JBL 2012-H Brochure
2012H
Maximum Output 250 mm
Midrange/Mid-Bass
Transducer
Key Features:
䉴
300 W AES continuous pink noise
power capacity
䉴
76 mm (3 in) edgewound
aluminum ribbon voice coil
䉴
75 Hz - 7 kHz response
䉴
100 dB sensitivity, 1 W, 1 m (3.3 ft)
䉴
New magnet structure with
enhanced distortion-reduction
characteristics
䉴
Flat impedance curve for constant
power transfer
The JBL Model 2012H Maximum
Output transducer is specifically
designed to provide smooth, low-distortion midrange output for the highest quality sound reinforcement applications. It is suitable for use in both
direct radiator and horn-loaded applications. It is especially well-suited
for use in high-powered, multi-way
systems for concert and theatrical
use, and for high output stage monitor and studio monitor applications.
Because of its relatively high resonance and very low Qtsvalues, the
2012H can be mounted in small
enclosures while maintaining smooth,
peak-free response.
The 2012H has been designed with
a combination of flat power response
with rising on-axis response, and an
optimization of the critical interplay
between efficiency, sensitivity, power
handling and low dynamic power
compression.
The 2012H is built around an
enhanced motor structure that provides dramatic performance benefits
for professional users. JBL’s traditional SFG (Symmetrical Field Geometry)
motor structures use an aluminum
shorting ring at the base of the pole
piece to reduce second order harmonic distortion along with saturated
undercut pole tips to reduce third
order harmonic distortion. The
2012H employs a new magnetic
structure with a copper sleeve symmetrically positioned on the pole
piece above and below the top plate.
This copper sleeve is located on the outside of the pole piece throughout
the entire length of the coil. It functions as a “shorting ring”, and provides
significant reductions in both second and third order harmonic distortion
with a single design element. The top of the plate is much thicker than traditional drivers, providing much better heat dissipation for the voice coil.
Due to this innovative new magnet structure design, the 2012H exhibits
extremely low midband distortion. It features a very smooth, gradually rising response over the transducer’s target operating range from 100 Hz to
1600 Hz. Even at extremely high power levels, over this frequency interval
the values of second and third order harmonic distortion do not rise above
a value of 3%. Distortion in the critical lower midrange region from 100 to
500 Hz is below 1%.
A hallmark of the 2012H is its enhanced dynamic compression characteristics. Power compression in all loudspeakers results from the increase in
voice coil temperature and the consequent rise in DC resistance. Power
compression at high operating levels can rob music of its essential dynamics. While most manufacturers of professional transducers do not present
performance data on power compression, JBL routinely tests for and presents this data. Professional users who are concerned with performance
under long-term periods of continuous usage at or near rated power will
find that the 2012H exhibits only 3.4 dB of compression at full rated power,
and only 0.6 dB of compression at 10 dB below full rated power.
Each of these engineering principles combine to result in a maximum
output, low distortion midrange/mid-bass device that has nearly a pure
resistive minimum-phase impedance characteristic through its useable range
and in the area of crossover. The flat impedance curve results in constant
power being delivered to the transducer at all frequencies, with the final
result being a low distortion speaker with an extended range of flat power
response.
Like all JBL loudspeakers, the 2012H is built to traditional JBL standards
of precision. It will continue to deliver superior performance over extended periods of time without special care or attention.
Professional Series
䉴 2012H Maximum Output 250 mm Midrange/Mid-Bass Transducer
JBL Professional
8500 Balboa Boulevard, P.O. Box 2200
Northridge, California 91329 U.S.A.
A Harman International Company
SS 2012H
CRP 10M
9/98
TYPICAL RESPONSE and
IMPEDANCE CURVES
Frequency response contour of the 2012H taken in a hemispherical
free-field environment, a closed box of 280 liters (10 ft3) internal
volume enclosing the rear of the driver. Input signal is 2.83V @
1 meter. Measured response of a typical production unit, including
all peaks and dips, does not deviate more than 2 dB from the above
curve. The dotted line represents measured 45 degree off-axis
response. The dashed curve represents the response when the driver is mounted in a 8.5 liter (0.3 ft3) enclosure tuned to 75 Hz. The
impedance magnitude curve is measured in the 280 liter (10 ft3)
sealed enclosure.
