How to JBL L40
Tools
These are some common tools used to work on this device. You might not need every tool for every procedure.
Background and Identification
The JBL L40 is a speaker system released in the mid-1980s and identified by the model number L40. It was designed as a bookshelf-type system and includes two loudspeakers with a bass-reflex scheme. JBL is an American company that produces audio equipment including loudspeakers and headphones.
The JBL L40 system includes a 25-centimeter diameter 127-Amp woofer attached to the back shell of each speaker. The speakers feature an output sound pressure level of 88 decibels (75 decibels is generally considered a comfortable listening volume). It includes a 10-inch loudspeaker with a 2-inch voice coil and a 2.5-pound magnetic assembly energized by an Alnico V magnet. The L40’s voice coil and magnetic assembly are large in comparison to most other 10-inch loudspeakers of the time, resulting in improved transient response and increased efficiency. JBL recommends using an amplifier of 10 to 60 Watts. The system has a crossover frequency of 1800 Hz and an impedance of 8 ohms.
Most JBL L40 models include a 1- by 25-millimeter bass cone and a 1- by 25-millimeter tweeter dome. The speaker systems were sold in a variety of colors, including brown, rust, or tan, and generally feature an oiled walnut finish. JBL L40 speakers include a stretched fabric grille.
Technical Specifications
Scheme: 2 ways, 2 loudspeakers bass-reflex scheme, and a bookshelf type
Using unit:
- For low-pass: 25cm (127A)
- For high regions: 2.5cm (033)
Allowable Input: 35W (succession special NetWare program)
Impedance: 8ohms
Crossover Frequency: 1800Hz
Output sound pressure level: 88dB (new Japanese Industrial Standard)
Dimensions: Width 381x height 584x depth of 302mm
Weight: 20kg (at the time of original packaging)
Additional Information
Manual: L40om.pdf
Spec Sheet:
Crossover Wiring Diagrams:
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