Later, ultimate and swift to disappear, version of the famed L250, launched after the 250Ti, the Everest or the K2.
Pretty different than the original L250 if nevertheless close to the nearby neighborood.
Fairly rare 55kg loudspeaker at any rate that was assembled in Denmark with drivers coming, naturally, from Northridge, California.
Low-frequency driver
- 30cm Aquaplas-treated pulp with diecast aluminium frame,
- 75mm edge-wound bobbin with SFG (Symmetrical Field Geometry).
Aquaplas mixed with selected pulp makes for a composite material that has, according to JBL, the perfect balance between damping, low-mass and high rigidity.
SFG is possible through the use of a flux stabilizer aluminium anneal ; interactions between the constant flux (magnetic structure) and non-linear flux generated by the signal in the bobbin are eliminated.
Mid-frequency drivers
- 2x 13cm polypropylene with diecast aluminium frame
- 30mm edge-wound bobbin with SFG.
High-frequency driver
- 2,5cm titanium dome with diamond suspension and diecast aluminium frame
- edge-wound bobbin with SFG.
The dome and its suspension are made in one piece to allow for a more accurate choice of suspension compliance, air amount behind the dome, type and quantity of damping in the caity, damping vs. frequency etc. The support of the dome is made of diecast zinc.
Filter
- individually adjusted
- low-loss polypropylene caps
- low-distortion inductances etc.
Enclosure
27mm "two-in-one" separated by a 3mm bituminous material with excellent damping and friction proprieties
Compared to regular 35mm MDF enclosures, the JBL two-in-one system reduces low and mid resonances by 90% and up to 20dB in the highs region.
The lavish catalog I have, the only one, is alas not too talkative regarding the drivers and doesn't show them in detail either...