JBL 63482/JBL.2020H.SpecSht 2020H Spec Sheet

User Manual: JBL JBL - Manuals+

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2020H

Maximum Output 300 mm

Midrange/Low Frequency

Transducer

Key Features:

䉴

300 W AES continuous pink noise

power capacity

䉴

76 mm (3 in) edgewound

aluminum ribbon voice coil

䉴

50 Hz - 5.5 kHz response

䉴

103 dB sensitivity, 2.83 V,

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 2020H Maximum

Output transducer is specifically

designed to provide smooth, low-dis-

tortion midrange output for the high-

est quality sound reinforcement appli-

cations. It is suitable for use in both

direct radiator and horn-loaded appli-

cations. It is especially well-suited

for use in high-powered multi-way

systems for concert and theatrical

use, and for high output stage moni-

tor and studio monitor applications.

Because of its relatively high reso-

nance and very low Qts values, the

2020H can be mounted in small

enclosures while maintaining

smoother, peak-free response as com-

pared to other 300 mm (12 in) loud-

speakers.

The 2020H 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 2020H is built around an

enhanced motor structure that pro-

vides dramatic performance benefits

for professional users. JBL’s tradition-

al SFG (Symmetrical Field Geometry)

motor structures use an aluminum

shorting ring at the base of the pole

piece to reduce second order har-

monic distortion along with saturated

undercut pole tips to reduce third

order harmonic distortion. The

2020H employs a new magnetic

structure with a copper sleeve sym-

metrically 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 tra-

ditional drivers, providing much better heat dissipation for the voice coil.

Due to this innovative new magnet structure design, the 2020H exhibits

extremely low midband distortion. It features remarkably low distortion

over the frequency decade from 100 Hz to 1 kHz. Even at extremely high

power levels, distortion in the critical lower midrange region from 100 to

500 Hz is less than 1%.

A hallmark of the 2020H is its enhanced dynamic compression character-

istics. 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 dynam-

ics. While most manufacturers of professional transducers do not present

performance data on power compression, JBL routinely tests for and pre-

sents 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 2020H exhibits only 2.8 dB of compression at full rated power,

and only 0.5 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/low frequency 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 of JBL loudspeakers, the 2020H is built to traditional JBL stan-

dards of precision. It will continue to deliver superior performance over

extended periods of time without special care or attention.

Professional Series

䉴2020H Maximum Output 300 mm Midrange/Low Frequency Transducer

JBL Professional

8500 Balboa Boulevard, P.O. Box 2200

Northridge, California 91329 U.S.A.

A Harman International Company

SS 2020H

CRP 10M

9/98

TYPICAL RESPONSE and

IMPEDANCE CURVES

Frequency response contour of the 2020H 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 2.83 V @

1 m. 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 dri-

ver is mounted in a 42.5 liter (1.5 ft3) enclosure tuned to 40 Hz. The

impedance magnitude curve is measured in the 280 liter (10 ft3)

sealed enclosure.

DISTORTION vs. FREQUENCY

Measurements taken with an input of 15.5 V @ 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 the 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: 300 mm (12 in)

Rated Impedance: 8 ohms

Power Capacity1:

300 W AES continuous pink noise

Sensitivity2: 103 dB, 1 W, 1 m (3.3 ft)

Frequency Range3: 50 Hz - 5.5 kHz

Power Compression4:

at -10 dB power (30 W): 0.5 dB

at -3 dB power (150 W): 1.7 dB

at rated power (300 W): 2.8 dB

Distortion5:

2nd harmonic: <1%

3rd harmonic: <1%

Highest Recommended Crossover: 5 kHz

Recommended Enclosure Volume: 30 - 90 liters (1.05 - 3.2 ft3)

Effective Piston Diameter: 260 mm (10.2 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: 15.2 mm (0.6 in)

Magnetic Gap Depth: 12.7 mm (0.5 in)

Magnetic Assembly Weight:: 7.7 kg (17 lb)

Bl Factor: 18.3 tesla meters

Flux Density: 1.0 tesla

Effective Moving Mass: 44 g

Polarity: EIA (Positive voltage to RED

terminal gives forward cone

motion)

THIELE/SMALL PARAMETERS6:

fs: 60 Hz

Re: 4.8 ohms

Qts: 0.23

Qms: 4.6

Qes: 0.24

Vas: 65 L

Sd: 0.053 m2(82.2 in2)

Xmax (10 % THD): 5 mm (0.20 in)

Vd: 265 cm3(16.75 in3)

Le: N/A (Purely resistive at 1 kHz)

␩0(half-space): 5.32%

Pe(Max)1: 300 W continuous pink noise

MOUNTING INFORMATION:

Overall Diameter: 311 mm (12.2 in)

Bolt Circle Diameter: 294 mm (11.6 in)

Baffle Cutout Diameter:

Front Mount: 280 mm (11.0 in)

Rear Mount: 284 mm (11.2 in)

Depth: 152 mm (6 in)

Volume Displaced by Driver: 4 liters (0.11 ft3)

Net Weight: 8.6 kg (19 lb)

Shipping Weight: 9.5 kg (21 lb)

1AES standard (60 - 600 Hz pink noise)

2Sensitivity is based on a swept 500 - 2500 Hz signal for an input of 2.83 V @ 8 ohms.

3Frequency range is defined as the frequency extremes over which the response is

-10 dB relative to the rated sensitivity.

4Power compression is the sensitivity loss at the specified power, measured from 60 to

600 Hz, after a 5 minute AES standard pink noise preconditioning test at the specified

power.

5Distortion is measured at -10 dB rated power, from 100 to 500 Hz.

6Thiele/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)