|The 4181 features an advanced technology 460mm low-frequency transducer mounted in a direct radiator|
At CinemaCon 2013, HARMAN’s JBL Professional is introducing the 4181 Cinema Subwoofer System, a cost-effective movie soundtrack reproduction loudspeaker for basic cinema applications. The 4181 is a high-quality subwoofer system featuring an advanced technology 460-millimeter (18-inch), low-frequency transducer mounted in a direct radiator, bass-reflex enclosure for smooth response to the lowest audible frequencies.
“JBL has recognised a need for cost-effective, low-frequency augmentation of digital soundtracks in motion picture theaters and for general sound reinforcement applications,” said Chuck Goodsell, Senior Manager, Cinema, JBL Professional. “The 4181 addresses this need at a very affordable price point.”
The driver unit utilises a vented cooling loop, which pumps air through the magnetic gap and directly over and around the voice coil, providing immediate heat transfer. Through the use of computer-aided magnet optimisation and analysis techniques, JBL engineers were able to optimise magnet weight, flux density and field saturation, resulting in a significant reduction in harmonic distortion.
The 75-millimeter (3-inch) voice coil, using dual coils in parallel and with holes in bobbin, offers greater thermal stability with increased power handling. All elements of the optimised parts of the driver ensure smooth low frequency response, lower power compression and enable the system to carry a 500 watts continuous pink noise rating.
The enclosure is constructed of dense stock and is extensively braced on all panels. It is tuned to 30Hz with three large ports to minimise port compression and to reduce distortion due to turbulent airflow.