81FHW 81FHW
LF Woofer 8"

81FHW

Code: 81FHWX4-289

Woofer/8inch/Ferrite/Paper/100W/4ohm

Key Features

  • Good low frequency response
  • Lightweight surround, stiff paper cone
  • Affordable woofer

Quick Specs

Impedance

4 Ω

Program Power

200 W

Sensitivity

85.94 dB

Fs

39.00 Hz

Magnet

Ferrite

Voice Coil

35.6 mm

Design Notes

The 81FHW woofer was designed with smaller hi-fi subwoofers in mind. The woofer works well in vented enclosures or combined with a passive radiator. Optimized magnetic structure delivers good level of performance and balancing well performance vs cost.
We have chosen lightweight foam surround in this design. Our extensive development and testing of this material yielded in custom formulation of the raw material we use for the surround and guaranties its long lasting performance.

Specifications

General Specs

Nominal Diameter 8"
Rated Impedance 4 Ohm
Magnet Ferrite
Basket Material Steel

Power Handling

AES Power 100 W
Continuous Power 200 W
Peak Power 400 W

Voice Coil

Diameter 35.6 mm
Winding Wire Copper
Former Aluminum
Winding Height 18.2 mm

T/S Parameters

Resonant Frequency (Fs) 39.00 Hz
Re 3.60 \u2126
Qes 0.580
Qms 5.40
Qts 0.520
Vas 21.50 liters
Sd 201.10 cm\u00B2
Mms 44.00 grams
Rms 2.00
Cms 0.3800
Bl 8.25 T\u00B7m
Le 1.120 mH
Sensitivity 85.94 dB

Design Details

Surround Material Foam
Cone/Dome Material Paper GF
Spider Nomex
T-Plate 6 mm
Xmax (peak) 6.1 mm
Xmech 12.1 mm
Overall Diameter 209.00 mm
Bolt Circle Diameter 197.00 mm
Baffle Cutout Dia. 180.00 mm
Mounting Holes 8
Depth (flange to rear) 95.00 mm
Net Weight 1.70 kg

Ordering Codes

Product Code 81FHWX4-289

Frequency Response & Impedance

Frequency response of 81FHW

2D Drawing

2D drawing of 81FHW

Enclosure Recommendations

Recommended enclosure alignments (bass reflex):
- 10 liters tuned to 45 Hz: high output, strong mid-bass, reduced excursion; -3 dB approx. 41 Hz, HP filter 37 Hz
- 12 liters tuned to 41 Hz: balanced response, general-purpose (recommended); -3 dB approx. 38 Hz, HP filter 31 Hz
- 16 liters tuned to 37 Hz: extended low-frequency, requires HP filter protection; -3 dB approx. 31 Hz, HP filter 25 Hz

Frequently Asked Questions

  • - Good low frequency response
  • - Lightweight surround, stiff paper cone
  • - Affordable woofer
Recommended enclosure alignments (bass reflex):
- 10 liters tuned to 45 Hz: high output, strong mid-bass, reduced excursion; -3 dB approx. 41 Hz, HP filter 37 Hz
- 12 liters tuned to 41 Hz: balanced response, general-purpose (recommended); -3 dB approx. 38 Hz, HP filter 31 Hz
- 16 liters tuned to 37 Hz: extended low-frequency, requires HP filter protection; -3 dB approx. 31 Hz, HP filter 25 Hz
Sealed or vented pa mid-woofer, 2-way compact top
AES Power: 100 W, Continuous: 200 W, Peak: 400 W. Sensitivity: 85.94 dB (1W/1m).

Related Products