Table 8: Impedance Of Multiple Loudspeaker Columns - Community Entasys Installation & Operation Manual

Impedance
The ENTASYS Full-Range column loudspeaker has a 12 ohm rated impedance. The ENTASYS Low
Frequency column loudspeaker also has a 12 ohm rated impedance. Because of the unique design of
ENTASYS it is possible to stack multiple enclosures together and drive them from a single amplifier channel.
See Table 8 below for details on the impedance of multiple ENTASYS loudspeakers driven in parallel.

Table 8: Impedance of Multiple Loudspeaker Columns

Low Frequency
Columns
‐
‐
‐
1
1
1
2
Recommended Amplifier Power
See Table 9 for the recommended amplifier power for each specific ENTASYS loudspeaker and
combination of full-range and low frequency columns in an array driven from a single amplifier channel. Using
an amplifier of less power than recommended will not allow maximum performance of the system and may
damage the loudspeaker if the amplifier is driven into clipping. Correspondingly, using an amplifier of more
power than recommended can result in overdriving the loudspeaker with the potential for damaging the drivers
and/or the protection circuitry.
Use of Limiters
Community recommends the use of a limiter to help prevent loudspeaker damage due to sudden
transients (dropped microphones, etc.) and to prevent amplifier clipping. When used for this purpose, connect
the limiter as the last item in the signal chain before the power amplifier (at the input to the power amplifier). Set
the limiter's "threshold" high enough so that no limiting occurs until the signal is near the level of clipping the
amplifier. This will be dependent on the input sensitivity setting of the amplifier. Generally, this will be 3 dB
greater than the rated input sensitivity of the amplifier. See Table 10 for typical amplifier sensitivities and the
corresponding peak voltage threshold setting.
Set the limiter's "compression ratio" high enough so that the limiter can stop any unwanted signal level
from appearing at its output. This should be 10:1 at minimum. Ratios of 20:1 or higher (infinity:1) are
recommended.
Total Rated
Full‐Range Impedance
Columns (ohm)
1 12
2 6
3 4
‐ 12
1 6
2 4
1 4
Community ENTASYS Installation/Operation Manual — Page 38
INSTALLATION
Minimum Frequency of
Impedance Minimum Impedance
(ohm)
8.4 7,170
4.4 7,060
3.0 7,040
12.1
5.9
3.9
4.1
(Hz)
380
370
370
380