TOA PROFESSIONAL SOUND SYSTEM
COMPRESSION DRIVER
HFD-220-8/16
DESCRIPTION
The TOA HFD-220-8/16 compression driver, in 8-ohm and
16-ohm versions, is designed for use in high-level
applications where sound systems of the highest quality are
required. With a throat diameter of 2 in. (49mm), the TOA
HFD-220-8/16 is intended for use with the TOA LE Series
constant directivity horns, and it will provide highly efficient
sound reproduction and a smooth frequency response from
800Hz to 15kHz. The voice coil of the TOA HFD-220-8/16
compression driver consists of a 1.76 in. (44.6mm) edge-
wound, copper-clad aluminum ribbon coupled to a 50-
micron hard duralumin diaphragm. The diaphragm voice
coil assembly can be replaced in the field without having to
disassemble the entire driver. The diaphragm voice coil
employs self-aligning dowels to center it perfectly in the
voice coil gap. The gap has a flux density of 19,000 gauss,
generated by a 2.4 Ibs. (1.1 kg) ferrite magnet. A machined
phasing plug with two acoustic slots serves as the pole
piece, providing the proper phase relationship between the
sound emanating from the center and that coming from the
edge of the diaphragm/voice coil assembly.
FEATURES
1. Smooth frequency response from 800Hz to 15kHz.
2. Highly efficient sound pressure level of 110dB/W/m
with LE-940 horn.
3. High power capacity: 30 watts continuous pink noise
(800Hz to 20kHz, test duration: 24 hours).
4. Throat diameter of 2 in. (49mm).
5. Edge-wound, copper-clad aluminum ribbon voice coil.
6. 50-micron duralumin diaphragm.
7. Diaphragm voice coil can be easily replaced in the
field.
