FOSTEX FW31DV
¥ 18,500 (1 unit, sold in April 1994)
Commentary
A 30 cm cone type woofer that uses a double voice coil system.
It has a double-voice structure with two independent 8 Ω voice coils, so that one of the two voice coils can be used as a normal 8 Ω woofer, two in parallel can be used as an efficient 4 Ω woofer, and two in series can be used as a 16 Ω woofer.
In addition, if two voice coils are connected to Lch and Rch respectively, it can be used efficiently as a 3D woofer.
You can also use one voice coil as a pickup coil for motional feedback.
Large ferrite ferrite magnet is used for the magnetic circuit.
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Model Rating
| Method | Cone type woofer unit |
| Aperture | 30cm |
| Impedance | 8 Ω + 8 Ω |
| fo | 20Hz |
| Playback frequency band | Fo ~ 3.5 kHz |
| Output sound pressure level | 92dB/W/1m (8 Ω) |
| Input | 120W(Mus.) |
| Mo | 66.3g |
| Qo | 0.38 |
| Effective vibration radius (a) | 12.95cm |
| Recommended crossover frequency | 2.5 kHz or less |
| Magnet weight | 1,090g |
| Gross weight | 4.43kg |
| Standard enclosure method | Bass reflex type |
| Standard enclosure volume | 70L |
| Input terminal | 4 Terminal |