Frequency response
This measurement is useful in
determining how accurately a given unit
reproduces an input signal. The frequency
response of the SP
™
Subcompact 18X is
measured at a distance of 1 meter using a
1 Watt (into the nominal impedance)
swept-sine input signal. The lower curve is
anechoic response, while the upper curve
is typical room response. As shown in
figure 1, the selected drivers in the SP
Subcompact 18X combine to give a
smooth frequency response from 52 Hz -
180 Hz.
Power handling
There are many different approaches
to power handling ratings. Peavey rates
this loudspeaker system’s power handling
using a full-range form of the AES
Standard 2-1984. Using audio band 20 Hz
to 20 kHz pink noise with peaks of four
times the RMS level, this strenuous test
signal assures the user that every portion
of this system can withstand today’s high
technology music. This rating is contingent
upon having a minimum of 3 dB of
amplifier headroom available.
Harmonic distortion
Second and third harmonic distortions
vs. frequency are plotted in figures 5 & 6
for two power levels, ten percent (10%) of
rated input power and either one percent
(1%) of rated input power or one Watt,
whichever is greater. Distortion is read
from the graph as the difference between
the fundamental signal (frequency
response) and the desired harmonic. As
an example, a distortion curve that is
down 40 dB from the fundamental is
equivalent to 1% distortion.
Architectural and engineering
specifications
The loudspeaker system shall have an
operating bandwidth of 52 Hz - 180 Hz.
The nominal output level shall be 98.0 dB
when measured at a distance of one
meter with an input of one Watt. The
nominal impedance shall be 8 Ohms. The
maximum continuous power handling shall
be 500 Watts, maximum program power of
1000 Watts and a peak power input of at
least 2000 Watts, with a minimum
amplifier headroom of 3 dB. The outside
dimensions shall be 28.13 inches high by
23.75 inches wide by 24.19 inches deep.
The weight shall be 102 pounds. The
loudspeaker system shall be a Peavey
model SP Subcompact 18X.
3 + 2 YEAR LIMITED WARRANTY
NOTE:
For details, refer to the
warranty statement. Copies of
this statement may be obtained
by contacting Peavey Electronics
Corporation, P.O. Box 2898, Meridian,
Mississippi 39301-2898.
20
50
100
200
500
1k
2k
5k
10k
20k
Frequency (Hz)
70
80
90
100
110
120
dB
SPL
(re
20
Pa)
Amplitude Response (1W 1m On-Axis)
Figure 1
20
50
100
200
500
1k
2k
5k
10k
20k
Frequency (Hz)
1
2
3
5
10
20
30
50
100
Impedance
Z
( )
Figure 2