; see the AAW cable guide.

How long does it take?

6–8 weeks from the day we receive your ear impressions or scan, plus shipping.

What if the fit isn’t right?

We refit it for free within 30 days of delivery. For overseas orders, return shipping is charged separately.

What warranty and returns apply?

One year against defects in materials and workmanship, on the monitors and the cable. Custom IEMs are made to your ears, so they can’t be returned for a change of mind; quality problems are covered by the warranty.

Read the full return policy

Next in the chain

Follow the signal further.

Routes picked for this page, all from the same bench in Singapore.

AAW Halcyon Electrostatic Hybrid Custom In-Ear Monitor

Halcyon, made for your ears.

The build behind the listen