JBL 2447 J

Preliminary Specifications:

Throat Diameter: 38 mm (1½ in)

Nominal Impedance: 2447H 8 ohms 2447J 16 ohms

Minimum Impedance: 6 ohms (H), 12 ohms (J) @ 5 kHz

DC Resistance: 4.3 ohms (H), 8.5 (J) ±10% @ 25°C

Power Rating¹: 100 W continuous program above 500 Hz
1 Continuous program power is defined as 3 dB greater than continuous pink noise and is a conservative expression of the transducer's ability to handle normal speech and music program material. Continuous pink noise power ratings are tested with a pink noise input having a 6 dB crest factor, with a high pass filter set to the specified lower frequency, for two hours duration.

150 W continuous program above 1 kHz

Sensitivity: 112 dB SPL, 1 W @ 1 m, JBL 2352 horn²

114 dB SPL, 1 W @ 1 m, JBL 2353 horn²

115 dB SPL, 1 W @ 1 m, JBL 2354 horn
² Sensitivity measured on-axis in the far field with 2.83 V rms at 8 ohms or 4.0 V rms at 16 ohms and referred to a 1 meter distance calculated by inverse square law. Listed sound pressure level (SPL re 20 µPa ) represents an average from 1 kHz to 4 kHz

118 dB SPL, 1 mW on plane wave tube
³ As specified by recognized standards organizations, JBL plane wave tube measurements represent the SPL referred to a 25 mm diameter terminated tube, using a 1 mW input signal (0.126 V rms into 16 ohms; 0.089 V rms into 8 ohms) swept from 500 Hz to 2.5 kHz. The sensitivity with a 1 W input would be 30 dB greater.

Nominal Efficiency: 30% (500 Hz to 2.5 kHz)

Frequency Range: 500 Hz to 20 kHz

Recommended Crossover: 500 Hz or higher, 12 dB/octave minimum

Recommended Amplifier Power : 200 W into 8 ohms
4 Recommended power amplifier rating is a guide for amplifier selection considering normal program material and line voltage available to amplifiers, although lower power amplifiers may be utilized

Diaphragm: 0.05 mm (0.002 in) pure titanium

Voice Coil Diameter: 100 mm (4 in)

Voice Coil Material: Edge wound aluminum ribbon

Flux Density: 1.85 T (18,500 gauss)

B1 Factor: 12.7 (H) T m 18 (J) T m