Helix PR W165 – 6.5″ premium woofer
The HELIX PR W165 is a 165 mm (6.5″) woofer from the PURE R-series, the top tier of the HELIX PURE speakers aimed at demanding audiophiles. Audiotec Fischer presents it as the top woofer in the PURE lineup, delivering bass that can be felt as well as heard, together with a balanced midrange.
Its stiff mica-paper composite cone provides punchy bass, while a very powerful magnet system and a rigid, flow-optimized die-cast aluminum basket support fast and precise impulse response. Additional ventilation holes in the basket improve cooling of the voice coil and therefore power handling. Discreet HELIX grilles are included to protect the cones.
Key Features
- PURE R-series woofer: top woofer of the HELIX PURE line.
- Mica-paper composite cone: stiff cone for punchy bass and balanced mids.
- Die-cast aluminum basket: rigid, aerodynamically shaped for improved impulse response.
- Ventilated basket: extra ventilation holes for voice coil cooling and higher power handling.
- Powerful magnet system: high efficiency and linear magnetic flux.
- Grilles included: discreet HELIX grilles protect the cones.
- Power handling: 100 W RMS / 200 W max.
- Full T/S data: complete Thiele/Small parameters published for system design.
Drivers & Construction
- Cone: mica-paper composite, Sd 133 cm².
- Voice coil: 25 mm diameter, 12 mm winding height.
- Basket: die-cast aluminum with ventilation holes.
- Moving mass: Mms 17.9 g.
Acoustic Performance
- Power handling: 100 W RMS / 200 W max.
- Impedance: 4 Ω (DC resistance Re 3.1 Ω).
- Sensitivity: 91 dB @ 2.83 V / 1 m; 88 dB @ 1 W / 1 m.
- Frequency response: 40 Hz – 4,000 Hz.
- T/S parameters: Fs 57 Hz, Qms 5.35, Qes 0.63, Qts 0.57, Vas 10.8 l, Cms 440 µm/N, BL 6.1 Tm, Rms 1.19 kg/s, Xmax ±3 mm.
Installation Notes
- Dimensions: outer diameter 166 mm, installation diameter 141 mm, installation depth 66.5 mm.
- Supplied: grilles and mounting material included.
Technical Specifications
| Power handling RMS / Max. | P |
100 / 200 Watts |
| Impedance | Z | 4 Ω |
| DC resistance | Re | 3.1 Ω |
| Frequency response | 40 Hz – 4,000 Hz | |
| Resonance frequency | Fs | 57 Hz |
| Mechanical Q factor | Qms | 5.35 |
| Electrical Q factor | Qes | 0.63 |
| Total Q factor | Qts | 0.57 |
| Compliance | Cms | 440 µm/N |
| Equivalent air volume | Vas | 10.8 L |
| Force factor | B*I | 6.1 Tm |
| Sensitivity | SPL | 91 dB @ 2.83 V / 1m 88 dB @ 1W / 1m |
| Cone area | Sd | 133 cm² |
| Moving mass | Mms | 17.9 g |
| Cone material | Mica-Paper composite cone | |
| Mechanical resistance | Rms | 1.19 kg/s |
| Voice coil diameter | ø | 25 mm |
| Voice coil winding height | 12 mm | |
| Max. linear excursion | Xmax | +/- 3 mm |
| Outer diameter | ø | 166 mm / 6.54″ |
| Installation diameter | ø | 141 mm / 5.55″ |
| Installation depth | 66.5 mm / 2.62″ |
Scope of Delivery
2 x Woofer PR W165
2 x Grille
1 x Mounting material
