T221M Biampable, Compact, Two-Way Floor Monitor Speaker System
“BIAMP”. The crossover is now in biamp mode. Carefully replace the crossover and screws. When the crossover is in biamp mode, there is an 18-microfarad capacitor in series with the high-frequency driver for protection against DC voltages or amplifier failure. This is not a crossover. It is how- ever, protection against some forms of am- plifier failure. An active crossover with a crossover frequency of 1,600 Hz (1.6 kHz) with slopes of 12 dB per octave or greater is required. Whenever possible, a crossover with 24-dB-per-octave slopes should be used.
Note: The PROTM circuit is still protecting the high-frequency driver when the system is in biamp mode.
Connections
The T221M is equipped with Neutrik Speakon® NL4MPR connectors. Two con- nectors are installed in parallel, one mounted on each end of the enclosure allowing multiple T221M’s to be used and “daisy- chained” together. These NL4FC connectors are used because they are locking, self-po- larizing and capable of 30 amps rms con- tinuously.
Full-range pin arrangements are:
1– = IN, FULL RANGE(–)
1+ = IN, FULL RANGE(+)
2– = Not used
2+ = Not used
Biamp pin arrangements are:
1– = IN, LOW FREQUENCY (–)
1+ = IN, LOW FREQUENCY (+)
2– = IN, HIGH FREQUENCY (–)
2+ = IN, HIGH FREQUENCY (+)
If you experience any difficulty in obtain- ing cables, connectors or wiring accessories, the following companies can be contacted:
Neutrik USA, Inc.
1600 Malone Street
Millville, NJ 08332
Pro Co Sound, Inc.
135 E. Kalamazoo Avenue
Kalamazoo, MI 49007
Whirlwind Music Distributors, Inc.
P.O. Box 1075
Rochester, NY 14603
Power-Handling Capacity
To our knowledge, Electro-Voice was the first U.S. manufacturer to develop and pub- lish a power test closely related to real-life conditions. First, we use a random-noise in- put signal because it contains many frequen- cies simultaneously, just like real voice or instrument program. Second, our signal con- tains more energy at extremely high and low frequencies than typical actual program, add- ing an extra measure of reliability. Third, the test signal includes not only the overall “long-term average” or “continuous” level— which our ears interpret as loudness—but also short-duration peaks which are many times higher than the average, just like ac- tual program. The long-term average level stresses the speaker thermally (heat). The instantaneous peaks test mechanical reliabil- ity (cone and diaphragm excursion). Note that the sine-wave test signals sometimes used have a much less demanding peak value relative to their average level. In actual use, long-term average levels exist from several seconds on up, but we apply the long-term average for several hours, adding another extra measure of reliability.
Specifically, the T221M is designed to with- stand the power test described in EIA Stan- dard RS-426A. The EIA test spectrum is applied for eight hours. To obtain the spec- trum, the output of a white-noise generator (white noise is a particular type of random noise with equal energy per bandwidth in Hz) is fed to a shaping filter with 6-dB-per-oc- tave slopes below 40 Hz and above 318 Hz. When measured with an analyzer having the usual constant-percentage bandwidth (one- third octave), this shaping filter produces
aspectrum 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 400 watts into the 5.98-ohm EIA equivalent impedance (48.9 volts true rms). Amplifier clipping sets instantaneous peaks at 6 dB above the continuous power, or 1,600-watts peak (97.8 volts peak). This procedure provides a rigorous test of both thermal and mechani- cal failure modes.
Architects' and Engineers'
Specifications
The loudspeaker system shall be a two-way, full-range design consisting of a 305-mm (12-inch) woofer in a vented enclosure, a high-frequency compression driver mounted on a 80° x 55° constant-directivity horn, and a passive crossover/equalizer network, which may be bypassed for use with an external low-level active dividing network with a corner frequency of 1,600 Hz. The loud- speaker shall meet the following perfor- mance criteria: frequency response of 100-16,000 Hz, –3 dB; full-range power handling of 400 watts long term and 1,600- watts short term with a shaped random-noise input per EIA Standard RS-426A; low-fre- quency power handling below 1,600 Hz in the biamp mode of 400-watts long term and 1,600-watts short term with a shaped ran- dom-noise input per EIA Standard RS-426A; high-frequency power handling above 1,600 Hz in the biamp mode of 60-watts long term and 240-watts short term with a shaped random-noise input per EIA Standard RS-426A; sensitivity of 101 dB SPL at 1 meter with a 1-watt, 300- to 3,000-Hz pink-noise input; 6-dB-down horizontal coverage angle of 55° ±5° in the 5,000- to 16,000-Hz range; 6-dB-down vertical coverage angle of 80° ±5° in the 5,000- to 16,000-Hz range; cross- over frequency of 2,600 Hz (electrical); nominal impedance of 8 ohms; and mini- mum impedance of 6.7 ohms. Input con- nections shall be two paralleled Neutrik Speakon® NL4MPR connectors for full- range and biamp operation. The enclosure shall be constructed of curved plywood, covered with black textured paint and fit- ted with a 16-gauge black steel grille, rub- ber feet and a recessed carrying handle. Di- mensions shall be 371 mm (14.62 in.) high x 594 mm (23.4 in.) wide x 406 mm (16.0 in.) deep. Net weight shall be 22.3 kg (49 lb).
The loudspeaker system shall be the Electro- Voice T221M.
