Electro-Voice T221M manual Description, Frequency Response, Directivity, Biamping

T221M

Biampable, Compact,

Two-Way Floor Monitor

Speaker System

•Constant-directivity80°x55°horn with2-inchtitaniumdriver

•High-output,400-watt,12-inchwoofer

•Biampedorfull-rangeoperation- simplebiampinstructionsincluded insidetheenclosure

•Rock-solidenclosuremadewith 12-plycurvedplywoodshell

•PROTM circuitprovidesHFdriver protection

•Professional NeutrikSpeakon® connectorsforbiamporfull-range operation

Description

The Electro-Voice T221M is a 400-watt, two- way, high-efficiency floor monitor system. It combines professional-quality components, highlighted by the DH2T compression driver and 400-watt, high-output 12-inch woofer. The system may be biamplified or used full range with the internal passive crossover. Either way, the result is clear and articulate, high-quality sound.

The enclosure is constructed of a void-free 3/4-in. 12-ply curved plywood shell which is extremely rigid. The baffle and end pieces are made from 13-ply birch plywood. This high-strength enclosure is sprayed with a resilient, textured black finish for a truly pro- fessional appearance. The end-mounted, heavy-duty, recessed handle makes trans- portation easy and three rubber feet on the opposite end help keep the finish looking new.

The high-frequency section of the T221M utilizes a compact 80° x 55° constant-direc- tivity horn driven by a wide-bandwidth, two- inch-titanium-diaphragm driver. The voice coil is coupled to the diaphragm with EV’s exclusive Resonant DriveTM technology. This increases and smooths the high-frequency

response and reduces the amount of internal equalization required for flat frequency re- sponse.

EV’s self-resetting PROTM circuit is built into the crossover network to guard the compres- sion driver from damage. If input power to the driver exceeds the nominal rating, the PROTM circuit is activated, reducing the power delivered to the driver by 6 dB. The system will remain in this mode of opera- tion until input power is reduced to a safe level.

The optimally vented bass section of the T221M is designed using Thiele-Small pa- rameters for efficient performance to below

100Hz. The high-output 12-inch woofer delivers outstanding performance. It features beryllium copper lead wires with a low-mass, edge-wound voice coil and high-temperature materials. The coil is driven by a massive, 15-lb magnetic structure.

Frequency Response

The combination of a 12-inch woofer, DH2T wide-bandwidth high-frequency driver and an equalized crossover results in the wide and smooth overall response shown in Figure 2. The T221M’s axial frequency response was measured in Electro-Voice’s large anechoic

chamber at a distance of 10 feet with a swept sine-wave input of 4 volts. Figure 2 has been averaged and corrected for 1 watt/1 meter, half-space operation.

Directivity

The polar response of the T221M speaker system at selected one-third-octave band- widths is shown in Figure 1. These polar responses were measured in an anechoic environment at 20 feet using one-third-oc- tave pink-noise inputs. The frequencies selected are fully representative of the polar response of the system. Beamwidth of the system utilizing the complete one-third-oc- tave polar data is shown in Figure 1. Rθ and directivity index (Di) are plotted in Figure 4.

Biamping

The T221M may be easily converted for biamp operation. To do this, first carefully remove the crossover. Notice the instruc- tions on the circuit board and the four-wire “Molex” connector. The T221M comes from the factory in passive (full-range) mode. To convert the T221M to biamp operation, un- plug the “Molex” connector from the header marked “PASSIVE MODE (FULL RANGE”) and plug it into the header labeled