Navigate
Wavecor-logo
WF120BD05/06     4 die cast, paper/glass fiber mid/woofers, 4/8 ohm

 

 

 

 

Balanced-Drive-120pix

The 4” transducers WF120BD05 (4 ohm) and WF120BD06 (8 ohm) were designed as high performance bass and midrange units for very compact monitors and high-end hi-fi speakers.

Frequency resp.
Specifications
Dimensions
Ordering info

FEATURES

WF120BD05_06_photo
  • Balanced Drive motor structure for optimal drive force symmetry resulting in largely reduced even order harmonic distortion
  • Copper cap on center pole to reduce voice coil inductance and to minimize variations in voice coil inductance as a function of voice coil position
  • Cone made of a new paper/glass fiber mix with improved consistency and stability
  • Rigid die cast alu chassis with extensive venting for lower air flow speed reducing audible distortion
  • Vented voice coil former for reduced distortion and compression
  • Vented center pole with dual flares for reduced noise level at large cone excursions
  • Heavy-duty black fiber glass voice coil former to reduce mechanical losses resulting in better dynamic performance and low-level details
  • Large motor with 1” voice coil diameter for better control and power handling
  • Built-in alu field-stabilizing ring for reduced distortion at high levels
  • Low-loss suspension (high Qm) for better reproduction of details and dynamics
  • Black motor parts for better heat transfer to the surrounding air
  • Conex spider for better durability under extreme conditions
  • Gold plated terminals to ensure long-term trouble free connection

FREQUENCY RESPONSE

WF120BD05-SPL-&-IMP-response

Measuring conditions, SPL
Driver mounting: Flush in infinite
     baffle, back side open  (no cabinet)
Microphone distance: 1.0 m
Input signal: 2.83 VRMS stepped sine wave
Smoothing: 1/6 oct.

Measuring conditions, impedance
Driver mounting: Free air, no baffle,
     back side open (no cabinet)
Input signal: Stepped sine wave, semi-
     current-drive, nominal current 2 mA
Smoothing: None

WF120BD06-SPL-&-IMP-resp

Measuring conditions, SPL
Driver mounting: Flush in infinite
     baffle, back side open  (no cabinet)
Microphone distance: 1.0 m
Input signal: 2.83 VRMS stepped sine wave
Smoothing: 1/6 oct.

Measuring conditions, impedance
Driver mounting: Free air, no baffle,
     back side open (no cabinet)
Input signal: Stepped sine wave, semi-
     current-drive, nominal current 2 mA
Smoothing: None

NOMINAL SPECIFICATIONS

Notes

  Parameter

WF120BD05

WF120BD06

Unit

Before burn-in

After burn-in

Before burn-in

After burn-in

 

Nominal size

4

4

[inch.]

 

Nominal impedance

4

8

[ohm]

 

Recommended max. upper frequency limit

3.5

3.5

[kHz]

1, 4

Sensitivity, 2.83V/1m (average SPL in range 300 - 1,000 Hz)

87

84

[dB]

2, 4

Power handling, short term, IEC 268-5, no additional filtering

 

 

[W]

2, 4

Power handling, long term, IEC 268-5, no additional filtering

 

 

[W]

2, 4

Power handling, continuous, IEC 268-5, no additional filtering

60

60

[W]

 

Effective radiating area, Sd

54

54

[sq.cm]

3, 4, 6

Resonance frequency (free air, no baffle), Fs

52

48

54

50

[Hz]

 

Moving mass, incl. air (free air, no baffle), Mms

7.3

6.7

[g]

3

Force factor, Bxl

4.1

5.2

[N/A]

3, 4, 6

Suspension compliance, Cms

1.29

1.50

1.29

1.50

[mm/N]

3, 4, 6

Equivalent air volume, Vas

5.3

6.2

5.3

6.2

[lit.]

3, 4, 6

Mechanical resistance, Rms

0.30

0.30

0.30

0.30

[Ns/m]

3, 4, 6

Mechanical Q, Qms

7.9

7.4

7.6

7.0

[-]

3, 4, 6

Electrical Q, Qes

0.45

0.42

0.54

0.50

[-]

3, 4, 6

Total Q, Qts

0.43

0.40

0.50

0.47

[-]

4

Voice coil resistance, RDC

3.2

6.4

[ohm]

5

Voice coil inductance, Le (measured at 10 kHz)

0.087

0.16

[mH]

 

Voice coil inside diameter

32

32

[mm]

 

Voice coil winding height

12

12

[mm]

 

Air gap height

4

4

[mm]

 

Theoretical linear motor stroke, Xmax

4

4

[mm]

 

Magnet weight

370

370

[g]

 

Total unit net weight excl. packaging

1.0

1.0

[kg]

3, 4, 5

Krm

40

109

[mohm]

3, 4, 5

Erm

0.39

0.35

[-]

3, 4, 5

Kxm

61

145

[mH]

3, 4, 5

Exm

0.32

0.27

[-]

Note 1

Measured in infinite baffle.

Note 2

Tested in free air (no cabinet).

Note 3

Measured using a semi-constant current source, nominal level 2 mA.

Note 4

Measured at 25 deg. C

Note 5



 

It is generally a rough simplification to assume that loudspeaker transducer voice coils exhibit the characteristics of an inductor. Instead it is a far more accurate approach to use the more advanced model often referred to as the “Wright empirical model”, also used in LEAP-4 as the TSL model (www.linearx.com), involving parameters Krm, Erm, Kxm, and Exm. This more accurate transducer model is described in a technical paper (PDF) here.

Note 6

 

After burn-in specifications are measured 12 hours after exiting the transducer by a 20 Hz sine wave for 2 hours at level 7.75/11 VRMS (4/8 ohm version). The unit is not burned in before shipping.
 

OUTLINE DRAWING AND NOMINAL DIMENSIONS (mm)

WF120BD05/06 outline drawing
WF120BD05_06-outline-drawing

TERMINAL NOMINAL DIMENSIONS (mm)

Terminals-dimensions

PACKAGING AND ORDERING INFORMATION

Part no. WF120BD05-01

4 ohm version, individual packaging (one piece per box)

Part no. WF120BD05-02

4 ohm version, bulk packaging

Part no. WF120BD06-01

8 ohm version, individual packaging (one piece per box)

Part no. WF120BD06-02

8 ohm version, bulk packaging

Latest update: January 27, 2013
 

 

Specifications are subject to change without any further notice.
Copyright © 2006-2014 by Wavecor Ltd., Guangzhou, China. All rights reserved.

 

DataBoxTop1

MORE INFO

WF120BD05/06 specificationsPDF data sheet
(942 KB)

 

Balanced Drive technical paper

Balanced Drive technical paper (2.34 MB)

 

 

 

 

List of all mid/woofers

 

All Wavecor drive units

 

Technical pages

DataBoxShadow1
DataBoxBottom1