The 15-inch Celestion CF1540HD bass speaker is the smaller sibling of the well-established and
best-selling CF1840JD. Featuring a cast aluminum chassis, it reproduces frequencies from 35Hz
to 2,000Hz. With a power handling rated at 1,200W (AES standard) and 2,400W continuous,
the speaker is well-suited to the high output of the Class-D amplifier sections that see nearly
ubiquitous use today among P.A. and powered speaker manufacturers.
This impressive power rating is achieved first by using strategically sized and located airflow channels
in the magnet assembly, producing a balanced airflow both within and around the voice coil and
keeping the motor system cool. This counteracts power compression where a speaker’s output SPL is
restricted as the voice coil increases in temperature—and therefore resistance—during operation. The
CF1540HD’s suspension and dust cap pump air as the driver cone moves, and its balanced airflow
venting channels behave like a one-way valve. This ensures that air that has been heated in proximity
to the motor assembly does not immediately return but is instead replaced by cooler air.