SP 3G PASSIVE 3-WAY SPEAKER SYSTEM
The SP 3G is a full-range 3-way speaker system engineered for high performance and versatility. Useful for sound reinforcement, monitoring, public address and musical playback. The system is comprised of a 15″ Black Widow woofer with Kevlar-impregnated cone, a 6.5″ professional mid-range driver, and a 22XT compression driver coupled with a CH 3 constant directivity horn. This unit can be driven in a fullrange or bi-amp mode by simply plugging into the desired jack on the input plate. The SP 3G has a trapezoidal shaped box, rather than a rectangular shaped box, that allows arrays to be constructed much more easily. This shape also greatly reduces the build-up of standing waves on the inside of the enclosure. This ensures a minimum of mid-bass and mid-range coloration of the reproduced sound due to the cabinet. The SP 3G is constructed of 3/4″ plywood and is covered with Peavey’s durable black carpet. Polymer corners are also a part of the unit to provide added protection to the enclosure. A powder-coated, expanded metal grille covers the lower part of the front of the enclosure to protect the mid- and low-frequency drivers from unforeseen accidents. Sound Guard, Peavey’s proprietary circuit for high-frequency driver protection, has been included as a integral part of the crossover for the SP 3G. The input signal is routed through the Sound Guard circuit in both full-range and bi-amp modes of operation. When the highfrequency drive level to the SP 3G exceeds a predetermined threshold, the Sound Guard circuit is engaged. This subtly decreases the signal going to the 22XT so that it will not be damaged due to long-term overpowering. Short duration transients will not be attenuated by Sound Guard and have the possibility to damage the 22XT. The Sound Guard 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 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, an automotive type 1156 bulb can be substituted for temporary use until a Peavey bulb can be obtained.
FREQUENCY RESPONSE
This measurement is useful in determining how accurately a given unit reproduces an input signal. The frequency response of the SP 3G is measured at a distance of 1 meter using a 2.8 volt swept-sine input signal. As shown in Figure 1, the selected drivers in the SP 3G combine to give a smooth frequency response from 54 Hz to 17 kHz.
DIRECTIVITY
Beamwidth is derived from the -6 dB points from the polar plots (see Figure 3) which are measured in a whole space anechoic environment. Q and Directivity Index are plotted for the on-axis measurement position. These are specifications which provide a reference to the coverage characteristics of the unit. These parameters provide insight for proper placement and installation in the chosen environment. The blending of the components of the SP 3G exhibits a desirable beamwidth and directivity (Figures 3 and 4) suitable for sound reinforcement applications.
POWER HANDLING
There are many different approaches to power handling ratings. Peavey Electronics rates this unit’s system power handling using a modified form of the AES Standard 2- 1984, utilizing audio band limited (20 Hz – 20 kHz) pink noise with peaks over 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. The test signal contains large amounts of very low-frequency energy, effectively simulating the frequency content of live music situations. The full measure of high frequencies in the test signal allow for exposure of the speaker system to synthesized tones that may extend beyond audibility. This rating is contingent on having a minimum of 3 dB of amplifier headroom available so as to ensure that clipping does not occur.
ARCHITECTURAL & ENGINEERING SPECIFICATIONS
The loudspeaker system shall have an operating bandwidth of 54 Hz to 17 kHz. The nominal output level shall be 99 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 350 watts, maximum program power of 700 watts and a peak power input of at least 1,400 watts, with minimum amplifier headroom of 3 dB. The nominal radiation geometry shall be 96 degrees in the horizontal plane and 95 degrees in the vertical plane. The outside dimensions shall be 33.50 inches high by 21.50 inches wide by 22.50 inches deep. The weight shall be 95 pounds. The loudspeaker system shall be a Peavey model SP 3G.
