Brax GRAPHIC GL3 MK2 – 80 mm High-End Midrange Speaker
The GL3 MK2 is the 3.15″ (80 mm) midrange driver of the BRAX GRAPHIC series. Combined with the GL1 MK2 tweeter and the GL6 MK2 mid-woofer it completes a three-way GRAPHIC system, and it is designed for a lively, dynamic sound over a particularly wide frequency range. Like the entire series, it is made in Germany.
The cone is a light paper cone with a modified version of the patented MicroSphere coating, in which ceramic micro hollow spheres of 75 µm diameter are embedded in a polymer layer. The MK2 update adds a new, very soft polyurethane dust cap for a more balanced upper midrange and greater tonal neutrality. The cone is driven by a linear push-pull neodymium motor in an aerodynamically shaped die-cast aluminium basket.
Key Features
- MicroSphere-coated paper cone: patented coating of 75 µm ceramic micro hollow spheres in a polymer layer, giving a very stiff yet light cone.
- New polyurethane dust cap (MK2): very soft material for a more balanced upper-midrange response and higher tonal neutrality.
- Push-pull neodymium magnet system: ultra-precisely machined and vented for high magnetic flux linearity.
- Long-stroke voice coil with ventilation: thermal stability that prevents compression effects.
- Soft, low-reflection rubber surround: smooth high-frequency roll-off and a very low resonance frequency (Fs 80 Hz).
- Low crossover possible: the low resonance allows low crossover points, particularly in fully active systems.
- Aerodynamic die-cast aluminium basket: with optimised voice coil ventilation.
- Wide bandwidth: 250–8,000 Hz frequency response.
- Optional MR3 ring: the solid stainless steel BRAX MR3 can act as mounting ring or grille support ring depending on the installation position.
- Serial-numbered pairs: recorded in a service database; supplied in an elegant wooden box.
Drivers & Construction
The GL3 MK2 uses a 25 mm (1″) voice coil with 6 mm winding height in a push-pull neodymium motor. The MicroSphere-coated paper cone has an effective area (Sd) of 35 cm² and a moving mass (Mms) of 3.4 g, with a soft rubber surround, polyurethane dust cap and aerodynamically shaped die-cast aluminium basket.
Acoustic Performance
- Power handling: 100 W RMS / 150 W max. (with high-pass above 300 Hz, 24 dB/oct.).
- Impedance: 3 Ohms (DC resistance 2.9 Ohms).
- Frequency response: 250–8,000 Hz.
- Sensitivity: 91 dB @ 2.83 V; 87 dB @ 1 W / 1 m.
- T/S parameters: Fs 80 Hz, Qms 2.90, Qes 0.29, Qts 0.26, Vas 1.95 L, Cms 1180 µm/N, BxL 4.1 Tm, Rms 0.62 kg/s.
- Max. linear excursion: ±1.5 mm.
Installation Notes
Outer diameter is 92 mm (3.6″), installation diameter 76 mm (3.0″) and installation depth 35.5 mm (1.4″). BRAX recommends a sealed enclosure of at least 250 ml net volume, always filled with suitable damping material:
- 0.4 L: system resonance 200 Hz; crossover 350 Hz, min. 12 dB/oct.
- 0.8 L: system resonance 155 Hz; crossover 300 Hz, min. 12 dB/oct.
- 1.2 L: system resonance 140 Hz; crossover 250 Hz, min. 24 dB/oct.
Technical Specifications
| Power handling RMS / max. | P | 100 / 150 Watts (highpass > 300 Hz at 24 dB/Oct.) |
| Impedance | Z | 3 Ω |
| DC resistance | Re | 2.9 Ω |
| Frequency response | 250 Hz – 8.000 Hz | |
| Resonance frequency | Fs | 80 Hz |
| Mechanical Q factor | Qms | 2.90 |
| Electrical Q factor | Qes | 0.29 |
| Total Q factor | Qts | 0.26 |
| Compliance | Cms | 1180 μm/N |
| Equivalent air volume | Vas | 1.95 L |
| Force factor | B*I | 4.1 Tm |
| Sensitivity | SPL | 91 dB @ 2.83V 87 dB @ 1W / 1m |
| Cone area | Sd | 35 cm² |
| Moving mass | Mms | 3.4 g |
| Cone material | Paper cone with “MicroSphere” coating consisting of micro ceramic hollow spheres embedded in a polymer layer | |
| Mechanical resistance | Rms | 0.62 kg/s |
| Voice coil diameter | ø | 25 mm / 1″ |
| Voice coil winding height | 6 mm / 0.2″ | |
| Max. linear excursion | Xmax | +/- 1.5 mm |
| Outer diameter | ø | 92 mm / 3.6″ |
| Installation diameter | ø | 76 mm / 3.0″ |
| Installation depth | 35.5 mm / 1.4″ | |
| Recommended enclosure volumes | ||
| Sealed box with minimum 250 ml net volume | ||
| Net volumes | Recommended DSP / amplifier settings | |
| 0.4 liter (System resonance: 200 Hz) | Crossover frequency: 350 Hz Min. filter slope: 12 dB/Oct. |
|
| 0.8 liter (System resonance: 155 Hz) | Crossover frequency: 300 Hz Min. filter slope: 12 dB/Oct. |
|
| 1.2 liter (System resonance: 140 Hz) | Crossover frequency: 250 Hz Min. filter slope: 24 dB/Oct. |
Note: The enclosure should always be filled with appropriate damping material.
Scope of Delivery
2 x High-End Cone Midrange Speaker BRAX GRAPHIC GL3 MK2
1 x Allen key
1 x Data sheet














