Duo is 64 Audio’s latest universal in-ear monitors with dual driver hybrid design. Duo offer an open back experience with the intimacy of an in-ear monitor. Built with the complete Tia System, Apex Core, Wave Sync, and LID, Duo presents 64 Audio’s signature balanced sound in a whole new way. The simple audio design captures the listener’s auditory senses while forgetting they’re wearing IEMs in the first place.

The complex faceplate assembly not only serves an important role in protecting the shell of the IEM while allowing air to flow freely, it is also a major step in 64 Audio’s product design evolution. Duo is a timeless and elegant design reminiscent of open-back over-ear headphones.

Duo feels light, leaving your ears feeling open and relaxed even for long listening periods. You feel simultaneously connected to your physical surroundings while you’re enveloped by music. Relaxed tonality lets you put them on and get lost. It’s able to present a non-analytical top-end while retaining air and sizzle. The vast open air sensation supports an unobstructed soundstage with impactful centre imaging (unlike many other open back headphones) as well as no loss of bass. Duo effortlessly produces deep and rich low frequencies with plenty of sub bass.

Get closer to your music.

TIA System
Rather than constricting the sound of the drivers by fitting a tube onto them, Duo’s complete Tia System reduces unwanted resonance and distortion by allowing the 9mm Dynamic Driver + Tia High Driver to radiate freely into the single large Tia bore with no obstructions to the front of the drivers. 

Apex Core
Apex Core is a deeper understanding of air movement within an earphone system. Duo’s faceplate features a striking perforated grill that leaves the shell of the IEM open to the outside atmosphere for a less obstructed airflow resulting in an effortless reproduction of music and minimal physical fatigue. 

Wave Sync
Due to the high crossover point between the two drivers, Wave Sync was developed to ensure coherence; another industry first. By using a type of 'all-pass”'filter, 64 audio are able to introduce a crossover while correcting for time without having to change the physical distance between the drivers. 

Linear Impedance Design
LID Design, enables a consistent, reliable sound regardless of what source. This proprietary circuit corrects the non-linear impedances of the drivers, restoring proper interaction with the source and preserving the desired sound signature. LID ensures your IEMs are delivering the desired sound signature consistently.

64 Audio Duo - Dual Drivers Universal IEM

Write a review
| Ask a question
£1,199.00
£1,199.00
Easy Returns
Secure Checkout
Pay in 3 Interest-free payments on purchases from £30 - £2000

Duo is 64 Audio’s latest universal in-ear monitors with dual driver hybrid design. Duo offer an open back experience with the intimacy of an in-ear monitor. Built with the complete Tia System, Apex Core, Wave Sync, and LID, Duo presents 64 Audio’s signature balanced sound in a whole new way. The simple audio design captures the listener’s auditory senses while forgetting they’re wearing IEMs in the first place.

The complex faceplate assembly not only serves an important role in protecting the shell of the IEM while allowing air to flow freely, it is also a major step in 64 Audio’s product design evolution. Duo is a timeless and elegant design reminiscent of open-back over-ear headphones.

Duo feels light, leaving your ears feeling open and relaxed even for long listening periods. You feel simultaneously connected to your physical surroundings while you’re enveloped by music. Relaxed tonality lets you put them on and get lost. It’s able to present a non-analytical top-end while retaining air and sizzle. The vast open air sensation supports an unobstructed soundstage with impactful centre imaging (unlike many other open back headphones) as well as no loss of bass. Duo effortlessly produces deep and rich low frequencies with plenty of sub bass.

Get closer to your music.

TIA System
Rather than constricting the sound of the drivers by fitting a tube onto them, Duo’s complete Tia System reduces unwanted resonance and distortion by allowing the 9mm Dynamic Driver + Tia High Driver to radiate freely into the single large Tia bore with no obstructions to the front of the drivers. 

Apex Core
Apex Core is a deeper understanding of air movement within an earphone system. Duo’s faceplate features a striking perforated grill that leaves the shell of the IEM open to the outside atmosphere for a less obstructed airflow resulting in an effortless reproduction of music and minimal physical fatigue. 

Wave Sync
Due to the high crossover point between the two drivers, Wave Sync was developed to ensure coherence; another industry first. By using a type of 'all-pass”'filter, 64 audio are able to introduce a crossover while correcting for time without having to change the physical distance between the drivers. 

Linear Impedance Design
LID Design, enables a consistent, reliable sound regardless of what source. This proprietary circuit corrects the non-linear impedances of the drivers, restoring proper interaction with the source and preserving the desired sound signature. LID ensures your IEMs are delivering the desired sound signature consistently.

Specification Value
Driver Type/Count Single (1) dynamic driver, Single (1) balanced armature driver
Driver Configuration tia high, dynamic low
Frequency Response 20Hz – 20kHz
Sensitivity 98dB/mW (98dB @ 1kHz @ 1mW (95mV))
Impedance
Crossover Integrated 2-way passive crossover
Isolation -12dB internal apex technology
Cable Multi-Twist Silver Plated OCC Copper Wire (0.23 Ohms Total Impedance)
Easy Returns
Secure Checkout
Pay in 3 Interest-free payments on purchases from £30 - £2000
  • DUO Universal In-Ear Monitors
  • 64 Audio Premium Leather Case
  • TrueFidelity Foam Ear Tips (S,M,L)
  • SpinFit Silicone Ear Tips (S,M,L)
  • Silicone Ear Tips (S,M,L)
  • 3.5mm Black Premium Cable
  • Apex Modules: m20, m15, *m12, mX
  • Cable Clip
  • Cleaning Tool
  • Round Sticker
  • Dual hybrid dynamic and balanced armature drivers universal IEM earphones
  • Open back headphone experience with the intimacy of in-ear monitor design
  • Tia tubeless design reduces resonance for transparent and lifelike sound
  • Apex Core venting system with perforated grill provides less obstructed airflow
  • LID design enables consistent, reliable sound regardless of audio source
  • Wave Sync system manages crossover coherence perfectly
  • Premium detachable silver-plated multi-twist audio cable
  • Timeless and elegant faceplate design reminiscent of open-back over-ear headphones
Delivery & Returns Information

Item Ships from our UK Warehouse - Typical delivery is 3 - 5 business days for mainland UK. OTIC can be contacted for updates.

Free shipping on all baskets over £250.

We offer a refund on any unused items, subject to our returns policy.

Click here to view all delivery & returns info - including shipping, tax, and duty information for International Customers.

Products purchased from OTIC Audio are supplied with a manufacturer warranty that is specified on the product page on our website. Most products come with a 1Y manufacturer warranty (or 3 months for B-grade, open box, refurbished, ex-demo, and second-hand items).

The manufacturer's warranties are limited to physical defects in the materials, parts, and workmanship used in making the product. Abnormal conditions, deliberate abuse, and damage due to accidents, operator's error, or unauthorized service attempts are excluded from any warranty claims.

Faulty goods returned under the manufacturer's warranty are to be returned to OTIC Audio at the cost of the customer. OTIC Audio will cover the cost of shipping the repaired or replacement product back to the customer.

64 Audio Duo - Dual Drivers Universal IEM

64 Audio Duo - Dual Drivers Universal IEM

£1,199.00

64 Audio Duo - Dual Drivers Universal IEM

£1,199.00

Recently Viewed Products