[. . . ] This unit can be driven in full-range or bi-amp mode simply by plugging into the desired jack on the input plate. The SPTM 4G 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 SPTM 4G 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 low frequency driver from unforeseen accidents. Sound GuardTM, Peavey's proprietary circuit for high frequency driver protection, has been included as an integral part of the crossover for the SPTM 4G. The input signal is routed through the Sound GuardTM circuit in both full-range and bi-amp modes of operation. When the high frequency drive level to the SPTM 4G exceeds a predetermined threshold the Sound GuardTM circuit in engaged. 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 to 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. FREQUENCY RESPONSE This measurement is useful in determining how accurately a given unit reproduces an input signal. The frequency response of the SPTM 4G is measured at a distance of 1 meter using a 2. 0 volt swept-sine input signal. As shown in Figure 1, the selected drivers in the SPTM 4G combine to give a smooth frequency response from 39 Hz to 17. 5 kHz. DIRECTIVITY Beamwidth and directivity factors are derived from the -6 dB points from the polar plots (see Figure 3), which are measured in a whole space anechoic environment. [. . . ] As shown in Figure 1, the selected drivers in the SPTM 4G combine to give a smooth frequency response from 39 Hz to 17. 5 kHz. DIRECTIVITY Beamwidth and directivity factors are derived from the -6 dB points from the polar plots (see Figure 3), which are measured in a whole space anechoic environment. These are specifications that provide a reference to the coverage characteristics of the unit. These parameters provide insight for proper THREE + TWO YEAR LIMITED WARRANTY NOTE: For details, refer to the warranty statement. [. . . ]