of random noise with equal energy per band- width in Hz) is fed to a shaping filter with 6-dB-per-octave slopes below 40 Hz and above 318 Hz. When measured with the usual constant-percentage bandwidth ana- lyzer (one-third-octave), this shaping filter produces a spectrum whose 3-dB-down points are at 100 Hz and 1,200 Hz with a 3-dB-per-octave slope above 1,200 Hz. This shaped signal is sent to the power amplifier with the continuous power set at 300 watts into the 7.1-ohm EIA equivalent impedance (46.2 volts true rms). Amplifier clipping sets instantaneous peaks at 6 dB above the con- tinuous power, or 1,200-watts peak (92.5 volts peak). This procedure provides a rigorous test of both thermal and mechani- cal failure modes.
Amplifier Power Recommendations
As noted in the Power-Handling Capacity section above, the Sx300PI has a random- noise power capacity of 300-watts long term (1,200-watts peak) (nontransformer) per ANSI/EIA RS-426-A 1980. The following guidelines will help relate this number to an appropriate power amplifier output rat- ing.
1.To use the Sx300PI to full capacity, skilled experts in sound system installa- tion and operation will obtain the best results if the power amplifier is 2.0 to 4.0 times the long-term average noise- power rating of the speaker system. For the Sx300PI this is 600 to 1,200 watts (nontransformer).
The caution cannot be made strongly enough, however, that this arrange- ment is only for experts or for those who can discipline themselves against “pushing” the system for ever-higher sound levels and who can avoid “ac- cidents” such as catastrophic feedback or dropped microphones.
2.A more conservative, “normal” ampli- fier size, which will produce audible re- sults nearly equal to those of the “ex- pert” recommendation, is 1.0 to 1.4 times the long-term average noise-power rat- ing of the speaker. For the Sx300PI, this is 300 to 420 watts (nontransformer).
3.To be very conservative, one can use an amplifier rated at 0.5 to 0.7 times the long-term average noise-power rating of the loudspeaker. For the Sx300PI this is 150 to 210 watts (nontransformer).
Request P.A. Bible Addition No. Two (“Power Handling Capacity”) for more background on these recommendations.
Sx300PI Connections
The Sx300PI is equipped with two Neu- trik Speakon® NL4MP connectors.
In continued high-power applications, Electro-Voice recommends the use of the Speakon connector. The Speakon NL4MP will mate to a NL4FC Speakon connector, which is a 4-pin connector. Figure 7 shows typical wiring configurations using banana plugs. Cable connections for the Sx300PI should be made to the 1+ and 1– terminals only. Cable connections for the Sx300PIX should be made as shown in Figure 9, de- pending on the given input voltage and the desired output wattage. Cables utilizing the Speakon NL4FC are available from your local dealer or from the companies listed below:
Pro Co Sound, Inc.
135 E. Kalamazoo Ave.
Kalamazoo, MI 49007
616/388-9675
Whirlwind Music Distributors, Inc.
P.O. Box 1075
Rochester, NY 14603
716/663-8820
Neutrik USA, Inc.
195-S3 Lehigh Ave.
Lakewood, NJ 08701
908/901-9488
It is recommended that after making the proper connection with the Speakon connec- tor to the input on the enclosure, a bead of sealant should be applied around the con- nection to assure a watertight seal.
Weather-Resistant Mounting
When mounting the Sx300 PI in a location where a weather-resistant system is required
aminimum of a five-degree down angle is recommended. (See figure 9.) This will help prevent any moisture from wicking through the foam and mesh-backed grille and accumulating inside the enclosure un- der extreme weather conditions.
Architects' and Engineers'
Specifications
The loudspeaker shall consist of a 305-mm
(12-inch) low-frequency transducer in a trapezoidal-shaped enclosure; a high-fre- quency compression driver with a pure tita- nium diaphragm coupled to a 65° x 65° constant-directivity horn molded into the front baffle of the enclosure; and a passive crossover-equalizer network with protection for the high-frequency driver. The loud- speaker shall meet the following perfor- mance criteria: frequency response of 80 to 25,000 Hz, –3 dB; power handling of 300-watts long term and 1,200-watts short term (nontransformer), with a shaped ran- dom-noise input per ANSI/EIA RS-426-A 1980; sensitivity of 99 dB SPL at 1 meter with a 1-watt, 300- to 2,000-Hz pink-noise input; 6-dB-down horizontal coverage angle of 65° ±15° in the 2,000- to 20,000-Hz range; 6-dB-down vertical coverage angle of 65° ±15° in the 2,000- to 20,000-Hz range; crossover frequency of 1,500 Hz; nominal impedance of 8 ohms and minimum impedance of 6 ohms. Paralleled input and output connectors shall be present, consist- ing of Neutrik Speakon® NL4MP connec- tors. The enclosure shall be constructed of polypropylene structural foam and fitted with a full-face, foam-backed, stainless- steel grille, an integral handle, a stand socket for mounting on 13/8-inch stands, rubber feet and mating sockets to facili- tate stacking. Dimensions shall be 586 mm (23.1 in.) high x 429 mm (16.9 in.) wide x 312 mm (12.3 in.) deep. Net weight shall be 17.7 kg (39 lb)nontransformer; 21.7 kg (48 lb)transformer. The loudspeaker sys- tems shall be the Electro-Voice S x 3 0 0 P I , S x 3 0 0 P I X , S x 3 0 0 P I - W, Sx300PIX-W.
Uniform Limited Warranty
Electro-Voice products are guaranteed against malfunction due to defects in mate- rials or workmanship for a specified period, as noted in the individual product-line statement(s) below, or in the individual product data sheet or owner’s manual, be- ginning with the date of original purchase. If such malfunction occurs during the speci- fied period, the product will be repaired or replaced (at our option) without charge. The product will be returned to the customer pre- paid. Exclusions and Limitations: The Limited Warranty does not apply to: (a) ex- terior finish or appearance; (b) certain spe- cific items described in the individual prod- uct-line statement(s) below, or in the indi-
Sx300PI and Sx300PIX 300-Watt Two-Way Weather-Resistant Speaker Systems
