Audio Database

The

JBL L220
240,000yen(one-set, around the 1979 time)

Description
 
The technology of the studio monitor loudspeaker which JBL has, and the floor type speaker system which introduced a new technology.

LE14A which is the 36cm cone type Woofer adopted also as L101 is adopted as low-pass.
The Alnico V magnet of JBL tradition is adopted as a magnetic circuit, and the copper ribbon line is made into an edgewise volume, and is used for a voice coil 10.2cm in diameter. To aperture, since the diameter of a voice coil is large, it has the outstanding transient response and efficiency ratio.
Moreover, passive radiator PR15C of the same 38cm aperture as Olympus S508 is adopted as low-pass.
Since compliance is very high and an about 30% dimension is larger than a Woofer, the low-pass response has been improved by using together with LE14A.

LE5-9 of a 13cm cone type squawker is adopted as a mid range.
In order to prevent the interference from a Woofer, it is dedicated in the independent chamber, and a sub baffle board is formed behind a main baffle board, and it mounts on it.
The acoustic lens for exclusive use is attached to the front of this subbaffle, and the sound which came out of the squawker with this acoustic lens is led to a main baffle side, and you are making it spread.

076 of a horn type tweeter is adopted as a high region.
It is an ellipse horn type with a ring diaphragm peculiar to JBL, and, as for the structure which leads to the exponential horn which the cross section made the ellipse form, the control of directional characteristics is performed from the phasing plug which keeps a phase and a swing constant.

Each unit arranges the location of the voice source of a unit, and the sound which comes out of each voice source keeps equal attainment time until it results in a front baffle.
Moreover, the voice source which the unification was able to take is acquired by considering it as the in-line placement arranged in the vertical single row, and the more exact image lateralization is enabled.

Equalization and the phase compensator of an impedance are built in the network, and the design is carried out to it so that neither a peek dual in-line package in the cross-over-frequency neighborhood of each loudspeaker unit nor phase disorder may be caused.

The enclosure is given hand polish finish traditional to a black walnut.
The front had the floor form which carried out the large trapezoid, and form has minimized the proprietary floor space.


Rating of a mode
Form 3 ways, 3 loudspeaker passive radiator scheme, and a floor type
Using unit For low-pass: 36cm cone type (LE14A)
For mid ranges: 13cm cone type (LE5-9) + acoustic lens
For high regions: Horn type (076)
Passive radiator :P R15C
Exclusive 3 way network
Rated input 75W (succession sine wave)
Impedance 8ohms
Cross over frequency 800Hz, 5000Hz
Output sound pressure level 90dB (new Japanese Industrial Standard)
Dimensions Width 512x height 1225x depth of 390mm
Weight 48kg (at the time of an original packaging)