DISTORTION vs. FREQUENCY
Distortion measurements taken with an input of 15.5V @ 1 meter
(30 watts at 8 ohms). Distortion levels shown have been raised by
20 dB. The dashed line shows 2nd harmonic and the dotted line
shows the 3rd harmonic. Note lack of 3rd harmonic at high
frequencies.
JBL continually engages in research related to product improvement. Some materials,
production methods and design refinements are introduced into existing products
without notice as a routine expression of that philosophy. For this reason, any current
JBL product may differ in some respect from its published description, but will always
equal or exceed the original design specifications unless otherwise stated.
Specifications:
Nominal Diameter: 250 mm (10 in)
Rated Impedance: 8 ohms
Power Capacity1: 300 W
Sensitivity2: 100 dB SPL, 1 W, 1 m (3.3 ft)
Frequency Range3: 75 Hz - 7 kHz
Power Compression4:
at -10 dB power (30 W): 0.6 dB
at -3 dB power (150 W): 2.0 dB
at rated power (300 W): 3.4 dB
Distortion5:
2nd harmonic: <1%
3rd harmonic: <1%
Highest Recommended Crossover: 5.5 kHz
Recommended Enclosure Volume: 10 - 30 liters (0.35 - 1.05 ft3)
Effective Piston Diameter: 199 mm (7.8 in)
Maximum Excursion
Before Damage: 16 mm (0.65 in)
Minimum Impedance: 7 ohms ± 10% @ 25° C
Voice Coil Diameter: 76 mm (3 in)
Voice Coil Material: Edgewound Aluminum Ribbon
Voice Coil Winding Depth: 20.3 mm (0.8 in)
Magnetic Gap Depth: 12.6 mm (0.5 in)
Magnetic Assembly Weight:: 7.7 kg (17 lb)
Bl Factor: 15.5 tesla meters
Flux Density: 1.0 tesla
Effective Moving Mass: 30 g
Polarity: EIA (Positive voltage to RED
terminal gives forward cone
motion)
THIELE/SMALL PARAMETERS6:
fs: 61 Hz
Re: 4.7 ohms
Qts: .21
Qms:4
Qes: .22
Vas: 31 l
Sd: 0.031 m2(48.05 in2)
X
max
(10 % THD): 5 mm (0.20 in)
Vd: 155 cm3(9.46 in3)
Le: N/A (purely resistive at 1 kHz)
0(half-space): 3.1%
Pe(Max)1: 300 W continuous pink noise
MOUNTING INFORMATION:
Overall Diameter: 237 mm (9.33 in) square
261 mm (10.25 in) round
Bolt Circle Diameter: 245 mm (9.63 in)
Baffle Cutout Diameter:
Front Mount: 229 mm (9.0 in)
Rear Mount: 222 mm (8.75 in)
Depth: 117 mm (4.6 in)
Volume Displaced by Driver: 2.15 liters (0.076 ft3)
Net Weight: 8.6 kg (19 lb)
Shipping Weight: 9.1 kg (20 lb)
1
AES standard (100 Hz - 1000 Hz pink noise)
2
Sensitivity is based on a swept 500 - 2500 Hz signal for an input of 2.83 V @ 8 ohms.
3
Frequency range is defined as the frequency extremes over which the response is
-10 dB relative to the rated sensitivity.
4
Power compression is the sensitivity loss at the specified power, measured from 100 to
1000 Hz, after a 5 minute AES standard pink noise preconditioning test at the specified
power.
5
Distortion is measured at -10 dB rated power, from 100 to 500 Hz.
6
Thiele/Small parameters are measured after 2 hour exercise period using a 300 W AES
power test and reflect the expected long-term parameters once the driver has been
installed and operated for a short period of time.
Impedance (ohms)
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