Full Specifications and Features
Size & Weight
- Approx. 11 g (0.39 oz)
- Headphone Type
- Closed, Penta Balanced Armature
- Driver Unit
- Penta Balanced Armature
- Impedance (Ohm)
- 20 ohms (at 1 kHz)
- Frequency Response
- 5 Hz–40,000 Hz
- Sensitivities (dB/mW)
- 103 dB / mW
- Cord Type
- Cord Length
- Approx. 1.2 m (3.94 ft), silver-coated OFC strands, ear hanger, L-shaped non-magnetic gold-plated stereo mini plug, approx. 1.2 m (3.94 ft), silver-coated OFC strands, ear hanger, L-shaped non-magnetic gold-plated balanced standard plug
- L-shaped non-magnetic gold-plated stereo mini plug, L-shaped non-magnetic gold-plated balanced standard plug
What's In The Box
- Triple Comfort ear buds: SS, S, MS, M, ML, L
- Hybrid Silicone ear buds: SS, S, MS, M, ML, L, LL
- Carrying case
- Cable holder
- Cleaning cloth
Discover a new realm of musical expression
On stage, the IER-M9 In-ear monitor headphones authentically reproduce raw emotion and musical nuances.
Faithfully reproduce every performance
With a Penta Balanced Armature system including a magnesium diaphragm super tweeter, integrated magnesium inner housing, and an optimized sound path, these stage monitor headphones faithfully reproduce even the most subtle sounds and emotions.
Penta Balanced Armature system for optimal stage sound
For clean high notes, natural tones, and the pure emotion behind every performance, the IER-M9 has a Penta BA system including a magnesium diaphragm super tweeter. Sony's original T-shaped Balanced Armature directly drives the diaphragm for a more linear motion and clean, faithful high notes.
Sony's original design Balanced Armature (BA) Driver Units
The unique T-shaped Balanced Armature directly drives the diaphragm for a more linear motion and clean, faithful high notes.
Magnesium diaphragm super tweeter
The IER-M9 super tweeter diaphragm is made of lightweight and rigid magnesium alloy to deliver the fast, dynamic transience of performance. The unique BA unit design also benefits from extremely low resonance thanks to a high internal loss. The internal wiring has been upgraded with a new silver-coated copper voice coil and gold-plated terminals, faithfully reproducing sound without sacrificing even micro signals, so pitch, harmonics, and emotion are portrayed.
Audio-grade film capacitor for less distortion
Our custom audio-grade film capacitor in the cross-over circuit delivers much lower distortion. The audio-grade capacitor of the IER-M9 delivers fine detail sound. Audio-grade solder also helps to minimize any loss in signal path.
Integrated magnesium inner housing to reduce vibration
A highly rigid housing keeps the BA units firmly in place, helping to eliminate vibration and keeping sound clear without losing even the most minute detail in your sound.
Optimized sound path
A wide and short sound path made of magnesium alloy reduces frequency peaks and dips, to give a monitor sound you can rely on for critical listening accuracy.
Balanced connection available
The IER-M9 In-ear monitors come with a 4.4-mm standard balanced connection cable which completely separates left and right sound signals, unlike conventional headphone cables where both channels share a ground wire. This minimizes cross-talk that results in sound deterioration.
Silver-coated oxygen-free copper wire minimizes resistance and signal-transmission loss. The result is less sound degradation, finer detail, and smoother treble sounds.
Silk braid and non-magnetic undercoat plug
The IER-M9 uses silk braid as a cable insulator. This fiber works as an absorber against vibration and prevents rustling or bumping noises when you touch the cord. The gold plating of the plug has a non-magnetic undercoat which transfers the signal preserving subtle nuances.
The cable is fully detachable so you can replace it if needed, or fine tune your monitor sound through a different cable.
Pre-formed ear hanger for easy positioning
The IER-M9 In-ear headphones fit firmly in your ears with the universally shaped ear hanger. With a firm fit and optimal housing shape, each earbud stays in the right position.
13 variations of earbuds
Our earbuds come in thirteen variations — six triple comfort and seven hybrid silicon. So you can find a snug fit for all kinds of ear shape. Combining hard silicone rubber and specially developed formed silicone, they perfectly match sound with stability and are comfortable to wear for long periods of time.
Light, durable magnesium outer housing
Own the stage and the moment with the light, durable magnesium outer housing of the IER-M9 In-ear headphones. Snug fit and can withstand knocks or accidents.
The IER-M9 are designed to stay firmly in place with a snug fit for all ear sizes. With a firm fit and optimal housing shape, each earbud stays in the right position, even while moving on stage.
Designed with professionals
We developed these in-ear monitor headphones in cooperation with professional musicians and live-sound engineers. Their opinions are reflected in this product.