Peavey SP 115MX - Manual (Page 2)

Enclosure materials and finish:
3/4" OSB finished in black carpet
Mounting provisions:
This unit is not designed for over head
suspension
SA 1 stand mount adapter
Dimensions (H x W x D):
Front:
15.25 in. x 24.50 in. x 16.00 in.
387 mm x 622 mm x 406 mm
Net weight:
57 lbs. (25.9 kg)
Features
• Two-way, full range/biampable PA
enclosure
• Sound Guard HF driver protection circuit
• RX
™ 22 driver with a 2" titanium
diaphragm coupled to a CH ® 3 90° x
45° constant-directivity horn
• 15" BWX Black Widow ® with Kevlar ®
cone and field replaceable basket
• SP ™ X series cabinet styling with
integral stand adapter
• Neutrik biamp jack
• 30° or 45° baffle angle
Description
The SP 115MX is both a cosmetic and
performance redesign of the SP 115M
floor monitor loudspeaker system. This
high power handling two-way loudspeaker
system is comprised of a 15" BWX woofer
with a Kevlar impregnated cone and an
RX 22 compression driver coupled to a
CH 3 constant directivity horn. This unit
can be driven in full-range mode simply by
plugging into one of the two 1/4" phone
jacks on the input plate. A Neutrik
Speakon connector is provided as an
input for biamp operation. The unique
design of the enclosure allows the baffle
to be angled at either 30° or 45° from the
floor. The SP 115MX is constructed of 3/4"
OSB and covered with Peavey’s durable
black carpet. A powder coated expanded
metal grille covers the front of the
enclosure to protect the drivers from
unforeseen accidents. A stand mount
adapter is also included in one of the ends
of the enclosure. This will allow it to be
used as a PA type loudspeaker if needed.
Sound Guard III is the redesign of
Peavey’s proprietary circuit for high
frequency driver protection for the new
RX 22 compression driver. This is an
integral part of the crossover for the SP
115MX. The input signal is routed through
the Sound Guard III circuit in both full-
range and biamp modes of operation.
When the high frequency drive level to the
SP 115MX exceeds a predetermined
threshold the Sound Guard III circuit in
engaged. The effect that this has is to
subtly decrease the signal level going to
the RX 22 so that it will not be damaged
due to long term overpowering. Short
duration transients will not be attenuated
by Sound Guard III and have the
possibility to damage the RX 22. The
Sound Guard III circuit is a dynamic circuit
that will attenuate the signal more the
larger the signal is, very similar to a
compressor. This is accomplished through
the use of a specially selected dynamically
resistive light bulb. If the bulb in your
Sound Guard III should ever burn out a
replacement may be obtained from an
Authorized Peavey Service Center.
However, if a Peavey replacement bulb is
not readily available, a Sylvannia SK3
bulb may be located at various
loudspeaker or electronics parts stores.
Frequency response
This measurement is useful in
determining how accurately a given unit
reproduces an input signal. The frequency
response of the SP 115MX is measured at
a distance of 1-meter using a 1 Watt (into
the nominal impedance) swept-sine input
signal. As shown in figure 1, the selected
drivers in the SP 115MX combine to give a
smooth frequency response from 100 Hz -
14 kHz.
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 3 and
4 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.
Mounting
Warning: This unit is not designed for
overhead suspension.
20 50 100 200 500 1k 2k 5k 10k 20k
Frequency (Hz)
60
70
80
90
100
110
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