Electro-Voice 309-4TWB 8" 16W Two-Way Ceiling Loudspeaker with Premounted Round, 85Hz-18kHz Frequency Response, 8 Ohms Nominal Impedance, Single, White Baffle

The Electro-Voice 309-4TWB 8" 16W Two-Way Ceiling Loudspeaker with premounted round is low-frequency cones and high temperature voice-coil assemblies coaxially mounted with wide-dispersion cone tweeters. The dual magnet construction allows each speaker to be structurally, magnetically, electrically and mechanically independent of the other. The 309-8A/309-4T/309-8T utilize a single section crossover network, centered at 3,000 Hz, which provides 6 dB of attenuation for the tweeter outside its operating range. The 309-4T is provided with a 25/70.7/ 100-V line transformer that offers <1 dB insertion loss and a selection of 0.5-, 1-, 2- and 4-W taps. The 309-8T is features a 70.7/100-V line transformer that offers <1 dB insertion loss and a selection of 1-, 2-, 4- and 8-W taps. These components are designed to work together as a complete system of in-ceiling loudspeakers and accessories. They provide wide dispersion, high-efficiency, high- maximum output, ease of installation and wide-range reproduction of music or voice. WB versions come complete with a pre-mounted ceiling grille.

Architects' and Engineers' Specifications
The loudspeaker shall have an 8-inch low-frequency cone radiator and a coaxially mounted, wide-dispersion cone tweeter. The loudspeaker shall meet the following criteria: AES power rating shall be 16 watts of band-limited pink noise (85 Hz to 18 kHz, 6 dB crest factor). Frequency response will be uniform from 85 Hz to 18 kHz on both the transformer and non-transformer versions. Pressure sensitivity, 96 dB SPL at 1 meter (94 dB at 4 feet) on axis with one watt of band-limited pink noise from 500 Hz to 3 kHz (ref. 20 mPa). Minimum impedance, 6.0 ohms.

Recommended Connections
The 309 is a nominal 8-ohm impedance loudspeaker with a 10-watt input capability. However, it is also available with transformer, the 309-4T and with transformer and grille, the 309-4TWB. The 309-4T utilizes a 4-watt, 25/70.7/100-volt universal line matching transformer with power taps ranging from 0.5 to 4 watts as indicated in the table for the 309-4T. The transformer is mounted to the frame and the primary winding is accessible for the user to select any of the power taps indicated in the table for the 309-4T. All wattages marked for the various taps refer to the load on the amplifier, with the insertion loss of the transformer being less than 2 dB.

Recommended Enclosures and Baffles
309-8A and 309-4T are designed to fit on standard 8-inch ceiling speaker baffles. Additionally, the 209 series loudspeakers will accommodate the use of any standard back enclosure with a diameter of 8.6 inches or greater and a depth of at least 3.5 inches. Larger back volumes will increase the low frequency output. The frequency response of a 209 in a typical 0.25-cubic-foot and 1.8-cubic-foot back enclosure are shown in Figure 1.

Mounting
The 309 may be front- or rear-mounted against either surface of its mounting flange and requires a 18.4 cm (7.25") diameter cutout and a 19.5 cm (7.68") bolt circle. Normal fasteners up to 5 mm (0.20") will fit through the eight holes in the frame. The 309 is designed for mounting on standard ceiling speaker baffles.