User manual GENELEC 7073APM

[. . . ] 7073A Operating Manual Genelec 7073A Active Subwoofer 7073A Active Subwoofer General description Genelec 7073A is a powerful active subwoofer incorporating all the amplifier and crossover electronics needed for bass management and reproduction of low frequency information in modern 6. 1 or 5. 1 channel surround sound or traditional stereo systems. Its 19 to 120 Hz (±3 dB) frequency range and 124 dB sound pressure output capability are sufficient to handle the most demanding and powerful applications. The low pass section sensitivity can be adjusted from +6 dBu to -12 dBu to allow easy subwoofer level matching with various main speakers. The low pass frequency of the LFE input channel can be set to 85 Hz, 120 Hz or 85 Hz with "Redirect" function that routes LFE content above 85 Hz to the front center monitor. [. . . ] The reflex port and connector panel should always have a clearance of at least 20 centimeters (8") to any objects to ensure proper function of the port and cooling for the electronics attached to the connector panel. absorbing front wall structure and the depth of the absorbing material exceeds the depth of the 7073A cabinet, there is a risk of low frequency comb filtering due to the reflections from the wall behind the subwoofer (See Fig. 6. ). Setting the input sensitivity The subwoofer requires input sensitivity alignment to the source to obtain a correctly balanced system. The input sensitivity control is located on the connector panel of the subwoofer. An input voltage of -6 dBu with a -6 dBu input sensitivity setting will produce 100 dB SPL @ 1m in free field. To obtain a 110 dB SPL output an input voltage of +10 dBu is required when the input sensitivity is set to 0 dBu. Flush mounting the subwoofer If the 7073A subwoofer is flush mounted into a wall or a cabinet, it is important to ensure unrestricted airflow from the reflex port and cooling for the electronic components. This can be done by making the recess 20 centimeters (8") wider than the subwoofer. Place the subwoofer into the right end of the recess with the drivers' side facing the room. This leaves 20 centimeters (8") of free space on the connector panel and reflex port side. The height and depth of the recess should not be any bigger than those needed to fit the subwoofer flush with the wall surface (See Fig 4-5). If the 7073A is flush-mounted in a semi- Setting the Bass Roll-Off switches The acoustic response of the subwoofer may have to be matched to the characteristics of the room and the positioning in which it will be used. To adjust the subwoofer to match these characteristics use the ''Bass Roll-Off' control switches located on the connector panel. Table 1 Minimum clearances to walls or other objects The power amplifiers are attached to the lower part of the aluminium grilles, which function as a heatsink. Do not cover the Finally, set the -180° phase switch (DIP 4) to the opposite setting and deactivate the test signal. Phase Difference: 0° Phase Difference: 90° Phase correction method with test equipment The following procedure matches the phase between the subwoofer and the main monitors using a frequency analyser and a pink noise generator. Connect a high grade measuring microphone to the analyser and feed pink noise into the "CENTER IN" input of the subwoofer. The subwoofer's bass management system will direct the frequencies above 85 Hz to the 85 Hz 85 Hz Phase Difference: 180° Phase Difference: 270° 85 Hz 85 Hz center main monitor while the subwoofer reproduces the frequencies below 85 Hz. Position the microphone at the listening Figure 7. The effect of phase difference between the subwoofer and the main monitors position and adjust the input sensitivity of the subwoofer until frequencies below and above 85 Hz are reproduced at equal level. provides some suggestions for the "Bass Roll-Off" switch settings. When both rolloff switches are set to "OFF", a flat anechoic response is obtained. generator to accomodate easy phase alignment. The test tone generator is connected to the subwoofer's "FRONT CENTER OUT" channel only. In a stereo system it is necessary to temporarily connect either of the channels to this output. Power up the system and set the DIP switches 3 (SUM IN MODE) and 4 (LFE +10 dB) on the first switch group to "ON" Now you should hear an 85 Hz test signal from the subwoofer and the main monitor connected to the center channel output. Toggle the -180° phase switch (DIP 4 on the second switch group) on and off, and set it to the position which gives the lowest sound level at the listening position. [. . . ] This enables the subwoofer to correctly reproduce all the bass information in the mix. The LFE channel on the 7073A can be set to two frequency ranges: 19 to 85 Hz dB and four subwoofers 12 dB compared to a single subwoofer. Adjust the sensitivity control of all subwoofers in the group to match the SPL level of the main monitor system. Phase and Bass Roll-Off adjustments should be done individually for each subwoofer in the chain, especially if they are not placed close together. [. . . ]