Electro-Voice Sentry 100A loudspeakers

 The Electro-Voice Sentry 100A monitor speaker system is the direct result of "human engineering" with the broadcast/recording studio engineer in mind. Our product engineers' non-nonsense design efforts have culminated in a system that speaks to the needs of professionals with specific requirements, high efficiency with extended low-frequency range, uniform frequency response and dispersion, all in a compact, no-frills package.

The Sentry 100A employs a Super-Dome tweeter capable of handling 25 watts of input power (most tweeter operate in the 5 watt range), while faithfully reproducing the program material with response out to 18,000 Hz and uniform dispersion (120° at 5,000 Hz ). No longer will accidental high-frequency blasts from tape head contact in rewind / fast-forward mode result in a curl of smoke where a tweeter used to be. The low-frequency section is an 8" direct radiator woofer installed in an optimally vented enclosure with fourth-order Butterworth tuning. The optimally vented design is responsible for the unusual combination of small size, extended bass response, and high efficiency. Such performance is simply not available in other enclosure of similar size.

The Sentry 100A is housed in a utility cabinet wrapped in a special, scratch-resistant, mattle black vinyl. The cabinet size is intentionally designed for rack mounting. The steel-reinforced grille is covered with a custom grey cloth. This provides maximum protection, acoustic transparency and pleasing esthetic quality.

 

Loudspeaker response Due To The Acoustical Environment

Several factors must be considered when determining the overall response of a speaker system in any listening environment. Physical characteristics of the room itself, and placement of speakers and listener can have considerable effect on SPL capability, perceived and/or measured frequency response, and stereo imaging.

 

As pointed out in several texts on room acoustics, as the source-listener distance increases, the sound pressure level (SPL) decreases, in the direct field as a steady rate (inverse square law; 6 dB drop for every doubling of distance) until a certain distance is reached. This point is often called the critical distance . Beyond this point, the SPL approaches a constant value (the reverberation field). The listening position in the sound field determines the amount of acoustic power output of the speaker system needed to produce a certain sound pressure level at the engineer's ears. Generally speaking, the amount of power output needed from the speaker/amplifier system decreases as the room becomes smaller and/or more reverberant (shorter critical distance). In most cases, the audio engineer will be working well within the direct field. If indeed this is the case, the amplifier power requirement is entirely dependent on the loss in SPL due to inverse square law.

Th elow frequency response of the overall system can be adversely affected by poor placement of the monitor speakers themselves. The Sentry 100A was designed for 1/4 to 1/2 space use. This requires that the speaker system be mounted as close as possible to floor/ceiling and/or wall surfaces. Placement in loose cavities or resonant mountings can also seriously degrade the overall response.

 

Specifications:

Frequency Response:  45 - 18,000 Hz ±3 dB

Half-Space Reference Efficiency:  0,6%

Dispersion Angle

Horizontal : 

250 - 6,300 Hz (158 ° ±32°); 

8,000 - 20,000 Hz (55° ±18°)

Vertical :

250 - 6,300 Hz (140° ±40°)

8,000 - 20,000 Hz (52° ±13°)

Maximum Midband Acoustic Output Power:  0,18 watt

Crossover Frequency:  2,000 Hz

Sound Pressure Level (at 1m/1W):  91 dB

EIA Sensitivity Rating:  41,8 dB

Long-Term Average Power Handling Capacity:  300 watts

Short-term Power Handling Capacity:  300 watts

Nominal Impedance:  6 Ω

Minimum Impedance:  4,5 Ω

Optional Accessory:  SRB-7 rack mount / wall-mount bracket

Dimensions (W x H x D):  305 x 438 x 282 mm (12" x 17,25" x 11,126")

Weight:  12m7 kg (28 lb)