Description
The Altec Lansing 409 series Duplex® loud-
speaker systems are two-way loudspeakers
with 8-inch low-frequency cones and high-
temperature voice-coil assemblies coaxially
mounted with wide-dispersion cone tweet-
ers. The dual magnet construction allows
each speaker to be structurally, magnetically,
electrically and mechanically independent of
the other. The 409 series utilize a single sec-
tion crossover network, centered at 2500Hz
and providing 6dB of attenuation for each
element outside it’s operating range.
The 409-8E is an 8 ohm, 32 watt speaker.
The 409-ST (with 15700 transformer) and
the 409-4T (with 15704 transformer) both
offer a selection of 0.5, 1, 2 and 4W. The
409-8T (with 15708 transformer) offers a se-
lection of 1, 2, 4 and 8W. The 409-16T (with
15716 transformer) offers 2,4,8 and 16W and
the 409-32T (with 15732 transformer) offers
a 4, 8, 16, 32W selection.
Architect’s and Engineer’s
Specifications
409 SERIES DUPLEX LOUDSPEAKERS
The loudspeaker shall be a Duplex® type
with a 8-inch low-frequency cone and a high-
temperature voice coil assembly coaxially
mounted with a wide dispersion cone
tweeter. The Duplex® loudspeaker shall
meet the following criteria. AES power rat-
ing shall be 32 watts of band limited pink
noise (85 Hz to 18 kHz, 6 dB crest factor).
Frequency response, uniform from 85 Hz to
18 kHz. Pressure sensitivity, 97 dB SPL at 1
meter (95 dB at 4 feet) on axis with one watt
of band-limited pink noise from f 3 kHz (ref.
20 uPa). Minimum impedance, 6.0 ohms.
The loudspeaker shall be 8.13 in (20.6 di-
ameter and _in (_cm) deep and shall weigh
_lbs (_ kg). For dimensions see page 6.
The Duplex® loudspeakers shall be Altec
Lansing models 409-8E, 409-ST (with 15700
transformer), 409-4T (with 15704 trans-
former), 409-8T (with 15708 transformer),
409-16T (with15716 transformer) and the
409-32T (with 15732 transformer).
Notes on Measurement Conditions
l. Pink noise signal, one Watt calculated us-
ing E2 / Zmin, 3.16 measurement distance
referred to one meter.
2. On-axis, one Watt calculated using E2/
Zmin, 3.16 meter measurement distance
referred to one meter, low frequencies cor-
rected for anechoic chamber error.
3. This system rating patterned after the
A.E.S method for individual driver, where
the test signal is pink noise with a 6dB
crest factor over the bandwidth of the sys-
tem, with power calculated using the E2/
Zmin, for two hours.
4. This measurement made under the same
conditions as Pressure Sensitivity, but at
rated power, and takes into account any
power compression effects due to non-
linearities in the system.
5. Distortion components invalid above
10kHz. The distortion at any given
frequency may be found by graphically
taking the difference between the
fundamental and harmonic, and adding
the number of Decibels which the
harmonic has been raised on the graph
and apply the formula: Percent Distor-
tion = 100 x 10 - (difference in dB/20)
409 SERIES
8-Inch Premium High
Performance Duplex
Ceiling Loudspeakers
•
409-8E
409-8E
409-8E
409-8E
409-8E
, 8 ohm,32 watts
(EIA RS-426-A)
•
409-ST
409-ST
409-ST
409-ST
409-ST
, with 4 watt multi-tap
transformer-(15700)
•
409-4T
409-4T
409-4T
409-4T
409-4T
, with 4 watt multi-tap
transformer-(15704)
•
409-8T
409-8T
409-8T
409-8T
409-8T
, with 8 watt multi-tap
transformer-(15708)
•
409-16T
409-16T
409-16T
409-16T
409-16T
, with 16 watt multi-tap
transformer-(15716)
•
409-32T
409-32T
409-32T
409-32T
409-32T
, with 32 watt multi-tap
transformer-(15732)
• High efficiency: 97 dB for 1W @ 1M
• Maximum SPL: 112 dB for 32W @ 1M
• Frequency response: 85 Hz - 18 kHz
• Wide dispersion
• Dual magnet construction
