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For connections up to 15 m (50 ft). 1 mm (#18 AWG) insulated wire 

(ordinary household lamp cord) is the minimum size recommended. For 

longer distances, we recommend the following minimum sizes: 1.3 mm 

(#16 AWG) up to 30 m (100 It),and 1.6 mm (#14 AWG) up to 60 m (200 ft). 

If lamp cord is used, wires can be differentiated by noting that one of the 

insulating jackets is smooth, while the other has a distinct ridge. 

Locate the loudspeaker output terminals on the back of the receiver or 

power amplifier For each loudspeaker system, connect the "black" wire to 

the amplifier output terminal labeled "common:' "ground" or  ( - ) , and the 

"red" wire to the remaining 8-ohm speaker output? The specified 8-ohm 

impedance raling is a nominal figure which suggests a connection giving 

the most efficient power transler between amplifier and loudspeaker system 

Note that many amplifiers have a chassis grounding terminal which is 

usually separated from the other connectors. This should not be confused 

with the "ground" designation sometimes used to describe one of the two 

terminals for each loudspeaker connection. 

Bass Loudspeakers 

It is good practice to keep a loudspeaker in its original carton or placed 

face down on a clean surface until installed in order to prevent accidental 

cone damage. The aluminum center dome ot an extended range loud 

speaker is particularly fragile and should not be touched. A grille on the 

front of the enclosure will restrain the curious once the loudspeaker 

system is complete 

Mounting In An Enclosure

 Widest sound distribution will be realized 

and response through the midrange region will be just a little more natural 

and transparent when a loudspeaker is mounted to the front, rather than 

back surface of the baffle panel. Use of T-nuts and machine screws, 

provided within the carton packing material, allows the loudspeaker to be 

removed and reinstalled repeatedly without damaging the enclosure. A 

second, larger sei of hardware is supplied for rear mounting 300 mm 

(12 in) units. 

The seal between the loudspeaker frame and baffle panel must be airtight 

When front mounted, a seal is achieved by fitting the white tubular vinyl 

gasket into a groove on the back of the loudspeaker frame. (A flat, fiber 

gasket is supplied with the D208H.) Loudspeakers that can be rear mounted 

are provided with a facing gasket to form a seal. An airtight seal must also 

be maintained where the input wires enter the enclosure. 

When installing the loudspeaker, tighten the mounting screws evenly to 

avoid the possibility of frame warpage. Avoid excessive force; tighten the 

screws just enough to prevent air leaks between the frame and the 

enclosure, 

2 Connecting both speakers as described will insure proper in-phase operation: 

i e.. iheir cones will respond to a monophonic signal by moving simultaneously in 

the same direction, and not opposite to each other Inadvertent out-ol-phase operation 

(which occurs when one set ot speaker wires is reversed v/ith respect to the other) 

will not harm the system, but will cause some acoustical cancellation which will have 

the audible effect ol reducing low Iroquency response. 

Summary of Contents for D208H

Page 1: ......

Page 2: ...ontinually engages in research related to product improvement New materials production methods and design relinements are introduced into existing products without notice as a routine expression ol th...

Page 3: ...essential for optimum bass performance An enclosure having the proper internal volume and tuning for the loud speaker increases low frequency dynamic range and improves tonal quality it also reduces...

Page 4: ...ent is properly adjusted and the overall volume level of the sound system should be reduced In almost all cases the acoustic level generated by a JBL loudspeaker will become noticeably discomforting t...

Page 5: ...peaker system is complete Mounting In An Enclosure Widest sound distribution will be realized and response through the midrange region will be just a little more natural and transparent when a loudspe...

Page 6: ...ize 1 ront Mount Rear Mounl Boll Circle Diymoior Frame Mourning Hoie Drill Size Front Mount Rear Mount D208H 179 mm 7X m 179 mm 7Vi in 194 mm 7 in 5 4 mm in 5 8 mm m b 8 mm 1 LE8T H t 7 9 m m 7M m Noi...

Page 7: ...s are attached to the center of the PR15C The fiberboard disc in fronl of them is integral to the passive radiator and must not be removed Each of the metal discs weighs 100 grams Six fiberboard discs...

Page 8: ...D130H 380 mm 15 in extended rango 45 Hz 130H 380 mm 15 in lowfrequency D208H 200 mm 6 in extended range 55 Hz I system tuning is higner than recomn eindcd for the loudspeake covai a portun pi the non...

Page 9: ...o moderate density with fiberglass acoustic damping material A sub chamber can be fabricated of a tube having an internal diameter of 114 mm 4ftin and a length of 130 mm 5 in flush mounted on the baff...

Page 10: ...I 105 mm Diameter 075 077 Mounting Dimensions 075 Or 077 Installation Install the 077 as shown lor widest sound distribution in the horizontal plane LE21H Mounting Dimensions...

Page 11: ...support the driver However the driver must be separately braced or removed from the enclosure whenever the loudspeaker system is transported since under such circum stances it is possible lor the wei...

Page 12: ...10...

Page 13: ......

Page 14: ...with staples or small carpet tacks As the lens is removed from the tape a ripping sound will be heard indicating normal disengagement A clearance of 67 mm 2 in between the baffle panel and the grille...

Page 15: ...Adjustment of the level control should be made on the basis of evaluation of normal program material played monaurally with amplifier tone controls at the middle generally referred to as flat position...

Page 16: ...the control assembly of the larger LX30 LX50A and LX80A Wood screws as well as machine screws and T nuls are pro vided to secure the assembly to the enclosure Be certain that the white vinyl flange ga...

Page 17: ...s well as the horn lens assembly utilized The wiring illustrations are correct when an HI 87 HL91 HL92 or HL93 is mounted on the enclosure baffle panel and when an HL88 HL89 or I1L90 is positioned so...

Page 18: ...strations Noie The color codes illustrated represent the latest configuration Earlier units were supplied with Iwo black wires instead ot green black and yellow black wires and a red wire instead of I...

Page 19: ...The color codes illustrated represent the latest configuration Earlier units were supplied with two black wires instead ol green black and yeilow Wack wires and a red wire instead ol Ine yellow wire...

Page 20: ...The color codes illustrated represent the latest configuration Earlier units wore supplied with two black wires instead ot green black and yellow black wires and a red wire instead of the yellow wire...

Page 21: ...tie Black Input Terminal Ol The N7000 Network YELLOW BLACK Note The color codes illustrated represent the latest configuration Earlier units were supplied with two black wires instead of green black a...

Page 22: ...mi nal of the primary net work would have lieen connected to the red torrrvna of the com YELLOW BLACK pression driver connect it to the red input of this network YELLOW Note The color codes illustrate...

Page 23: ......

Page 24: ...will be energized and the compression driver will be phased as if it were still connected 10 Ihe network When Ihe swilch is thrown tho phase of the driver will be reversed II is recommended thai Ihe...

Page 25: ...er trom whom It was purchased If it is not possible to contact a dealer write directly to the JBL Service Department describing the difficulty as fully as possible Products returned to the factory mus...

Page 26: ...James B Lansing Sound Inc 8500 Balboa Boulevard Northridge California 91329 50711 IMLCS 7 S0 Printed n U S A...

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